26 research outputs found
Antiplasmodial and antileishmanial inhibitory activity of triterpenes and steroidal alkaloid from the leaves of Funtumia elastica (Preuss) Stapf (Apocynaceae)
peer reviewedThe phytochemical study of leaves of Funtumia elastica led to the isolation of three undescribed ursane derivatives, funtumic acids A, B and C (1–3), as well as one steroidal alkaloid, elasticine (4) and five other known compounds (5–9). Their structures were elucidated on the basis of NMR, MS, IR, UV spectroscopic data as well as by comparison with the literature. The compound 5-hydroxypyridine-3-carboxamide (9) was isolated for the first time from the Apocynaceae family. All the isolated compounds were evaluated for their antiparasitic effects against 3D7 and Dd2 strains of Plasmodium falciparum and promastigotes of Leishmania donovani (MHOM/SD/62/1S). Compounds 1–4 possessed good in vitro antimalarial activities against CQR Dd2 with IC50 values ranging from 4.68 to 5.36 μg/mL and moderate on CQS 3D7. Only compounds 1 and 2 showed leishmanicidal activities with IC50 values ranging between 10.49 and 13.21 μg/mL. In addition, crude extract exhibited potent antiplasmodial (IC50 0.91 and 3.12 μg/mL) and antileishmanial (IC50 3.32 μg/mL) activities, thus demonstrating their potential synergistic action
In vitro antitubercular activity of extract and constituents from the stem bark of Disthemonanthus benthamianus
A new C-glycosylflavone, apigenin 7-methyl ether 6-C-[β-xylopyranosyl-(1→3)-β- glucopyranoside] named distemonanthoside was isolated from the stem bark of Distemonanthus benthamianus Baill., Fabaceae, along with six known compounds, sitosterol 3-O-β-d-glucopyranoside, 4-methoxygallic acid, syringic acid, quercetin, 6″- O-acetylvitexin, quercetin 3-O-β-d-glucopyranoside. The structures of those compounds and others were determined through spectral analyses. Compounds distemonanthoside, sitosterol 3-O-β-d-glucopyranoside, 4-methoxygallic acid and quercetin were tested against a clinical isolate strain of Mycobacterium tuberculosis AC 45; they exhibited good to moderate antitubercular activities with MIC values ranged from 31.25 to 125μg/ml
Secondary metabolites from Triclisia gilletii (De Wild) Staner (Menispermaceae) with antimycobacterial activity against Mycobacterium tuberculosis
Triclisinone (2), a new ochnaflavone derivative, was isolated from the aerial parts of Triclisia gilletii, along with known drypemolundein B (1) and eight other known compounds. The chemical shifts of drypemolundein B (1) have been partially revised based on reinterpretation of NMR spectroscopic data. The eight other secondary metabolites are composed of: (+)-nonacosan-10-ol (3); stigmasterol (4), 3-O-β-D- glucopyranosylsitosterol (5), 3-O-β-D-glucopyranosylstigmasterol (6); oleanic acid (7); myricetin (8), quercetin (9) and 3-methoxyquercetin (10). Their structures were elucidated using IR, MS, NMR 1D and 2D, 1H and 13C and comparison with literature data. Furthermore, compounds 1, 2, 5, 6, 8, 9 and the crude extract were tested against Mycobacterium tuberculosis. Compounds 1, 2, 8 and 9 displayed moderate to very good activity against resistant strain (codified AC 45) of M. tuberculosis with minimum inhibitory concentrations MICs ranging from 3.90 to 62.5 μg/mL
Rauvolfianine, a new antimycobacterial glyceroglycolipid and other constituents from Rauvolfia caffra. Sond (Apocynaceae)
The chemical investigation of the extract of the dried leaves of Rauvolfia caffra (Sond) (synonym Rauvolfia macrophylla) (Apocynaceae) led to isolation of a new glycoside derivative, rauvolfianine (1) as well as six known compounds: oleanolic acid (2), sitosterol-3-O-β-D-glucopyranoside (3), betulinic acid (4), vellosimine (5), sarpagine (6) and D-fructofuranosyl-β-(2→1)-α-D-glucopyranoside (7). Compounds 1, 2, 3, 4 and 7 were evaluated for antitubercular activity. Compounds 1 and 2 were the most active (MIC = 7.8125 and 31.25 μg/mL) towards the Isoniazid resistant strain of Mycobacterium tuberculosis AC45. Their structures and relative stereochemistry were elucidated by spectroscopic methods
FLAVONOIDES ISOLES DES FEUILLES DE OCHNA AFZELII ET HEMISYNTHESE DES AFZELODINES A, B ET C A PARTIR DE LA DIHYDROLOPHIRONE C
L'étude phytochimique des feuilles de la plante médicinale camerounaise Ochna afzelii nous a permis d'isoler et de caractériser neuf flavonoïdes parmi lesquelles la dihydrolophirone C 9. Le traitement de cette dernière avec une solution de KOH à 20 % a permis d'obtenir trois nouveaux biflavonoïdes : les afzelodines A 10, B 11 et C 12 à des rendements différents.
