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Kornpointner C, Berger A, Traxler F, Hadžiabdić A, Massar M, Matek J, Brecker L, Schinnerl J. Alkaloid and iridoid glucosides from Palicourea luxurians (Rubiaceae: Palicoureeae) indicate tryptamine- and tryptophan-iridoid alkaloid formation apart the strictosidine pathway. PHYTOCHEMISTRY 2020; 173:112296. [PMID: 32087436 DOI: 10.1016/j.phytochem.2020.112296] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Revised: 01/21/2020] [Accepted: 02/06/2020] [Indexed: 06/10/2023]
Abstract
The first phytochemical examination of extracts from leaves and stem bark of Palicourea luxurians (Rusby) Borhidi yielded two undescribed and one known alstrostine derivative together with the oxindole alkaloid javaniside as well as with 5α-carboxystrictosidine. Additionally, five iridoids and four secologanin derived isolation artifacts have been isolated. Lack of strictosidine and its follow-up metabolization products suggested that the Pictet-Spenglerase in P. luxurians does barely or not catalyze the formation of strictosidine. Against this background the biosynthesis of javaniside and 5α-carboxystrictosidine is discussed with regard to possible reaction mechanisms. Similarly, P. luxurians used an independent biosynthetic pathway to produce alstrostine type structures from secologanin and tryptamine in a 2:1 ratio. The structure of isoalstrostine A, which was isolated for the first time, allowed the refinement of a previously reported pathway to the alstrostine type carbon skeleton as well as to some follow-up metabolization products. In spite of various biosynthetic pathways incorporating secologanin to gain different types of tryptophan- and tryptamine-iridoid alkaloids, P. luxurians accumulates this compound as well a couple of further metabolized iridoids deriving from loganin and secologanin.
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Affiliation(s)
- Christoph Kornpointner
- Department of Organic Chemistry, University of Vienna, Währinger Strasse 38, A-1090, Vienna, Austria
| | - Andreas Berger
- Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, A-1030, Vienna, Austria
| | - Florian Traxler
- Department of Organic Chemistry, University of Vienna, Währinger Strasse 38, A-1090, Vienna, Austria
| | - Azra Hadžiabdić
- Department of Organic Chemistry, University of Vienna, Währinger Strasse 38, A-1090, Vienna, Austria
| | - Magdalena Massar
- Department of Organic Chemistry, University of Vienna, Währinger Strasse 38, A-1090, Vienna, Austria
| | - Joanna Matek
- Department of Organic Chemistry, University of Vienna, Währinger Strasse 38, A-1090, Vienna, Austria
| | - Lothar Brecker
- Department of Organic Chemistry, University of Vienna, Währinger Strasse 38, A-1090, Vienna, Austria.
| | - Johann Schinnerl
- Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, A-1030, Vienna, Austria.
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Snow AD, Castillo GM, Nguyen BP, Choi PY, Cummings JA, Cam J, Hu Q, Lake T, Pan W, Kastin AJ, Kirschner DA, Wood SG, Rockenstein E, Masliah E, Lorimer S, Tanzi RE, Larsen L. The Amazon rain forest plant Uncaria tomentosa (cat's claw) and its specific proanthocyanidin constituents are potent inhibitors and reducers of both brain plaques and tangles. Sci Rep 2019; 9:561. [PMID: 30728442 PMCID: PMC6365538 DOI: 10.1038/s41598-019-38645-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 01/04/2019] [Indexed: 01/15/2023] Open
Abstract
Brain aging and Alzheimer's disease both demonstrate the accumulation of beta-amyloid protein containing "plaques" and tau protein containing "tangles" that contribute to accelerated memory loss and cognitive decline. In the present investigation we identified a specific plant extract and its constituents as a potential alternative natural solution for preventing and reducing both brain "plaques and tangles". PTI-00703 cat's claw (Uncaria tomentosa from a specific Peruvian source), a specific and natural plant extract from the Amazon rain forest, was identified as a potent inhibitor and reducer of both beta-amyloid fibrils (the main component of "plaques") and tau protein