8 Ergebnisse
The synthesis of new ester derivatives of betulin (3a-c) and betulinic acid (4) with conjugated linoleic acid isomers (CLA; in a mixture of 43.4% 9c, 11t; 49.5% 10t, 12c; 7.1% other isomers) is presented. Esterification was carried out with N,N'-dicyclohexylcarbodiimide (DCC) as the coupling agent
A simple procedure is described for the simultaneous extraction and determination of betulin and betulinic acid in white birch bark. The extraction was checked using different solvents: dichloromethane, ethyl acetate, acetone, chloroform, methanol and 95% ethanol (aqueous solution, v/v). It was
Context: Garcinia hombroniana Pierre, known as manggis hutan in Malaysia is a rich source of xanthones and benzophenones.
OBJECTIVE
This study was aimed to isolate and characterize potential cholinesterase inhibitors from the extracts of G. hombroniana bark and investigate their interactions with
BACKGROUND
In folk medicine, the stem bark of Streblus asper Lour. (Moraceae) has been reported to possess anticonvulsant activity. However, no systematic/scientific validation is available. Objective This study explores the constituents in the stem bark, their biosassy-guided isolation and their
Bioassay-guided fractionation of the ethanolic extract of Pterodon emarginatus Vogel stem bark (EtEx) resulted in the isolation and characterization of lupeol and betulin. Their structures were elucidated by spectroscopic methods including IR, (1)H-NMR, (13)C-NMR and comparison with literature
Antifungal activities of Eugenia umbelliflora Berg. (Myrtaceae) were tested in vitro against a panel of standard and clinical isolates of human fungal pathogens (dermatophytes and opportunistic saprobes). Methanol extracts of leaves and fruits of E. umbelliflora were separately prepared and
Triterpene bidesmosides are considered as highly cytotoxic saponins, usually less toxic against normal cells than monodesmosides, and less haemolytic. Biological activity of the betulin-type bidesmosides, rarely found in Nature, and seldom prepared due to serious synthetic problems, is poorly
Six compounds, namely, Lupeol (1), Betulin (2), beta-Taraxerol (3), Taraxerone (4), Stigmasterol (5) and beta-Sitosterol (6) were isolated from the petroleum ether extract of the leaves of Sapium baccatum based on spectroscopic evidence. Lupeol (1), Betulin (2) and Stigmasterol (5) were isolated for