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Pradeepkiran JA, Rawat P, Reddy AP, Orlov E, Reddy PH. DDQ anti-aging properties expressed with improved mitophagy in mutant tau HT22 neuronal cells. Mitochondrion 2024; 75:101843. [PMID: 38244850 DOI: 10.1016/j.mito.2024.101843] [Citation(s) in RCA: 0] [Impact Index Per Article: 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: 11/25/2023] [Revised: 12/28/2023] [Accepted: 01/01/2024] [Indexed: 01/22/2024]
Abstract
The purpose of our study is to develop age-related phosphorylated tau (p-tau) inhibitors, for Alzheimer's disease (AD). There are wide-ranging therapeutic molecules available in the market and tested for age-related p-tau inhibition to enhance phosphatase activity and microtubule stability in AD neurons. Until now there are no such small molecules claimed to show promising results to delay the disease process of AD. However, a recently developed molecule, DDQ, has been shown to reduce abnormal protein-protein interactions and protect neurons from mutant protein-induced toxicities in the disease process. In addition, DDQ reduced age- and Aβ-induced oxidative stress, mitochondrial dysfunction, and synaptic toxicity. To date, there are no published reports on the p-tau interaction of DDQ and Sirt3 upregulation with CREB-mediated mitophagy activation in AD neurons. In the current study, HT22 cells were transfected with mutant Tau (mTau) cDNA and treated with the novel molecule DDQ. Cell survival, immunoblotting, and immunofluorescence analysis were conducted to assess cell viability and synaptic and mitophagy proteins in treated and untreated cell groups. As expected, we found cell survival was decreased in mTau-HT22 cells when compared with control HT22 cells. However, cell survival was increased in DDQ-treated mTau-HT22 cells when compared with mTau HT22 cells. P-tau and total tau proteins were significantly reduced in DDQ-treated mTau-HT22 cells, and MAP2 levels were increased. Anti-aging proteins like Sirt3, and CREB levels were increased in DDQ-treated HT22 cells and also in mTau-HT22 cells treated DDQ. Mitophagy proteins were decreased in mTau-HT22 cells and these were increased in DDQ-treated mTau-HT22 cells. These observations strongly suggest that DDQ has anti-p-tau and anti-aging properties, via Sirt3 overexpression and increased mitophagy proteins. Our study findings may have implications for healthy aging to the development of p-tau targeted therapeutics in AD and tauopathies.
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Affiliation(s)
- Jangampalli Adi Pradeepkiran
- Internal Medicine Department, Texas Tech University Health Sciences Center, 3601 4th Street, Lubbock, TX 79430, United States.
| | - Priyanka Rawat
- Internal Medicine Department, Texas Tech University Health Sciences Center, 3601 4th Street, Lubbock, TX 79430, United States; Nutritional Sciences Department, College of Human Sciences, Texas Tech University, 1301 Akron Ave, Lubbock, TX 79409, United States
| | - Arubala P Reddy
- Nutritional Sciences Department, College of Human Sciences, Texas Tech University, 1301 Akron Ave, Lubbock, TX 79409, United States
| | - Erika Orlov
- Internal Medicine Department, Texas Tech University Health Sciences Center, 3601 4th Street, Lubbock, TX 79430, United States
| | - P Hemachandra Reddy
- Internal Medicine Department, Texas Tech University Health Sciences Center, 3601 4th Street, Lubbock, TX 79430, United States; Pharmacology & Neuroscience Department, Texas Tech University Health Sciences Center, 3601 4(th) Street, Lubbock, TX 79430, United States; Neurology Department, Texas Tech University Health Sciences Center, 3601 4(th) Street, Lubbock, TX 79430, United States; Speech, Language and Hearing Sciences Departments, Texas Tech University Health Sciences Center, 3601 4(th) Street, Lubbock, TX 79430, United States; Public Health Department, Texas Tech University Health Sciences Center, 3601 4(th) Street, Lubbock, TX 79430, United States; Nutritional Sciences Department, College of Human Sciences, Texas Tech University, 1301 Akron Ave, Lubbock, TX 79409, United States.
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2
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Schwengers SA, Gerosa GG, Amatov T, Yasukawa N, Brunen S, Leutzsch M, Mitschke B, Shevchenko GA, List B. Direct Regioselective Dehydrogenation of α-Substituted Cyclic Ketones. Angew Chem Int Ed Engl 2023; 62:e202307081. [PMID: 37337974 DOI: 10.1002/anie.202307081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 06/19/2023] [Accepted: 06/20/2023] [Indexed: 06/21/2023]
Abstract
We disclose a highly regioselective, catalytic one-step dehydrogenation of α-substituted cyclic ketones in the presence of 2,3-dichlorobenzo-5,6-dicyano-1,4-benzoquinone (DDQ). The high regioselectivity originates from a phosphoric acid-catalyzed enolization, selectively affording the thermodynamically preferred enol, followed by the subsequent oxidation event. Our method provides reliable access to several α-aryl and α-alkyl substituted α,β-unsaturated ketones.
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Affiliation(s)
| | | | - Tynchtyk Amatov
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| | - Naoki Yasukawa
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| | - Sebastian Brunen
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| | - Markus Leutzsch
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| | - Benjamin Mitschke
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| | - Grigory André Shevchenko
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| | - Benjamin List
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
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3
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Abu-Hassan AA. A novel spectrophotometric approach relies on a charge transfer complex between atomoxetine with quinone-based π-acceptor. Application to content uniformity test. BMC Chem 2023; 17:40. [PMID: 37087453 PMCID: PMC10122339 DOI: 10.1186/s13065-023-00951-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Accepted: 04/05/2023] [Indexed: 04/24/2023] Open
Abstract
Atomoxetine (ATO) belongs to psychoanaleptic drugs and is utilized in attention-deficit hyperactivity syndrome treatment. In this study, two facile and selective approaches are implemented for the spectrophotometric analysis of atomoxetine. The two approaches rely on charge transfer formed between ATO base (n-donor) with p-chloranil and 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ; π-acceptor). The generated complexes exhibit absorption intensity maxima at 550 and 460 nm in acetonitrile for p-chloranil and DDQ in the order. Under the optimum reaction condition, Beer's law was followed for p-chloranil and DDQ at concentrations of 30-320 and 10-80 µg mL- 1, respectively. The ICH guidelines were followed for work validation, and the outcomes were excellent and satisfactory. The assessment of ATO in pharmaceutical capsules using the suggested procedures was successful, and the results were contrasted with those obtained using a different published method to show accuracy and precision. Additionally, the two methods were used to assess the homogeneity of ATO content in the commercialized capsule.
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Affiliation(s)
- Ahmed A Abu-Hassan
- Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Al-Azhar University, Assiut branch, Assiut, 71524, Egypt.
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4
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Samir A, Salem H, Abdelkawy M. Optimization of two charge transfer reactions for colorimetric determination of two beta 2 agonist drugs, salmeterol xinafoate and salbutamol, in pharmaceutical and biological samples. Spectrochim Acta A Mol Biomol Spectrosc 2022; 269:120747. [PMID: 34952438 DOI: 10.1016/j.saa.2021.120747] [Citation(s) in RCA: 4] [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: 11/08/2021] [Revised: 11/28/2021] [Accepted: 12/09/2021] [Indexed: 06/14/2023]
Abstract
Beta 2 agonists are well known for their use in the treatment of asthma and COPD however in the last few years new indications of beta 2 agonist appeared like reduction of local fats and treatment of preterm labour which required the formulation of new dosage forms and administration strategies. The new developments require accurate, economic and feasible methods the determination of these drugs to facilitate testing the newly introduced dosage forms and to study the pharmacokinetics and pharmacodynamics regarding the modern uses. In this study two rapid, sensitive and economic colorimetric methods for the determination of salmeterol xinafoate and salbutamol in pharmaceutical dosage forms and spiked plasma were developed and validated. The developed methods depends on the optimized reaction of the studied drugs with two charge transfer reagents, 2,3-dochloro-5,6-dicyano-1,4-benzoquonone (DDQ) and chloranilic acid (CA) to produce coloured complexes measured at 460 and 529 nm for DDQ and CA respectively. The developed methods showed high accuracy of 99.52 ± 1.108, 101.03 ± 0.389, 100.04 ± 1.520 and 100.3 ± 0.951 for salmetrol xinafoate and salbutamol with DDQ and CA respectively. The proposed methods were successfully used for the determination of the studied drugs in their dosage forms and spiked plasma with high accuracy and precision and the results were compared to reported methods.
