FOUR NATURAL TRITERPENE SAPONINS
369
5.52 (dd, J ¼ 9.9, 7.7 Hz, 1 H, H-2000), 5.31 (br s, 1 H, H-300), 5.30 (t, J ¼ 3.8 Hz, 1 H,
H-12), 5.12 (d, J ¼ 12.7 Hz, 1 H, PhCHH), 5.08 (d, J ¼ 12.7 Hz, 1 H, PhCHH), 5.05
(br s, 1 H, H-10), 5.02 (s, 1 H, H-200), 4.99 (d, J ¼ 7.7 Hz, 1 H, H-1000), 4.69 (d,
J ¼ 1.7 Hz, 1 H, H-100), 4.62 (dd, J ¼ 12.7, 1.7 Hz, 1 H, H-6000-1), 4.49 (dd, J ¼ 12.7,
2.8 Hz, 1 H, H-6000-2), 4.15 (m, 1 H, H-5000), 4.12 (dd, J ¼ 9.9, 3.8 Hz, 1 H, H-30),
3.92 (m, 1 H, H-40), 3.82–3.85 (m, 3 H, H-400, H-500, H-50-1), 3.77 (t, J ¼ 3.9,
2.6 Hz, 1 H, H-20), 3.61 (dd, J ¼ 12.1, 4.4 Hz, 1 H, H-50-2), 3.10 (dd, J ¼ 11.5,
3.8 Hz, 1 H, H-3), 2.91 (dd, J ¼ 14.3, 4.4 Hz, 1 H, H-18), 2.06, 2.05 (s each, 3 H each,
CH3CO ꢃ 2), 1.08 (d, J ¼ 6.0 Hz, 3 H, H-600), 1.12, 0.94, 0.93, 0.91, 0.89, 0.79, 0.61 (s
each, 3 H each, CH3 ꢃ 7); 13C NMR (CDCl3): d 177.5 (C-28), 170.4, 169.5, 165.9,
165.1, 164.8, 143.8 (C-13), 136.5, 133.5, 133.4, 133.2, 129.9, 129.8, 128.6, 128.5,
128.4, 128.3, 128.1, 128.0, 122.5 (C-12), 101.9 (C-100), 101.7 (C-1000), 98.0 (C-100),
90.4 (C-3), 76.2, 75.9, 72.9, 72.1, 72.0, 71.7, 70.4, 69.3, 67.0, 66.0, 65.4, 62.7, 55.5,
47.7, 46.8, 46.0, 41.8, 41.5, 39.4, 39.2, 38.6, 36.8, 33.9, 33.2, 32.7, 32.5, 30.8, 29.8,
28.2, 27.7, 25.9, 25.8, 23.7, 23.5, 23.1, 21.0, 18.3, 17.4, 16.9, 16.5, 15.4
HRMALDI-MS: m=z calcd for [M þ Na]þ C86H102O22: 1509.6772; found:
1509.6755.
Typical Procedure for Removal of the Protecting Groups of
Triterpene Saponins 3–4
A mixture of 19 or 20 (0.03 mmol) and 10% Pd-C (30 mg) in CH2Cl2-MeOH
(v:v=1:1, 8 mL) in the presence of AcOH (two drops) was stirred under 1 atm of
H2 for 4 h. The reaction mixture was then filtered and the filtrate, was concentrated
to dryness to give a white solid. The solid was dissolved in MeOH-CH2Cl2 (v:v = 2:1,
8 mL), and then NaOMe (40 mg) was added. After stirring at rt for 8 h, the solution
was neutralized with ion-exchange resin (Hþ), filtered, and concentrated. The residue
was purified by column chromatography on silica gel (3:1, CHCl3–MeOH) to give
triterpene saponins as a white solid.
3-O-[O-b-D-Glucopyranosyl-(1!3)-O-a-L-rhamnopyranosyl-(1!2)-a-
L-arabinopyranosyl] Oleanolic Acid (3)
Mp 229–231 ꢀC; ½aꢂD25ꢁ1.0 (c 0.65, MeOH); Rf 0.27 (2:1, CHCl3–MeOH); IR
1
(KBr) nmax 3393, 2945, 1692, 1455, 1389, 1054 cmꢁ1; H NMR (C5D5N): d 6.19 (br
s, 1 H, H-100), 5.45 (d, J ¼ 7.3 Hz, 1 H, H-1000), 5.48 (t, J ¼ 3.6 Hz, 1 H, H-12), 5.03
(br s, 1 H, H-200), 4.86 (d, J ¼ 6.0 Hz, 1 H, H-10), 4.83 (dd, J ¼ 9.0, 3.2 Hz, 1 H,
H-300), 4.65 (dq, J ¼ 9.6, 5.9 Hz, 1 H, H-500), 4.49–4.55 (m, 3 H, H-20, H-400, H-6000-
1), 4.37 (dd, J ¼ 11.9, 5.0 Hz, 1 H, H-6000-2), 4.32 (t, J ¼ 10.1, 3.8 Hz, 1 H, H-50-1),
4.27–4.30 (m, 3 H, H-30, H-3000, H-4000), 4.24 (dd, J ¼ 7.8, 3.7 Hz, 1 H, H-40), 4.14 (t,
J ¼ 9.1, 7.8 Hz, 1 H, H-2000), 3.98 (m, 1 H, H-5000), 3.83 (dd, J ¼ 12.4, 2.3 Hz, 1 H,
H-50-2), 3.29–3.33 (m, 2 H, H-3, H-18), 1.56 (d, J ¼ 5.9 Hz, 3 H, H-600), 1.35, 1.33,
1.15, 1.03, 0.99, 0.98, 0.85 (s each, 3 H each, CH3 ꢃ 7); 13C NMR (C5D5N): d 180.8
(C-28), 145.1 (C-13), 123.8 (C-12), 107.0 (C-1000), 105.7 (C-10), 102.0 (C-100), 89.1
(C-3), 83.5 (C-300), 78.9, 78.8, 76.2, 74.7, 73.3, 71.9, 71.8, 70.1, 69.7, 66.0, 62.8, 56.3,
48.4, 47.1, 46.8, 42.5, 42.3, 40.1, 39.9, 39.2, 37.4, 34.6, 33.7, 31.3, 28.5, 27.0, 26.5,