Antibacterial activity of pisiferic acid and its derivatives against gram-negative and -positive becteria.

Derivatives of pisiferic acid (2), an antibiotic found in Chamaecyparis pisifera var.plumosa, were tested for antibacterial activities against Proteus vulgaris, Staphylocoecus aureus and Bacillus subtilis.As structural factors for the activities, the C-10 COOHand/or C-12 OHwere estimated to be the most important factors.In the mode of action of the pisiferic acid species on the bacterial macromolecule, peptidoglycan synthesis was predominantly inhibited in B. subtilis, while nonspecific inhibition was observed in P. vulgaris.