1
|
Dahab MA, Mahdy HA, Elkady H, Taghour MS, Elwan A, Elkady MA, Elsakka EGE, Elkaeed EB, Alsfouk AA, Ibrahim IM, Metwaly AM, Eissa IH. Semi-synthesized anticancer theobromine derivatives targeting VEGFR-2: in silico and in vitro evaluations. J Biomol Struct Dyn 2024; 42:4214-4233. [PMID: 37261471 DOI: 10.1080/07391102.2023.2219333] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Accepted: 05/23/2023] [Indexed: 06/02/2023]
Abstract
Vascular endothelial cell proliferation and angiogenesis are all crucially impacted by Endothelial Growth Factor Receptor-2 (VEGFR-2). Its expression is significantly boosted throughout pathologic angiogenesis causing the development of tumors. Sothat, inhibition of VEGFR-2 has crucial role in cancer treatment. In this study, novel semisynthetic theobromine derivatives were rationally designed as VEGFR-2 inhibitors and subjected to in vitro testing for their ability to block VEGFR-2 activation. Furthermore, the antiproliferative effects of these derivatives were evaluated. Compound 7 g exhibited the most potent anti-VEGFR-2 activity, with an IC50 value of 0.072 µM, and demonstrated excellent dose-dependent inhibitory activity against both MCF-7 and HepG2 cancer cells with IC50 values of 19.35 and 27.89 µM, respectively. Notably, compound 7 g exhibited high selectivity indices of 2.6 and 1.8 against MCF-7 and HepG2 cells, respectively. Compound 7 g induced G2/M phase cell cycle arrest, promoted apoptosis, and boosted immunomodulation by downregulating TNF-α expression and upregulating IL-2 levels in MCF-7 cells. The molecular docking analysis revealed that compound 7 g could bind effectively to the active site of VEGFR-2, and molecular dynamic simulations confirmed the stability of the VEGFR-2/compound 7 g complex. Furthermore, ADME and toxicity profiling indicated the potential suitability of these compounds as drug candidates. In summary, compound 7 g hold promise as a VEGFR-2 inhibitor.Communicated by Ramaswamy H. Sarma.
Collapse
Affiliation(s)
- Mohammed A Dahab
- Pharmaceutical Medicinal Chemistry & Drug Design Department, Faculty of Pharmacy (Boys), Al-Azhar University, Cairo, Egypt
| | - Hazem A Mahdy
- Pharmaceutical Medicinal Chemistry & Drug Design Department, Faculty of Pharmacy (Boys), Al-Azhar University, Cairo, Egypt
| | - Hazem Elkady
- Pharmaceutical Medicinal Chemistry & Drug Design Department, Faculty of Pharmacy (Boys), Al-Azhar University, Cairo, Egypt
| | - Mohammed S Taghour
- Pharmaceutical Medicinal Chemistry & Drug Design Department, Faculty of Pharmacy (Boys), Al-Azhar University, Cairo, Egypt
| | - Alaa Elwan
- Pharmaceutical Medicinal Chemistry & Drug Design Department, Faculty of Pharmacy (Boys), Al-Azhar University, Cairo, Egypt
| | - Mohamed A Elkady
- Biochemistry and Molecular Biology Department, Faculty of Pharmacy (Boys), Al-Azhar University, Cairo, Egypt
| | - Elsayed G E Elsakka
- Biochemistry and Molecular Biology Department, Faculty of Pharmacy (Boys), Al-Azhar University, Cairo, Egypt
| | - Eslam B Elkaeed
- Department of Pharmaceutical Sciences, College of Pharmacy, AlMaarefa University, Riyadh, Saudi Arabia
| | - Aisha A Alsfouk
- Department of Pharmaceutical Sciences, College of Pharmacy, Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia
| | - Ibrahim M Ibrahim
- Biophysics Department, Faculty of Science, Cairo University, Cairo, Egypt
| | - Ahmed M Metwaly
- Pharmacognosy and Medicinal Plants Department, Faculty of Pharmacy (Boys), Al-Azhar University, Cairo, Egypt
- Biopharmaceutical Products Research Department, Genetic Engineering and Biotechnology Research Institute, City of Scientific Research and Technological Applications (SRTA-City), Alexandria, Egypt
| | - Ibrahim H Eissa
- Pharmaceutical Medicinal Chemistry & Drug Design Department, Faculty of Pharmacy (Boys), Al-Azhar University, Cairo, Egypt
| |
Collapse
|
2
|
Kaneko F, Yamamoto Y, Yoshikawa S. Structural Study on Fat Crystallization Process Heterogeneously Induced by Graphite Surfaces. Molecules 2020; 25:molecules25204786. [PMID: 33086514 PMCID: PMC7587562 DOI: 10.3390/molecules25204786] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 10/11/2020] [Accepted: 10/13/2020] [Indexed: 11/16/2022] Open
Abstract
Some inorganic and organic crystals have been recently found to promote fat crystallization in thermodynamically stable polymorphs, though they lack long hydrocarbon chains. The novel promoters are talc, carbon nanotube, graphite, theobromine, ellagic acid dihydrate, and terephthalic acid, among which graphite surpasses the others in the promotion effect. To elucidate the mechanism, we investigated the influence of graphite surfaces on the crystallization manner of trilaurin in terms of crystal morphology, molecular orientation, and crystallographic features. Polarized optical microscopy, cryo-scanning electron microscopy, synchrotron X-ray diffractometry, and polarized Fourier-transform infrared spectroscopy combined with the attenuated total reflection sampling method were employed for the analyses. All the results suggested that the carbon hexagonal network plane of graphite surfaces have a high potential to facilitate the clustering of fat molecules against high thermal fluctuations in fat melt, the fat molecules form a layer structure parallel to the graphite surface, and the clusters tend to grow into thin plate crystals of the β phase at the temperatures corresponding to low supercooling. The β' phase also has a larger chance to grow on the graphite surface as supercooling increases.
Collapse
Affiliation(s)
- Fumitoshi Kaneko
- Graduate School of Science, Osaka University, Toyonaka 560-0044, Japan;
- Correspondence: ; Tel.: +81-6-6850-5453
| | | | - Shinichi Yoshikawa
- Research Institute for Creating the Future, Fuji Oil Holdings Inc., Izumisano 598-8540, Japan;
| |
Collapse
|
3
|
Shyamlal BRK, Mathur M, Yadav DK, Chaudhary S. Microwave-assisted modified synthesis of C 8-analogues of naturally occurring methylxanthines: Synthesis, biological evaluation and their practical applications. Fitoterapia 2020; 143:104533. [PMID: 32145313 DOI: 10.1016/j.fitote.2020.104533] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 02/26/2020] [Accepted: 03/01/2020] [Indexed: 01/17/2023]
Abstract
An efficient, microwave-assisted, oxidant-interceded, transition-metal-free, cross-dehydrogenative Csp2-Csp3 coupling of C8-Caffeine 2/Theobromine 3/theophylline 4 with substituted aliphatic alcohols 11a-lvia CH bond activation for the preparation of series of substituted C8-(hydroxymethyl) Caffeine 12a-l/theobromine 13a-c/theophylline 14a-b has been developed using microwave irradiation upto 98% yield. The reaction proceeds smoothly in the presence of tert-butyl hydroperoxide (TBHP) under solvolysis condition at 120 °C for 20 min to corresponding substituted C8-(hydroxymethyl)-methylxanthine derivatives in good to excellent yields. The good substrate scope, control experiments, gram-scale synthesis, and practical synthetic transformations further highlights the practicality of this methodology. These C8-(hydroxymethyl) Caffeine 12a-l, 13a-c and 14a-b have been found to show promising in vitro antioxidant as well as antiplatelet activities.
Collapse
Affiliation(s)
- Bharti Rajesh Kumar Shyamlal
- Laboratory of Organic & Medicinal Chemistry, Department of Chemistry, Malaviya National Institute of Technology, Jawaharlal Nehru Marg, Jaipur 302017, India
| | - Manas Mathur
- School of Agriculture, Suresh Gyan Vihar University, Mahal Road, Jagatpura, Jaipur 302017, India
| | - Dharmendra K Yadav
- Gachon Institute of Pharmaceutical Sciences, Department of Pharmacy, College of Pharmacy, Gachon University of Medicine and Science, Incheon 21936, South Korea
| | - Sandeep Chaudhary
- Laboratory of Organic & Medicinal Chemistry, Department of Chemistry, Malaviya National Institute of Technology, Jawaharlal Nehru Marg, Jaipur 302017, India.
| |
Collapse
|
4
|
Wu F, Liu R, Shen X, Xu H, Sheng L. Study on the interaction and antioxidant activity of theophylline and theobromine with SOD by spectra and calculation. Spectrochim Acta A Mol Biomol Spectrosc 2019; 215:354-362. [PMID: 30852283 DOI: 10.1016/j.saa.2019.03.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 02/28/2019] [Accepted: 03/02/2019] [Indexed: 06/09/2023]
Abstract
Theophylline (TP) and theobromine (TB) are the methyl derivatives of xanthine. The antioxidation of TP and TB as well as the effect of the antioxidation and activity of copper‑zinc superoxide dismutase (SOD) with TP and TB were investigated. The contents of MDA in cells showed that both TP (14.49 μmol/g) and TB (14.25 μmol/g) are active in oxidation resistance and closed to the antioxidant effect of SOD (13.77 μmol/g). With the formation of TP-SOD and TB-SOD, the antioxidant ability can be superimposed. The interactions between TP/TB and SOD were studied by ultraviolet spectrum, fluorescence spectrum and molecular docking. The results showed that the complex of TP/TB and SOD with 1:1 component was stabilized by hydrogen bonding and van der Waals forces. The analysis also indicated that the microenvironment and structure of SOD were changed. All of the results indicate that the complex formation of TP-SOD and TB-SOD can maintain their respective antioxidant effects without changes in the activity of SOD.
