Triterpenoid constituents of rose-bay willow-herb

Glen, Angela; Lawrie, W.; McLean, John W.; Younes, M. El-Garby

doi:10.1039/j39670000510

Cited by 25 publications

(12 citation statements)

References 0 publications

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“…Our work on the dichloromethane-methanol extract of the stem bark of E. angolense has resulted in the isolation of ten known compounds: 7α-acetoxydihydronomilin 1 (Ahmed et al, 1978), 7α-obacunylacetate 2 (Bennett and Hasegawa, 1982), methylangolensate 3 (Connolly, 1983), tricosanoic acid 4 (Francis, 1939), 22hydroxyhopan-3-one 5 (Mahato and Kundu, 1994), 24-methylenecycloartenol 6 (Ferreira et al, 2000) (structure to be confirmed), methyloleanate (Glen et al, 1967), betulinic acid (Mahato and Kundu, 1994), β-sitosterol (Furuya et al, 1987) and β-sitosterol-3-O-β-D-glucoglucopyranoside (Sakakibara et al, 1983).…”

Section: Discussionmentioning

confidence: 99%

The antiplasmodial agents of the stem bark of <i>Entandrophragma angolense</i> (Meliaceae).

Bickii

Tchouya²,

Tchouankeu³

et al. 2008

Afr. J. Trad. Compl. Alt. Med.

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In the search of active principles from the stem bark of Entandrophragma angolense, we submitted the compounds isolated from the dichloromethane-methanol (1:1) extract of the stem bark to antimalarial test against chloroquine resistant strain W2 of Plasmodium falciparum malaria parasite. Only 7α-obacunyl acetate and a cycloartane derivative exhibited a good activity, with IC 50 s of 2 and 5.4 µg/ml respectively. Other compounds were moderately active.

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Section: Discussionmentioning

confidence: 99%

The antiplasmodial agents of the stem bark of <i>Entandrophragma angolense</i> (Meliaceae).

Bickii

Tchouya²,

Tchouankeu³

et al. 2008

Afr. J. Trad. Compl. Alt. Med.

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“…The similarity in the chemical shifts of the seven methyl groups in the NMR spectra of the compound and its diacetate suggested the two oxygen functions to be a and a. The formation of an o,o-isopropylidene derivative with acetone supported the cis-configuration or at least a diequatorial conformation [7]. When two hydroxyls are on @-side, the signals of two methyls (24 and 25) would shift to low field in comparison to those of the diacetate in question.…”

Section: Cooch3mentioning

confidence: 92%

2α, 3α–DIHYDROXYOLEAN–12–EN–28–OIC ACID FROMHOLOPTELEA INTEGRIEOLIAHEARTWOOD

Misra¹,

Sc²,

Sk³

1975

Planta Med

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2a, 3a-Dihydroxyolean-12-en-28-oic acid has been isolated from Holoptelea integrifolia heartwood and its structure elt~cidated by physico-chemical methods and comparison with synthetic sample. Holoptelea integrifolia PLANCH. syn. Ulmzrs integrifolia ROXB. (Lllmaceae) locally known as Chilbil, is a roadside tree distributed throughout the greater part of India [I]. T h e bark yields friedelin and friedelin-3fi-01 and the leaves yield hexacosanol, octacosanol, fi-sitosterol and fi-amyrin [2]. In pursuance of the investigations on different parts of H. integrifolia, a systematic chemical examination of its heartwood has been taken up and a rare triterpene acid (Fig. 1 a), 2a, 3a-dihydroxyolean-12-en-28-oic acid has been isolated and its structure elucidated. T h e hexane and ether soluble sticky semi-solid fractions of the alcohblic extractive of the heartwood on chromatography (silica gel) yielded an LB and T N M positive product, m. p. 150-200' which was acidic in nature and showed 5 spots on TLC (silica geI G plates; Bz-MeOH, 9 5 5). Repeated column chromatography (silica gel and alumina) could not furnish any pure product. The mixture was, therefore, methylated with diazomethane and the resultant methylester mixture o n chromatography (alumina) resolved into 3 .different fractions having melting ranges 170-190°, 280-290' and 225-230" respectively. The major and the highest melting methylester was purified by rechromatography and crystallisations from alcohol as needles when it melted a t 294-296'; (a):;, + 62.7O! mol. wt. 486 (M'). The elemental analysis answered the molecular formula, CSIHj004 for the compound (Fig. l b) which formed a crystalline dibenzoate, C45H5S06 and an amorphous acetate found mixture of a monoacetate and a diacetate (M* = 570; Fig. lc).

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“…The method of analysis of the DNA and RNA content of peripheral blood lymphocytes has been described elsewhere (Glen, 1967). It is carried out in two stages.…”

Section: Methodsmentioning

confidence: 99%