Expedient MPLC-based isolation of lupane triterpenoids from Glochidion zeylanicum var. tomentosum (Dalzell) Trimen. Bark

An automated medium-pressure liquid chromatography (MPLC) system was employed for the preparative-scale isolation of lupane-type triterpenoids from Glochidion zeylanicum var. tomentosum (Dalzell) Trimen. Seven compounds were isolated and identified as glochidone (1), glochidonol (2), glochidiol (3), lupeol (4), epilupeol (5), lup-20(29)-ene-3α,23-diol (6) and lup-20(29)-ene-1α,3β-diol (7). The antimicrobial activity of these compounds was evaluated against Micrococcus luteus, Staphylococcus aureus, Aspergillus fumigatus and Rhizopus oryzae using the minimum inhibitory concentration (MIC) method. Glochidiol (3) showed moderate activity against S. aureus (64 µg/mL) and R. oryzae (32 µg/mL). Compound 6 also showed moderate antifungal activity against A. fumigatus (64 µg/mL). The results highlight the efficiency of MPLC and the influence of hydroxyl substitution on antimicrobial activity.