DOI 10.1007/s10600-015-1379-4 Chemistry of Natural Compounds, Vol. 51, No. 4, July, 2015
PHENYLETHANOID GLYCOSIDES FROM THE FRUITS OF Magnolia obovata
Kyeong-Hwa Seo,1 Dae-Young Lee,2 Seo-Ji In,1 Dong-Geol Lee,3 Hee-Cheol Kang,3 Myoung-Chong Song,4 and Nam-In Baek1*
Chromatographic methods such as silica gel, ODS, and Sephadex LH-20 column chromatographic techniques were used to identify three new phenylethanoid glycosides along with three known ones, 2-(3,4-dihydroxyphenyl)ethyl O-D-L-rhamnopyranosyl-(1o2)-E-D-allopyranoside (1), magnoloside D (2), and magnoloside A (3), from the fruits of Magnolia obovata. Using the spectroscopic data, including NMR, MS, and IR, the new phenylethanoid glycosides were identified and named magnoloside F (4), magnoloside G (5), and magnoloside H (6). Keywords: Magnoliaceae, Magnolia obovata, phenylethanoid glycoside, magnoloside F, magnoloside G, magnoloside H. Phytochemicals are valuable resources in the development of insecticides, flavors, and functional foods [1]. Magnolia obovata, belonging to the family Magnoliacea, is distributed broadly across Korea, China, and Japan. The fruits of this plant have been widely used as a traditional medicine for the treatment of dyspepsia and abdominal pain in Korea [2]. Previous phytochemical research has reported the isolation of several phenylethanoid glycosides from Magnolia species [3, 4]. However, phytochemical studies of the fruits of M. obovata have rarely been performed up to this point. Therefore, the present study focused on the isolation of phenylethanoid glycosides from the fruits of this plant. Phenylethanoid glycoside is a type of phenolic compound characterized by a natural alcohol C6–C2 skeleton. Phenolic compounds are classified as phenolic acids (C6–C1), hydroxylcinnamates (C6–C3), stilbenes (C6–C2–C6), and flavonoids (C6–C3–C6) [5]. This paper describes the isolation and structural determination of three new phenylethanoid glycosides (4–6) and three known ones (1–3) from the fruits of M. obovata. The three known phenylethanoid glycosides were determined to be 2-(3,4-dihydroxyphenyl)ethyl O-D-L-rhamnopyranosyl-(1o2)-E-D-allopyranoside (1), magnoloside D (2), and magnoloside A (3) through comparison of their NMR data with those in the literature [3, 4, 6]. OR4 6'
R3O
HO HO
E
O OR2
6''
O O O
1'
1
OH
3
D
R1
Caff =
3'''
HO 5
1''
O
7'''
HO
OH
1''' 5'''
9''' 8'''
O
Coum = 1-6
HO
1: R1 = OH, R2 = R3 = R4 = H; 2: R1 = OH, R2 = R3 = H, R4 = Caff; 3: R1 = OH, R2 = Caff, R3 = R4 = H 4: R1 = OH, R2 = R4 = H, R3 = Caff; 5: R1 = OH, R2 = Coum, R3 = R4 = H; 6: R1 = H, R2 = Caff, R3 = R4 = H
1) Graduate School of Biotechnology and Department of Oriental Medicinal Materials and Processing, Kyung Hee University, Yongin 446-701, Republic of Korea, fax: 82 31 204 8116, e-mail:
[email protected]; 2) Department of Herbal Crop Research, National Institute of Horticultural and Herbal Science, RDA, Eumseong 369-873, Republic of Korea; 3) R&D Center, GFC Co., Ltd., Suwon 443-813, Republic of Korea; 4) Intelligent Synthetic Biology Center, KAIST, Daejeon 305-701, Republic of Korea. Published in Khimiya Prirodnykh Soedinenii, No. 4, July–August, 2015, pp. 569–573. Original article submitted November 19, 2013. 660
0009-3130/15/5104-0660 2015 Springer Science+Business Media New York
TABEL 1. 1H NMR (400 MHz) Data of Compounds 4–6 (G, ppm, J/Hz) C atom
4
2 3 5 6
6.69 (1H, d, J = 2.0)
D E
6.67 (1H, d, J = 8.0) 6.57 (1H, dd, J = 8.0, 2.0) 4.04 (1H, overlap) 3.72 (1H, overlap) 2.79 (2H, t, J = 8.0)
1c 2c 3c 4c 5c 6c
4.82 (1H, d, J = 8.0) 3.57 (1H, dd, J = 8.0, 2.4) 4.47 (1H, dd, J = 2.4, 2.4) 4.81 (1H, dd, J = 9.6, 2.4) 4.01 (1H, m) 3.74 (1H, dd, J = 12.8, 3.6) 3.62 (1H, dd, J = 12.8, 4.8)
1cc 2cc 3cc 4cc 5cc 6cc
4.89 (1H, br.s) 3.89 (1H, dd, J = 2.4, 1.6) 3.72 (1H, dd, J = 9.6, 2.4) 3.44 (1H, dd, J = 9.6, 9.6) 4.02 (1H, dq, J = 9.6, 6.4) 1.27 (3H, d, J = 6.4) Caffeoyl 7.04 (1H, d, J = 2.0) – 6.76 (1H, d, J = 8.4) 6.96 (1H, dd, J = 8.4, 2.0) 6.31 (1H, d, J = 16.0) 7.62 (1H, d, J = 16.0)
2ccc 3ccc 5ccc 6ccc D ccc E ccc
5 Aglycone 6.68 (1H, d, J = 2.0) 6.66 (1H, d, J = 8.0) 6.56 (1H, dd, J = 8.0, 2.0) 4.03 (1H, overlap) 3.67 (1H, overlap) 2.78 (2H, t, J = 6.8) Allose 4.73 (1H, d, J = 8.0) 3.70 (1H, overlap) 5.72 (1H, dd, J = 2.8, 2.8) 3.72 (1H, dd, J = 9.2, 2.8) 3.73 (1H, m) 3.89 (1H, dd, J = 12.0, 2.0) 3.73 (1H, dd, J = 12.0, 4.4) Rhamnose 4.89 (1H, br.s) 3.69 (1H, overlap) 3.59 (1H, dd, J = 9.2, 3.2) 3.40 (1H, dd, J = 9.2, 9.2) 3.99 (1H, dq, J = 9.2, 6.4) 1.23 (3H, d, J = 6.4) p-Coumaroyl 7.49 (1H, d, J = 8.8) 6.81 (1H, d, J = 8.8) 6.81 (1H, d, J = 8.8) 7.49 (1H, d, J = 8.8) 6.43 (1H, d, J = 16.0) 7.67 (1H, d, J = 16.0)
6 7.07 (1H, d, J = 8.8) 6.69 (1H, d, J = 8.8) 6.69 (1H, d, J = 8.8) 7.07 (1H, d, J = 8.8) 4.03 (1H, overlap) 3.67 (1H, overlap) 3.29 (2H, t, J = 7.6) 4.73 (1H, d, J = 8.0) 3.70 (1H, overlap) 5.71 (1H, dd, J = 2.8, 2.8) 3.72 (1H, dd, J = 9.6, 2.8) 3.72 (1H, m) 3.87 (1H, dd, J = 12.0, 2.0) 3.71 (1H, overlap) 4.89 (1H, br.s) 3.69 (1H, dd, J = 2.8, 1.2) 3.59 (1H, dd, J = 9.6, 2.8) 3.39 (1H, dd, J = 9.6, 9.6) 3.99 (1H, dq, J = 9.6, 6.4) 1.22 (3H, d, J = 6.4) Caffeoyl 7.06 (1H, d, J = 2.0) – 6.79 (1H, d, J = 8.4) 6.98 (2H, dd, J = 8.4, 2.0) 6.36 (1H, d, J = 16.0) 7.60 (1H, d, J = 16.0)
Compound 4 was isolated as an amorphous powder and showed absorbance bands at 3335, 1695, and 1604 cm–1, suggesting the presence of hydroxyl, conjugated carbonyl, and aromatic ring functionalities, respectively. The molecular formula was determined to be C29H36O15 from the molecular ion peak [M – H]– m/z 623.1965 (calcd for C29H35O15, 623.1976) in the negative HR-FAB-MS. The 1H NMR spectrum showed six olefin methine proton signals at G 6.69 (1H, d, J = 2.0 Hz, H-2), 6.67 (1H, d, J = 8.0 Hz, H-5), 6.57 (1H, dd, J = 