Collapse
Affiliation(s)
- Fufang Wu
- School of Chemistry and Materials Engineering, Fuyang Normal College, Fuyang 236037, China; Engineering Research Center of Biomass Conversion and Pollution Prevention Control of Anhui Provincial Department of Education, Fuyang 236037, China
| | - Ruirui Liu
- School of Chemistry and Materials Engineering, Fuyang Normal College, Fuyang 236037, China; Engineering Research Center of Biomass Conversion and Pollution Prevention Control of Anhui Provincial Department of Education, Fuyang 236037, China
| | - Xiaobao Shen
- School of Chemistry and Materials Engineering, Fuyang Normal College, Fuyang 236037, China; Engineering Research Center of Biomass Conversion and Pollution Prevention Control of Anhui Provincial Department of Education, Fuyang 236037, China
| | - Huajie Xu
- School of Chemistry and Materials Engineering, Fuyang Normal College, Fuyang 236037, China; Engineering Research Center of Biomass Conversion and Pollution Prevention Control of Anhui Provincial Department of Education, Fuyang 236037, China
| | - Liangquan Sheng
- School of Chemistry and Materials Engineering, Fuyang Normal College, Fuyang 236037, China; Engineering Research Center of Biomass Conversion and Pollution Prevention Control of Anhui Provincial Department of Education, Fuyang 236037, China.
| |
Collapse
|
5
|
Camps-Bossacoma M, Garcia-Aloy M, Saldaña-Ruiz S, Cambras T, González-Domínguez R, Franch À, Pérez-Cano FJ, Andres-Lacueva C, Castell M. Role of Theobromine in Cocoa's Metabolic Properties in Healthy Rats. J Agric Food Chem 2019; 67:3605-3614. [PMID: 30855143 DOI: 10.1021/acs.jafc.8b07248] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Cocoa is rich in polyphenols and methylxanthines, and it has been reported that its consumption, among other properties, has beneficial effects on metabolism. This study aimed to investigate the role of theobromine in cocoa's metabolic properties in healthy rats. In addition to morphometric measurements, biochemical markers of lipids and glucose metabolism and gene expression of molecules related to immune cells in adipose and hepatic tissues were assessed after 7 or 18 days of diet. Additionally, a metabolomic analysis was carried out at day 7. This study revealed the presence of six discriminant metabolites in plasma due to the diets. Moreover, the results showed that theobromine is the main responsible factor for cocoa's effects on body weight gain as well as on lipid and glucose metabolism. The effects on body weight and lipids appeared as early as after 7 days of diet, whereas those affecting glucose metabolism required a longer intervention.
Collapse
Affiliation(s)
- Mariona Camps-Bossacoma
- Secció de Fisiologia, Departament de Bioquímica i Fisiologia, Facultat de Farmàcia i Ciències de l'Alimentació; Institut de Recerca en Nutrició i Seguretat Alimentària (INSA-UB) , Universitat de Barcelona (UB) , Barcelona 08028 , Spain
| | - Mar Garcia-Aloy
- Biomarkers and Nutrimetabolomics Laboratory, Departament de Nutrició, Ciències de l'Alimentació i Gastronomia, XaRTA, INSA-UB, Facultat de Farmàcia i Ciències de l'Alimentació, UB, Barcelona; CIBER de Fragilidad y Envejecimiento (CIBERFES) , Instituto de Salud Carlos III , Madrid 28029 , Spain
| | - Sandra Saldaña-Ruiz
- Secció de Fisiologia, Departament de Bioquímica i Fisiologia, Facultat de Farmàcia i Ciències de l'Alimentació; Institut de Recerca en Nutrició i Seguretat Alimentària (INSA-UB) , Universitat de Barcelona (UB) , Barcelona 08028 , Spain
| | - Trinitat Cambras
- Secció de Fisiologia, Departament de Bioquímica i Fisiologia, Facultat de Farmàcia i Ciències de l'Alimentació; Institut de Recerca en Nutrició i Seguretat Alimentària (INSA-UB) , Universitat de Barcelona (UB) , Barcelona 08028 , Spain
| | - Raúl González-Domínguez
- Biomarkers and Nutrimetabolomics Laboratory, Departament de Nutrició, Ciències de l'Alimentació i Gastronomia, XaRTA, INSA-UB, Facultat de Farmàcia i Ciències de l'Alimentació, UB, Barcelona; CIBER de Fragilidad y Envejecimiento (CIBERFES) , Instituto de Salud Carlos III , Madrid 28029 , Spain
| | - Àngels Franch
- Secció de Fisiologia, Departament de Bioquímica i Fisiologia, Facultat de Farmàcia i Ciències de l'Alimentació; Institut de Recerca en Nutrició i Seguretat Alimentària (INSA-UB) , Universitat de Barcelona (UB) , Barcelona 08028 , Spain
| | - Francisco J Pérez-Cano
- Secció de Fisiologia, Departament de Bioquímica i Fisiologia, Facultat de Farmàcia i Ciències de l'Alimentació; Institut de Recerca en Nutrició i Seguretat Alimentària (INSA-UB) , Universitat de Barcelona (UB) , Barcelona 08028 , Spain
| | - Cristina Andres-Lacueva
- Biomarkers and Nutrimetabolomics Laboratory, Departament de Nutrició, Ciències de l'Alimentació i Gastronomia, XaRTA, INSA-UB, Facultat de Farmàcia i Ciències de l'Alimentació, UB, Barcelona; CIBER de Fragilidad y Envejecimiento (CIBERFES) , Instituto de Salud Carlos III , Madrid 28029 , Spain
| | - Margarida Castell
- Secció de Fisiologia, Departament de Bioquímica i Fisiologia, Facultat de Farmàcia i Ciències de l'Alimentació; Institut de Recerca en Nutrició i Seguretat Alimentària (INSA-UB) , Universitat de Barcelona (UB) , Barcelona 08028 , Spain
| |
Collapse
|
6
|
Hernández-Hernández C, Morales-Sillero A, Fernández-Bolaños J, Bermúdez-Oria A, Morales AA, Rodríguez-Gutiérrez G. Cocoa bean husk: industrial source of antioxidant phenolic extract. J Sci Food Agric 2019; 99:325-333. [PMID: 29876932 DOI: 10.1002/jsfa.9191] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 04/23/2018] [Accepted: 06/01/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND Cocoa bean husk (CBH) is the principal by-product of the cocoa industry and a significant agro-industrial residue. In this study, using different hydrothermal treatments of CBH, it is shown that CBH is an important source of bioactive compounds, including theobromine, epicatechin and catechin. RESULTS Treatment over 150 °C significantly increased the yield of total and individual phenols and theobromine as well as the antioxidant capacity of the liquid fraction. A total of 52 different genotypes of CBH harvested in two seasons of production were analyzed. Overall, higher amounts of total phenols, theobromine and epigallocatechin were detected in samples from the 2015 season, while samples from 2014 had higher quantities of catechin and similar quantities of epicatechin. CONCLUSION CBH treatment at 170 °C for 30 min produces an antioxidant-rich extract high in phenols (55 mg g-1 ), sugars (220 mg g-1 ) and theobromine (56 mg g-1 ) that is suitable for applications in the food, cosmetic and nutraceutical industries. © 2018 Society of Chemical Industry.
Collapse
Affiliation(s)
- Carolina Hernández-Hernández
- Instituto de la Grasa, Consejo Superior de Investigaciones Científicas (CSIC), Campus Universitario Pablo de Olavide, Seville, Spain
| | - Ana Morales-Sillero
- Departamento de Ciencias Agroforestales, ETSIA, Universidad de Sevilla, Seville, Spain
| | - Juan Fernández-Bolaños
- Instituto de la Grasa, Consejo Superior de Investigaciones Científicas (CSIC), Campus Universitario Pablo de Olavide, Seville, Spain
| | - Alejandra Bermúdez-Oria
- Instituto de la Grasa, Consejo Superior de Investigaciones Científicas (CSIC), Campus Universitario Pablo de Olavide, Seville, Spain
| | - Alfonso Azpeitia Morales
- Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias, Campo Experimental Huimanguillo, Tabasco, Mexico
| | - Guillermo Rodríguez-Gutiérrez
- Instituto de la Grasa, Consejo Superior de Investigaciones Científicas (CSIC), Campus Universitario Pablo de Olavide, Seville, Spain
| |
Collapse
|
7
|
Raynal C. [Louis-Marie Rousseau and the "Chocolat rationnel des pharmaciens français" (Rational Chocolate of French pharmacists)]. Rev Hist Pharm (Paris) 2015; 62:65-78. [PMID: 26043464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In 1883, the chemist Louis-Marie Rousseau (1849-1930) creats the "Compagnie hygiénique française" (French Hygienic Company). The company manufactures and sells the "Poudre de viande Rousseau" (Rousseau meat powder) and the "Chocolat Rousseau" (Rousseau Chocolate) by methods developed and patented by the pharmacist. Ten years after a successful collaboration, L.-M. Rousseau separates from his associates and founds the "Chocolaterie spéciale d'Ermont" (Special Chocolate factory of Ermont) in the village of Ermont near Paris. Here is manufactured the "Chocolat Rationnel des pharmaciens français" (Rational Chocolate of French pharmacists), hygienic chocolate sold only in pharmacies. The factory is also a pharmaceutical laboratory where is extracted theobromine from waste vegetable substances of cocoa. It then produces the "Théobromine Rousseau cristallisée" (crystallized Rousseau's Theobromine) sold as tablets, then the "Théosol" that will be commercialized until the middle of 1930s.
