Phytotoxic and antimicrobial constituents of Bacopa monnieri and Holmskioldia sanguinea.

The phytochemicals betulinic acid (1), wogonin (2) and oroxindin (3) isolated from the aerial parts of Bacopa monnieri and Holmskioldia sanguinea showed significant antifungal activity against the two fungi Alternaria alternata and Fusarium fusiformis. Inhibition of root growth germination of wheat seeds was observed for all three compounds which showed 100% inhibition at 10 micro g/mL. Compounds (1) and (2) showed potent inhibition of Alternaria alternata compared with oroxindin at a concentration of 4 micro g/mL, whereas compound (2) was an effective inhibitor of both fungi. The structures of the compounds were established by spectral and chemical studies.