8.0, 2.0 Hz, H-6), 7.04 (1H, d, J = 2.0 Hz, H-2ccc), 6.96 (1H, dd, J = 8.4, 2.0 Hz, H-6ccc), 6.76 (1H, d, J = 8.4 Hz, H-5ccc) due to two 1,2,4-trisubstituted benzene rings and a pair of trans-olefinic proton signals G 7.62 and 6.31 (each 1H, d, J = 16.0 Hz). One oxygenated methylene proton signal at G 4.04 and 3.72 (each 1H, overlap, H-Da, Db) and a benzylic methylene proton signal at G 2.79 (2H, t, J = 8.0 Hz, H-E) were observed. In addition, there were two hemiacetal proton signals at G 4.89 (1H, br.s, H-1cc), and 4.82 (1H, d, J = 8.0 Hz, H-1c), one oxygenated methylene proton signal at G 3.74 (1H, dd, J = 12.8, 3.6 Hz, H-6ca), and 3.62 (1H, dd, J = 12.8, 4.8 Hz, H-6cb), eight oxygenated methine proton signals G 4.81 (1H, dd, J = 9.6, 2.4 Hz, H-4c), 4.47 (1H, dd, J = 2.4, 2.4 Hz, H-3c), 4.02 (1H, dq, J = 9.6, 6.4 Hz, H-5cc), 4.01 (1H, m, H-5c), 3.89 (1H, dd, J = 2.4, 1.6 Hz, H-2cc), 3.72 (1H, dd, J = 9.6, 2.4 Hz, H-3cc), 3.57 (1H, dd, J = 8.0, 2.4 Hz, H-2c), and 3.44 (1H, dd, J = 9.6, 9.6 Hz, H-4cc), and one methyl proton signal at G 1.27 (3H, d, J = 6.4 Hz, H-6cc) due to one hexose and one deoxyhexose. The 13C NMR spectrum showed 29 carbon signals. The multiplicity of each carbon was determined using a DEPT experiment. Two oxygenated olefin quaternary carbon signals at G 146.0 (C-3) and 144.6 (C-4), one olefin quaternary carbon signal at G 131.6 (C-1), and three olefin methine carbon signals at G 121.3 (C-6), 117.1 (C-2), and 116.3 (C-5) were due to a 1,2,4-trisubstituted benzene ring. One oxygenated methylene carbon signal at G 72.2 (C-D) and one methylene carbon signal at G 36.7 (C-E) were observed, suggesting the presence of 3,4-dihydroxyphenylethanol.
661
TABEL 2. 13C NMR (100 MHz) Data of Compounds 1–6 (G, ppm) C atom
1 2 3 4 5 6
1
2
D E
131.6 117.1 145.9 144.5 116.3 121.3 72.2 36.7
131.4 117.1 145.9 144.5 116.5 121.3 72.3 36.7
1c 2c 3c 4c 5c 6c
100.3 74.8 68.8 68.7 75.1 63.0
100.5 74.7 68.7 68.8 72.7 65.0
1cc 2cc 3cc 4cc 5cc 6cc
97.7 72.1 72.3 73.9 69.8 17.9
97.7 72.1 72.3 73.9 69.8 17.9
1ccc 2ccc 3ccc 4ccc 5ccc 6ccc D ccc E ccc CO
– – – – – – – – –
127.6 115.0 146.7 149.5 116.4 123.1 114.9 147.1 169.2
3 Aglycone 131.5 117.0 145.7 144.3 116.3 121.2 71.9 36.4 Allose 100.5 73.6 71.0 66.9 75.7 62.5 Rhamnose 98.2 71.8 72.0 73.7 69.7 17.8
4
5
6
131.6 117.1 146.0 144.6 116.3 121.3 72.2 36.7
131.5 117.1 146.0 114.6 116.3 121.3 72.1 36.7
130.7 130.9 116.1 157.9 116.1 130.9 72.1 36.5
100.4 74.4 66.6 70.5 73.1 62.3
100.7 73.7 71.1 67.1 76.0 62.6
100.8 73.7 71.1 67.1 75.6 62.7
97.8 72.2 72.3 73.9 69.9 17.9
98.4 71.9 72.2 73.8 69.9 17.9
98.4 72.0 72.2 73.8 69.9 17.9
127.6 115.1 146.8 149.7 116.5 123.0 114.6 147.6 168.0
127.2 131.2 116.8 161.3 116.8 131.2 115.2 146.8 168.8
p-Coumaroyl
Caffeoyl 127.6 115.2 146.4 149.3 116.4 123.0 114.9 147.1 168.8
127.7 115.2 146.8 149.6 116.5 123.0 115.1 147.2 168.8