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Affiliation(s)
- Ahmed Samir
- Faculty of pharmacy, October University for Modern sciences and Arts, Egypt.
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5
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Alghanmi RM, Basha MT, Soliman SM, Alsaeedi RK. New Charge Transfer Complexes of K +-Channel-Blocker Drug (Amifampridine; AMFP) for Sensitive Detection; Solution Investigations and DFT Studies. Molecules 2021; 26:molecules26196037. [PMID: 34641581 PMCID: PMC8512129 DOI: 10.3390/molecules26196037] [Citation(s) in RCA: 2] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/26/2021] [Accepted: 09/28/2021] [Indexed: 11/16/2022] Open
Abstract
UV-Vis spectroscopy was used to investigate two new charge transfer (CT) complexes formed between the K+-channel-blocker amifampridine (AMFP) drug and the two π-acceptors 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) and tetracyanoethylene (TCNE) in different solvents. The molecular composition of the new CT complexes was estimated using the continuous variations method and found to be 1:1 for both complexes. The formed CT complexes' electronic spectra data were further employed for calculating the formation constants (KCT), molar extinction coefficients (εCT), and physical parameters at various temperatures, and the results demonstrated the high stability of both complexes. In addition, sensitive spectrophotometric methods for quantifying AMFP in its pure form were proposed and statistically validated. Furthermore, DFT calculations were used to predict the molecular structures of AMFP-DDQ and AMFP-TCNE complexes in CHCl3. TD-DFT calculations were also used to predict the electronic spectra of both complexes. A CT-based transition band (exp. 399 and 417 nm) for the AMFP-TCNE complex was calculated at 411.5 nm (f = 0.105, HOMO-1 → LUMO). The two absorption bands at 459 nm (calc. 426.9 nm, f = 0.054) and 584 nm (calc. 628.1 nm, f = 0.111) of the AMFP-DDQ complex were theoretically assigned to HOMO-1 → LUMO and HOMO → LUMO excitations, respectively.
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Affiliation(s)
- Reem M. Alghanmi
- Department of Chemistry, College of Science, University of Jeddah, P.O. 80327, Jeddah 21589, Saudi Arabia; (M.T.B.); (R.K.A.)
- Correspondence:
| | - Maram T. Basha
- Department of Chemistry, College of Science, University of Jeddah, P.O. 80327, Jeddah 21589, Saudi Arabia; (M.T.B.); (R.K.A.)
| | - Saied M. Soliman
- Department of Chemistry, Faculty of Science, Alexandria University, P.O. 426, Ibrahimia, Alexandria 21525, Egypt;
| | - Razan K. Alsaeedi
- Department of Chemistry, College of Science, University of Jeddah, P.O. 80327, Jeddah 21589, Saudi Arabia; (M.T.B.); (R.K.A.)
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Wang PW, Lin HC, Liu TL, Hsu CY, Yang YY, Wu HC, Yen CF. Craving for Ketamine and Its Relationship With Clinical Outcome Indicators in Males With Ketamine Use Disorder. Front Psychiatry 2021; 12:476205. [PMID: 34168574 PMCID: PMC8217450 DOI: 10.3389/fpsyt.2021.476205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Accepted: 04/13/2021] [Indexed: 11/13/2022] Open
Abstract
Background: Craving is considered a hallmark of substance use disorder and is one of the criteria of substance use disorder. The Desires for Drug Questionnaire (DDQ) is a widely used questionnaire to assess craving for heroin. This study aimed to examine the psychometric properties of the ketamine version of the DDQ (DDQ-K) and the associations between craving for ketamine as measured using the DDQ-K and clinical outcome indicators in individuals with ketamine use disorder. Methods: In total, 651 individuals with ketamine use disorder completed the DDQ-K and the Visual Analog Craving Scale (VACS). Demographic data, severity of ketamine use, money spent on ketamine, positive/negative aspects of ketamine use, and readiness to change ketamine use were also recorded. We examined the reliability (internal consistency), construct validity (factor structure), and concurrent validity of the DDQ-K. Multiple regression analysis was used to examine the relationships of craving measured using the DDQ-K with clinical outcome indicators, including money spent on ketamine, severity of ketamine use, positive/negative aspects of ketamine use, and readiness to change ketamine use. Results: The original three-factor model of the DDQ-K was acceptable for use in individuals with ketamine use disorder according to confirmatory factor analysis. The subscales of Desire and Intention and Negative Reinforcement of the DDQ-K, but not the subscale of Control, were of acceptable concurrent validity. The score on the Desire and Intention subscale was positively associated with the level of ketamine dependence, money spent on ketamine use, and positive/negative aspects of ketamine use and negatively associated with readiness to change ketamine use. Conclusion: This study supported the use of the Desire and Intention and Negative Reinforcement subscales of the DDQ-K to assess craving in patients with ketamine use.
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Affiliation(s)
- Peng-Wei Wang
- Department of Psychiatry, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
- Department of Psychiatry, Faculty of Medicine and Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Huang-Chi Lin
- Department of Psychiatry, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
- Department of Psychiatry, Faculty of Medicine and Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Tai-Ling Liu
- Department of Psychiatry, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
- Department of Psychiatry, Faculty of Medicine and Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Chih-Yao Hsu
- Departments of Addiction Science, Kai-Suan Psychiatric Hospital, Kaohsiung, Taiwan
| | - Yu-Yi Yang
- Department of Psychiatry, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
| | - Hung-Chi Wu
- Departments of Addiction Science, Kai-Suan Psychiatric Hospital, Kaohsiung, Taiwan
| | - Cheng-Fang Yen
- Department of Psychiatry, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
- Department of Psychiatry, Faculty of Medicine and Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
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7
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Adam AMA, Saad HA, Alsuhaibani AM, Refat MS, Hegab MS. Charge-transfer chemistry of azithromycin, the antibiotic used worldwide to treat the coronavirus disease (COVID-19). Part III: A green protocol for facile synthesis of complexes with TCNQ, DDQ, and TFQ acceptors. J Mol Liq 2021; 335:116250. [PMID: 33903781 PMCID: PMC8061087 DOI: 10.1016/j.molliq.2021.116250] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 02/14/2021] [Accepted: 02/22/2021] [Indexed: 12/15/2022]
Abstract
Investigating the chemical properties of molecules used to combat the COVID-19 pandemic is of vital and pressing importance. In continuation of works aimed to explore the charge-transfer chemistry of azithromycin, the antibiotic used worldwide to treat COVID-19, the disease resulting from infection with the novel SARS-CoV-2 virus, in this work, a highly efficient, simple, clean, and eco-friendly protocol was used for the facile synthesis of charge-transfer complexes (CTCs) containing azithromycin and three π-acceptors: 7,7,8,8-tetracyanoquinodimethane (TCNQ), 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ), and tetrafluoro-1,4-benzoquinone (TFQ). This protocol involves grinding bulk azithromycin as the donor (D) with the investigated acceptors at a 1:1 M ratio at room temperature without any solvent. We found that this protocol is environmentally benign, avoids hazardous organic solvents, and generates the desired CTCs with excellent yield (92–95%) in a straightforward means.
