*3.3. Extraction and Isolation*

The rice of the *P. citrinum* BCRC 09F0458 (1.5 kg) was extracted with 95% EtOH (3 × 10 L, 3 d each) at room temperature. The ethanol extract was concentrated under reduced pressure, and was partitioned with *n*-BuOH/H2O (1:1, v/v) to afford *n*-BuOH soluble fraction (36.2 g), H2O soluble fraction (13.0 g), and insoluble fraction (500 mg). The *n*-BuOH fraction (fraction A, 36.2 g) was purified by column chromatography (CC) (1.6 kg of silica gel, 70–230 mesh ((63–200 μm); *n*-hexane/EtOAc 25:1–0:1, 1500 mL) to afford 13 fractions: A1–A13. Fraction A2 (1.54 g) was subjected to medium pressure liquid chromatography (MPLC) (69 g of silica gel, 230–400 mesh (40–63 μm)); *n*-hexane/acetone 1:0–0:1, 700 mLfractions) to give 11 subfractions: A2-1–A2-11. Fraction A2-6 (126 mg) was further purified by semipreparative normal-phase high performance liquid chromatography (HPLC) (silica gel; *n*-hexane/dichloromethane/EtOAc, 6:3:1) to obtain 8-hydroxy-1-methoxycarbonyl-6 methylxanthone (**6**) (14.9 mg). Fraction A6 (1.18 g) was subjected to MPLC (53 g of silica gel, 230–400 mesh (40–63 μm); *n*-hexane/acetone 1:0–0:1, 500 mL-fractions) to give 13 subfractions: A6-1–A6-13. Fraction A6-9 (150 mg) was further purified by preparative TLC (silica gel; *n*-hexane/EtOAc, 1:9) to afford penicitrinone A (**5**) (18.3 mg). Fraction A9 (1.44 g) was subjected to MPLC (65 g of silica gel, 230–400 mesh (40–63 μm)); dichloromethane/EtOAc 1:0–2:3, 650 mL-fractions) to give 12 subfractions: A9-1–A9-12. Fraction A9-6 (128 mg) was further purified by preparative TLC (silica gel; *n*-hexane/acetone, 3:2) to afford epiremisporine C (**1**) (12.2 mg). Fraction A10 (0.98 g) was subjected to MPLC (44 g of silica gel, 230–400 mesh (40–63 μm); *n*-hexane/acetone 1:0–0:1, 450 mL-fractions) to give 10 subfractions: A10-1–A10-10. Fraction A10-4 (120 mg) was further purified by preparative TLC (silica gel; *n*-hexane/EtOAc, 7:3) to afford isoconiochaetone C (**7**) (11.2 mg). Fraction A11 (2.38 g) was subjected to MPLC (107 g of silica gel, 230–400 mesh (40–63 μm); *n*hexane/acetone 1:0–0:1, 1000 mL-fractions) to give 14 subfractions: A11-1–A11-14. Fraction A11-2 (138 mg) was further purified by semipreparative normal-phase HPLC (silica gel; *n*-hexane/EtOAc, 1:1) to afford epiremisporine D (**2**) (14.6 mg). Fraction A11-4 (168 mg) was further purified by preparative TLC (silica gel; dichloromethane/methanol, 19:1) to afford epiremisporine B (**4**) (23.8 mg). Fraction A12 (1.28 g) was subjected to MPLC (58 g of silica gel, 230–400 mesh (40–63 μm); *n*-hexane/EtOAc 1:0–0:1, 600 mL-fractions) to give 10 subfractions: A12-1–A12-10. Fraction A12-1 (122 mg) was further purified by preparative TLC (silica gel; *n*-hexane/dichloromethane/acetone, 5:3:2) to afford epiremisporine E (**3**) (13.7 mg).

Epiremisporine C (**1**): [α] 25 <sup>D</sup> = +527.6◦ (*c* 0.22, CHCl3); UV (MeOH) λmax nm (log ε): 241 (4.35), 326 (3.50) nm; 1H NMR data, see Table 4; 13C NMR data, see Table 5.


