ABSTRACT
College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612, U.S.A.
INTRODUCTION
The alarming spread of the devastating disease, acquired immunodeficiency syndrome (AIDS), has served to stimulate an intense dem and and all-out research effort for the discovery of new and novel anti-human immunodeficiency viral (HIV) agents12. Problems such as toxicity and drug resistance have been associated with AZT (3-azido-3'-deoxy thymidine), DDI (2’,3'-dideoxyinosine) and DDC (2',3'-dideoxycytosine), the only three currently approved antiretro viral drugs for the treatm ent of AIDS in the United States2. One group of potential therapeutic agents for the treatm ent of AIDS are substances of natural origin, which traditionally have been isolated from either animals, microorganisms or plants. O f these, the natural products which presently have the greatest diversity of therapeutic value are from the plant kingdom, inclusive of such clinically useful substances as codeine, digoxin, m orphine, pilocarpine, quinine, reserpine, tubocurarine, and vincristine3. Some 120 plant secondary metabolites are now used as drugs in one or m ore countries, and many synthetic drugs are modifications of plant-derived lead compounds. In addition, perhaps 75% of the world’s population relies on plants used in traditional medicine for their primary health care3. There are over 250,000 higher plants (gymnosperms and angiosperms) on the earth, and it is estimated that as many as 90% of these species have no t been subjected to any form of scientific phytochemical a n d /o r biological screening. H igher plants therefore represent a potential treasure-trove of biologically active organic compounds of diverse structure4.