One ester carbon signal at G 168.0 (C-9ccc), two oxygenated olefin quaternary carbon signals at G 149.7 (C-4ccc) and 146.8 (C-3ccc), one olefin quaternary carbon signal at G 127.6 (C-1ccc), and five olefin methine carbon signals at G 147.6 (C- Eccc), 114.6 (C-Dccc), 123.0 (C-6ccc), 116.5 (C-5ccc), and 115.1 (C-2ccc) corresponded to the carbons of a caffeoyl moiety. The carbon signals of the sugar moieties were observed as two hemiacetal carbon signals at G 100.4 (C-1c) and 97.8 (C-1cc), eight oxygenated methine carbon signals at G 74.4 (C-2c), 73.9 (C-4cc), 73.1 (C-5c), 72.3 (C-3cc), 72.2 (C-2cc), 70.5 (C-4c), 69.9 (C-5cc), and 66.6 (C-3c), one oxygenated methylene carbon signal at GC 62.3(C-6c), and one methyl carbon signal at G 17.9 (C-6cc), suggesting the presence of a E-D-allopyranosyl and D-L-rhamnopyranosyl group. An oxygenated methylene carbon signal (C-D) was observed at G 72.2 due to the glycosidation shift, which is usually observed at approximately G 64 [7]. The connection between the allopyranosyl unit (C-1c) and the C-D of the phenylethanol was verified by the cross-peak between the oxygenated methylene proton signal at G 4.04 (H-D) and the anomer carbon signal at G 100.4 (C-1c) in the HMBC spectrum. Moreover, the oxygenated methine carbon signal (C-2c) of the allopyranosyl moiety was observed at G 74.4 due to the glycosidation shift, which is usually observed at approximately G 70 in allopyranose [8]. In the gHMBC spectrum, the cross-peak between the anomer proton signal of the rhamnopyranosyl moiety at G 4.89 (H-1cc) and the oxygenated methine carbon signal of the allopyranosyl moiety at G 74.4 (C-2c) indicated that rhamnopyranose was linked to the hydroxyl of C-2c. The attachment of the caffeoyl at C-4c of the allopyranose was proved from the downfield shift of the oxygenated methine proton signal (H-4c) to G 4.81, which usually occurs at G 3.64. Compound 4 is an isomer of magnoloside D (2) and A (3), whose caffeoyl moieties were linked at C-6c and C-3c, respectively, instead of C-4c in compound 4. Therefore, the structure of 4 was determined to be 2-(3,4-dihydroxyphenyl)ethanol O-(4-Ocaffeoyl)-[D-L-rhamnopyranosyl-(1o2)-E-D-allopyranoside], and it was named magnoloside F (4). 662
Compound 5 was isolated as an amorphous powder and showed absorbance bands at 3380, 1699, and 1604 cm–1, suggesting the presence of hydroxyl, conjugated carbonyl, and aromatic ring functionalities. The molecular formula was determined to be C29H36O14 from the molecular ion peak [M – H]– m/z 607.2032 (calcd for C29H35O14, 607.2027) in the negative HR-FAB-MS, which was 16 units less than those of magnoloside D (2), magnoloside A (3), and magnoloside F (4), indicating that 5 had one less hydroxyl group than compounds 2–4. The NMR signals of 5 were also very similar to those of 3 [3, 4]. Compound 5 differs from magnoloside A (3) in the replacement of caffeoyl with the p-coumaroyl