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Affiliation(s)
- Abdel Majid A Adam
- Department of Chemistry, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
| | - Hosam A Saad
- Department of Chemistry, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
| | - Amnah M Alsuhaibani
- Department of Physical Sport Science, Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia
| | - Moamen S Refat
- Department of Chemistry, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
| | - Mohamed S Hegab
- Deanship of Supportive Studies (D.S.S.), Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
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8
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Vijayan M, Bose C, Reddy PH. Protective effects of a small molecule inhibitor, DDQ against amyloid beta in Alzheimer's disease. Mitochondrion 2021; 59:17-29. [PMID: 33839321 DOI: 10.1016/j.mito.2021.04.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 04/03/2021] [Accepted: 04/05/2021] [Indexed: 01/20/2023]
Abstract
The purpose of our study is to determine the protective effects of the newly discovered molecule DDQ (diethyl (3,4-dihydroxyphenethylamino)(quinolin-4-yl) methylphosphonate) against mutant APP and amyloid-beta (Aβ) in Alzheimer's disease (AD). To achieve our objective, we used a well characterized amyloid-beta precursor protein (APP) transgenic mouse model (Tg2576 strain). We administered DDQ, a 20 mg/kg body weight (previously determined in our laboratory) intra-peritoneally 3-times per week for 2 months, starting at the beginning of the 12th month, until the end of the 14th month. Further, using biochemical and molecular methods, we measured the levels of DDQ in the blood, skeletal muscle, and brain. Using Morris Water Maze, Y-maze, open field, and rotarod tests, we assessed cognitive behavior after DDQ treatment. Using q-RT-PCR, immunoblotting, transmission electron microscopy, and Golgi-cox staining methods, we studied mRNA and protein levels of longevity genes SIRTUINS, mitochondrial number & length, and dendritic spine number and length in DDQ-treated APP mice. Our extensive pharmacodynamics analysis revealed high peak levels of DDQ in the skeletal muscle, followed by serum and brain. Our behavioral analysis of rotarod, open field, Y-maze, and Morris Water Maze tests revealed that DDQ ameliorated cognitive decline (Morris Water Maze), improved working memory (Y-Maze), exploratory behavior (open field), and motor coordination (rotarod) in DDQ-treated APP mice. Interestingly, longevity genes SIRTUINS, mitochondrial biogenesis, fusion, mitophagy, autophagy and synaptic genes were upregulated in DDQ-treated APP mice relative to untreated APP mice. Dendritic spines and the quality mitochondria were significantly increased in DDQ treated APP mice. Current study findings, together with our previous study observations, strongly suggest that DDQ has anti-aging, and anti-amyloid-beta effects and a promising molecule to reduce age-and amyloid-beta-induced toxicities in AD.
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Affiliation(s)
- Murali Vijayan
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Chhanda Bose
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - P Hemachandra Reddy
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA; Neuroscience & Pharmacology, Texas Tech University Health Sciences Center, Lubbock, TX, USA; Neurology, Departments of School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA; Public Health Department of Graduate School of Biomedical Sciences, Texas Tech University Health Sciences Center, Lubbock, TX, USA; Department of Speech, Language and Hearing Sciences, School Health Professions, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
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9
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Mostafa GAE, Bakheit A, AlMasoud N, AlRabiah H. Charge Transfer Complexes of Ketotifen with 2,3-Dichloro-5,6-dicyano- p-benzoquinone and 7,7,8,8-Tetracyanoquodimethane: Spectroscopic Characterization Studies. Molecules 2021; 26:molecules26072039. [PMID: 33918481 PMCID: PMC8038309 DOI: 10.3390/molecules26072039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 03/02/2021] [Revised: 03/25/2021] [Accepted: 03/27/2021] [Indexed: 11/16/2022] Open
Abstract
The reactions of ketotifen fumarate (KT) with 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) as π acceptors to form charge transfer (CT) complexes were evaluated in this study. Experimental and theoretical approaches, including density function theory (DFT), were used to obtain the comprehensive, reliable, and accurate structure elucidation of the developed CT complexes. The CT complexes (KT-DDQ and KT-TCNQ) were monitored at 485 and 843 nm, respectively, and the calibration curve ranged from 10 to 100 ppm for KT-DDQ and 2.5 to 40 ppm for KT-TCNQ. The spectrophotometric methods were validated for the determination of KT, and the stability of the CT complexes was assessed by studying the corresponding spectroscopic physical parameters. The molar ratio of KT:DDQ and KT:TCNQ was estimated at 1:1 using Job's method, which was compatible with the results obtained using the Benesi-Hildebrand equation. Using these complexes, the quantitative determination of KT in its dosage form was successful.
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Affiliation(s)
- Gamal A. E. Mostafa
- Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia; (G.A.E.M.); (A.B.)
- Micro-analytical Lab., Applied Organic Chemistry Department, National Research Center, Dokki, Cairo 12622, Egypt
| | - Ahmed Bakheit
- Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia; (G.A.E.M.); (A.B.)
- Department of Chemistry, Faculty of Science and Technology, El-Neelain University, P.O. Box 12702, Khartoum 11121, Sudan
| | - Najla AlMasoud
- Department of Chemistry, College of Science, Princess Nourah bint Abdulrahman University, Riyadh 11671, Saudi Arabia;
| | - Haitham AlRabiah
- Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia; (G.A.E.M.); (A.B.)
- Correspondence:
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10
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Vijayan M, Bose C, Reddy PH. Anti-brain Aging Effects of Small Molecule Inhibitor DDQ. Mol Neurobiol 2021; 58:3588-600. [PMID: 33768469 DOI: 10.1007/s12035-021-02360-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 03/15/2021] [Indexed: 12/13/2022]
Abstract
The purpose of our study is to determine the protective effects of the newly discovered molecule DDQ (diethyl (3,4-dihydroxyphenethylamino)(quinolin-4-yl) methylphosphonate) against aging in an in vitro, mouse primary hippocampal neurons, HT22 cells, and in vivo, 24-month-old C57BL6/J mice. Using biochemical and molecular methods, we studied the half-life period in the blood and brain, optimized the dose, determined dose-response (using 1, 5, 10, 20, and 50 mg/kg body weight), and measured the levels of blood, skeletal muscle, and brain. Using Morris water maze (cognitive behavior), q-RT-PCR (mRNA and protein levels of longevity genes SIRTUINS), transmission electron microscopy (mitochondrial number and length), and Golgi-Cox staining (dendritic spine number and length) were assessed in 24-month-old C57BL6/J mice. Out of 5 different doses of DDQ, the 20 mg/kg body weight dose showed the strongest protective effects against aging in C57BL6/J mice. The half-life time of DDQ is 20 h in the serum and 12 h in the brain. Our extensive pharmacodynamics analysis revealed high peak levels of DDQ in the skeletal muscle, followed by serum and brain. Using mouse primary hippocampal (HT22) neurons and 24-month-old C57BL6/J mice, we tested the protective effects of DDQ. Interestingly, longevity genes SIRTUINS were upregulated in DDQ-treated HT22 cells, and DDQ-treated aged wild-type mice relative to DDQ-untreated cells and untreated aged control mice. Dendritic spines and the quality of mitochondria were significantly increased in DDQ-treated aged mice. Current study findings, together with our previous study observations, strongly suggest that DDQ has anti-aging effects and warrants further investigations of anti-inflammatory, anti-DNA damage, and telomerase activity studies.
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11
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Abdulai AY, Tia R, Adei E. A DFT mechanistic study on oxidative dehydrogenative Diels-Alder reaction of alkylbenzenes. J Mol Graph Model 2021; 104:107839. [PMID: 33524922 DOI: 10.1016/j.jmgm.2021.107839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 12/18/2020] [Accepted: 01/05/2021] [Indexed: 11/23/2022]
Abstract
Cross-dehydrogenative Diels-Alder cycloaddition reaction between readily-available alkyl benzenes and electron-deficient dienophiles is an attractive synthetic route to access carbocyclic compounds which have high utility in the chemical and pharmaceutical industries. This work reports a study at the M06-2X/6-311G(d) and M06-2X/6-311++G(d,p) levels of theory on the reaction of alkyl benzenes with electron-deficient dienophiles in the presence of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as an oxidant and hydroquinone as an activator, so as to understand the chemoselectivity of the reaction (addition across the alkene functionality versus the ketone functionality), the role of the activator, the effects of substituents and the effect of solvent on the reaction. The results show the addition of the alkene bonds of methylstyrene across the alkene functionality of the electron-deficient dienophiles has generally low barriers compared to the addition across the carbonyl functionality of the electron-deficient dienophile. Powerful electron-withdrawing group (cyano) on the electron-deficient dienophile decrease the energy barrier for the cycloaddition and decrease the stability of the product whiles weak electron-withdrawing (bromine and chlorine) and electron-donating groups increase the energy barrier for the cycloaddition and decrease the stability of the product. The hydroquinone as an activator decreases the activation barrier for the Diels-Alder cycloaddition reaction.
