ABSTRACT
Two new coumestan glycosides, coumestoside C (1) and coumestoside D (2), were isolated from the stem bark of Cylicodiscus gabunensis Harms. Their structures were established by spectroscopic means and chemical transformations as 9-O-alpha-L-rhamnopyranosyl-3-hydroxy-4-(5'-hydroxy-3'-methylbut-2'E-enyl) coumestan (1) and 9-O-beta-D-galactopyranosyl-3-O- prenyl-4-hydroxycoumestan. Coumestoside C exhibited antimicrobial activity against Proteus vulgaris.
Subject(s)
Coumarins/chemistry , Fabaceae/chemistry , Glycosides/chemistry , Carbohydrates/chemistry , Coumarins/isolation & purification , Coumarins/pharmacology , Glycosides/isolation & purification , Hydrolysis , Microbial Sensitivity Tests , Plant Bark/chemistry , Plant Extracts/chemistry , Plant Stems/chemistry , Proteus vulgaris/drug effects , Spectrometry, Mass, Fast Atom Bombardment , Spectrophotometry, Infrared , Spectrophotometry, UltravioletABSTRACT
Bioassay-guided fractionation of the stem bark of Symphonia globulifera has yielded three known xanthones, ugaxanthone (1), mbarraxanthone (2) and gentisein (3), two biflavonoid derivatives named GB2 (4) and manniflavanone GB3 (5), and one new polyoxygenated xanthone with an isoprenoid group, named globulixanthone F (6). The structures of these compounds were elucidated by means of spectroscopic methods. The spectral data of 1 and 2 are reported here for the first time, as well as the antimicrobial activity of globulixanthone F against a range of microorganisms. We also report the total synthesis of the xanthone skeleton.
Subject(s)
Anti-Infective Agents/chemistry , Clusiaceae/chemistry , Flavonoids/chemistry , Flavonoids/pharmacology , Plant Bark/chemistry , Xanthones/chemistry , Anti-Infective Agents/pharmacology , Bacteria/drug effects , Microbial Sensitivity Tests , Molecular BiologyABSTRACT
The air-dried stems and ripe fruit of Drypetes inaequalis Hutch. (Euphorbiaceae) were studied. Four triterpene derivatives, characterized as lup-20(29)-en-3beta,6alpha-diol, 3beta-acetoxylup-20(29)-en-6alpha-ol, 3beta-caffeoyloxylup-20(29)-en-6alpha-ol and 28-betad-glucopyranosyl-30-methyl 3beta-hydroxyolean-12-en-28,30-dioate along with 10 known compounds were isolated from the whole stems. One triterpene, characterized as 3alpha-hydroxyfriedelan-25-al along with six known compounds were isolated from the ripe fruit. Their structures were established on the basis of spectroscopic analysis and chemical evidence. The triterpenes were tested for antimicrobial activity against some Gram-positive and Gram-negative bacteria, and two of them appeared to be modestly active.
Subject(s)
Anti-Infective Agents/chemistry , Anti-Infective Agents/pharmacology , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Magnoliopsida/chemistry , Triterpenes/chemistry , Triterpenes/pharmacology , Anti-Infective Agents/isolation & purification , Fruit/chemistry , Molecular Structure , Nuclear Magnetic Resonance, Biomolecular , Plant Stems/chemistry , Triterpenes/isolation & purificationABSTRACT
The CH(2)Cl(2)/MeOH extract of the stem bark of Erythrina vogelii (Fabaceae) from Nigeria has yielded two novel isoflavones, 7,4'-dihydroxy-8-(gamma,gamma-dimethylallyl)-2''zeta-(4''-hydroxyisopropyl)dihydrofurano[1'',3'':5,6]isoflavone (vogelin H) (1) and 7,4'-dihydroxy-8-[(2'''zeta,3'''-dihydroxy-3'''-methyl)butyl]-2'',2''-dimethyl-3'',4''-dehydropyrano[1'',4'':5,6]isoflavone (vogelin I) (2), a novel flavone, 7,4'-dihydroxy-2'',2''-dimethyl-3'',4''-dehydropyrano[1'',4'':5,6]flavone (vogelin J) (3), and eight known flavonoids.