moiety. The 1H NMR spectrum showed four olefin methine proton signals due to a para-disubstituted benzene ring at G 7.49 (2H, d, J = 8.8 Hz, H-2ccc, 6ccc) and 6.81 (2H, d, J = 8.8 Hz, H-3ccc, 5ccc) and two olefinic proton signals due to a trans-double bond at G 7.67 (1H, d, J = 16.0 Hz, H-Eccc) and 6.43 (1H, d, J = 16.0 Hz, H-Dccc). The 13C NMR spectrum showed one ester carbon signal at G 168.8 (C-9ccc), one oxygenated olefin quaternary carbon signal at G 161.3 (C-4ccc), one olefin quaternary carbon signal at G 127.2 (C-1ccc), and six olefin methine carbon signals at G 146.8 (C-Eccc), 131.2 (C-2ccc, 6ccc), 116.8 (H-3ccc, 5ccc), and 115.2 (C-Dccc), confirming the presence of a p-coumaroyl moiety. The position of the carbonyl group was determined on the basis of an esterification effect in the 1H NMR spectrum as well in the HMBC experiment. The oxygenated methine proton signal for H-3c (G 5.72) shifted by 1.49 and 1.47 ppm downfield compared to those of 1 and 2, respectively. This was verified from the cross-peak between the ester carbon signal at G 168.8 (C-9ccc) and the oxygenated methine proton signal at G 5.72 (H-3c) in the gHMBC spectrum. Finally, the structure of 5 was determined to be 2-(4-hydroxyphenyl)ethanol O-(3-O-caffeoyl)[D-L-rhamnopyranosyl-(1o2)-E-D-allopyranoside], named magnoloside G (5). Compound 6 was isolated as an amorphous powder and showed absorbance bands at 3384, 1695, and 1610 cm–1, suggesting the presence of hydroxyl, conjugated carbonyl, and aromatic ring functionalities. The molecular formula was determined to be C29H36O14 from the molecular ion peak [M – H]– m/z 607.2030 (calcd for C29H35O14, 607.2027) in the negative HR-FAB-MS, which was 16 units less than those of magnoloside D (2), magnoloside A (3), and magnoloside F (4), indicating that 6 had one less hydroxyl group than compounds 2–4. The NMR signals of 6 were also very similar to those of 3 [3, 4] with the exception of the structure of the aglycone. The 1H NMR spectrum showed four olefin methine proton signals at G 7.07 (2H, d, J = 8.8 Hz, H-2, 6) and 6.69 (2H, d, J = 8.8 Hz, H-3, 5) due to a para-disubstituted benzene ring, one oxygenated methylene proton signal at G 3.29 (2H, t, J = 7.6 Hz, H-E), and one benzylic methylene proton signal at G 4.03 and 3.67 (each 1H, overlap, H-Da, Db). The 13C NMR spectrum showed one oxygenated olefin quaternary carbon signal at G 157.9 (C-4), one olefin quaternary carbon signal at G 130.7 (C-1), four olefin methine carbon signals at G 130.9 (C-2, 6) and G 116.1 (C-3, 5), one oxygenated methylene carbon signal at G 72.1 (C-D), and one benzyl methylene carbon signal at G 36.5 (C-E), suggesting the presence of a p-hydroxyphenylethanol moiety. The structure of 6 was finally identified as 2-(4-hydroxyphenyl)ethanol O-(3-O-caffeoyl)-[D-L-rhamnopyranosyl-(1o2)-E-D-allopyranoside], and the compound was named magnoloside H (6).