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12
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Balraj C, Balaji S, Karthikeyan M. Systematic measurements of charge transfer complexes caused from 1-phenyl-1,2,3,4-tetrahydroisoquinoline and 4-aminoacetanilide with series of π-acceptors (BQ, DDQ, TCNQ). Spectrochim Acta A Mol Biomol Spectrosc 2021; 245:118931. [PMID: 32950855 DOI: 10.1016/j.saa.2020.118931] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 09/04/2020] [Accepted: 09/05/2020] [Indexed: 06/11/2023]
Abstract
Molecular charge-transfer interaction of a series of electron π-acceptors of 1,4-benzoquinone (BQ), 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and Tetracyanoquinodimethane (TCNQ) with selected donors of 1-phenyl-1,2,3,4-tetrahydroisoquinoline (PTHIQ) and 4-aminoacetanilide (ACE) have been studied in methanol at room temperature. The stoichiometry of the complexes was determined by photometric titration method and was found to be 1:1, in all the cases. Spectro-kinetic interaction studies along with rate constants and observed formation constants (K) indicated that the strength of the complex formations is PTHIQ-BQ < PTHIQ-DDQ < PTHIQ-TCNQ. Also, Similar observations happened in ACE-BQ and < ACE-DDQ < ACE-TCNQ systems. FT-IR results indicated that the point of interaction was identifying in NH moiety of PTHIQ and NH2 moiety of ACE with series of π-acceptor complexes. The experimental results were compared with Ab initio DFT calculations at the B3LYP/6-31 + G(d) level of theory. The increasing order of the experimentally measured formation constant of CT-complexes (PTHIQ and ACE with series of acceptors) was well supported by theoretical HOMO-LUMO energy gap and drastically changes in Mulliken charges of NH moiety of PTHIQ, NH2 moiety of ACE with complexation with acceptors.
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Affiliation(s)
- C Balraj
- Department of Chemistry, Kongu Engineering College (Autonomous), Perundurai, Erode 638060, India.
| | - S Balaji
- Department of Chemistry, Indian Institute of Technology Madras, Chennai, India
| | - M Karthikeyan
- Department of Chemistry, Kongu Engineering College (Autonomous), Perundurai, Erode 638060, India
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13
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Wang JS, Liu JL, Zhang J, Tan J, Huang T, Lu CX, Peng XY, Guo Y, Zheng L. Descended Social Anxiety Disorder and Craving in Women Heroin Dependence Through Exercise Alerts Plasma Oxytocin Levels. Front Psychiatry 2021; 12:624993. [PMID: 34899404 PMCID: PMC8663167 DOI: 10.3389/fpsyt.2021.624993] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 10/25/2021] [Indexed: 11/13/2022] Open
Abstract
Purpose: This study explored the association between peripheral blood oxytocin (OT) and social anxiety disorder (SAD) and cue-induced cravings in female heroin addicts. The effect of exercise on alleviation of SAD and OT levels was also explored. Methods: A total of 72 females with heroin dependence were assigned to three groups based on SAD severity. The three groups were Non-SAD control, SAD control, and SAD exercise groups. Subjects in the SAD exercise group underwent aerobic exercise and resistance training for 8 weeks (60 min/day, 5 days/week). Enzyme-linked immunosorbent assay analysis and Liebowitz Social Anxiety Scale (LSAS) scores were used to determine plasma OT concentration and SAD, respectively. Cue-induced craving was assessed using Visual Analog Scale (VAS) and Desires for Drug Questionnaire (DDQ). Mixed-effect analysis of variance and Pearson correlation analysis were used to explore the effect and correlation between different parameters. Results: OT levels in the SAD exercise group were significantly high after exercise (p < 0.01). LSAS, VAS, and DDQ ("Desire and Intention" and "Negative reinforcement") scores in the SAD exercise group were significantly lower after exercise (p < 0.01). Plasma OT level was negatively correlated with LSAS score (r = -0.534, p < 0.001), VAS score (r = -0.609, p < 0.001), "Desire and Intention" score (r = -0.555, p < 0.001), and "Negative reinforcement" score (r = -0.332, p < 0.01) and positively correlated with the "control" score (r = 0.258, p < 0.05). LSAS was positively correlated with VAS score (r = 0.588, p < 0.001) and "Desire and Intention" score (r = 0.282, p < 0.05). Conclusions: The findings of the present study indicate that plasma OT is a potential peripheral biomarker for prediction of the severity of social anxiety in female heroin withdrawal patients. Aerobic exercise combined with resistance training plus incremental load for 8 weeks can increase plasma OT levels and significantly reduce severity of SAD and cue-induced cravings in female heroin addicts.
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Affiliation(s)
- Jing Song Wang
- Key Laboratory of Physical Fitness and Sports Rehabilitation of the Hunan Province, College of Physical Education, Hunan Normal University, Changsha, China
| | - Jing Lin Liu
- Key Laboratory of Physical Fitness and Sports Rehabilitation of the Hunan Province, College of Physical Education, Hunan Normal University, Changsha, China
| | - Jun Zhang
- Hunan Judicial Police Vocational College, Changsha, China
| | - Jun Tan
- College of Physical Education, Hunan International Economics University, Changsha, China
| | - Ting Huang
- Key Laboratory of Physical Fitness and Sports Rehabilitation of the Hunan Province, College of Physical Education, Hunan Normal University, Changsha, China
| | - Chun Xia Lu
- Key Laboratory of Physical Fitness and Sports Rehabilitation of the Hunan Province, College of Physical Education, Hunan Normal University, Changsha, China
| | - Xi Yang Peng
- Key Laboratory of Physical Fitness and Sports Rehabilitation of the Hunan Province, College of Physical Education, Hunan Normal University, Changsha, China
| | - Yin Guo
- Key Laboratory of Physical Fitness and Sports Rehabilitation of the Hunan Province, College of Physical Education, Hunan Normal University, Changsha, China
| | - Lan Zheng
- Key Laboratory of Physical Fitness and Sports Rehabilitation of the Hunan Province, College of Physical Education, Hunan Normal University, Changsha, China
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14
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Yousef TA, Ezzeldin E, Abdel-Aziz HA, Al-Agamy MH, Mostafa GAE. Charge Transfer Complex of Neostigmine with 2,3-Dichloro-5,6-Dicyano-1,4-Benzoquinone: Synthesis, Spectroscopic Characterization, Antimicrobial Activity, and Theoretical Study. Drug Des Devel Ther 2020; 14:4115-4129. [PMID: 33116400 PMCID: PMC7547768 DOI: 10.2147/dddt.s259369] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 08/12/2020] [Indexed: 12/26/2022]
Abstract
Background Electron donor-acceptor interactions are important molecular reactions for the activity of pharmacological compounds. The aim of the study is to develop a charge transfer (CT) complex: synthesis, characterization, antimicrobial activity, and theoretical study. Method and Results A solid CT complex of neostigmine (NSG) with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) was synthesized and characterized by infrared spectra, NMR, and UV-visible spectroscopy. The results confirm the formation of a CT complex. The stability of the CT complex between NSG and DDQ in acetonitrile was determined in solution via spectrophotometric measurement, ie, by calculating the formation constant, molar extinction coefficient, and different spectroscopic parameters. The stoichiometry of the formed NSG-DDQ complex was determined using Job's method. The absorption band of the NSG-DDQ complex can be used for the quantification of NSG. Conclusion The DFT geometry optimization of NSG, DDQ, and the CT complex and the UV comparative study of both theoretical and experimental structures are presented. The experimental results confirm the charge transfer structure. The bacterial study shows that the NSG-DDQ complex has good antibacterial activity against both Gram-positive and Gram-negative bacteria as well as antifungal activity against Candida albicans.
