Eucleanal: a new napthalene derivative from Euclea divinorum.

A new naphthalene derivative, named eucleanal (1), was isolated from Euclea divinorum Hiern., and its structure elucidated by detailed spectroscopic (1H, 13C NMR, COSY, HMQC, HMBC) and HREIMS analysis.

Drypetdimer A: a new flavone dimer from Drypetes gerrardii.

A new flavone dimer, drypetdimer A (1), was isolated from Drypetes gerrardii J.Hutch The structure of the new compound was elucidated by detailed spectroscopic analysis such as 1H, 13C NMR, COSY, HMQC, HMBC and HREIMS.

Fermentation and antimicrobial activities of extracts from different species of fungus belonging to Genus, Trichoderma.

The present paper discusses the effects of the crude extracts of Trichoderma spp. on a number of fungal and bacterial organisms. These include Paecilomyces variotii, Penicillium notatum, Nematospora corylii, Mucor miehei, Bacillus brevis, Bacillus subtilis, Enterobacter dissolvens and Sarcina lutea.

Enhancement of the antiplasmodial activity of quassin by transformation into a gamma-lactone.

The naturally occurring bitter principle quassin (1) was converted chemically into the gamma-lactone quassilactone (13) in an attempt to enhance its antiplasmodial activity. The in vitro antiplasmodial activity of 13 against Plasmodium falciparum (K1) (IC(50) = 23 microM) was 40-fold greater than that of 1. However, one of the intermediates, compound 8, the 15beta-hydroxy,16-O-m-chlorobenzoyl analogue of 1, was 506-fold more active than 1 against P.

A simple synthesis of 7,4'-dihydroxy-6-methoxyisoflavone, glycitein, the third soybean isoflavone.

4-Methoxyresorcinol (3) was synthesized as the precursor for glycitein (6) synthesis by the oxidation of 3-hydroxy-4-methoxybenzaldehyde (1) to the aryl formate with H2O2 and a catalytic amount of SeO2. Glycitein (6) was synthesized by cyclization of 2,4,4'-trihydroxy-5-methoxydeoxybenzoin (5) with N,N-dimethylformamide, boron trifluoride diethyl ether, and methanesulfonyl chloride in a microwave oven.

Flavonoids from Tephrosia aequilata.

From the roots of the plant Tephrosia aequilata Baker, five flavonoids were isolated of which, 3,4:8,9-dimethylenedioxypterocarpan is reported for the first time. Its structure and those of the already known flavonoids were established by physical and spectroscopic analysis. Application of 2D NMR techniques was useful for complete characterization of the new pterocarpan as well as the other known flavonoids.