2.2. Isolation and Purification of Lanostane Triterpenoid Compounds (1–6)

P. cocos dried sclerotium (10 kg) was extracted three times by refluxing with 75% ethanol for 3 h. The concentrated extract was chromatographed on silica gel (70–230 mesh) using increasingly polar mixtures of CH₂Cl₂–MeOH (CH₂Cl₂: MeOH, 97:3; CH₂Cl₂: MeOH, 96:4; CH₂Cl₂: MeOH, 90:10; and MeOH only). According to the analytical thin-layer chromatography (TLC), four fractions (Fr.1~Fr.4) were collected for further separation. Fr.1~Fr.3 were subjected to HPLC preparation on a Waters XBridge RP-18 column (250 mm × 19 mm, 5 μm, Milford, MA, USA) using 85% methanol as the mobile phase system. The flow rate was 18 mL/min and six major peaks of interest were selectively collected. The fractions containing the targeted compounds were further condensed to dryness and produced pachymic acid (1) (106 mg), dehydropachymic acid (2) (53 mg), tumulosic acid (3) (120 mg), dehydrotumulosic acid (4) (68 mg), polyporenic acid C (5) (16 mg), and 3-epi-dehydrotumulosic acid (6) (12 mg). Their structures were elucidated using Nuclear Magnetic Resonance (NMR) spectroscopy (Table S1) and electrospray ionization mass (ESI-MS) analyses (Figures S2, S4, S6, S8, S10 and S12) and by comparison with the literature data [35] (Figure 2).