ABSTRACT
For thousands years of human history, natural products (NPs) derived from plants, animals, microbes, and marine organisms have played an important role for treating and preventing diseases. WHO has estimated that herbal medicines serve the health needs of about 80% of the world’s population[1]. An analysis of the origin of the drugs developed between 1981 and 2002 showed that NPs or NP-derived drugs comprised 28% of all new chemical entities (NCEs) launched onto the market[2]. In addition, 24% of these NCEs were synthetic or natural mimic compounds, based on the study of pharmacophores related to NPs[3]. This combined percentage (52% of all NCEs) suggests that NPs are important sources for new drugs and are also precursors for further modification as drugs. The large proportion of NPs in drug discovery was attributed to the diverse structures and intricate carbon skeletons of NPs. In fact, several important drugs of modern medicine have come from medicinal plant, e.g., taxol, vinblastine, vincristine, topotecan, irinotecan, etoposide, teniposide, etc.[4]. Study found that NPs or related substances accounted for 40%, 24%, and 26% of the top 35 worldwide ethical drug sales in 2000, 2001, and 2002, respectively[5].