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Affiliation(s)
- Tarek A Yousef
- College of Science, Chemistry Department, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh 11623, Kingdom of Saudi Arabia.,Department of Toxic and Narcotic Drug, Forensic Medicine, Mansoura Laboratory, Medicolegal Organization, Ministry of Justice, Mansoura, Egypt
| | - Essam Ezzeldin
- Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia.,Bioavailability Laboratory, Central Laboratory, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia
| | - Hatem A Abdel-Aziz
- Applied Organic Chemistry Department, National Research Center, Cairo 12622, Egypt
| | - Mohamed H Al-Agamy
- Department of Pharmaceutics, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia.,Department of Microbiology and Immunology, Faculty of Pharmacy, Al-Azhar University, Cairo, Egypt
| | - Gamal A E Mostafa
- Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia.,Applied Organic Chemistry Department, National Research Center, Cairo 12622, Egypt
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15
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Yu H, Kim H, Baek SH, Lee D. Direct and Efficient C(sp 3)-H Functionalization of N-Acyl/Sulfonyl Tetrahydroisoquinolines (THIQs) With Electron-Rich Nucleophiles via 2,3-Dichloro-5,6-Dicyano-1,4-Benzoquinone ( DDQ) Oxidation. Front Chem 2020; 8:629. [PMID: 32850649 PMCID: PMC7403605 DOI: 10.3389/fchem.2020.00629] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 06/17/2020] [Indexed: 11/25/2022] Open
Abstract
A highly efficient metal-free oxidative direct C(sp3)–H functionalization of N-acyl/sulfonyl 1,2,3,4-tetrahydroisoquinolines (THIQs) with a wide range of electron-rich nucleophiles was accomplished under mild conditions through oxidation with DDQ and subsequent trapping of the resulting reactive and stable N-acyl/sulfonyl iminium ions. The synthetic utility of this method was illustrated by a concise and efficient total synthesis of (±)-benzo[a]quinolizidine (10) in 3 steps from the known N-Cbz 1,2,3,4-THIQ 4b.
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Affiliation(s)
- Heesun Yu
- Research Institute of Pharmaceutical Science and Technology (RIPST), College of Pharmacy, Ajou University, Suwon, South Korea
| | - Hyoungsu Kim
- Research Institute of Pharmaceutical Science and Technology (RIPST), College of Pharmacy, Ajou University, Suwon, South Korea
| | - Seung-Hoon Baek
- Research Institute of Pharmaceutical Science and Technology (RIPST), College of Pharmacy, Ajou University, Suwon, South Korea
| | - Dongjoo Lee
- Research Institute of Pharmaceutical Science and Technology (RIPST), College of Pharmacy, Ajou University, Suwon, South Korea
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16
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Baker MM, El-Kafrawy DS, Abdel-Khalek MM, Belal TS. Validated spectrophotometric determination of maduramicin ammonium using three charge transfer complexation reactions. Ann Pharm Fr 2020; 78:388-397. [PMID: 32387175 DOI: 10.1016/j.pharma.2020.04.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 03/14/2020] [Accepted: 04/15/2020] [Indexed: 11/16/2022]
Abstract
Direct spectrophotometric determination of Maduramicin ammonium (MAD) represents an analytical challenge since it is a weak UV-absorbing and lacking a strong chromophore. This work represents the first spectrophotometric determination of MAD as no direct spectrophotometric or colorimetric determination methods for MAD are available in the literature. The present study illustrates the development of three simple, rapid and inexpensive colorimetric methods for the routine quality control analysis of MAD based on the formation of colored charge transfer complexes with three electron acceptors namely p-chloranilic acid (p-CA), 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) and picric acid (PA). The color products of MAD with p-CA, DDQ and PA were measured at 519, 588 and 405nm respectively. The proposed methods were validated in terms of linearity, ranges, precision, accuracy, robustness and limits of detection and quantification. MAD was effectively determined over concentration ranges of 100-1000, 25-250 and 30-150μg/mL using p-CA, DDQ and PA, respectively with good linearity as shown by the values of correlation coefficients not less than 0.9991. The developed methods were successfully implemented in the assay of MAD powder pharmaceutical formulation for veterinary use.
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Affiliation(s)
- M M Baker
- Methodology Department, Pharco Pharmaceuticals Company, Alexandria, Egypt
| | - D S El-Kafrawy
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, University of Alexandria, 21521 Elmessalah, Alexandria, Egypt
| | - M M Abdel-Khalek
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, University of Alexandria, 21521 Elmessalah, Alexandria, Egypt
| | - T S Belal
- Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, University of Alexandria, 21521 Elmessalah, Alexandria, Egypt.
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17
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Liu S, Chen R, He G, Zhang J. An Efficient Metal-Free Oxidative Esterification and Amination of Benzyl C-H Bond. Molecules 2020; 25:E1527. [PMID: 32230851 DOI: 10.3390/molecules25071527] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 03/17/2020] [Accepted: 03/26/2020] [Indexed: 11/16/2022]
Abstract
An esterification and amination of benzylic C-H bonds was developed by using 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) under metal- and iodide-free conditions. Both carboxylic acids and amines could be used as ideal coupling partners for the oxidative coupling reactions with various diarylmethanes. A close to equal amount of coupling reagents was enough to afford the product in good to high yields.
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18
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Shehab OR, Soliman FA, Abdel-Ghani NT, Mansour AM. Spectroscopic investigation of π-acceptors in the determination and photoinduced degradation of Sulfacetamide. Spectrochim Acta A Mol Biomol Spectrosc 2020; 228:117821. [PMID: 31791911 DOI: 10.1016/j.saa.2019.117821] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [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: 08/03/2019] [Revised: 11/13/2019] [Accepted: 11/18/2019] [Indexed: 06/10/2023]
Abstract
The presence of expired and unused Sulfacetamide (SA) drug in water led to a global need for the development of effective advanced method for the quantitative analysis and for minimizing its occurrence in the nature. To find new effective photochemical decomposition method close to that obtained by the well-known Fenton reaction, the photodegradation of SA was investigated in presence of dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and/or other common additives at two different wavelengths (365 and 256 nm). The role of DDQ in the degradation process of SA was evaluated in comparison to the other investigated π-acceptor systems (Chloranilic acid (CHL) and Picric acid (PA)). While the photodegradation process of SA was hardly to proceed in the absence of a catalyst and/or additive, addition of DDQ and NaNO2 to the solution of SA induced decomposition of about 94% of SA within 25 min upon the exposure to light source at 256 nm. On the other hand, SA was quantitatively analyzed by recording the absorbance of its charge transfer (CT) products with DDQ, CHL and PA at a certain wavelength. CHL is preferred with concentrated samples of SA, while PA is recommended for diluted samples of SA. SA → DDQ has a widely range of stability over the pH range of 4.5-12.0. While SA → CHL is stable only in the acidic medium (pH = 4.8-5.6), SA → PA is steady in the basic medium (pH = 7.5-11.0). The nature of the DDQ CT complex was investigated in the solid state. The electronic structures of the complexes were studied by calculating the time dependent density functional theory (TDDFT) spectra.