African Journal of Science and Technology Vol.5(1) 2004: 101-10
Acylsteryl glycosides and other constituents from Campylospermum densiflorum (Ochnaceae)
International audienceA mixture of two new acylsteryl glycosides named densifloside A and B was isolated from the leaves of Campylospermum densiflorum, together with serotobenine, decursivine, N-feruloyltriptamine , ent-16 ,17-dihydroxykauran-19-oic acid, menisdaurin, and secoisolariciresinol. The structure elucidations were based on spectroscopic evidence. The biological assay of crude extract of this plant showed good antimicrobial activity against Gram-positive cocci, weak activity against Gram-negative bacilli, and displayed moderate activity against two strains of fungi (C. albicans and C. neoformans) among several strains
Nitrile glucosides and serotobenine from Campylospermum glaucum and Ouratea turnarea
peer reviewedTwo nitrile glucosides (1S,3S,4S,5R)-4-benzoyloxy-2-cyanomethylene-3,5-dihydroxycyclohexyl-1-O-be ta-glucopyranoside (campyloside A) and (1S,3S,4S,5R)-5-benzoyloxy-2-cyanomethylene-3-hydroxy-4-(2-pyrrolcarboxylo xy)cyclohexyl-1-O-beta-glucopyranoside (campyloside B) were isolated from the stem roots of Campylospermum glaucum, whereas serotobenine was isolated from Ouratea turnarea. The structure elucidations were based on spectroscopic evidence. The biological assays of compounds and crude extract of plant species showed good antimicrobial activity of crude extracts against Gram-positive cocci
New flavonoids C-glycosides from Rhabdophyllum arnoldianum
International audienceTwo new flavone glycosides, 3 ''-O-acetyl-7-O-methylvitexin (1) and 6 ''-alpha-rhamnopyranosyl-7-O-methylvitexin (2), along with nine known compounds (3-11) were isolated from the leaves of Rhabdophyllum arnoldianum (Ochnaceae). The structures of the new compounds were established by detailed spectroscopic studies and mass spectrometry, while known compounds were characterised by direct comparison of their reported NMR data with those found in the literature. All these compounds were the first reported from Rhabdophyllum genus. The biological assays on crude extracts and compounds of this plant demonstrated that the crude extracts possess significant antimicrobial activity against Gram-positive bacteria
Isolation of linobiflavonoid, a novel biflavonoid from Linostoma pauciflorum Griff.
A novel biflavonoid, that we have named linobiflavonoid, and the known biscoumarin ether, daphnoretin, were isolated from the root extracts of Linostoma pauciflorum Griff. The structure of linobiflavonoid was determined from interpretation of its NMR spectroscopic data and from a comparison of this data with those of known biflavonoids and biflavones. The known flavones, 5,4\u27-dihydroxy- 7,3\u27,5\u27-trimethoxyflavone and 5,4\u27-dihydroxy-7-methoxyflavone along with stigmasterol were isolated from the vines of the same plant. 4\u27-Dihydroxy-7,3\u27-5\u27-trimethoxyflavone was active against Mycobacterium tuberculosis (MIC 3.13 mu M) and KB-oral cavity cancer (IC50 17.41 mu M). (C) 2011 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved
ACYLSTERYL GLYCOSIDES AND OTHER CONSTITUENTS FROM CAMPYLOSPERMUM DENSIFLORUM (OCHNACEAE)
ABSTRACT A mixture of two new acylsteryl glycosides named densifloside A and B was isolated from the leaves of Campylospermum densiflorum, together with serotobenine, decursivine, N-feruloyltriptamine , ent-16α,17-dihydroxykauran-19-oic acid, menisdaurin, and secoisolariciresinol. The structure elucidations were based on spectroscopic evidence. The biological assay of crude extract of this plant showed good antimicrobial activity against Gram-positive cocci, weak activity against Gram-negative bacilli, and displayed moderate activity against two strains of fungi (C. albicans and C. neoformans) among several strains