Stizolophus balsamita subsp. leaves, (Lam.) K. Koch (Lam.) K. Koch

3.3. Extraction and isolation of compounds from S. balsamita leaves

The dried leaves of S. balsamita ( 630 g) were crushed and soaked in MeOH. The MeOH extract was evapd, and the residue was dissolved in H 2 O. The aq. soln was re-extracted with CH 2 Cl 2 and then with AcOEt. The CH 2 Cl 2 extract which was dried with Na 2 SO 4, filtrated and evapd gave a residue ( 15.5 g). The AcOEt extract evapd and gave a residue 4.6 g.

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The CH 2 Cl 2 extract was chromatographed on silica gel with a mixtures of CH 2 Cl 2 and ( CH 3) 2 CO (ratio 15:1) as eluent. The polarity was gradually increased with added ( CH 3) 2 CO. Some collected fractions needed purifying and were rechromatographed on silica gel with mixture of n-hexane and ( CH 3) 2 CO (ratio1:3 or 1:8) or n-hexane and AcOEt (ratio1:3). The result was the isolation of the following compounds: balsamin ( 1) ( 35.6 mg, m.p. 225–228 °C), izospiciformin ( 2) ( 98.9 mg, m.p. 192–195 °C), stizolin ( 3) ( 176 mg, m.p. 183–188 °C), 9α-hydroxyparthenolide ( 4) ( 15.3 mg, m.p. 140–142 °C), 8α- E- (4′-hydroxy)-senecioyloxy-9α-hydroxyparthenolide ( 5) ( 24.1 mg, m.p. 188–190 °C), 11βH,13-dihydrostizolicin ( 6) ( 5.3 mg, amorphous solid) and stizolicin ( 7) ( 342 mg, m.p. 143–144 °C). NMR data in Tables 2–4 View Table 2 View Table 3 View Table 4

The purified AcOEt extract ( 4.6 g) was chromatographed on silica gel. A mixture of CH 2 Cl 2 and ( CH 3) 2 CO (ratio 4:1) was used as eluent, and the polarity was gradually increased with added ( CH 3) 2 CO. The collected fractions with the dominating compound needed purifying, so it was rechromatographed on silica gel with a mixture of CH 2 Cl 2 and CH 3 OH (ratio 25:1 then 20:1 and 15:1). The result was a white amorphous solid ( 40.4 mg) identified as 3-(3,4-dihydroxyphenyl)propyl senecioate 3- O -β-glucopyranoside = [(3-(3,4- dihydroxyphenyl)propyl-3-methylbut-2-enoate- 3- O -β-glucopyranoside)] ( 8). 1 H and 13 C NMR data in Table 6 View Table 6 . HR-ESI-MS (positive mode): m/z 435.1631 [M+Na] + (calcd for C 20 H 28 O 9 +Na, 435.1625), 413.1812 [M+H] + (calcd for C 20 H 28 O 9 +H, 413.1806); LR-ESI-MS (negative mode): m/z 411 [M-H] -, 249 [M-H-162] ¯; LR-EI-MS (70 eV) m/z 250.2 [M-163 + H] +, 168.0, 150.0, 83.0.