RESUMEN
A series of Wrightia hanleyi extracts was screened for activity against Mycobacterium tuberculosis H37Rv. One active fraction contained a compound that initially appeared to be either the isoflavonoid wrightiadione or the alkaloid tryptanthrin, both of which have been previously reported in other Wrightia species. Characterization by NMR and MS, as well as evaluation of the literature describing these compounds, led to the conclusion that wrightiadione (1) was misidentified in the first report of its isolation from W. tomentosa in 1992 and again in 2015 when reported in W. pubescens and W. religiosa. Instead, the molecule described in these reports and in the present work is almost certainly the isobaric (same nominal mass) and isosteric (same number of atoms, valency, and shape) tryptanthrin (2), a well-known quinazolinone alkaloid found in a variety of plants including Wrightia species. Tryptanthrin (2) is also accessible synthetically via several routes and has been thoroughly characterized. Wrightiadione (1) has been synthesized and characterized and may have useful biological activity; however, this compound can no longer be said to be known to exist in Nature. To our knowledge, this misidentification of wrightiadione (1) has heretofore been unrecognized.
Asunto(s)
Antituberculosos/aislamiento & purificación , Apocynaceae/química , Quinazolinas/aislamiento & purificación , Antituberculosos/química , Antituberculosos/farmacología , Espectroscopía de Resonancia Magnética con Carbono-13 , Isoflavonas , Espectrometría de Masas , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Mycobacterium tuberculosis/efectos de los fármacos , Espectroscopía de Protones por Resonancia Magnética , Quinazolinas/química , Quinazolinas/farmacologíaRESUMEN
Coronaridine (1) was isolated from the CH2Cl2 root extract of Tabernaemontana ternifolia. The structure of 1 was established from 1D- and 2D-NMR and HR-ESIMS experiments, and by comparison with reported spectroscopic data. To date, this is the first report of compound 1 from T. ternifolia, introduced as new Tabernaemontana species from Philippines in 2005 on the basis of morphological characters. Coronaridine, an iboga-type indole alkaloid, has been isolated from over 50 Tabernaemontana species and can thus be inferred as a chemotaxonomic marker of the genus. T. ternifolia has a distinct arrangement of leaves not known in the genus, but is variable in other genera. Its isolation from endemic T. ternifolia establishes its position in the genus and supports the claim that coronaridine is a chemical marker of the genus Tabernaemontana. Interestingly, coronaridine exhibited relatively weak activity against Mycobacterium tuberculosis H37Rv (MIC 82.64 µg/mL) (Rifampicin MIC 0.05 µg/mL).
Asunto(s)
Antituberculosos/farmacología , Alcaloides Indólicos/aislamiento & purificación , Tabernaemontana/química , Antituberculosos/aislamiento & purificación , Clasificación , Ibogaína/análogos & derivados , Ibogaína/aislamiento & purificación , Alcaloides Indólicos/química , Mycobacterium tuberculosis/efectos de los fármacos , Hojas de la Planta/anatomía & histologíaRESUMEN
The first seco-uleine alkaloids, manilamine (1) (18-hydroxy-19,20-dehydro-7,21-seco-uleine) and N4-methyl angustilobine B (2), were isolated from the (pH 5) alkaloid extract of Philippine Alstonia scholaris leaves together with the known indole alkaloids 19,20-(E)-vallesamine (3), angustilobine B N4-oxide (4), 20(S)-tubotaiwine (5), and 6,7-seco-angustilobine B (6). The structure of the alkaloids was established from MS and NMR experiments.