EXPERIMENTAL General Methods. The resins used for column chromatography (c.c.) were Kieselgel 60 (63–200 Pm; Merck, Darmastadt, Germany) and LiChroprep RP-18 (40–60 Pm; Merck). Thin-layer chromatography (TLC) analysis was carried out using Kieselgel 60 F254 and RP-18 F254s plates (Merck), and the spots on the TLC were detected using a UV lamp (Spectroline Model ENF-240 C/F, Spectronics Corporation, Westbury, NY, USA), and spraying with a 10% H2SO4 solution followed by heating. Deuterium solvents for nuclear magnetic resonance (NMR) measurement were purchased from Merck Co. Ltd. NMR spectra were recorded on a 400 MHz FT-NMR spectrometer (Varian, Palo Alto, CA, USA), and chemical shifts were calibrated on the solvent used for NMR measurement. IR spectra were obtained from a PerkinElmer Spectrum One FT-IR spectrometer (model 599B, Waltham, MA, USA). FAB-MS were obtained using a JMS-700 mass spectrometer (JEOL, Tokyo, Japan). Optical rotations were measured using a JASCO P-1010 digital polarimeter (JASCO, Tokyo, Japan). Plant Material. The fruits of Magnolia obovata were collected at Kyung Hee University, Yongin, Republic of Korea in September 2010 and identified by Prof. Seoug-Woo Lee, Department of Horticultual Biotechnology, Kyung Hee University. A voucher specimen (KHU-NPCL-201009) is deposited at the Laboratory of Natural Products Chemistry, Kyung Hee University. Extraction of M. obovata Fruits and Isolation of Phenylethanoid Glycosides. The dried fruits (11 kg) were chopped and extracted in 80% MeOH (40 L u 4) at room temperature for 24 h, filtered, and concentrated in vacuo. The MeOH extracts (740 g) were poured into H2O and successively extracted with EtOAc (3.5 L u 4) and n-BuOH (3 L u 3). The concentrated EtOAc fraction (MOE, 238 g) was subjected to SiO 2 column chromatography (CC) ( 12 u 15 cm) and eluted with 663
n-hexane–EtOAc (5:1o2:1o1:2, 2.8 L of each)oCHCl3–MeOH (10:1o8:1o6:1, 2.8 L of each)oCHCl3–MeOH–H2O (6:4:1, 3 L) with monitoring by TLC to provide 15 fractions (MOE-1 to MOE-15). Fraction MOE-13 [7.6 g, elution volume/ total volume (Ve/Vt) 0.899–0.932] was subjected to SiO2 CC ( 5 u 12 cm) and eluted with CHCl3 –MeOH–H2 O (36:3:1o33:3:1o30:3:1o27:3:1o 24:3:1o 17:3:1o10:3:1o6:4:1, 1.5 L of each), yielding 14 fractions (MOE-13-1 to MOE-13-14), along with a purified compound 2 [MOE-13-8, 82 mg, Ve/Vt 0.609–0.640, TLC (RP-18 F254s), Rf 0.62, MeOH–H2O (2:1)]. Fraction MOE-13-1 (3.02 g, Ve/Vt 0.000–0.348) was subjected to SiO2 CC ( 5.0 u 14 cm) and eluted with CHCl3–MeOH–H2O (11:3:1o10:3:1o9:3:1o 6:4:1, 3.5 L of each), yielding 12 fractions (MOE-13-1-1 to