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Affiliation(s)
- Ola R Shehab
- Chemistry Department, Faculty of Science, Cairo University, Cairo University street, Giza 12613, Egypt
| | - Fatma A Soliman
- Chemistry Department, Faculty of Science, Cairo University, Cairo University street, Giza 12613, Egypt
| | - Nour T Abdel-Ghani
- Chemistry Department, Faculty of Science, Cairo University, Cairo University street, Giza 12613, Egypt.
| | - Ahmed M Mansour
- Chemistry Department, Faculty of Science, Cairo University, Cairo University street, Giza 12613, Egypt.
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19
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Kanojia SV, Chatterjee S, Chattopadhyay S, Goswami D. A chemoenzymatic synthesis of ceramide trafficking inhibitor HPA-12. Beilstein J Org Chem 2019; 15:490-496. [PMID: 30873232 PMCID: PMC6404422 DOI: 10.3762/bjoc.15.42] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 01/26/2019] [Indexed: 12/21/2022] Open
Abstract
A chemoenzymatic synthesis of the title compound has been developed using an efficient and highly enantioselective lipase-catalyzed acylation in a hydrophobic ionic liquid, [bmim][PF6], followed by a diastereoselective asymmetric dihydroxylation as the key steps for incorporating the stereogenic centers. The further conversion to the appropriate intermediates and subsequent acylation with lauric acid furnished the target compound.
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Affiliation(s)
- Seema V Kanojia
- Bio-Organic Division, Bhabha Atomic Research Centre, Mumbai 400 085, India
| | - Sucheta Chatterjee
- Bio-Organic Division, Bhabha Atomic Research Centre, Mumbai 400 085, India
| | | | - Dibakar Goswami
- Bio-Organic Division, Bhabha Atomic Research Centre, Mumbai 400 085, India.,Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400 094, India
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20
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Thakur K, Wang D, Lindeman SV, Rathore R. Synthesis of Doubly Annulated m-Terphenyl-Based Molecular Tweezers and Their Charge-Transfer Complexes with DDQ as a Guest. Chemistry 2018; 24:13106-13109. [PMID: 30033629 DOI: 10.1002/chem.201803137] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 07/19/2018] [Indexed: 11/06/2022]
Abstract
The synthesis of a doubly-annulated m-terphenyl-based tweezer platform has been developed, which affords ready incorporation of various pincer units from monobenzenoid to polybenzenoid electron donors. The complexation study with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as guest has been carried out, and the crystal structure of T-Py∩DDQ reveals the sandwich-type binding mode in the solid state.
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Affiliation(s)
- Khushabu Thakur
- Department of Chemistry, Marquette University, Milwaukee, WI, 53201-1881, USA
| | - Denan Wang
- Department of Chemistry, Marquette University, Milwaukee, WI, 53201-1881, USA
| | - Sergey V Lindeman
- Department of Chemistry, Marquette University, Milwaukee, WI, 53201-1881, USA
| | - Rajendra Rathore
- Department of Chemistry, Marquette University, Milwaukee, WI, 53201-1881, USA
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21
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Mohamed ME, Frag EYZ, Hathoot AA, Shalaby EA. Spectrophotometric determination of fenoprofen calcium drug in pure and pharmaceutical preparations. Spectroscopic characterization of the charge transfer solid complexes. Spectrochim Acta A Mol Biomol Spectrosc 2018; 189:357-365. [PMID: 28830039 DOI: 10.1016/j.saa.2017.08.027] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [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: 01/12/2017] [Revised: 08/04/2017] [Accepted: 08/09/2017] [Indexed: 06/07/2023]
Abstract
Simple, accurate and robust spectrophotometric method was developed for determination of fenoprofen calcium drug (FPC). The proposed method was based on the charge transfer (CT) reaction of FPC drug (as n-electron donor) with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), 2,4,6-trinitrophenol (picric acid, PA) or 1,2,5,8-tetrahydroxyanthraquinone (Quinalizarin, QZ) (as π-acceptors) to give highly colored charge transfer complexes. Different variables affecting the reaction such as reagent concentration, temperature and time have been carefully optimized to achieve the highest sensitivity. Beer's law was obeyed over the concentration ranges of 2-60, 0.6-90 and 4-30μgmL-1 using DDQ, PA and QZ CT reagents, respectively, with correlation coefficients of 0.9986, 0.9989 and 0.997 and detection limits of 1.78, 0.48 and 2.6μgmL-1 for the CT reagents in the same order. Elucidation of the chemical structure of the solid CT complexes formed via reaction between the drug under study and π-acceptors was done using elemental, thermal analyses, IR, 1H NMR and mass spectrometry. X-ray diffraction was used to estimate the crystallinity of the CT complexes. Their biological activities were screened against different bacterial and fungal organisms. The method was applied successfully with satisfactory results for the determination of FPC drug in fenoprofen capsules. The method was validated with respect to linearity, limit of detection and quantification, inter- and intra-days precision and accuracy. The proposed method gave comparable results with the official method.
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Affiliation(s)
- Marwa E Mohamed
- Chemistry Department, Faculty of Science, Cairo University, 12613 Giza, Egypt.
| | - Eman Y Z Frag
- Chemistry Department, Faculty of Science, Cairo University, 12613 Giza, Egypt
| | - Abla A Hathoot
- Chemistry Department, Faculty of Science, El-Menoufia University, Shebin AL-Kom, Egypt
| | - Essam A Shalaby
- Chemistry Department, Faculty of Science, El-Menoufia University, Shebin AL-Kom, Egypt
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22
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Mohamed GG, Hamed MM, Zaki NG, Abdou MM, Mohamed MEB, Abdallah AM. Melatonin charge transfer complex with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone: Molecular structure, DFT studies, thermal analyses, evaluation of biological activity and utility for determination of melatonin in pure and dosage forms. Spectrochim Acta A Mol Biomol Spectrosc 2017; 182:143-159. [PMID: 28431312 DOI: 10.1016/j.saa.2017.03.068] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [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: 10/30/2016] [Revised: 03/23/2017] [Accepted: 03/30/2017] [Indexed: 06/07/2023]
Abstract
A simple, accurate and fast spectrophotometric method for the quantitative determination of melatonin (ML) drug in its pure and pharmaceutical forms was developed based on the formation of its charge transfer complex with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as an electron acceptor. The different conditions for this method were optimized accurately. The Lambert-Beer's law was found to be valid over the concentration range of 4-100μgmL-1 ML. The solid form of the CT complex was structurally characterized by means of different spectral methods. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations were carried out. The different quantum chemical parameters of the CT complex were calculated. Thermal properties of the CT complex and its kinetic thermodynamic parameters were studied, as well as its antimicrobial and antifungal activities were investigated. Molecular docking studies were performed to predict the binding modes of the CT complex components towards E. coli bacterial RNA and the receptor of breast cancer mutant oxidoreductase.
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Affiliation(s)
- Gehad G Mohamed
- Chemistry Department, Faculty of Science, Cairo University, Giza 12613, Egypt.
| | - Maher M Hamed
- Chemistry Department, Faculty of Science, Cairo University, Giza 12613, Egypt
| | - Nadia G Zaki
- Narcotic Research Department, National Center for Social and Criminological Research (NCSCR), Giza 11561, Egypt
| | - Mohamed M Abdou
- Narcotic Research Department, National Center for Social and Criminological Research (NCSCR), Giza 11561, Egypt
| | | | - Abanoub Mosaad Abdallah
- Narcotic Research Department, National Center for Social and Criminological Research (NCSCR), Giza 11561, Egypt
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23
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Giovenzana GB, Masciocchi N, Negri R, Palmisano G, Penoni A, Toma L. Quinone-related hexacyclic by-products in the production process of exemestane. Steroids 2017; 120:26-31. [PMID: 28167101 DOI: 10.1016/j.steroids.2017.01.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 01/05/2017] [Accepted: 01/18/2017] [Indexed: 11/25/2022]
Abstract
Exemestane, a 3rd-generation aromatase inhibitor, is clinically used in the treatment of breast cancer in postmenopausal women. The key step of the industrial synthetic process, i.e., a dehydrogenation to introduce the Δ1-unsaturation, is normally performed with quinones such as p-chloranil or DDQ. We observed the formation of two different hexacyclic by-products, depending on the quinone used in the oxidation step. These compounds arise from an initial [4+2] cycloaddition between the precursor 6-methylenandrost-4-ene-3,17-dione and the quinone reagent, followed by a twofold dehydrohalogenation (with p-chloranil) or dehydrogenation (with DDQ). The structures of these unprecedented hexacyclic adducts were determined by a combination of mass spectrometry, NMR techniques and crystallographic analysis.