Collapse
|
8
|
Grases F, Rodriguez A, Costa-Bauza A. Theobromine inhibits uric acid crystallization. A potential application in the treatment of uric acid nephrolithiasis. PLoS One 2014; 9:e111184. [PMID: 25333633 PMCID: PMC4205022 DOI: 10.1371/journal.pone.0111184] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Accepted: 09/29/2014] [Indexed: 11/18/2022] Open
Abstract
PURPOSE To assess the capacity of methylxanthines (caffeine, theophylline, theobromine and paraxanthine) to inhibit uric acid crystallization, and to evaluate their potential application in the treatment of uric acid nephrolithiasis. MATERIALS AND METHODS The ability of methylxathines to inhibit uric acid nucleation was assayed turbidimetrically. Crystal morphology and its modification due to the effect of theobromine were evaluated by scanning electron microscopy (SEM). The ability of theobromine to inhibit uric acid crystal growth on calculi fragments resulting from extracorporeal shock wave lithotripsy (ESWL) was evaluated using a flow system. RESULTS The turbidimetric assay showed that among the studied methylxanthines, theobromine could markedly inhibit uric acid nucleation. SEM images showed that the presence of theobromine resulted in thinner uric acid crystals. Furthermore, in a flow system theobromine blocked the regrowth of post-ESWL uric acid calculi fragments. CONCLUSIONS Theobromine, a natural dimethylxanthine present in high amounts in cocoa, acts as an inhibitor of nucleation and crystal growth of uric acid. Therefore, theobromine may be clinically useful in the treatment of uric acid nephrolithiasis.
Collapse
Affiliation(s)
- Felix Grases
- Laboratory of Renal Lithiasis Research, University Institute of Health Sciences Research (IUNICS-IdISPa) and Faculty of Science of the University of the Balearic Islands, Palma, Spain
| | - Adrian Rodriguez
- Laboratory of Renal Lithiasis Research, University Institute of Health Sciences Research (IUNICS-IdISPa) and Faculty of Science of the University of the Balearic Islands, Palma, Spain
| | - Antonia Costa-Bauza
- Laboratory of Renal Lithiasis Research, University Institute of Health Sciences Research (IUNICS-IdISPa) and Faculty of Science of the University of the Balearic Islands, Palma, Spain
| |
Collapse
|
9
|
Schimpl FC, Kiyota E, Mayer JLS, Gonçalves JFDC, da Silva JF, Mazzafera P. Molecular and biochemical characterization of caffeine synthase and purine alkaloid concentration in guarana fruit. Phytochemistry 2014; 105:25-36. [PMID: 24856135 DOI: 10.1016/j.phytochem.2014.04.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 02/17/2014] [Accepted: 04/25/2014] [Indexed: 06/03/2023]
Abstract
Guarana seeds have the highest caffeine concentration among plants accumulating purine alkaloids, but in contrast with coffee and tea, practically nothing is known about caffeine metabolism in this Amazonian plant. In this study, the levels of purine alkaloids in tissues of five guarana cultivars were determined. Theobromine was the main alkaloid that accumulated in leaves, stems, inflorescences and pericarps of fruit, while caffeine accumulated in the seeds and reached levels from 3.3% to 5.8%. In all tissues analysed, the alkaloid concentration, whether theobromine or caffeine, was higher in young/immature tissues, then decreasing with plant development/maturation. Caffeine synthase activity was highest in seeds of immature fruit. A nucleotide sequence (PcCS) was assembled with sequences retrieved from the EST database REALGENE using sequences of caffeine synthase from coffee and tea, whose expression was also highest in seeds from immature fruit. The PcCS has 1083bp and the protein sequence has greater similarity and identity with the caffeine synthase from cocoa (BTS1) and tea (TCS1). A recombinant PcCS allowed functional characterization of the enzyme as a bifunctional CS, able to catalyse the methylation of 7-methylxanthine to theobromine (3,7-dimethylxanthine), and theobromine to caffeine (1,3,7-trimethylxanthine), respectively. Among several substrates tested, PcCS showed higher affinity for theobromine, differing from all other caffeine synthases described so far, which have higher affinity for paraxanthine. When compared to previous knowledge on the protein structure of coffee caffeine synthase, the unique substrate affinity of PcCS is probably explained by the amino acid residues found in the active site of the predicted protein.
Collapse
Affiliation(s)
- Flávia Camila Schimpl
- Departamento de Biologia Vegetal-IB, CP 6109, Universidade Estadual de Campinas, 13083-970 Campinas, SP, Brazil
| | - Eduardo Kiyota
- Departamento de Biologia Vegetal-IB, CP 6109, Universidade Estadual de Campinas, 13083-970 Campinas, SP, Brazil
| | | | | | - José Ferreira da Silva
- Departamento de Produção Animal e Vegetal, Faculdade de Ciências Agrárias, Universidade Federal do Amazonas, Manaus, AM, Brazil
| | - Paulo Mazzafera
- Departamento de Biologia Vegetal-IB, CP 6109, Universidade Estadual de Campinas, 13083-970 Campinas, SP, Brazil.
| |
Collapse
|
10
|
Huang R, Hippauf F, Rohrbeck D, Haustein M, Wenke K, Feike J, Sorrelle N, Piechulla B, Barkman TJ. Enzyme functional evolution through improved catalysis of ancestrally nonpreferred substrates. Proc Natl Acad Sci U S A 2012; 109:2966-71. [PMID: 22315396 PMCID: PMC3286912 DOI: 10.1073/pnas.1019605109] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
In this study, we investigated the role for ancestral functional variation that may be selected upon to generate protein functional shifts using ancestral protein resurrection, statistical tests for positive selection, forward and reverse evolutionary genetics, and enzyme functional assays. Data are presented for three instances of protein functional change in the salicylic acid/benzoic acid/theobromine (SABATH) lineage of plant secondary metabolite-producing enzymes. In each case, we demonstrate that ancestral nonpreferred activities were improved upon in a daughter enzyme after gene duplication, and that these functional shifts were likely coincident with positive selection. Both forward and reverse mutagenesis studies validate the impact of one or a few sites toward increasing activity with ancestrally nonpreferred substrates. In one case, we document the occurrence of an evolutionary reversal of an active site residue that reversed enzyme properties. Furthermore, these studies show that functionally important amino acid replacements result in substrate discrimination as reflected in evolutionary changes in the specificity constant (k(cat)/K(M)) for competing substrates, even though adaptive substitutions may affect K(M) and k(cat) separately. In total, these results indicate that nonpreferred, or even latent, ancestral protein activities may be coopted at later times to become the primary or preferred protein activities.
Collapse
Affiliation(s)
- Ruiqi Huang
- Department of Biological Sciences, Western Michigan University, Kalamazoo, MI 49008; and
| | - Frank Hippauf
- Institute of Biological Sciences, Biochemistry, University of Rostock, 18059 Rostock, Germany
| | - Diana Rohrbeck
- Institute of Biological Sciences, Biochemistry, University of Rostock, 18059 Rostock, Germany
| | - Maria Haustein
- Institute of Biological Sciences, Biochemistry, University of Rostock, 18059 Rostock, Germany
| | - Katrin Wenke
- Institute of Biological Sciences, Biochemistry, University of Rostock, 18059 Rostock, Germany
| | - Janie Feike
- Institute of Biological Sciences, Biochemistry, University of Rostock, 18059 Rostock, Germany
| | - Noah Sorrelle
- Department of Biological Sciences, Western Michigan University, Kalamazoo, MI 49008; and
| | - Birgit Piechulla
- Institute of Biological Sciences, Biochemistry, University of Rostock, 18059 Rostock, Germany
| | - Todd J. Barkman
- Department of Biological Sciences, Western Michigan University, Kalamazoo, MI 49008; and
| |
Collapse
|
11
|
Abstract
The effect of native and hydroxypropylated beta-cyclodextrin on the solubility and activity of some purine alkaloids was examined. For this purpose, the solubility of purine alkaloids in pure water and in aqueous solutions of mentioned beta-cyclodextrins was determined at 298.15 K. Stability constants of inclusion complexes and their stoichiometry were obtained from solubility diagrams. Enthalpic characteristics of interactions occurring between beta-cyclodextrins and purine alkaloids in aqueous solution were calculated from the direct calorimetric measurements. It was found, that beta-cyclodextrin forms with purine alkaloids weak complexes which are stabilized only by the entropy term. Due to very low complexing affinity of both beta-cyclodextrins to studied purine alkaloids their solubilizing effect is insignificant. The influence of structure of purine alkaloids and beta-cyclodextrin on the thermodynamic parameters of interaction was discussed.