Subject(s)
Erythrina/chemistry , Flavones/chemistry , Isoflavones/chemistry , Flavones/isolation & purification , Isoflavones/isolation & purification , Magnetic Resonance Spectroscopy , Nigeria , Plant Bark/chemistry , Plant Stems/chemistryABSTRACT
The study of the chemical constituents of the root bark and the nut of Calophyllum inophyllum has resulted in the isolation and characterization of a xanthone derivative, named inoxanthone, 3, together with 12 known compounds: caloxanthones A, 4 and B, 5, macluraxanthone, 6, 1,5-dihydroxyxanthone, 7, calophynic acid, 8, brasiliensic acid, 9 inophylloidic acid, 10, friedelan-3-one, 11, calaustralin, 12, calophyllolide, 13, inophyllums C, 14 and E, 15. Their structures were established on the basis of spectral evidence. Their in vitro cytotoxicity against the KB cell line and their antibacterial activity and potency against a wide range of micro organisms were evaluated.
Subject(s)
Anti-Bacterial Agents/chemistry , Antineoplastic Agents, Phytogenic/chemistry , Calophyllum/chemistry , Anti-Bacterial Agents/isolation & purification , Antineoplastic Agents, Phytogenic/isolation & purification , Bacteria/drug effects , Carcinoma, Squamous Cell/drug therapy , Humans , KB Cells , Molecular Structure , Plant Bark/chemistry , Plant Extracts/chemistry , Plant Extracts/pharmacology , Seeds/chemistry , Xanthones/chemistry , Xanthones/isolation & purificationABSTRACT
Two prenylated xanthone derivatives, named globulixanthones C and D and one bis-xanthone, designated globulixanthone E, have been isolated from the root bark of Symphonia globulifera. The structures of these compounds were elucidated by a detailed spectroscopic analysis. They have been shown to exhibit in vitro significant antimicrobial activity against a range of micro-organisms.
Subject(s)
Plant Bark/chemistry , Plant Roots/chemistry , Trees/chemistry , Xanthenes/chemistry , Xanthenes/pharmacology , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/isolation & purification , Anti-Bacterial Agents/pharmacology , Bacteria/drug effects , Magnetic Resonance Spectroscopy , Molecular Structure , Xanthenes/isolation & purificationABSTRACT
A new prenylated xanthone, named allanxanthone A, was isolated from the stem bark of Allanblackia floribunda in addition to known compounds, 1,5-dihydoxyxanthone, 1,5,6-trihydroxy-3,7-dimethoxyxanthone, stigmasterol and stigmasteryl-3-O-beta-D-glucopyranoside. The structure of the new compound was assigned as 1,3,5-trihydroxy-2-(3-methylbut-2-enyl)-4-(1,1-dimethylprop-2-enyl) xanthone, by means of spectroscopic analysis. The 13C NMR spectral data of 1,5-dihydroxyxanthone is reported here for the first time as well as the in vitro cytotoxic activity of xanthone metabolites against the KB cell line.
Subject(s)
Plants, Medicinal/chemistry , Xanthenes/chemistry , Xanthones , Cameroon , Cell Survival/drug effects , Humans , KB Cells/drug effects , Magnetic Resonance Spectroscopy/methods , Plant Bark/chemistry , Plant Extracts/chemistry , Plant Extracts/isolation & purification , Plant Extracts/pharmacology , Plant Stems/chemistry , Protein Prenylation , Spectrometry, Mass, Electrospray Ionization , Spectrophotometry, Infrared , Spectrophotometry, Ultraviolet , Xanthenes/isolation & purification , Xanthenes/toxicityABSTRACT
Bioassay-guided fractionation of a root bark extract of Symphonia globulifera has yielded, in addition to stigmasterol, two new xanthones with isoprenoid units, named globulixanthones A (1) and B (2). The structures of these compounds have been elucidated by spectroscopic means. They possess significant cytotoxicity in vitro against the KB cell line.