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Affiliation(s)
- Giovanni Battista Giovenzana
- Università del Piemonte Orientale "A. Avogadro", Dipartimento di Scienze del Farmaco, Largo Donegani 2, I-28100 Novara, Italy.
| | - Norberto Masciocchi
- Università degli Studi dell'Insubria, Dipartimento di Scienza e Alta Tecnologia, Via Valleggio 11, I-22100 Como, Italy
| | - Roberto Negri
- Università del Piemonte Orientale "A. Avogadro", Dipartimento di Scienze del Farmaco, Largo Donegani 2, I-28100 Novara, Italy
| | - Giovanni Palmisano
- Università degli Studi dell'Insubria, Dipartimento di Scienza e Alta Tecnologia, Via Valleggio 11, I-22100 Como, Italy
| | - Andrea Penoni
- Università degli Studi dell'Insubria, Dipartimento di Scienza e Alta Tecnologia, Via Valleggio 11, I-22100 Como, Italy
| | - Lucio Toma
- Università degli Studi di Pavia, Dipartimento di Chimica, Via Taramelli 12, I-27100 Pavia, Italy
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24
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Abstract
Advances in lightweight, flexible, and conformal electronic devices depend on materials that exhibit high electrical conductivity coupled with high mechanical strength. Defect-free graphene is one such material that satisfies both these requirements and which offers a range of attractive and tunable electrical, optoelectronic, and plasmonic characteristics for devices that operate at microwave, terahertz, infrared, or optical frequencies. Essential to the future success of such devices is therefore the ability to control the frequency-dependent conductivity of graphene. Looking to accelerate the development of high-frequency applications of graphene, here we demonstrate how readily accessible and processable organic and organometallic molecules can efficiently dope graphene to carrier densities in excess of 10(13) cm(-2) with conductivities at gigahertz frequencies in excess of 60 mS. In using the molecule 3,6-difluoro-2,5,7,7,8,8-hexacyanoquinodimethane (F2-HCNQ), a high charge transfer (CT) of 0.5 electrons per adsorbed molecule is calculated, resulting in p-type doping of graphene. n-Type doping is achieved using cobaltocene and the sulfur-containing molecule tetrathiafulvalene (TTF) with a CT of 0.41 and 0.24 electrons donated per adsorbed molecule, respectively. Efficient CT is associated with the interaction between the π electrons present in the molecule and in graphene. Calculation of the high-frequency conductivity shows dispersion-less behavior of the real component of the conductivity over a wide range of gigahertz frequencies. Potential high-frequency applications in graphene antennas and communications that can exploit these properties and the broader impacts of using molecular doping to modify functional materials that possess a low-energy Dirac cone are also discussed.
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Affiliation(s)
- Alexander J Samuels
- Advanced Technology Institute and ‡Department of Electrical and Electronic Engineering, University of Surrey , Guildford, GU2 7XH, United Kingdom
| | - J David Carey
- Advanced Technology Institute and ‡Department of Electrical and Electronic Engineering, University of Surrey , Guildford, GU2 7XH, United Kingdom
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25
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Lievaart M, Erciyes F, van der Veen FM, van de Wetering BJM, Muris P, Franken IHA. Validation of the cocaine versions of the Obsessive Compulsive Drug Use Scale and the Desires for Drug Questionnaire. Am J Drug Alcohol Abuse 2015; 41:358-65. [PMID: 26010120 DOI: 10.3109/00952990.2015.1043210] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND The Obsessive Compulsive Drug Use Scale (OCDUS) and the Desires for Drug Questionnaire (DDQ) are two frequently used drug craving questionnaires. Although both heroin and cocaine versions of the questionnaires exist, only the heroin versions have been psychometrically evaluated. The present study was conducted to evaluate the psychometric qualities of the cocaine versions of the OCDUS (OCDUS-C) and DDQ (DDQ-C). METHODS Cocaine-dependent inpatients (n = 101) completed both scales as well as a Visual Analogue Craving Scale (VACS), an alternative, one-item index for assessing momentary craving. We examined the reliability (internal consistency), construct validity (factor structure), and concurrent validity (correlations among both questionnaires, the VACS, and indicators of severity of dependence). A subsample also completed the OCDUS-C and DDQ-C for a second time, one week after the initial administration to obtain a preliminary investigation of the test-retest reliability. RESULTS In general, both questionnaires displayed good internal consistency, test-retest reliability, and concurrent validity. Further, the construct validity of both the DDQ and OCDUS was demonstrated by means of confirmatory factor analyses showing the expected three-factor models. CONCLUSION Our results indicate that the OCDUS and DDQ for cocaine are both easy to administer and reliable instruments to assist the clinical practitioner or researcher to measure craving in cocaine dependent subjects. Moreover, the factor structure for the cocaine versions were similar to the heroin versions, indicating the OCDUS and the DDQ can be reliably used to measure craving for both substances, enabling a direct comparison between heroin and cocaine craving.
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Affiliation(s)
- Marien Lievaart
- Institute of Psychology, Erasmus University Rotterdam , Rotterdam, the Netherlands
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26
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Berto S, Chiavazza E, Ribotta V, Daniele PG, Barolo C, Giacomino A, Vione D, Malandrino M. Charge-transfer complexes of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone with amino molecules in polar solvents. Spectrochim Acta A Mol Biomol Spectrosc 2015; 149:75-82. [PMID: 25942088 DOI: 10.1016/j.saa.2015.04.044] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [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: 12/04/2014] [Revised: 04/01/2015] [Accepted: 04/16/2015] [Indexed: 06/04/2023]
Abstract
The charge-transfer complexes have scientific relevance because this type of molecular interaction is at the basis of the activity of pharmacological compounds and because the absorption bands of the complexes can be used for the quantification of electron donor molecules. This work aims to assess the stability of the charge-transfer complexes between the electron acceptor 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and two drugs, procaine and atenolol, in acetonitrile and ethanol. The stability of DDQ in solution and the time required to obtain the maximum complex formation were evaluated. The stoichiometry and the stability of the complexes were determined, respectively, by Job's plot method and by the elaboration of UV-vis titrations data. The latter task was carried out by using the non-linear global analysis approach to determine the equilibrium constants. This approach to data elaboration allowed us to overcome the disadvantages of the classical linear-regression method, to obtain reliable values of the association constants and to calculate the entire spectra of the complexes. NMR spectra were recorded to identify the portion of the donor molecule that was involved in the interaction. The data support the participation of the aliphatic amino groups in complex formation and exclude the involvement of the aromatic amine present in the procaine molecule.