Collapse
Affiliation(s)
- Irina V Terekhova
- Institute of Solution Chemistry of Russian Academy of Sciences, 1 Akademicheskaya Str., Ivanovo, Russian Federation.
| |
Collapse
|
12
|
Nogueira T, do Lago CL. Determination of caffeine in coffee products by dynamic complexation with 3,4-dimethoxycinnamate and separation by CZE. Electrophoresis 2007; 28:3570-4. [PMID: 17768736 DOI: 10.1002/elps.200700039] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
A method based on the formation of pi-complexes with chlorogenate-like species was proposed for the determination of caffeine in regular (nondecaffeinated) and decaffeinated coffee. Both caffeate and 3,4-dimethoxycinnamate were able to transform caffeine--a neutral species in aqueous solutions--into an anionic species. The usage of 3,4-dimethoxycinnamate in the running electrolyte is advantageous, because of its greater chemical stability and the improved resolution of the peaks of caffeine, theobromine, and theophylline. Negative peaks were registered with a capacitively coupled contactless conductivity detector when solutions of these alkylxanthines were analyzed with a BGE composed of 20 mmol/L 3,4-dimethoxycinnamic acid and pH adjusted to 8.5 with Tris. This behavior was expected, because the complex is larger and thus should move slower than the free anion. Caffeine was determined in ground and instant coffee with precision and accuracy that meet Brazilian norms about such products. The LOD was estimated as 33 mg/L, which corresponds to 0.8 and 0.3 mg of caffeine per gram of dry instant coffee and ground coffee, respectively. For the case of decaffeinated coffee, ten times preconcentration with dichloromethane was carried out to allow the quantitation of caffeine, which should not exceed the concentration of 1 mg/g in dry matter.
Collapse
Affiliation(s)
- Thiago Nogueira
- Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, Avenida Prof. Lineu Prestes 748, CEP 05508-000 São Paulo, SP, Brazil
| | | |
Collapse
|
13
|
Abstract
Riboflavin-binding protein (RBP) from chicken egg, which was recently reported to be a selective sweet inhibitor for protein sweeteners, was also found to be a bitter inhibitor. RBP elicited broadly tuned inhibition of various bitter substances including quinine-HCl, naringin, theobromine, caffeine, glycyl-L-phenylalanine (Gly-Phe), and denatonium benzoate, whereas several other proteins, such as ovalbumin (OVA) and beta-lactoglobulin, were ineffective in reducing bitterness of these same compounds. Both the bitter tastes of quinine and caffeine were reduced following an oral prerinse with RBP. It was found that RBP binds to quinine but not to caffeine, theobromine, naringin, and Gly-Phe. However, the binding of RBP to quinine was probably not responsible for the bitter inhibition because OVA bound to quinine as well as RBP. Based on these results, it is suggested that the bitter inhibitory effect of RBP is the consequence of its ability to interact with taste receptors rather than because it interacts with the bitter tastants themselves. RBP may have practical uses in reducing bitterness of foods and pharmaceuticals. It may also prove a useful tool in studies of mechanisms of bitter taste.
Collapse
Affiliation(s)
- Kenji Maehashi
- Department of Fermentation Science, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo, Japan.
| | | | | | | | | |
Collapse
|
14
|
Sriamornsak P, Kennedy RA. Effect of drug solubility on release behavior of calcium polysaccharide gel-coated pellets. Eur J Pharm Sci 2007; 32:231-9. [PMID: 17889515 DOI: 10.1016/j.ejps.2007.08.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2007] [Revised: 07/16/2007] [Accepted: 08/01/2007] [Indexed: 11/16/2022]
Abstract
The aim of this study was to investigate the effect of drug solubility on the release behavior from calcium polysaccharide gel (CaPG)-coated pellets. Three different drugs with similar chemical structure, but different water solubility, namely caffeine (CAF), theophylline (TPL) and theobromine (TBR), were used. Drug-loaded spherical pellets were manufactured by an extrusion-spheronization method. The CaPG was applied on the pellets loaded with different drugs by interfacial complexation coating. The encapsulation efficiency of coated pellets was found to vary from 57.6 to 84.3%, depending on the solubility of the active drug and polysaccharide type. Drug release from different uncoated pellets was relatively unaffected by pH and release media but depended mainly on drug solubility. Release behavior was significantly modified in the pellets coated with CaPG, for all of the drugs tested. Drug release from coated pellets of the different drugs showed different release kinetics. The difference in the drug release is probably due to the difference in the drug dissolution within the core, before its partition and diffusion through the CaPG coat. The CAF dissolved faster and achieved a higher concentration in solution, which drove diffusion. The release of TBR from the coated pellets was much slower than that of the CAF or TPL because of its low solubility. However, the release of all drugs was about four- to sixfold slower for coated than uncoated pellets, suggesting that the coating influenced the retardation of drug release from the coated pellets. Therefore, the CaPG coating may provide a sustained release delivery system for all drugs tested.
Collapse
Affiliation(s)
- Pornsak Sriamornsak
- School of Biomedical Sciences, Charles Sturt University, Locked Bag 588, Wagga Wagga 2678, NSW, Australia
| | | |
Collapse
|
15
|
Nolasco MM, Amado AM, Ribeiro-Claro PJA. Computationally-assisted approach to the vibrational spectra of molecular crystals: study of hydrogen-bonding and pseudo-polymorphism. Chemphyschem 2007; 7:2150-61. [PMID: 16983716 DOI: 10.1002/cphc.200600308] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A new computationally-assisted methodology (PiMM), which accounts for the effects of intermolecular interactions in the crystal, is applied to the complete assignment of the Raman and infrared vibrational spectra of room temperature forms of crystalline caffeine, theobromine, and theophylline. The vibrational shifts due to crystal packing interactions are evaluated from ab initio calculations for a set of suitable molecular pairs, using the B3LYP/6-31G* approach. The proposed methodology provides an answer to the current demand for a reliable assignment of the vibrational spectra of these methyl-xanthines, and clarifies several misleading assignments. The most relevant intermolecular interactions in each system and their effect on the vibrational spectra are considered and discussed. Based on these results, significant insights are obtained for the structure of caffeine in the anhydrous form (stable at room temperature), for which no X-ray structure has been reported. A possible structure based on C((8))--H...N((9)) and C((1,3))--H...O intermolecular interactions is suggested.
Collapse
Affiliation(s)
- Mariela M Nolasco
- CICECO, Departamento de Química Universidade de Aveiro, 3810-193 Aveiro, Portugal
| | | | | |
Collapse
|
16
|
Ucun F, Sağlam A, Güçlü V. Molecular structures and vibrational frequencies of xanthine and its methyl derivatives (caffeine and theobromine) by ab initio Hartree-Fock and density functional theory calculations. Spectrochim Acta A Mol Biomol Spectrosc 2007; 67:342-9. [PMID: 16942910 DOI: 10.1016/j.saa.2006.07.029] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2006] [Revised: 06/07/2006] [Accepted: 07/14/2006] [Indexed: 05/11/2023]
Abstract
The molecular structures, vibrational frequencies and corresponding vibrational assignments of xanthine and its methyl derivatives (caffeine and theobromine) have been calculated using ab initio Hartree-Fock (HF) and density functional theory (B3LYP) methods with 6-31G(d, p) basis set level. The calculations were utilized to the C(S) symmetries of the molecules. The obtained vibrational frequencies and optimised geometric parameters (bond lengths and bond angles) were seen to be well agreement with the experimental data. The used scale factors which have been obtained the ratio of the frequency values of the strongest peaks in the calculated and experimental spectra seem to cause the gained vibrations well corresponding to the experimental ones. Theoretical infrared intensities and Raman activities are also reported.
