Biogenesis of rosmarinic acid in Mentha

The biogenesis of rosmarinic acid (alpha-O-caffeoyl-3,4-dihydroxyphenyl-lactic acid), the second most common ester of caffeic acid in the plant kingdom, was studied in Mentha arvense and Mentha piperita. Administration of (14)C-labelled compounds showed that, whereas the caffeoyl moiety was formed from phenylalanine via cinnamic acid and p-coumaric acid, the 3,4-dihydroxyphenyl-lactic acid moiety was formed from tyrosine and 3,4-dihydroxyphenylalanine. Time-course studies and the use of labelled rosmarinic acid showed that endogenous rosmarinic acid had a low turnover rate. The caffeoyl moiety did not appear to contribute to the formation of insoluble polymers, as has been suggested for chlorogenic acid in other plants.     

Sex differences in behavior of endangered mangabeys (Cercocebus galeritus chrysogaster)

Six adult golden-bellied mangabeys (Cercocebus galeritus chrysogaster) displayed sex differences in aggression, grooming, and vocalization. These sex differences persisted across different current living conditions, time in captivity, rearing conditions, presence of offspring, and active mating conditions. The sex differences are evidently quite robust.     

Ultra-violet mediated cytotoxic activity of β-carboline alkaloids

Six β-carboline alkaloids were screened for phototoxicity using yeast and bacterial bioassay systems. Five of the compounds tested showed various degrees of activity. The remaining compound, 6-methoxy-tetrahydroharman, was devoid of activity.     

UV-mediated antibiotic activity of some compositae species

Roots, leaves, and flowers of 80 species of Compositae were tested for phototoxic activity against Candida albicans. Many genera showed activity, especially in the roots. No active genera were found in the tribe Cichorieae. Phototoxic compounds were isolated from Chrysanthemum leucanthemum florets and Cirsium arvense roots. Chemotaxonomic evidence plus preliminary chemical data suggests that the compounds are polyacetylenic in nature. Unlike other phototoxic compounds, these are inactive against human skin.     

Styrylpyrone biosynthesis in Polyporus hispidus: I. Action spectrum and photoregulation of pigment and enzyme formation

Low energies of white light (5·10⁴ ergs/cm²) were found to be effective at inducing styrylpyrone biosynthesis in the fungus, Polyporus hispidus. Action spectrum studies showed that the system responded to light of 380 and 440 nm. Light initiated a sequential increase in activity of enzymes involved in styrylpyrone biosynthesis prior to appearance of pigment. Cycloheximide blocked light induced styrylpyrone biosynthesis and p-coumarate hydroxylase activity. Inhibitors of RNA synthesis had no apparent effect.     

Insect feeding deterrent property of alantolactone

The sesquiterpene lactone, alantolactone, significantly reduces feeding and survival of Tribolium confusum. These findings support the view that alantolactone may protect plants such as composites from insect attack.