paired helical filaments/fibrils (the main component of "tangles"). PTI-00703 cat's claw demonstrated both the ability to prevent formation/aggregation and disaggregate preformed Aβ fibrils (1-42 and 1-40) and tau protein tangles/filaments. The disaggregation/dissolution of Aβ fibrils occurred nearly instantly when PTI-00703 cat's claw and Aβ fibrils were mixed together as shown by a variety of methods including Thioflavin T fluorometry, Congo red staining, Thioflavin S fluorescence and electron microscopy. Sophisticated structural elucidation studies identified the major fractions and specific constituents within PTI-00703 cat's claw responsible for both the observed "plaque" and "tangle" inhibitory and reducing activity. Specific proanthocyanidins (i.e. epicatechin dimers and variants thereof) are newly identified polyphenolic components within Uncaria tomentosa that possess both "plaque and tangle" reducing and inhibitory activity. One major identified specific polyphenol within PTI-00703 cat's claw was epicatechin-4β-8-epicatechin (i.e. an epicatechin dimer known as proanthocyanidin B2) that markedly reduced brain plaque load and improved short-term memory in younger and older APP "plaque-producing" (TASD-41) transgenic mice (bearing London and Swedish mutations). Proanthocyanidin B2 was also a potent inhibitor of brain inflammation as shown by reduction in astrocytosis and gliosis in TASD-41 transgenic mice. Blood-brain-barrier studies in Sprague-Dawley rats and CD-1 mice indicated that the major components of PTI-00703 cat's claw crossed the blood-brain-barrier and entered the brain parenchyma within 2 minutes of being in the blood. The discovery of a natural plant extract from the Amazon rain forest plant (i.e. Uncaria tomentosa or cat's claw) as both a potent "plaque and tangle" inhibitor and disaggregator is postulated to represent a potential breakthrough for the natural treatment of both normal brain aging and Alzheimer's disease.
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Affiliation(s)
- Alan D Snow
- Cognitive Clarity Inc., Edmonds, WA, USA.
- ProteoTech Inc., Kirkland, WA, USA.
| | | | - Beth P Nguyen
- ProteoTech Inc., Kirkland, WA, USA
- Healthcare Legacy Consulting LLC, Dallas, TX, USA
| | | | - Joel A Cummings
- Cognitive Clarity Inc., Edmonds, WA, USA
- ProteoTech Inc., Kirkland, WA, USA
| | - Judy Cam
- ProteoTech Inc., Kirkland, WA, USA
- Preclinical GPS, Washington University, St. Louis, MO, USA
| | - Qubai Hu
- ProteoTech Inc., Kirkland, WA, USA
| | - Thomas Lake
- Cognitive Clarity Inc., Edmonds, WA, USA
- ProteoTech Inc., Kirkland, WA, USA
| | - Weihong Pan
- Blood-Brain Barrier Laboratory, Pennington Biomedical Research Center at Louisiana State University, Baton Rouge, Louisiana, USA
- Biopotentials Sleep Center, Baton Rouge, LA, USA
| | - Abba J Kastin
- Blood-Brain Barrier Laboratory, Pennington Biomedical Research Center at Louisiana State University, Baton Rouge, Louisiana, USA
| | | | - Steven G Wood
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, USA
| | - Edward Rockenstein
- Departments of Neurosciences and Pathology, University of California- San Diego, La Jolla, CA, USA
| | - Eliezer Masliah
- Departments of Neurosciences and Pathology, University of California- San Diego, La Jolla, CA, USA
- Division of Neurosciences, National Institute on Aging, Bethesda, MD, USA
| | - Stephen Lorimer
- Department of Chemistry, University of Otago, Dunedin, New Zealand
- VicLink Ltd., Wellington, New Zealand
| | - Rudolph E Tanzi
- Genetics and Aging Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Lesley Larsen
- Department of Chemistry, University of Otago, Dunedin, New Zealand
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Paradowska K, Wolniak M, Pisklak M, Gliński JA, Davey MH, Wawer I. (13)C, (15)N CPMAS NMR and GIAO DFT calculations of stereoisomeric oxindole alkaloids from Cat's Claw (Uncaria tomentosa). SOLID STATE NUCLEAR MAGNETIC RESONANCE 2008; 34:202-209. [PMID: 19019638 DOI: 10.1016/j.ssnmr.2008.10.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2008] [Revised: 08/19/2008] [Accepted: 10/06/2008] [Indexed: 05/27/2023]