Collapse
Affiliation(s)
- Fatih Ucun
- Department of Physics, Faculty of Arts and Sciences, Süleyman Demirel University, Isparta, Turkey.
| | | | | |
Collapse
|
17
|
Yang M, Soohoo D, Soelaiman S, Kalla R, Zablocki J, Chu N, Leung K, Yao L, Diamond I, Belardinelli L, Shryock JC. Characterization of the potency, selectivity, and pharmacokinetic profile for six adenosine A2A receptor antagonists. Naunyn Schmiedebergs Arch Pharmacol 2007; 375:133-44. [PMID: 17310264 DOI: 10.1007/s00210-007-0135-0] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2007] [Accepted: 01/09/2007] [Indexed: 10/23/2022]
Abstract
Antagonists of adenosine A2A receptors (A2A -antagonists) with different chemical structures have been developed by several pharmaceutical companies for the potential treatment of Parkinson's disease. Pharmacological characterization of these antagonists was incomplete, and different assay conditions were used in different labs. Therefore, we characterized the potencies, selectivities, and pharmacokinetic profiles of six prototypical A2A -antagonists. Displacements of [3H]MSX-2 and of [3H]CGS21680 binding to the human cloned and rat A2A receptors were performed. The rank order of potency of antagonists to displace [(3)H]MSX-2 binding to the human A2A was SCH58261 > or = Biogen-34 > or = Ver-6623 > or = MSX-2 > KW-6002 > > DMPX. For the rat striatal A2A, the order of potency was Biogen-34 > or = SCH58261 > or = Ver-6623 > or = MSX-2 > or = KW-6002 > > DMPX. SCH58261 was the most potent antagonist of the human A2A with a K(i) value of 4 nM, whereas Biogen-34 was the most potent antagonist of the rat A2A with a K(i) value of 1.2 nM. Similar results were obtained from cAMP assays. Selectivities of A2A-antagonists were determined using radioligands [3H]DPCPX, [3H]ZM241385, and [125I]-AB-MECA for A1, A2B, and A3 receptors, respectively. KW-6002 and Biogen-34 exhibited the highest selectivity for A2A vs A1 (human and rat), respectively. The pharmacokinetic profiles of antagonists were evaluated in vivo in rats. DMPX and KW-6002 had the greatest oral bioavailability. In contrast, SCH58261, MSX-2, and Ver-6623 had low or poor oral bioavailability. In summary, SCH58261, Biogen-34, MSX-2, and Ver-6623 had high affinities for both human and rat A2A receptors, with reasonable selectivity for A2A over A1 and A2B receptors. They are suitable as A2A -antagonists for in vitro pharmacological studies. Among the six A2A-antagonists, KW-6002 is the best for use in in vivo animal studies, particularly for a CNS target, based on its bioavailability, half life, and brain penetration.
Collapse
Affiliation(s)
- Ming Yang
- Department of Pharmacology, CV Therapeutics, Inc., Palo Alto, CA 94304, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Bilensoy E, Abdur Rouf M, Vural I, Šen M, Atilla Hincal A. Fluid bed drying of guarana (Paullinia cupana HBK) extract: effect of process factors on caffeine content. AAPS PharmSciTech 2006; 7:E54. [PMID: 16796371 PMCID: PMC2750288 DOI: 10.1208/pt070254] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2005] [Accepted: 02/24/2006] [Indexed: 11/30/2022] Open
Abstract
The aim of this study was to study the convective drying of the hydroalcoholic extracts obtained from powdered guarana seeds in a spouted bed dryer. The influence of process variables, such as the convective airflow rate, extract feed rate, and air inlet temperature, on the quality of the dry extract was determined using the caffeine and moisture content for the process evaluation. The caffeine content in the alcoholic and dried extracts was determined by capillary gas chromatography. The experiments were performed following a 3(3) factorial design and the data analyzed by response surface. The analysis of dry extract showed that the air and extract feed rates did not significantly affect (25% level) the caffeine content, but that drying temperature is a major factor to consider when the extract is submitted to fluid bed drying. Caffeine losses were significant (1% level) for drying temperatures above 120 degrees C, while moisture content was lower than 3% for temperatures above 120 degrees C. The data showed that there is an optimum temperature for the drying of guarana extracts in spouted beds, and under the conditions used in this study it was 120 degrees C.
Collapse
Affiliation(s)
- Erem Bilensoy
- />Department of Pharmaceutical Technology, Hacettepe University, Faculty of Pharmacy, 06100 Ankara, Turkey
| | - M. Abdur Rouf
- />Department of Pharmaceutical Technology, Hacettepe University, Faculty of Pharmacy, 06100 Ankara, Turkey
| | - Imran Vural
- />Department of Pharmaceutical Technology, Hacettepe University, Faculty of Pharmacy, 06100 Ankara, Turkey
| | - Murat Šen
- />Department of Chemistry, Hacettepe University, 06532 Beytepe-Ankara, Turkey
| | - A. Atilla Hincal
- />Department of Pharmaceutical Technology, Hacettepe University, Faculty of Pharmacy, 06100 Ankara, Turkey
| |
Collapse
|
19
|
Ribeiro-Claro PJA, Amado AM. Comment on vibrational spectral investigation on xanthine and its derivatives-theophylline, caffeine and theobromine. Spectrochim Acta A Mol Biomol Spectrosc 2005; 61:2796-7. [PMID: 16043080 DOI: 10.1016/j.saa.2004.11.026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2004] [Accepted: 11/17/2004] [Indexed: 05/03/2023]
|
20
|
Wei YL, Dong C, Shuang SM, Liu DS. Study for luminescence performance of three methyl xanthine derivatives. Spectrochim Acta A Mol Biomol Spectrosc 2005; 61:2584-9. [PMID: 16043051 DOI: 10.1016/j.saa.2004.09.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2004] [Accepted: 09/29/2004] [Indexed: 05/03/2023]
Abstract
In this paper, the low-temperature phosphorescence (LTP), the low-temperature fluorescence (LTF), the paper substrate room-temperature phosphorescence (PS-RTP) and the room fluorescence (RTF) properties of caffeine (CF), theophylline (TP), and theobromine (TB) are investigated and compared, and some rules are found out: their maximal excitation wavelength and emission wavelength are in the range of 270-300 nm and 395-445 nm, respectively. And the PS-RTP characters of lifetime, polarization and quanta yield are also investigated and compared. It is found that their lifetimes of PS-RTP are all in the level of 0.1s. They belong to long-life phosphorescence and their PS-RTP spectra are incompletely polarized.
Collapse
Affiliation(s)
- Yan-Li Wei
- Institute of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, PR China
| | | | | | | |
Collapse
|
21
|
Sugawara M, Mochizuki T, Takekuma Y, Miyazaki K. Structure–affinity relationship in the interactions of human organic anion transporter 1 with caffeine, theophylline, theobromine and their metabolites. Biochimica et Biophysica Acta (BBA) - Biomembranes 2005; 1714:85-92. [PMID: 16038872 DOI: 10.1016/j.bbamem.2005.06.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2004] [Revised: 06/02/2005] [Accepted: 06/14/2005] [Indexed: 11/30/2022]
Abstract
It is well known that human organic anion transporter 1 (hOAT1) transports many kinds of drugs, endogenous compounds, and toxins. However, little is known about the structure-affinity relationship. The aim of this study was to elucidate the structure-affinity relationship using a series of structurally related compounds that interact with hOAT1. Inhibitory effects of xanthine- and uric acid-related compounds on the transport of p-aminohippuric acid were examined using CHO-K1 cells stably expressing hOAT1. The order of potency for the inhibitory effects of xanthine-related compounds on PAH uptake was 1-methyl derivative>7-methyl derivative>3-methyl derivative falling dotsxanthine>1,3,7-trimethyl derivative (caffeine). The order of potency of the inhibition was 1,3,7-trimethyluric acid>1,3-dimethyluric acid>1,7-dimethyluric acid>1-methyluric acid>uric acid. A significant correlation between inhibitory potency and lipophilicity of the tested uric acid-related compounds was observed. The main determinant of the affinity of xanthine-related compounds is the position of the methyl group. On the other hand, lipophilicity is the main determinant of the affinity of uric acid-related compounds.
Collapse
Affiliation(s)
- Mitsuru Sugawara
- Department of Pharmacy, Hokkaido University Hospital, Kita-14-jo, Nishi-5-chome, Kita-ku, Sapporo, Hokkaido 060-8648, Japan.
| | | | | | | |
Collapse
|
22
|
Edwards HGM, Munshi T, Anstis M. Raman spectroscopic characterisations and analytical discrimination between caffeine and demethylated analogues of pharmaceutical relevance. Spectrochim Acta A Mol Biomol Spectrosc 2005; 61:1453-1459. [PMID: 15820878 DOI: 10.1016/j.saa.2004.10.022] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2004] [Accepted: 10/22/2004] [Indexed: 05/24/2023]
Abstract
The FT Raman spectrum of caffeine was analysed along with that of its demethylated analogues, theobromine and theophylline. The similar but not identical structures of these three compounds allowed a more detailed assignment of the Raman bands. Noticeable differences in the Raman spectra of these compounds were apparent and key marker bands have been identified for the spectroscopic identification of these three compounds.
Collapse
Affiliation(s)
- H G M Edwards
- Chemical and Forensic Sciences, The School of Pharmacy, University of Bradford, Bradford BD7 1DP, UK.
| | | | | |
Collapse
|
23
|
Gunasekaran S, Sankari G, Ponnusamy S. Vibrational spectral investigation on xanthine and its derivatives--theophylline, caffeine and theobromine. Spectrochim Acta A Mol Biomol Spectrosc 2005; 61:117-27. [PMID: 15556429 DOI: 10.1016/j.saa.2004.03.030] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2004] [Accepted: 03/25/2004] [Indexed: 05/11/2023]
Abstract
A normal coordinate analysis has been carried out on four compounds having a similar ring structure with different side chain substitutions, which are xanthine, caffeine, theophylline, and theobromine. Xanthine is chemically known as 2,6-dihydroxy purine. Caffeine, theophylline and theobromine are methylated xanthines. Considering the methyl groups as point mass, the number of normal modes of vibrations can be distributed as Gamma(vib) = 27 A' + 12 A" based on C(s) point group symmetry associated with the structures. In the present work 15 A' and 12 A'' normal modes are considered. A new set of orthonormal symmetry co-ordinates have been constructed. Wilson's F-G matrix method has been adopted for the normal coordinate analysis. A satisfactory vibrational band assignment has been made by employing the FTIR and FT Raman spectra of the compounds. The potential energy distribution is calculated with the arrived values of the force constants and hence the agreement of the frequency assignment has been checked.
