Chem. Pharm. Bull. 50(11) 1460—1466 (2002)

as a popular aromatic herb and spice since antiquity, and is cultivated throughout Europe. Its fruit has been used for medicine and in cooking, and is listed in British, German and European pharmacopoeia. For medicinal purposes, it is used to treat dyspeptic complaints and catarrh of the respiratory tract, and also as a mild expectorant. Studies on the fruit were made on the essential oil (1.5—5%), and transanethole (80—90%) is chiefly responsible for the taste and smell. Also, cis-anethole, estragole, p-anisaldehyde, anisketone, linalool and b-farnesene were reported as the constituents. However, no report has been published concerning the water-soluble portion of this fruit. In continuation of our studies on the water-soluble constituents of spices, and to learn the relationship between the essential oil and the water-soluble constituents, we undertook a detailed investigation of the constituents of this fruit. In this paper, we discuss the isolation and the characterization of twelve new glycosides of phenylpropanoid related to anethole. Commercial anise was extracted with 70% methanol, and the methanolic extract was suspended in water and successively extracted with ether and ethyl acetate. The aqueous layer was chromatographed on Amberlite XAD-II to give water and methanol eluate fractions. The methanol eluate fraction was chromatographed on Sephadex LH-20, and subjected to a combination of silica gel, Lobar RP-8 column chromatography and HPLC to isolate phenylpropanoids (1, 2 and 13) and their glucosides (3 to 12 and 14 to 20). Among the glucosides, 5 to 9, 11, 12, 14 to 17 and 20 are new. All new glucosides described in this paper were b-D-glucopyranosides as shown by their C-NMR data (Table 2), and this was confirmed by hydrolysis to yield D-glucose or by a comparison of the [a]D or [M]D values with those of their aglycones except 8, 9 and 18. Their molecular formulae were suggested from the accurate mass number of [M H] or [M Na] or [M K] ion peaks in the high-resolution positive FAB-MS. Phenylpropanoid 1 (C10H14O3, mp 115—117 °C, [a]D 0°) and 2 (C10H14O3, mp 62—63 °C, [a]D 0°), glucoside 3 (C16H24O8, mp 84—85 °C, [a]D 29°) and 4 (C16H24O8, mp 125—127 °C, [a]D 15°) were identified as erythroanethole, threo-anethole glycol, (1 R,2 S)-anethole glycol 2 -O-b-D-glucopyranoside and (1 S,2 R)-anethole glycol 2 O-b-D-glucopyranoside, respectively. Glucosides 5 (C16H24O8, mp 80—84 °C, [a]D 59°) and 6 (C16H24O8, mp 75—78 °C, [a]D 11°) showed [M Na] and [M C6H12O6 H] ion peaks at m/z 367 and 165 in the positive FAB-MS. Both glucosides were hydrolyzed with bglucosidase and, from the hydrolyzed mixtures, ( )-threoanethole glycol (2a; C10H14O3, mp 62—63 °C, [a]D 23°) and D-glucose from 5, and ( )-threo-anethole glycol (2b; C10H14O3, mp 62—63 °C, [a]D 25°) and D-glucose from 6 were obtained. The Hand C-NMR chemical shifts (Tables 1, 2) of 5 and 6 showed that both compounds were monoglucopyranosides of 2, and the position of the b-glucosyl units was proved to be C-2 from the cross-peaks between the glucosyl H-1/C-2 in the heteronuclear multiple bond connectivity (HMBC) spectrum. Thus, 5 and 6 were represented as ( )and ( )-threo-anethole glycol 2 -O-b-D-glucopyranoside. As the 1R ,2R form of threo-anethole glycol was reported to have a negative [a]D value, and the 1S ,2S form of threo-anethole glycol had a positive [a]D value, the absolute stereochemistry of C-1 and C-2 of ( )-threo-anethole glycol should be R, and that of ( )-threo-anethole glycol should be S. Furthermore, the absolute configurations at C-2 of 5 and 6 were confirmed to be R and S by the values of the glycosylation shift of the a-carbon (5; 8.5 ppm, 6; 11.1 ppm), and the chemical shifts of the glucosyl aromatic carbon (5; d 103.53, 6; d 106.36). Therefore, 5 and 6 were characterized as (1 R,2 R)-anethole glycol 2 -O-b-Dglucopyranoside and (1 S,2 S)-anethole glycol 2 -O-b-D-glucopyranoside, respectively. Glucoside 7 (C15H22O8, an amorphous powder, [a]D 38°) showed one peak on HPLC, but it was suggested to be an equivalent mixture of two diastereomeric compounds from NMR spectral data (Tables 1, 2). Its positive FAB-MS revealed [M Na] , [M H] and [M C6H12O6 H] ion peaks at m/z 353, 331 and 151, and its Hand C-NMR data suggested that 7 was built up with one b-glucopyranosyl group and one 1 -(4-hydroxyphenyl)propane-1 ,2 -diol moiety. Enzymatic hydrolysis of 7 gave D-glucose and an aglycone (21; C9H12O3, an amorphous powder, [a]D 0°) which was characterized as 1 -(4-hydroxyphenyl)propane-1 ,2 diol, and the position of the b-glucosyl unit was proved to be C-4 from the HMBC correlation of the glucosyl H-1/C-4. By