Abstract
Oxindole alkaloids, isolated from the bark of Uncaria tomentosa [Willd. ex Schult.] Rubiaceae, are considered to be responsible for the biological activity of this herb. Five pentacyclic and two tetracyclic alkaloids were studied by solid-state NMR and theoretical GIAO DFT methods. The (13)C and (15)N CPMAS NMR spectra were recorded for mitraphylline, isomitraphylline, pteropodine (uncarine C), isopteropodine (uncarine E), speciophylline (uncarine D), rhynchophylline and isorhynchophylline. Theoretical GIAO DFT calculations of shielding constants provide arguments for identification of asymmetric centers and proper assignment of NMR spectra. These alkaloids are 7R/7S and 20R/20S stereoisomeric pairs. Based on the (13)C CP MAS chemical shifts the 7S alkaloids (delta C3 70-71ppm) can be easily and conveniently distinguished from 7R (deltaC3 74.5-74.9ppm), also 20R (deltaC20 41.3-41.7ppm) from the 20S (deltaC20 36.3-38.3ppm). The epiallo-type isomer (3R, 20S) of speciophylline is characterized by a larger (15)N MAS chemical shift of N4 (64.6ppm) than the allo-type (3S, 20S) of isopteropodine (deltaN4 53.3ppm). (15)N MAS chemical shifts of N1-H in pentacyclic alkaloids are within 131.9-140.4ppm.
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Affiliation(s)
- Katarzyna Paradowska
- Faculty of Pharmacy, Medical University of Warsaw, 02-097 Warsaw, Banacha 1, Poland
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García Prado E, García Gimenez MD, De la Puerta Vázquez R, Espartero Sánchez JL, Sáenz Rodríguez MT. Antiproliferative effects of mitraphylline, a pentacyclic oxindole alkaloid of Uncaria tomentosa on human glioma and neuroblastoma cell lines. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2007; 14:280-4. [PMID: 17296291 DOI: 10.1016/j.phymed.2006.12.023] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2006] [Accepted: 12/07/2006] [Indexed: 05/13/2023]
Abstract
Uncaria tomentosa inner bark extract is a popular plant remedy used in folk medicine to treat tumor and inflammatory processes. In this study, the anti-tumoral effects of its pentacyclic alkaloid mitraphylline were investigated. Furthermore, its growth-inhibitory and cytotoxic effects on glioma GAMG and neuroblastoma SKN-BE(2) cell lines were studied using cyclophosphamide and vincristine as controls. A colter counter was used to determine viable cell numbers, followed by application of the tetrazolium compound [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)2-(4-sulfophenyl)-2H-tetrazolium], inner salt, colorimetric method to evaluate cell viability in this cytotoxicity assay. Micromolar concentrations of mitraphylline (from 5 to 40 microM) inhibited the growth of both cell lines. It inhibited the growth of the two cell lines studied in a dose-dependent manner. The IC(50) values were 12.3 microM (30h) for SKN-BE(2) and 20 microM (48 h) for GAMG, respectively. This action suggests that mitraphylline is a new and promising agent in the treatment of human neuroblastoma and glioma.
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Affiliation(s)
- E García Prado
- Department of Pharmacology, Faculty of Pharmacy, University of Seville, c/ Profesor García González n. 2, 41012 Seville, Spain
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Abstract
The tubers of Lepidium meyenii contain the benzylated derivative of 1,2-dihydro-N-hydroxypyridine, named macaridine, together with the benzylated alkamides (macamides), N-benzyl-5-oxo-6E,8E-octadecadienamide and N-benzylhexadecanamide, as well as the acyclic keto acid, 5-oxo-6E,8E-octadecadienoic acid. The structure elucidation of the isolated compounds was based primarily on 1D and 2D NMR spectroscopic analyses, including 1H-1H COSY, 1H-13C HMQC, 1H-13C HMBC and 1H-1H NOESY experiments, as well as from 1H-15N NMR HMBC correlations for macaridine and N-benzylhexadecanamide.
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Affiliation(s)
- Ilias Muhammad
- National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, School of Pharmacy, University of Mississippi, University MS 38677, USA.
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