The invention provides a pharmaceutical composition which comprises a
pharmaceutical carrier and at least one compound selected from the group
consisting of cobaltocene-octamethyl, stigmastan- 3,5 -diene, galoxolide,
benzyl salicylate, eucalyptol, and .alpha.-pinene. Also provided is a
method of preparing a composition having antimicrobial activity
comprising extracting a plant material in an organic solvent, contacting
the extracted material to a chromatographic column, and eluting from the
chromatographic column with a mobile polar phase to obtain a composition.
The plant material is from Mammea Americana, Marchantaceae polymorpha, or
Callistemon citrinus. Also provided is a method of inhibiting the growth
of a mycobacterium, comprising administering a composition comprising a
carrier and at least one compound selected from among
cobaltocene-octamethyl, stigmastan, 3,5 -diene, friedelin, galoxolide,
benzyl salicylate, eucalyptol, and .alpha.-pinene.