Recent studies on natural products as anti-HIV agents

The discovery of medicinal agents capable of specifically inhibiting human immunodeficiency virus (HIV) is urgently needed due to its globally widespread infection. Most of clinically useful anti-HIV agents are nucleosides but their use is limited due to their severe toxicity and emerging drug resistance. More than 50% of world marketed drugs have their origin of the nature. Natural products, of which structural diversity is so broad, are good sources for the effective discovery of anti-HIV agents with decreased toxicity. Over the past decade, substantial progress has been made in research on the natural products for the anti-HIV agents. New natural products that have potent anti-HIV activities with novel structures were reviewed in this article. These compounds, isolated mainly from medicinal plants, in this review have been classified as secondary metabolites such as terpenes, phenolics, and naturally scarce peptides and sugars. Especially, terpenes and phenol substances have gained much interest due to their significant anti-HIV activities along with their structural diversity. Recent studies also showed that several polysaccharides are effective inhibitors of HIV replication. Most of chemotherapeutic targets reviewed in this article are found to be HIV reverse transcriptase (RT).