MOE-13-1-12). Fraction MOE-13-1-5 (153.4 mg, Ve/Vt 0.427–0.480) was subjected to an ODS CC ( 2.5 u 5.0 cm) and eluted with MeOH–H2O (1:3o1:2, 0.4 L of each), yielding 13 fractions (MOE-13-1-5-1 to MOE-13-1-5-13), along with a purified compound 6 [MOE-13-1-5-5, 6.1 mg, Ve/Vt 0.251–0.312, TLC (RP-18 F254s) Rf 0.40, MeOH–H2O (2:3)] and compound 4 [MOE-13-1-5-8, 6.7 mg, Ve/Vt 0.576–0.650, TLC (RP-18 F254s) Rf 0.34, MeOH–H2O (2:3)]. Fraction MOE-13-1-8 (869 mg, Ve/Vt 0.568–0.744) was subjected to Sephadex LH-20 CC ( 2.5 u 59 cm) and eluted with 80% MeOH, yielding seven fractions (MOE-13-1-8-1 to MOE-13-1-8-7) and a purified compound 3 [MOE-13-1-8-5, 627.3 mg, Ve/Vt 0.563–0.708, TLC (RP-18 F254s) Rf 0.69, MeOH–H2O (1:1)]. Fraction MOE-11 (2.06 g, Ve/Vt 0.748–0.825) was subjected to SiO2 CC ( 5.0 u 12 cm) and eluted with CHCl3–MeOH (8:1o6:1, 0.3 L of each), yielding 10 fractions (MOE-11-1 to MOE-11-10). Fraction MOE-11-9 (533 mg, Ve/Vt 0.659–0.975) was subjected to ODS CC ( 3.5 u 5.0 cm) and eluted with MeOH–H2O (1:3o1:1, 0.2 L of each), yielding seven fractions (MOE-11-9-1 to MOE-11-9-7). Fraction MOE-11-9-2 (21 mg, Ve/Vt 0.059–0.158) was subjected to Sephadex LH-20 CC ( 10 u 22 cm) and eluted with 80% MeOH, yielding four fractions (MOE-11-9-2-1 to MOE-11-9-2-4), along with a purified compound 5 [MOE-11-9-2-2, 10.4 mg, Ve/Vt 0.261–0.348, TLC (RP-18 F254s) Rf 0.52, MeOH–H2O (1:1)]. The concentrated n-BuOH fraction (MOB, 97 g) was subjected to SiO2 CC ( 8.0 u 12 cm) and eluted with CHCl3–MeOH–H2O (12:3:1o10:3:1o7:3:1o6:4:1, 3 L of each) to provide 21 fractions (MOB-1 to MOB-21). Fraction MOB-15 (7.38 g, Ve/Vt 0.593–0.633) was subjected to ODS CC ( 6 u 8 cm) and eluted with MeOH–H2O (1:2o1:1, 0.4 L of each), yielding 18 fractions (MOB-15-1 to MOB-15-18). Fraction MOB-15-2 (555.6 mg, Ve/Vt 0.042–0.051) was subjected to Sephadex LH-20 CC ( 3.0 u 30 cm) and eluted with 80% MeOH, yielding 10 fractions (MOB-15-2-1 to MOB-15-2-10). Fraction MOB-15-2-2 (154.8 mg, Ve/Vt 0.245–0.296) was subjected to SiO2 CC ( 3.0 u 19 cm) and eluted with CHCl3–MeOH– H2O (10:3:1, 0.7 L), yielding 11 fractions (MOB-15-2-2-1 to MOB-15-2-2-11) and a purified compound 1 [MOB-15-2-2-10, 31.4 mg, Ve/Vt 0.261–0.348, TLC (RP-18 F254s) Rf 0.52, MeOH–H2O (1:1)]. o 2)-E-D-allopyranoside (1). EI-MS m/z 462 [M]+; 2-(3,4-Dihydroxyphenyl)ethyl O-D-L-Rhamnopyranosyl-(1o 31 –1 [D] D –56.4q (c 0.18, MeOH). IR (KBr, Qmax, cm ): 3421, 1610, 1528, 1448. 