Collapse
Affiliation(s)
- S Gunasekaran
- PG & Research Department of Physics, Pachaiyappa's College, Chennai 600 030, India.
| | | | | |
Collapse
|
24
|
Smit HJ, Gaffan EA, Rogers PJ. Methylxanthines are the psycho-pharmacologically active constituents of chocolate. Psychopharmacology (Berl) 2004; 176:412-9. [PMID: 15549276 DOI: 10.1007/s00213-004-1898-3] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2004] [Accepted: 03/24/2004] [Indexed: 11/30/2022]
Abstract
RATIONALE Liking, cravings and addiction for chocolate ("chocoholism") are often explained through the presence of pharmacologically active compounds. However, mere "presence" does not guarantee psycho-activity. OBJECTIVES Two double-blind, placebo-controlled studies measured the effects on cognitive performance and mood of the amounts of cocoa powder and methylxanthines found in a 50 g bar of dark chocolate. METHODS In study 1, participants ( n=20) completed a test battery once before and twice after treatment administration. Treatments included 11.6 g cocoa powder and a caffeine and theobromine combination (19 and 250 mg, respectively). Study 2 ( n=22) comprised three post-treatment test batteries and investigated the effects of "milk" and "dark" chocolate levels of these methylxanthines. The test battery consisted of a long duration simple reaction time task, a rapid visual information processing task, and a mood questionnaire. RESULTS Identical improvements on the mood construct "energetic arousal" and cognitive function were found for cocoa powder and the caffeine+theobromine combination versus placebo. In chocolate, both "milk chocolate" and "dark chocolate" methylxanthine doses improved cognitive function compared with "white chocolate". The effects of white chocolate did not differ significantly from those of water. CONCLUSIONS A normal portion of chocolate exhibits psychopharmacological activity. The identical profile of effects exerted by cocoa powder and its methylxanthine constituents shows this activity to be confined to the combination of caffeine and theobromine. Methylxanthines may contribute to the popularity of chocolate; however, other attributes are probably much more important in determining chocolate's special appeal and in explaining related self-reports of chocolate cravings and "chocoholism".
Collapse
Affiliation(s)
- Hendrik J Smit
- Department of Experimental Psychology, University of Bristol, 8 Woodland Road, Bristol, BS8 1TN, UK.
| | | | | |
Collapse
|
25
|
Zheng XQ, Koyama Y, Nagai C, Ashihara H. Biosynthesis, accumulation and degradation of theobromine in developing Theobroma cacao fruits. J Plant Physiol 2004; 161:363-369. [PMID: 15128023 DOI: 10.1078/0176-1617-01253] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We have studied the purine alkaloid content and purine metabolism in Theobroma cacao fruits at differing growth stages: Stage A (young small fruit, fresh weight, ca. 2 g); stage B (medium size fruit, fresh weight, ca. 100 g) and stage C (large size, fresh weight, ca. 500 g). The major purine alkaloid in stage A fruits (mainly pericarp) was theobromine (0.7 micromol g(-1) fresh weight), followed by caffeine (0.09 micromol g(-1) fresh weight). The theobromine content of the pericarp decreased sharply with tissue age, and the caffeine content decreased gradually. A large amount of theobromine (22 micromol g(-1) fresh weight) had accumulated in seeds (mainly cotyledons) of stage C fruits. Theobromine was found also in the seed coat and placenta. Tracer experiments with [8-(14)C]adenine show that the major sites of theobromine synthesis are the young pericarp and cotyledons of T. cacao fruits. Limited amounts of purine alkaloids may be transported from the pericarp to seed tissue, but most purine alkaloids that accumulated in seeds appeared to be synthesised in cotyledons. Degradation of [8-(14)C]theobromine and [8-(14)C]caffeine to CO2 via 3-methylxanthine and ureides (allantoin and allantoic acid) was detected only in the pericarp of stage C fruits.
Collapse
Affiliation(s)
- Xin-Qiang Zheng
- Department of Advanced Biosciences, Graduate School of Humanities and Sciences, Ochanomizu University, 2-1-1, Otsuka, Bunkyo-ku, Tokyo, 112-8610, Japan
| | | | | | | |
Collapse
|
26
|
Azam S, Hadi N, Khan NU, Hadi SM. Antioxidant and prooxidant properties of caffeine, theobromine and xanthine. Med Sci Monit 2003; 9:BR325-30. [PMID: 12960921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023] Open
Abstract
BACKGROUND Caffeine, along with its catabolic products theobromine and xanthine, is a key component of tea and coffee. These compounds are structurally similar to uric acid, a known antioxidant which is present in blood at relatively high concentrations, but also shows prooxidant activity. In view of the structural similarity between uric acid and caffeine and its metabolites, we studied the antioxidant and prooxidant properties of these compounds. MATERIAL/METHODS Antioxidant activity was determined by measuring the quenching effect of the compounds on oxidative DNA degradation by a hydroxyl radical generating system. Prooxidant activity was studied by measuring the ability of the compounds to oxidatively degrade DNA in the presence of copper ions. RESULTS Caffeine, theobromine and xanthine have a quenching effect on the production of hydroxyl radicals, as well as on oxidative DNA breakage by hydroxyl radicals. Consistent with previous observations that many known antioxidants of plant origin are also capable of prooxidant action, the purine alkaloids also show oxidative DNA breakage in the presence of transition metal ions. CONCLUSIONS The alkaloid caffeine and its catabolic products theobromine and xanthine exhibit both antioxidant and prooxidant properties. The results lead to the observation that caffeine and its metabolites may also contribute to the overall antioxidant and chemopreventive properties of caffeine-bearing beverages, such as tea.
Collapse
Affiliation(s)
- Sonish Azam
- Department of Biochemistry, Faculty of Life Sciences, AMU, Aligarh, India.
| | | | | | | |
Collapse
|
27
|
Moustafa H, Shalaby SH, El-sawy KM, Hilal R. Electronic structure of some adenosine receptor antagonists. III. Quantitative investigation of the electronic absorption spectra of alkyl xanthines. Spectrochim Acta A Mol Biomol Spectrosc 2002; 58:2013-2027. [PMID: 12164499 DOI: 10.1016/s1386-1425(01)00649-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Quantitative and comparative investigation of the electronic absorption spectra of theophylline, caffeine and their derivatives is reported. The spectra of theophylline, caffeine and theobromine were compared to establish the predominant tautomeric species in solution. This comparison, analysis of solvent effects and assignments of the observed transitions via MO computations indicate the exits of only one tautomeric species in solution that is the N7 form. A low-lying triplet state was identified which corresponds to a HOMO-LUMO transition. This relatively long-lived T1 state is always less polar than the ground state and may very well underlie the photochemical reactivity of alkyl xanthines. Substituents of different electron donating or withdrawing strengths and solvent effects are investigated and analyzed. The present analysis is facilitated via computer deconvolution of the observed spectra and MO computation.
Collapse
Affiliation(s)
- H Moustafa
- Faculty of Science, Department of Chemistry, University of Cairo, Giza, Egypt
| | | | | | | |
Collapse
|
28
|
Dubler E, Schmalle HW, Arod F, Schneider A. Platinum complexes of oxopurines: cis-bis(theophyllinato-N7)bis(triphenylphosphine)platinum(II) and cis-chloro(theobrominato-N1)bis(triphenylphosphine)platinum(II) ethanol hemisolvate. Acta Crystallogr C 2002; 58:m111-5. [PMID: 11828097 DOI: 10.1107/s0108270101020364] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2001] [Accepted: 11/28/2001] [Indexed: 11/11/2022] Open
Abstract
The syntheses and structures of two mixed-ligand complexes of platinum(II) with deprotonated oxopurine bases and triphenylphosphine are reported, namely the theophyllinate complex cis-bis(1,2,3,6-tetrahydro-1,3-dimethylpurine-2,6-dionato-kappaN(7))bis(triphenylphosphine-kappaP)platinum(II), [Pt(C(7)H(7)N(4)O(2))(2)(C(18)H(15)P)(2)], (I), and the theobrominate complex cis-chloro(1,2,3,6-tetrahydro-3,7-dimethylpurine-2,6-dionato-kappaN(1))bis(triphenylphosphine-kappaP)platinum(II) ethanol hemisolvate, [PtCl(C(7)H(7)N(4)O(2))(C(18)H(15)P)(2)].0.5C(2)H(5)OH, (II). In (I), the coordination geometry of Pt is square planar, formed by the two coordinating N atoms of the theophyllinate anions in a cis arrangement and two P atoms from the triphenylphosphine groups. In (II), there are two crystallographically independent molecules. They both exhibit a square-planar coordination geometry around Pt involving one Cl atom, the coordinating N atom of the theobrominate anion and two P atoms from the triphenylphosphine groups. The two triphenylphosphine groups are arranged in a cis configuration in both structures. The heterocyclic rings are rotated with respect to the coordination plane of the metal by 82.99(8) and 88.09(8) degree in complex (I), and by 85.91(16) and 88.14(18) degree in complex (II). Both structures are stabilized by intramolecular stacking interactions involving the purine rings and the phenyl rings of adjacent triphenylphosphine moieties.