**Table 4.** 1H NMR data (500 MHz, CDCl3) for **1**–**3**.

**Table 5.** 13C NMR data (125 MHz, CDCl3) for **1**–**3**.


Epiremisporine D (**2**): [α] 25 <sup>D</sup> = +526.8◦ (*c* 0.10, CHCl3); UV (MeOH) λmax nm (log ε): 237 (4.25), 317 (3.52) nm; 1H NMR data, see Table 4; 13C NMR data, see Table 5.

Epiremisporine E (**3**): [α] 25 <sup>D</sup> = +561.3◦ (*c* 0.09, CHCl3); UV (MeOH) λmax nm (log ε): 235 (4.30), 315 (3.54) nm; 1H NMR data, see Table 4; 13C NMR data, see Table 5.

Epiremisporine B (**4**): Yellow amorphous powder; [α] 25 <sup>D</sup> = +523.6◦ (*<sup>c</sup>* 0.16, CHCl3); 1H NMR data, see Table S1; 13C NMR data, see Table S2; HRESIMS: *m*/*z* 599.11558 [M + Na]+ (calcd. for C30H24O12 + Na, 599.11654).

Penicitrinone A (**5**): Orange crystalline powder; [α] 25 <sup>D</sup> = +102.6◦ (*<sup>c</sup>* 0.12, MeOH); 1H NMR (600 MHz, CDCl3) δ 1.32 (3H, d, *J* = 7.2 Hz, Me-4), 1.33 (3H, d, *J* = 7.0 Hz, Me-3 ), 1.42 (3H, d, *J* = 6.4 Hz, Me-2 ), 1.44 (3H, d, *J* = 6.7 Hz, Me-3), 2.11 (3H, s, Me-5), 2.21 (3H, s, Me-4 ), 3.12 (1H, qd, *J* = 7.2, 0.9 Hz, H-4), 3.16 (1H, qd, *J* = 7.0, 4.1 Hz, H-3 ), 4.61 (1H, qd, *J* = 6.4, 4.1 Hz, H-2 ), 4.96 (1H, qd, *J* = 6.7, 0.9 Hz, H-3), 6.37 (1H, s, H-7), 8.33 (1H, br s, OH-5 ); HRESIMS: *m*/*z* 381.17094 [M + H]+ (calcd. for C23H24O5 + H, 381.17020).

8-Hydroxy-1-methoxycarbonyl-6-methylxanthone (**6**): Yellow amorphous solid; 1H NMR (600 MHz, CDCl3) δ 2.44 (3H, s, Me-6), 4.03 (3H, s, COOMe-1), 6.64 (1H, br d, *J* = 1.4 Hz, H-5), 6.76 (1H, br d, *J* = 1.4 Hz, H-7), 7.31 (1H, dd, *J* = 7.3, 1.1 Hz, H-2), 7.53 (1H, dd, *J* = 8.5, 1.1 Hz, H-4), 7.74 (1H, dd, *J* = 8.5, 7.3 Hz, H-3), 12.15 (1H, s, OH-8); HRESIMS: *m*/*z* 285.07730 [M + H]<sup>+</sup> (calcd. for C16H12O5 + H, 285.07630).

Isoconiochaetone C (**7**): Colorless needles (MeOH), m.p. 99–100.5 ◦C; [α] 25 <sup>D</sup> = +79.3◦ (*c* 0.18, MeOH); 1H NMR (600 MHz, CDCl3) δ 2.15 (1H, dddd, *J* = 14.0, 8.5, 2.5, 1.4 Hz, Hβ-2), 2.32 (1H, dddd, *J* = 14.0, 9.4, 7.4, 6.8 Hz, Hα-2), 2.40 (3H, s, Me-8), 2.77 (1H, ddd, *J* = 18.0, 9.4, 2.5 Hz, Hβ-3), 3.17 (1H, dddd, *J* = 18.0, 8.5, 7.4, 1.4 Hz, Hα-3), 3.50 (3H, s, OMe-1), 4.94 (1H, dt, *J* = 6.8, 1.4 Hz, H-1), 6.63 (1H, br s, H-9), 6.71 (1H, br s, H-7), 12.55 (1H, s, OH-10); HRESIMS: *m*/*z* 247.09688 [M + H]<sup>+</sup> (calcd. for C14H14O4 + H, 247.09703).
