Bioactive icetexane and abietane diterpenes from Isodon phyllopodus

A new icetexane diterpenoid, 11, 12, 20α-trihydroxyl-7β-methoxyicetexa-8, 11, 13-triene-19, 10-lactone [Phyllane A (1)], and a new abietane diterpenoid, 7β, 20-epoxy-3β, 17-acetoxy-abieta-8, 11, 13-teriene-11, 12-diol [phyllane B (2)], along with two known compounds (3 and 4) were isolated from the methanol (MeOH) extract of twigs and leaves of the folk medicinal Isodon phyllopodus. Their structures were determined by spectroscopic analyses including 2 D NMR spectral data, and further confirmed by X-ray single crystal diffraction. Moreover, the compounds were evaluated for their cytotoxicity and anti-HIV activities, and phyllane A showed anti-HIV activity with an IC₅₀ value of 15.7 μM, but phyllane B was found to be cytotoxic to the A549 host cells with a CC₅₀ value of 108.5 μM.