Collapse
Affiliation(s)
- Erich Dubler
- Institute of Inorganic Chemistry, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
| | | | | | | |
Collapse
|
29
|
Abstract
Methylmethacrylate/dimethylaminoethyl methacrylate cross-linked with divinylbenzene is a pH-sensitive hydrogel. We have studied the diffusion mechanisms of drugs with different water solubilities through this hydrogel. A water-soluble model drug (aminopyrine) was used to study the diffusion coefficient changes in different pHs. The results showed a water-content dependent diffusion for this pH-sensitive polycationic hydrogel. However, decreasing the solubility of the drug and increasing the hydrophobic character of the polymer by changing the pH caused a greater affinity (or partition coefficient) between the hydrogel and the drug. Aminopyrine diffusion was shown to follow the free-volume theory, suggesting the 'pore' type mechanism for water soluble drugs, while the 'partition' or 'solution-diffusion' mechanism better described the slow diffusion of water insoluble solutes through this pH-sensitive hydrogel. Comparing the swelling interface number for aminopyrine release through this pH-sensitive hydrogel showed a non-Fickian mechanism in the hydrated form of the hydrogel (pH 1.2), while Fickian in the dehydrated form (pH 7.4).
Collapse
Affiliation(s)
- J Varshosaz
- Faculty of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran.
| | | |
Collapse
|
30
|
Abstract
Caffeine and theobromine were identified and quantified in leaf epicuticular waxes of Ilex paraguariensis A. St.-Hil. (Aquifoliaceae). The total epicuticular leaf wax content was ca. 0.5% on average of dry leaf weight. Epicuticular caffeine and theobromine contents varied from 0.16 to 127.6 microg/mg and from 0 to 9.5 microg/mg of wax, respectively. For some selected samples, the intracellular methylxanthine concentration was also determined. A positive correlation was found between inner and epicuticular caffeine contents.
Collapse
Affiliation(s)
- M L Athayde
- Departamento de Farmácia Industrial, Universidade Federal de Santa Maria, RS, Brazil
| | | | | |
Collapse
|
31
|
Abstract
A capillary electrochromatography (CEC) method has been developed for the separation of theophylline, caffeine and five related drugs on a normal-phase column with UV or photodiode array detection. Several binary, ternary and quaternary mobile phase compositions are evaluated for optimal resolution and elution of these drug analytes. The importance of selecting suitable organic solvents, buffer electrolyte, pH and applied voltage is demonstrated by a systematic study. Excellent separation is achieved for the eight drugs using a ternary mobile phase composition of isopropanol/hexane/1 mM Tris (52:40:8, pH 8), with an efficiency of 63000 theoretical plates per meter at room temperature. Detection limits are typically at the low microg/mL level. The developed method is simple to use and it gives acceptable day-to-day reproducibility.
Collapse
Affiliation(s)
- E P Lai
- Ottawa-Carleton Chemistry Institute, Department of Chemistry, Carleton University, ON, Canada.
| | | |
Collapse
|
32
|
Saldaña MD, Mohamed RS, Baer MG, Mazzafera P. Extraction of purine alkaloids from maté (Ilex paraguariensis) using supercritical CO(2). J Agric Food Chem 1999; 47:3804-3808. [PMID: 10552725 DOI: 10.1021/jf981369z] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Experimental data for the supercritical CO(2) extraction of purine alkaloids (caffeine, theobromine, and theophylline) from ground herbal maté tea (Ilex paraguaryensis) using a high-pressure apparatus are presented. Caffeine, theophylline, and theobromine were identified in the extracted fractions using HPLC. Results indicated a much higher CO(2) selectivity for caffeine in comparison with those for theophylline and theobromine. Solubilities of pure compounds in carbon dioxide were also determined at 313.2, 323.2, 338.2, and 343.2 K, and pressures ranging from 14 to 24 MPa. Caffeine solubility exhibited a retrograde behavior with temperature while theophylline and theobromine manifested a normal behavior at conditions explored in this study. Solubilities in binary CO(2)/purine alkaloid model systems were much higher than those obtained during extraction of maté tea, demonstrating the difficulty of using binary data in predicting complex multicomponent behavior.
Collapse
Affiliation(s)
- M D Saldaña
- Faculty of Chemical Engineering and Institute of Biology, State University of Campinas, C.P. 6066, CEP 13083-970, Campinas, SP, Brazil
| | | | | | | |
Collapse
|
33
|
Abstract
We report that caffeine, in millimolar concentrations, interacts strongly with four common calcium indicator dyes: mag-fura-2, magnesium green, fura-2, and fluo-3. Fluorescence intensities are either noticeably enhanced (mag-fura-2, fura-2) or diminished (magnesium green, fluo-3). The caffeine-induced changes in the fluorescence spectra are clearly distinct from those of metal ion binding at the indicator chelation sites. Binding affinities for calcium of either mag-fura-2 or magnesium green increased only slightly in the presence of caffeine. Caffeine also alters the fluorescence intensities of two other fluorescent dyes lacking a chelation site, fluorescein and sulforhodamine 101, implicating the fluorophore itself as the interaction site for caffeine. In the absence of caffeine, variation of solution hydrophobicity by means of water/dioxane mixtures yielded results similar to those for caffeine. These observations suggest that hydrophobic substances, in general, can alter dye fluorescence in a dye-specific manner. For the particular case of caffeine, and perhaps other commonly used pharmacological agents, the dye interactions can seriously distort fluorescence measurements of intracellular ion concentrations with metal indicator dyes.
Collapse
Affiliation(s)
- M Muschol
- Department of Neuroscience, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6074 USA
| | | | | |
Collapse
|
34
|
Abstract
Ninety Large White grower pigs were used to determine the most efficient way to hydrothermally detoxify sheanut cake (SNC) and to measure the influence of the detoxified SNC on the performance of grower and finisher pigs. In the first experiment, SNC was boiled in water for 30, 60, or 90 min, dried and included in the pigs' diets at a single level of 20%. There was also another treatment in which the SNC was only steeped in cold water overnight and a control in which the diet did not contain any SNC. In the second experiment, SNC which had been boiled for 90 min was included in the diets at 0%, 20%, 30% and 40%. In both studies, the pigs were fed from an average initial live weight of 20 kg until they attained an average final live weight of 90 kg. In the first experiment the average daily gains (ADG) of the pigs during the grower period were, respectively, 0.46, 0.32, 0.31 and 0.39 kg/day on the control, cold-treated SNC, 30, 60 and 90 min boiled SNC diets (p < 0.01). The corresponding ADGs of pigs during the finisher period were 0.41, 0.36, 0.33, 0.46 and 0.55 kg/day (p < 0.01). The feed conversion efficiencies (FCEs) were, respectively, 6.4, 7.2, 7.5, 7.1 and 6.5 kg feed/kg live weight gain. In experiment 2, the ADGs of pigs during the grower period were 0.44, 0.35, 0.20 and 0.09 kg/day on 0%, 20%, 30% and 40%, respectively, of 90 min boiled SNC diets. The corresponding ADGs of pigs during the finisher period were 0.66, 0.44, 0.27 and 0.13 kg/day (p < 0.01). The FCEs were 4.67, 5.10, 5.90 and 7.10, respectively. The study indicated that the theobromine in SNC is removed by boiling in water and that the level may be reduced to a greater extent by boiling for 90 min rather than for 30 min. It also indicated that a 20% level of inclusion of 90-min heat-treated SNC should not be exceeded for either grower or finisher pigs.
Collapse
Affiliation(s)
- S W Rhule
- Animal Research Institute, Achimota, Ghana
| |
Collapse
|
35
|
Pereira MM, Lloyd Mills C, Dormer RL, McPherson MA. Actions of adenosine A1 and A2 receptor antagonists on CFTR antibody-inhibited beta-adrenergic mucin secretion response. Br J Pharmacol 1998; 125:697-704. [PMID: 9831904 PMCID: PMC1571032 DOI: 10.1038/sj.bjp.0702128] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
1. The cystic fibrosis gene protein, the cystic fibrosis transmembrane conductance regulator (CFTR) acts as a chloride channel and is a key regulator of mucin secretion. The mechanism by which 3-isobutyl-1-methylxanthine (IBMX) corrects the defect in CFTR mediated beta-adrenergic stimulation of mucin secretion has not been determined. The present study has investigated the actions of adenosine A1 and A2 receptor antagonists to determine whether ability to stimulate mucin secretion correlates with correction of CFTR antibody inhibited beta-adrenergic response and whether excessive cyclic AMP rise is required. 2. CFTR antibodies were introduced into living rat submandibular acini by hypotonic swelling. Following recovery, mucin secretion in response to isoproterenol was measured. 3. The adenosine A1 receptor antagonist, 8 cyclopentyltheophylline (CPT) was a less potent stimulator of mucin secretion than was the A2 receptor antagonist dimethylpropargylxanthine (DMPX). A concentration of CPT close to the Ki for A1 receptor antagonism (10 nM) did not stimulate mucin secretion. 4. DMPX, although a potent stimulator of mucin secretion, did not correct CFTR antibody inhibited mucin secretion. 5. CPT corrected defective CFTR antibody inhibited mucin secretion at a high (1 mM) concentration, suggesting a mechanism other than adenosine receptor antagonism. 6. DMPX potentiated the isoproterenol induced cyclic AMP rise, whereas CPT did not. 7. Correction of the defective CFTR mucin secretion response did not correlate with ability to stimulate mucin secretion and did not require potentiation of beta-adrenergic induced increases in cyclic AMP. This affords real promise for the development of a selective drug treatment for cystic fibrosis.
