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M. Aasim Khan et al.
(9 : 1, 3 : 1, 1 : 1 and 1 : 3), pure chloroform, and finally a mixture of chloroform and
methanol (99 : 1, 49 : 1, 23 : 2, 19 : 1, 97 : 3, 9 : 1). Various fractions were collected
separately and matched by TLC to check homogeneity. Similar fractions (having the
same Rf values) were combined and crystallised. The isolated compounds were
recrystallised to obtain the pure compounds.
n-Hexacosanoic acid (1). Elution of the column with chloroform afforded colourless
crystals of 1, recrystallised from chloroform–methanol (1 : 1), 160 mg (0.01% yield) Rf
0.81 (chloroform), m.p.: 80–81ꢁC; IR ꢃmax (KBr): 3430, 2921, 2853, 1712, 1454, 1376,
1
1271, 1074, 722 cmꢀ1. H NMR (CDCl3): ꢁ 2.28 (2H, m, H2-2), 1.72 (2H, m, H2 -3), 1.61
(2H, m, H2 -4), 1.57 (2H0, m, CH2), 1.39 (2H, m, CH2), 1.34 (2H, m, CH2), 1.22 (36 H0 br s,
18CH2), 0.85 (3H, t, J ¼ 6.8 Hz, Me-26). þve ion FAB MS: m/z (rel. int.): 396 [M]þ
(C26H52O2) (100), 381 (12.6), 339 (3.2), 255 (10.6), 213 (11.6), 199 (11.7), 185 (12.3), 171
(15.8), 157 (16.9), 143 (20.7), 129 (21.1).
Reticulataursenoside (2). Elution of the column with chloroform–methanol (97 : 3)
furnished colourless crystals of 2, recrystallised from methanol, 275 mg, (0.183% yield).
Rf 0.73 (chloroform–methanol, 97 : 3), m.p. 210–211ꢁC. UV ꢄmax (MeOH): 223, 266 (log "
5.6, 2.1). IR ꢃmax (KBr): 3510, 3459, 3390, 2962, 2850, 1746, 1710, 1635, 1511, 1460, 1359,
1124, 1027 cmꢀ1. 1H NMR (DMSO-d6): Table 1, 13C NMR (DMSO-d6): Table 1. þve ion
FAB MS m/z (rel. int.): 898 [M]þ (C49 H70 O15) (1.1), 438 (11.5), 343 (5.6), 232 (1.1), 217
(11.3), 205 (16.3), 202 (17.6), 190 (14.8), 187 (19.5), 179 (12.3), 175 (26.8), 172 (9.8), 166
(31.9), 160 (34.1), 154 (98.6), 152 (26.3), 146 (26.5), 145 (53.2), 137 (71.6).
Alkaline hydrolysis of 2. Compound 2 (45 mg) was dissolved in ethanol (5 mL), 1 N
NaOH solution (1 mL) was added, and the reaction mixture was heated on a steam bath
for 1 h. It was dried under reduced pressure and the residue was dissolved in CHCl3
(5 mL). The CHCl3 layer was washed with H2O (2 ꢂ 5 mL), dried over anhydrous Na2SO4
and evaporated to get triterpene (IR ꢃmax 3450, 1710 cmꢀ1). The residue was dissolved in
H2O (5 mL), acidified with diluted HCl and re-extracted with CHCl3, which, on drying,
afforded protocatechuic acid, m.p. 197–199ꢁC. The aqueous layer was concentrated and
chromatographed over paper with a standard sample of D-glucose. Rf 0.12 (n-butenol–
acetic acid–water, 4 : 1 : 5, top layer).
Citrusteryl arachidate (3). Elution of the column with chloroform–methanol (23 : 2), gave
colourless amorphous powder of 3, recrystallised from methanol, 310 mg (0.26% yield) Rf
0.82 CHCl3–MeOH (8%) m.p.: 239–240ꢁC, IR ꢃmax (KBr): 3490, 3421, 3365, 2854, 1735,
.
1637, 1463, 1374, 1166, 1073, 1020 cmꢀ1 1H NMR (DMSO-d6): Table 1, 13C NMR
(DMSO-d6): Table 1. þve ion FAB MS m/z (rel. int.): 870 [M]þ (C55H98O7) (1.1), 576
(11.6), 457 (2.3), 413 (13.2), 396 (22.5), 381 (16.1), 295 (31.9), 278 (11.3), 267 (11.7), 255
(31.6), 253 (22.1), 240 (19.8), 239 (17.6), 225 (20.3), 213 (26.5), 211 (22.6), 198 (37.5), 197
(31.0), 191 (20.4), 183 (35.6), 177 (32.5), 174 (79.1), 169 (41.5), 163 (52.6), 162 (61.8),
160 (78.2), 155 (49.1), 146 (98.3), 141 (43.5), 137 (91.5), 123 (65.2), 120 (95.6), 106 (97.2),
95 (99.1).
Alkaline hydrolysis of 3. Compound 3 (45 mg) was dissolved in ethanol (5 mL), 1N
NaOH solution (1 mL) added and the reaction mixture heated on the steam bath for 1 h. It
was dried under reduced pressure and the residue was dissolved in CHCl3 (5 mL). The
CHCl3 layer was washed with water (2 ꢂ 5 mL), dried over anhydrous Na2SO4 and
evaporated to get ꢀ-sitosterol, m.p. 136–137ꢁC. The residue dissolved in H2O (5 mL),