Asunto(s)
Alstonia/química , Alcaloides Indólicos/química , Hojas de la Planta/química , Modelos Químicos , Estructura Molecular , FilipinasAsunto(s)
Alcaloides/farmacología , Antituberculosos/farmacología , Mycobacterium tuberculosis/efectos de los fármacos , Quinolinas/farmacología , Rutaceae/química , Alcaloides/química , Alcaloides/aislamiento & purificación , Antituberculosos/química , Antituberculosos/aislamiento & purificación , Relación Dosis-Respuesta a Droga , Técnicas In Vitro , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/farmacología , Quinolinas/química , Quinolinas/aislamiento & purificación , Relación Estructura-ActividadRESUMEN
ETHNOPHARMACOLOGICAL RELEVANCE: Antidesma bunius Spreng. (Phyllantaceae), Averrhoa bilimbi L. (Oxalidaceae), Biophytum sensitivum (L.) DC. (Oxalidaceae), Ceriops tagal (Perr.) C.B. Rob. (Rhizophoraceae), Kyllinga monocephala Rottb. (Cyperaceae), and Rhizophora mucronata Lam. (Rhizophoraceae) are used as remedies to control diabetes. In the present study, these plants were screened for their potential α-glucosidase inhibitory activity. MATERIALS AND METHODS: The 80% aqueous ethanolic extracts were screened for their α-glucosidase enzyme inhibitory activity using yeast alpha glucosidase enzyme. RESULTS: Except for A. bilimbi with IC(50) at 519.86±3.07, all manifested a significant enzyme inhibitory activity. R. mucronata manifested the highest activity with IC(50) at 0.08±1.82 µg mL(-1), followed by C. tagal with IC(50) at 0.85±1.46 µg mL(-1) and B. sensitivum with IC(50) at 2.24±1.58 µg mL(-1). CONCLUSION: This is the first report on the α-glucosidase inhibitory effect of the six Philippine plants; thus, partly defining the mechanism on why these medicinal plants possess antidiabetic properties.
Asunto(s)
Inhibidores Enzimáticos/farmacología , Inhibidores de Glicósido Hidrolasas , Magnoliopsida , Extractos Vegetales/farmacología , Diabetes Mellitus/tratamiento farmacológico , Filipinas , Componentes Aéreos de las Plantas , Raíces de Plantas , Plantas MedicinalesRESUMEN
A synthesis of a new alkaloid-fullerene conjugate (1) is reported. The reaction was carried out by photoinduced [3+2] cycloaddition of the Alstonia indole alkaloid, 6,7-seco-angustilobine B (2), to fullerene[C60] (3) under aerobic conditions. The major monoaddition photoadduct (1) was characterized unambiguously by UV, IR, MALDI-TOFMS and NMR experiments. A mechanism highlighted by sequential photoinduced electron transfer andradical recombination pathways is also proposed. No significant enhancement in inhibition against M. tuberculosis H37Rv was observed for 1 compared with its parent compounds 2 and 3.
Asunto(s)
Fulerenos/química , Alcaloides Indólicos/química , Fotoquímica/métodos , Espectroscopía de Resonancia Magnética , Estructura Molecular , Espectrometría de Masa por Láser de Matriz Asistida de Ionización DesorciónRESUMEN
Alpinia purpurata or red ginger was studied for its phytochemical constituents as part of our growing interest on Philippine Zingiberaceae plants that may exhibit antimycobacterial activity. The hexane and dichloromethane subextracts of the leaves were fractionated and purified using silica gel chromatography to afford a mixture of C(28)-C(32) fatty alcohols, a 3-methoxyflavone and two steroidal glycosides. The two latter metabolites were spectroscopically identified as kumatakenin (1), sitosteryl-3-O-6-palmitoyl-ß-D-glucoside (2) and b-sitosteryl galactoside (3) using ultraviolet (UV), infrared (IR), electron impact mass spectrometer (EIMS) and nuclear magnetic resonance (NMR) experiments, and by comparison with literature data. This study demonstrates for the first time the isolation of these constituents from A. purpurata. In addition to the purported anti-inflammatory activity, its phytomedicinal potential to treat tuberculosis is also described.
RESUMEN
A crude ethanol extract and hexane fraction from Morinda citrifolia Linn. (Rubiaceae) show antitubercular activity. The major constituents of the hexane fraction are E-phytol, cycloartenol, stigmasterol, beta-sitosterol, campesta-5,7,22-trien-3beta-ol and the ketosteroids stigmasta-4-en-3-one and stigmasta-4-22-dien-3-one. E-Phytol, a mixture of the two ketosteroids, and the epidioxysterol derived from campesta-5,7,22-trien-3beta-ol all show pronounced antitubercular activity.