Kolaviron, a mixture of C-3/C-8 linked biflavonoids obtained from Garcinia kola produces significant hypoglycaemic effects when administered intraperitoneally to normal and alloxan diabetic rabbits at a dose of 100 mg kg-1. The fasting blood sugar in normoglycaemic rabbits was reduced from 115 mg/100 mL to 65 mg/100 mL after 4 h. In alloxan diabetic rabbits, the blood sugar was lowered from 506 mg/100 mL to 285 mg/100 mL at 12 h. The hypoglycaemic effects have been compared with those of tolbutamide. Kolaviron inhibited rat lens aldose reductase (RLAR) activity, with an IC50 value of 5.4 x 10(-6). The significance of these findings in the potential use of kolaviron as an antidiabetic agent is discussed.

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The mold genus Alternaria is a widely distributed plant pathogen. Some of these species, e.g., A. alternata, are common decay organisms of fruits and vegetables. Two novel perylene oxide metabolites, altertoxins II and III, have been identified in extracts of A. alternata isolates that exhibit mutagenic responses in the Ames Salmonella typhimurium assay. These identifications were based on mass, optical rotational, and 1H- and 13C-nmr spectral studies. Previous reports of related perylene dione mycotoxins have been clarified.

Eremocarpus setigerus (Hook) Benth, a member of the spurge family, commonly known as "dove weed" and T h e ability to quantitatively analyze vicinal dideuteriated systems for erythro/ threo2s3 (e.g., 1) and m e s~/ d l *~~ (e.g., 2) ratios have been useful in many " 0 t-Bu

Two trimeric proanthocyanidins, cinnamtannin B-1 (1) and cinnamtannin D-1 (2), have been isolated from the bark of Cinnamomum cassia along with the known tetramer parameritannin A-1 (3) and a previously unreported tetramer, named cassiatannin A (4). The structures of 1-4 were elucidated on the basis of 1D and 2D NMR, MS, and CD analyses and compared to the reported data. Proanthocyanidins (1-4) possess significant in vitro inhibitory activity against cyclooxygenase-2 (COX-2) at micromolar concentrations.