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Affiliation(s)
- Silvia Berto
- Dept. of Chemistry, University of Torino, Via P. Giuria 7, 10125 Turin, Italy
| | - Enrico Chiavazza
- Dept. of Chemistry, University of Torino, Via P. Giuria 7, 10125 Turin, Italy.
| | - Valentina Ribotta
- Dept. of Chemistry, University of Torino, Via P. Giuria 7, 10125 Turin, Italy
| | | | - Claudia Barolo
- Dept. of Chemistry, University of Torino, Via P. Giuria 7, 10125 Turin, Italy; INSTM and NIS Centre, University of Torino, Via Quarello 15A, 10135 Turin, Italy
| | - Agnese Giacomino
- Dept. of Drug Science and Technology, University of Torino, Via Giuria 9, 10125 Turin, Italy
| | - Davide Vione
- Dept. of Chemistry, University of Torino, Via P. Giuria 7, 10125 Turin, Italy
| | - Mery Malandrino
- Dept. of Chemistry, University of Torino, Via P. Giuria 7, 10125 Turin, Italy
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27
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Zhang W, Pan D, Wu A, Shen L. Effective and mild method for converting 3β-hydroxysteroids to 3-keto steroids via DDQ/TEMPO. Steroids 2015; 96:16-20. [PMID: 25617739 DOI: 10.1016/j.steroids.2015.01.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 12/26/2014] [Accepted: 01/08/2015] [Indexed: 10/24/2022]
Abstract
A mild and efficient oxidation of 3β-hydroxysteroids to the corresponding 3-keto steroids can be carried out at room temperature, using DDQ in the presence of catalytic TEMPO. Oxidation of saturated 3β-hydroxysteroids gave the corresponding ketones in excellent yield. The 5-unsaturated 3β-hydroxysteroids are oxidized selectively to 4-en-3-one or 4,6-diene-3-one derivatives according to the amount of DDQ in reaction. This is a good method for the synthesis of 4,6-diene-3-one from the corresponding 3β-hydroxy-5-ene steroids. Meanwhile, configurations of the oxidation compounds 2a, 2b, 3b, 2c, 2f and 2g were identified by X-ray diffraction. A possible mechanism is presented and discussed.
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Affiliation(s)
- Wu Zhang
- College of Chemistry and Chemical Engineering, Guangxi University for Nationalities, Key Laboratory of Development and Application of Forest Chemicals of Guangxi, Nanning 530006, China
| | - Dan Pan
- College of Chemistry and Chemical Engineering, Guangxi University for Nationalities, Key Laboratory of Development and Application of Forest Chemicals of Guangxi, Nanning 530006, China
| | - Aiqun Wu
- College of Chemistry and Chemical Engineering, Guangxi University for Nationalities, Key Laboratory of Development and Application of Forest Chemicals of Guangxi, Nanning 530006, China
| | - Liqun Shen
- College of Chemistry and Chemical Engineering, Guangxi University for Nationalities, Key Laboratory of Development and Application of Forest Chemicals of Guangxi, Nanning 530006, China.
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28
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AlQaradawi SY, Mostafa A, Bazzi HS. Charge-transfer complexes of 4-methylpiperidine with σ- and π-acceptors. Spectrochim Acta A Mol Biomol Spectrosc 2015; 135:498-505. [PMID: 25123938 DOI: 10.1016/j.saa.2014.07.050] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [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: 01/08/2014] [Revised: 07/05/2014] [Accepted: 07/17/2014] [Indexed: 06/03/2023]
Abstract
The solid charge-transfer (CT) molecular complexes formed in the reaction of the electron donor 4-methylpiperidine (4MP) with the σ-electron acceptor iodine and π-acceptors 7,7,8,8-tetracyanoquinodimethane (TCNQ), 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and 2,4,4,6-tetrabromo-2,5-cyclohexadienone (TBCHD) have been investigated spectrophotometrically in chloroform at 25 °C. These were characterized through electronic and infrared spectra as well as elemental and thermal analysis. The obtained results showed that the formed solid CT-complexes have the formulas [(4MP) I](+)I(-)3, [(4MP)(DDQ)2] and [(4MP)(TBCHD)] and with TCNQ the adduct [TCMPQDM] is obtained through N-substitution reaction in full agreement with the known reaction stoichiometries in solution as well as the elemental measurements. The formation constant KCT, molar extinction coefficient εCT, free energy change ΔG(0), CT energy ECT and the ionization potential Ip have been calculated for the CT-complexes [(4MP) I](+)I(-)3, [(4MP)(DDQ)2] and [(4MP)(TBCHD)].
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Affiliation(s)
- Siham Y AlQaradawi
- Department of Chemistry and Earth Sciences, College of Arts and Sciences, Qatar University, P.O. Box 2713, Doha, Qatar.
| | - Adel Mostafa
- Department of Chemistry, Texas A&M University at Qatar, P.O. Box 23874, Doha, Qatar
| | - Hassan S Bazzi
- Department of Chemistry, Texas A&M University at Qatar, P.O. Box 23874, Doha, Qatar
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29
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Mohamed GG, Rizk MS, Zaky Frag EY. Spectrophotometric Determination of Distigmine Bromide, Cyclopentolate HCl, Diaveridine HCl and Tetrahydrozoline HCl via Charge Transfer Complex Formation with TCNQ and TCNE Reagents. Iran J Pharm Res 2015; 14:701-14. [PMID: 26330858 PMCID: PMC4518098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
The purpose of this investigation was directed to propose sensitive, accurate and reproducible methods of analysis that can be applied to determine distigmine bromide (DTB), cyclopentolate hydrochloride (CPHC), diaveridine hydrochloride (DVHC) and tetrahydrozoline hydrochloride (THHC) drugs in pure form and pharmaceutical preparations via charge-transfer complex formation with 7,7,8,8-tetracyanoquinodimethane (TCNQ) and tetracyanoethylene (TCNE) reagents. Spectrophotometric method involve the addition a known excess of TCNQ or TCNE reagents to DTB, CPHC, DVHC and THHC drugs in acetonitrile, followed by the measurement of the absorbance of the CT complexes at the selected wavelength. The reaction stoichiometry is found to be 1:1 [drug]: [TCNQ or TCNE]. The absorbance is found to increase linearly with concentration of the drugs under investigation which is corroborated by the correlation coefficients of 0.9954-0.9981. The system obeys Beer's law for 6-400, 20-500, 1-180 and 60-560 µg mL(-1) and 80-600, 10-300, 1-60 and 80-640 µg mL(-1) for DTB, CPHC, DVHC and THHC drugs using TCNQ and TCNE reagents, respectively. The apparent molar absorptivity, sandell sensitivity, the limits of detection and quantification are also reported for the spectrophotometric method. Intra- and inter-day precision and accuracy of the method were evaluated as per ICH guidelines. The method was successfully applied to the assay of DTB, CPHC, DVHC and THHC drugs in formulations and the results were compared with those of a reference method by applying Student's t and F-tests. No interference was observed from common pharmaceutical excipients.
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Mostafa A, El-Ghossein N, Alqaradawi SY. Spectrophotometric and thermal studies on the charge--transfer complexes of 4-(aminomethyl) piperidine as donor with σ- and π-electron acceptors. Spectrochim Acta A Mol Biomol Spectrosc 2014; 118:1012-1019. [PMID: 24184582 DOI: 10.1016/j.saa.2013.09.091] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [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: 06/21/2013] [Revised: 09/06/2013] [Accepted: 09/26/2013] [Indexed: 06/02/2023]
Abstract
The spectroscopic characteristics of the solid charge-transfer molecular complexes (CT) formed in the reaction of the electron donor 4-(aminomethyl) piperidine (4AMP) with the σ-acceptor iodine and the π-acceptors 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), 2,4,4,6-tetrabromo-2,5-cyclohexadienone (TBCHD) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) have been studied in chloroform at 25°C. These were investigated through electronic, infrared spectra and thermal analysis as well as elemental analysis. The results show that the formed solid CT-complexes have the formulas [(4AMP)I](+)I3(-), [(4AMP)(DDQ)2] and [(4AMP)(TBCHD)] while in the case of 4AMP-TCNQ reaction, a short-lived CT complex is formed followed by rapid N-substitution by TCNQ forming the final reaction product 7,7,8-tricyano-8-aminomethylpiperidinylquinodimethane [TCAMPQDM] in full agreement with the known reaction stoichiometries in solution as well as the elemental measurements and the thermal analysis confirmed the structure of the obtained compounds. The formation constant kCT, molar extinction coefficient εCT, free energy change ΔG(0) and CT energy ECT have been calculated for the CT-complexes [(4AMP)I](+)I3(-), [(4AMP)(DDQ)2] and [(4AMP)(TBCHD)].
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Affiliation(s)
- Adel Mostafa
- Science Program, Texas A&M University at Qatar, P.O. Box 23874, Doha, Qatar
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