Inhibition of Moloney murine leukemia virus reverse transcriptase activity by tetrahydroxyxanthones isolated from the Chinese herb, Tripterospermum lanceolatum (Hyata).
Five tetrahydroxyxanthones (THXs) isolated from Tripterospermum lanceolatum (Hyata) have been shown to have a strong inhibitory effect on Moloney murine leukemia virus reverse transcriptase (Mo-MLV RT) activity when (rA)n-(dT)15 and (rC)n-(dT)12-18 were used as template-primers. 50% inhibitory concentrations of 1,3,5,6-THX, 2,3,6,7-THX 1,3,6,7-THX, 3,4,5,6-THX, and 3,4,6,7-THX were determined to be 0.15, 0.27, 0.58, 0.12, and 0.12 microM, respectively. Their effects were concentration-dependent, and the mode of inhibition was found to be by competitive inhibition with respect to template-primer. The tetrahydroxyl groups of THXs were shown to be important for their inhibitory activity. Acylation of THXs with various groups resulted in a moderate or strong decrease in their inhibitory activity.
D000215:Acylation; D004256:DNA Polymerase I / Q000037:antagonists & inhibitors; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000494:pharmacology*; D007700:Kinetics; D008979:Moloney murine leukemia virus / Q000187:drug effects / Q000201:enzymology*; D012194:RNA-Directed DNA Polymerase / Q000378:metabolism; D018894:Reverse Transcriptase Inhibitors; D014966:Xanthenes / Q000302:isolation & purification / Q000494:pharmacology*
D004365:Drugs, Chinese Herbal; D018894:Reverse Transcriptase Inhibitors; D014966:Xanthenes; D012194:RNA-Directed DNA Polymerase; D004256:DNA Polymerase I