Ricardo Reyes-Chilpa1,4, Elizabeth Estrada-Muñiz1, Bertha Román2, Carlos Torres-Sosa2,
Manuel Jiménez-Estrada1, and Ezra Béjar2,3,. 1Institute of Chemistry, Universidad Nacional
Autónoma de México, Coyoacán, 04510, México, D.F. 2

College of Sciences, San Diego State University 5500 Campanile Drive, San Diego, Ca 92182.
3Plant Bioassay™, 5702 Baltimore Dr # 265, La Mesa, CA 91942-1667. 4 To whom
correspondence should be addressed.

Calophyllum brasiliense (“Bari or Jacareuba”) -Guttifereae- is a big tree from the tropical rain
forest which thrives from Brazil to México. Its medicinal importance as a vulnerary, pectoral and
a liver protectant has been documented in, Colombia, Cuba, Guatemala and México. The tree
yields a resinous balm which is applied directly by traditional healers on bites, wounds and burns.
The yellow latex is used to heal or hold an infant’s navel after cutting the umbilical cord, specially
when it does not heal promptly (García-Barriga, 1980, Morton, 1981). The timber is of excelent
quality and has commercial importance, it is also known for its durability and high resistance to
wood destroying organisms, such as brown and white rotting fungi and termites. A chemical
analysis of the heartwood has revealed the presence of five prenylated xanthones (1-5) in the
acetone and methanol extracts. Three compounds (3, 4, and 5) have been tested active against
the brown rot fungus Postia placenta (Reyes-Chilpa et al., 1997). We now report the isolation
and strucural elucidation of an minor xanthone (6) from the heartwood and the additional testing
of natural compounds and some synthetic derivatives on additional antimicrobial assays. The
assays include the brown rot fungus Lenzites trabea and a number of human pathogenic
microorganisms including Mycobacterium smegmatis, Staphylococcus aureus and
Escherichia coli.

The structure of compound 6 was determined by IR, NMR, UV and MS as:
1,3,5,6-tetrahydroxy-2-(3-hydroxy-3-methylbutyl)-xanthone. The majority component,
1,3,5,6-tetrahydroxy-2-(3,3-dimethylallyl)-xanthone (5), was re-isolated and its structure
confirmed by X-ray diffraction. Compound 5 inhibited L. trabea mycelial growth in 80-84%,
while acetylated and methylated derivatives were almost devoid of antifungal activity.
Compounds 3, 5 and the 1:1 mixture of 3 and 5 were also active against M. smegamatis, and S.
aureus, but were completely inactive against E. coli. Our results support the hypothesis that
prenylated xanthones are responsible of the C. brasiliense wood natural resistance to
biodegradation. The wide spectrum microbicidal and antifungal activity of the latex and pure
compounds represent a viable alternative with a future application in medicine.

Garcia Barriga, Flora Medicinal de Colombia, Instituto de Ciencias Naturales, Universidad
Nacional, 1980, p. .

Reyes-Chilpa, R. Jiménez-Estrada M. and Estrada-Muñoz E., Antifungal xanthones from
Callopyllum brasiliensis heartwood. J Chem Ecol, 1997, 23(7):1901-1911.

Morton, J. Atlas of Medicinal Plants of Middle America, Charles C. Thomas Publisher, 1980,
p. 564.

Supported by a grant from the SDSU-UCSD Minority International Research Training (MIRT)
of the Fogarty International