칼라놀라이드A

Calanolide A is a new non-nucleoside reverse transcriptase inhibitor (NNRTI) derived from a plant found in the Malaysian rain forest. A related compound, calanolide B, also has anti-HIV activity. Both drugs are being developed by Sarawak Pharmaceuticals. The drug is metabolised by cytochrome P450 CYP3A, and its developers have suggested that drug levels may be enhanced if co-administered with ritonavir (Norvir). The drug is active in the test tube against HIV with the two most common NNRTI-related mutations, K103N and Y181C, and selects for a mutation which does not cause cross-resistance with any other NNRTIs currently under investigation. A substitution at codon Y188H of reverse transcriptase has been associated with 30-fold resistance to calanolide A in vitro (Quan 1999). The compound is essentially inactive against strains of the less common HIV type 2.

Viral life-cycle studies indicate that calanolide A acts early in the infection process, similar to the known HIV reverse transcriptase (RT) inhibitor 2', 3'-dideoxycytidine. In enzyme inhibition assays, calanolide A potently and selectively inhibits recombinant HIV type 1 RT but not cellular DNA polymerases or HIV type 2 RT within the concentration range tested.