The National Cancer Institute (NCI) will be seeking licensees for threeplant-derived compounds that have stopped HIV replication in vitro.The compounds include michellamine B, calanolide A and prostratin.

They are among four compounds discovered through NCI's naturalproduct-screening program that the institute's Division of CancerTreatment has approved for preclinical development over the pastfew years. A fourth compound, conocurvone, derived fromConospermum (a flowering shrub in Australia), was recently licensedto AMRAD Corp. Ltd., a consortium of four biomedical researchorganizations in Victoria, Australia (see BioWorld, Dec. 20). NIH hasnot yet published a Federal Register notice seeking a licensee for theother three compounds.

Michellamine B, derived from Ancistrocladus korupensis, a vine thathas been found only in Cameroon, is the furthest along indevelopment. It entered toxicity testing in rodents and dogs late lastyear. The vine was first collected in 1987 by Duncan Thomas, whowas then a botanist with the Missouri Botanical Garden.

Gordon Cragg, chief of NCI's Natural Products Branch, said this is anew species of plant that is not very abundant. He noted that NCI hasbeen working with a group at Purdue University, the MissouriBotanical Garden, and scientists at the University of Yaounde inCameroon to develop cultivation of the plant in Cameroon.

Of the other two plants, calanolide A is derived from the Malaysianplant Calophyllum lanigerum and prostratin comes from the westernSamoan plant Homalanthus nutans. Cragg said the latter wascollected from traditional healers in Samoa, who use it for thetreatment of yellow fever.

Cragg told BioWorld that NCI's initial natural products collectionprogram, conducted from 1960 through the early 1980s, gatheredmaterial primarily from temperate regions of the world -- the U.S.,Canada and Europe. In the 1980s, NCI began collecting material fromtropical areas. Cragg said that under the new program the institutehas screened more than 40,000 plant extracts, 12,000-13,000 marineorganisms and 15,000-20,000 microorganisms for AIDS and cancer.

-- Brenda Sandburg News Editor

(c) 1997 American Health Consultants. All rights reserved.