Ceanothane- and lupane-type triterpenes with antiplasmodial and antimycobacterial activities from Ziziphus cambodiana

One new and eight known ceanothane- and lupane-type triterpenes were isolated from the root bark of Ziziphus cambodiana PIERRE (Rhamnaceae). Based on spectral analyses, the structure of the new compound was elucidated as 3-O-(4-hydroxy-3-methoxybenzoyl)ceanothic acid (3-O-vanillylceanothic acid) (1), while the known compounds were identified as lupeol (2), betulinaldehyde (3), betulinic acid (4), 2-O-E-p-coumaroyl alphitolic acid (5), alphitolic acid (6), zizyberanalic acid (7), zizyberenalic acid (8) and ceanothic acid (9). Compounds 1, 5 and 8 exhibited significant in vitro antiplasmodial activity against the parasite Plasmodium falciparum, with inhibitory concentration (IC50) values of 3.7, 0.9 and 3.0 microg/ml, respectively. Compounds 1 and 3-8 showed antimycobacterial activity against Mycobacterium tuberculosis with respective MIC values of 25, 25, 25, 12.5, 50, 50 and 100 microg/ml.     

Unique diketopiperazine dimers from the insect pathogenic fungus Verticillium hemipterigenum BCC 1449

[structure: see text]. Vertihemiptellides A (1) and B (2), unique diketopiperazine dimers, were isolated from the insect pathogenic fungus Verticillium hemipterigenum BCC 1449. Structures of these compounds were elucidated by NMR and mass spectral analysis, and the stereochemistry of 1 was determined by X-ray crystallography. The absolute stereochemistry of bisdethiodi(methylthio)-1-demethylhyalodendrin (3), previously isolated from the same fungus, was revised to the (3R,6R) configuration.