BTD-1, BTD-3, BTD-4 and BTD-7 have antimicrobial activity against the Gram-negative bacterium E.coli ML35, the Gram-positive bacterium S.aureus 502a, and the fungus C.albicans 16820. BTD-3 is more effective against E.coli than BTD-1, BTD-4 and BTD-7.