Collapse
Affiliation(s)
- M M Pereira
- Department of Medical Biochemistry, University of Wales College of Medicine, Heath Park, Cardiff
| | | | | | | |
Collapse
|
36
|
Müller CE, Geis U, Hipp J, Schobert U, Frobenius W, Pawłowski M, Suzuki F, Sandoval-Ramírez J. Synthesis and structure-activity relationships of 3,7-dimethyl-1-propargylxanthine derivatives, A2A-selective adenosine receptor antagonists. J Med Chem 1997; 40:4396-405. [PMID: 9435909 DOI: 10.1021/jm970515+] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A series of 8-substituted derivatives of 3,7-dimethyl-1-propargylxanthine (DMPX) was synthesized and investigated as A2A adenosine receptor antagonists. Different synthetic strategies for the preparation of DMPX derivatives and analogues were explored. A recently developed synthetic procedure starting from 3-propargyl-5,6-diaminouracil proved to be the method of choice for the preparation of this type of xanthine derivatives. The novel compounds were investigated in radioligand binding studies at the high-affinity adenosine receptor subtypes A1 and A2A and compared with standard A2A adenosine receptor antagonists. Structure-activity relationships were analyzed in detail. 8-Styryl-substituted DMPX derivatives were identified that exhibit high affinity and selectivity for A2A adenosine receptors, including 8-(m-chlorostyryl)-DMPX (CS-DMPX, Ki A2A = 13 nM, 100-fold selective), 8-(m-bromostyryl)-DMPX (BS-DMPX, Ki A2A = 8 nM, 146-fold selective), and 8-(3,4-dimethoxystyryl)-DMPX (Ki A2A = 15 nM, 167-fold selective). These and other novel compounds are superior to the standard A2A adenosine receptor antagonists KF17837 (4) and CSC (5) with respect to A2A affinity and/or selectivity.
Collapse
Affiliation(s)
- C E Müller
- Julius-Maximilians-Universität Würzburg, Institut für Pharmazie und Lebensmittelchemie, Pharmazeutische Chemie, Germany.
| | | | | | | | | | | | | | | |
Collapse
|
37
|
Benchekroun Y, Dautraix S, Désage M, Brazier JL. Isotopic effects on retention times of caffeine and its metabolites 1,3,7-trimethyluric acid, theophylline, theobromine and paraxanthine. J Chromatogr B Biomed Sci Appl 1997; 688:245-54. [PMID: 9061462 DOI: 10.1016/s0378-4347(96)00323-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Physicochemical parameters that influence gas chromatographic separation are numerous. Consequently, isotope labelling, because it modifies physicochemical properties, can induce isotopic effects on retention time. Caffeine has been chosen to study this influence because as itself and its metabolites, it allows the preparation of different methylxanthine isotopomers and thus is one of the best models to study isotopic effects induced by stable isotope labelling. Using a caffeine molecule labelled with deuterium at different positions and rat hepatocytes to obtain metabolites, it was possible to study the influence of labelling on retention time [(14% cyanopropylphenyl)methylpolysiloxane] and to point out the role of each labelled site. It appears that isotopic effects induced by the labelling depend not only on the number of labelling atoms but also on whether this labelling is at position 1, 3 or 7 and, consequently, on the role of the labelled site on the function of the molecule.
Collapse
Affiliation(s)
- Y Benchekroun
- Laboratoire d'Etudes Analytiques et Cinétiques du Médicament, Institut des Sciences Pharmaceutiques et Biologiques de Lyon, France
| | | | | | | |
Collapse
|
38
|
Salvadori MC, Rieser EM, Ribeiro Neto LM, Nascimento ES. Determination of xanthines by high-performance liquid chromatography and thin-layer chromatography in horse urine after ingestion of Guaraná powder. Analyst 1994; 119:2701-3. [PMID: 7879880 DOI: 10.1039/an9941902701] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The seeds of Guaraná are rich in xanthines and are used for the preparation of guaraná powder which is very commonly given to horses as a 'tonic' in Brazil. In this paper, the xanthine content of guaraná powder was determined, in addition to its clearance time in horses. Thin-layer chromatography was used as a screening procedure and high-performance liquid chromatography was performed to quantify the drugs in both the powder and urine samples. The guaraná powder was found to contain 2.16, 1.10 and 36.78 mg g-1 of theobromine (TB), theophylline (TP) and caffeine (CF), respectively, and in urine it was possible to detect TB and TP up to 13 d and CF up to 9 d after the administration of guaraná powder.
Collapse
|
39
|
Abstract
Organomercury(II) complexes of the types, p-XC6H4HgL (A) and p-XC6H4HgCl(L') (B) [LH = theophylline; L' = theobromine; X = Me, NO2], have been synthesised and characterized. Conductance measurements indicate that the complexes are non-electrolytes. The structures of the complexes have been elucidated by spectral studies (IR, UV, and 1H, 13C NMR). The complexes have been tested for diuretic activity. The structure-activity relationship has been propounded.
Collapse
Affiliation(s)
- J Kaur
- Department of Chemistry, University of Delhi, India
| | | |
Collapse
|
40
|
Abstract
A study of the fluorescence quenching of human serum albumin (HSA) by caffeine, theophylline and theobromine, based on temperature dependence, has shown that it is predominantly static. This quenching mechanism is due to the formation of a xanthine-HSA non-fluorescent complex. The Stern-Volmer equation let us determine the association constants. It seems that the quenching of the protein fluorescence depends on the number and position of the methyl groups. The temperature dependence of the association constant is used to estimate the values of the thermodynamic parameters involved in the interaction of the drugs with HSA. All three binding processes are exothermic and probably hydrophobic, and hydrogen bonds play a significant role in the stabilization of such complexes. The enthalpy and entropy changes observed appear to compensate each other to produce a relatively small Gibbs free energy.
Collapse
Affiliation(s)
- J González-Jimènez
- Departamento de Química-Fisica Farmacèutica, Facultad de Farmàcia, Ciudad Universitaria, Madrid, Spain
| | | | | |
Collapse
|
41
|
Danilov VI, Slyusarchuk ON, Poltev VI, Alderfer JL, Wollman RM, Brickmann JA, Lautenschlager P. A Monte Carlo simulation of hydration of xanthine-derivatives and their stacked forms. J Biomol Struct Dyn 1992; 9:1239-52. [PMID: 1637511 DOI: 10.1080/07391102.1992.10507989] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Results on a Monte Carlo simulation of the hydration of monomer and possible stacked dimer forms of a purine alkaloid series in 200- and 400-water molecule clusters are presented. Investigation of different purine stacked dimers in a 200-water molecule cluster reveals that for caffeine there exists one, for theophylline two and for theobromine four dimers are energetically favorable. For caffeine, the same energetically favored stacked dimer form is observed in both the 200- and 400-water molecule cluster. The main factor stabilizing the preferred dimer stacks is the change in the interaction between water molecules of the monomer cluster and those water molecules in the dimer cluster.
Collapse
Affiliation(s)
- V I Danilov
- Institute of Molecular Biology and Genetics, Ukrainian Academy of Sciences, Kiev
| | | | | | | | | | | | | |
Collapse
|
42
|
Blanchard J, Weber CW, Shearer LE. Methylxanthine levels in breast milk of lactating women of different ethnic and socioeconomic classes. Biopharm Drug Dispos 1992; 13:187-96. [PMID: 1576327 DOI: 10.1002/bdd.2510130305] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The purpose of this study was to evaluate the dietary caffeine and dimethylxanthine concentrations in breast milk of 40 mothers from different ethnic and socioeconomic backgrounds. Their diets and drug intake were not restricted in any way. Each nursing mother provided a fasting and a combined breast-milk sample each day for 3 consecutive days. No significant differences were found in intake levels of any of the methylxanthines among the groups tested. No significant differences were found among the four groups in breast-milk levels of caffeine, theobromine, or paraxanthine. However, the mean theophylline milk levels were significantly higher on 2 of the 3 days examined in Anglo-American woman compared to Hispanic-American women. Socioeconomic and ethnic variables were also compared among the four groups. The daily amounts of methylxanthines found in the breast milk of this free-living population of mothers do not appear to present clinically significant amounts to the infant.
Collapse
Affiliation(s)
- J Blanchard
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arizona, Tucson 85721
| | | | | |
Collapse
|
43
|
LYSENKO TN. [Improved technics for the production of theobromine]. Med Prom SSSR 1962; 4:36-8. [PMID: 14467665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
|
44
|
WOJCIECHOWSKI J. [A new method for the synthesis of theobromine, caffeine and 7-methylxanthine]. Acta Pol Pharm 1961; 18:409-13. [PMID: 14007866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
|