1H NMR (400 MHz, CD3OD, G, ppm, J/Hz): 6.68 (1H, d, J = 2.0, H-2), 6.67 (1H, d, J = 8.0, H-5), 6.55 (1H, dd, J = 8.0, 2.0, H-6), 4.87 (1H, d, J = 2.0, H-1cc), 4.73 (1H, d, J = 8.0, H-1c), 4.21 (1H, dd, J = 2.8, 2.8, H-3c), 4.01 (1H, m, H-Da), 3.98 (1H, dq, J = 9.2, 6.4, H-5cc), 3.91 (1H, dd, J = 3.2, 2.0, H-2cc), 3.84 (1H, dd, J = 11.2, 1.6, H-6ca), 3.74 (1H, dd, J = 9.2, 3.2, H-3cc), 3.70–3.60 (3H, overlap, H-Db, 5c, 6cb), 3.48 (1H, dd, J = 8.0, 2.8, H-2c), 3.46 (1H, d, J = 10.0, 2.8, H-4c), 3.44 (1H, dd, J = 9.2, 9.2, H-4cc), 2.77 (1H, t, J = 7.6, H-E), 1.27 (3H, d, J = 6.0, H-6cc). For 13C NMR (100 MHz, CD3OD), see Table 2. Magnoloside D (2). Yellow powder (MeOH), negative FAB-MS m/z 623 [M – H]–. [D]31 D +36.7° (c 0.80, MeOH). IR (KBr, Qmax, cm–1): 3421, 1697, 1610, 1528, 1448. 1H NMR (400 MHz, CD3OD, G, ppm, J/Hz): 7.57 (1H, d, J = 16.0, H-Eccc), 7.03 (1H, d, J = 1.6, H-2ccc), 6.90 (1H, dd, J = 8.4, 1.6, H-6ccc), 6.77 (1H, d, J = 8.4, H-5ccc), 6.76 (1H, d, J = 2.0, H-2), 6.64 (1H, d, J = 8.0, H-5), 6.54 (1H, dd, J = 8.0, 2.0, H-6), 6.60 (1H, d, J = 16.0, H-Dccc), 4.89 (1H, br.s, H-1cc), 4.76 (1H, d, J = 8.0, H-1c), 4.85 (1H, dd, J = 12.0, 2.0, H-6ca), 4.33 (1H, dd, J = 12.0, 5.6, H-6cb), 4.25 (1H, dd, J = 2.8, 2.8, H-3c), 3.99 (1H, dq, J = 9.6, 6.4, H-5cc), 3.96 (1H, m, H-5c), 3.95 (1H, overlap, H-Da) 3.92 (1H, dd, J = 3.2, 1.6, H-2cc), 3.74 (1H, dd, J = 9.6, 3.2, H-3cc), 3.65 (1H, m, H-Db), 3.57 (1H, dd, J = 9.6, 2.8, H-4c), 3.51 (1H, dd, J = 8.0, 2.8, H-2c), 3.44 (1H, t, J = 9.6, H-4cc), 2.77 (2H, t, J = 7.6, H-E), 1.25 (3H, d, J = 6.4, H-6cc). For 13C NMR (100 MHz, CD3OD), see Table 2. Magnoloside A (3). Yellow powder (MeOH), positive FAB-MS m/z 625 [M + H]+; [D]31 D +36.7q (c 0.80, MeOH). IR (KBr, Qmax, cm–1): 3421, 1699, 1610, 1528, 1448. 1H NMR (400 MHz, CD3OD, G, ppm, J/Hz): 7.61 (1H, d, J = 16.0, H-Eccc), 7.08 (1H, d, J = 2.0, H-2ccc), 6.96 (1H, dd, J = 8.4, 2.0, H-6ccc), 6.80 (1H, d, J = 8.4, H-5ccc), 6.71 (1H, d, J = 2.0, H-2), 6.69 (1H, d, J = 8.0, H-5), 6.57 (1H, dd, J = 8.0, 2.0, H-6), 6.37 (1H, d, J = 16.0, H-Dc), 5.75 (1H, dd, J = 2.4, 2.4, H-3c), 4.74 (1H, d, J = 8.0, H-1c), 4.94 (1H, br.s, H-1cc), 4.05–4.01 (2H, overlap, H-Da, 5cc), 3.88 (1H, dd, J = 12.0, 2.4, H-6ca), 3.81 (1H, m, H-5c), 3.77 (1H, dd, J = 10.4, 2.4, H-4c), 3.69–3.66 (2H, overlap, H-2c, 2cc), 3.64 (1H, dd, J = 9.6, 3.2, H-3cc), 3.45 (1H, t, J = 9.6, H-4cc), 2.78 (2H, t, J = 7.2, H-E), 1.25 (3H, d, J = 6.4, H-6cc). For 13C NMR (100 MHz, CD3OD), see Table 2.
664
Magnoloside F (4). Amorphous powder (MeOH). Negative HR-FAB-MS m/z 623.1965 (calcd for C29H35O15, –1 1 623.1976). [D]31 D –58.2q (c 0.05, MeOH). IR (KBr, Q max, cm ): 3335, 2928, 1695, 1629, 1604, 1519, 1445. For H NMR (400 MHz, CD3OD), see Table 1; for 13C NMR (100 MHz, CD3OD), see Table 2. Magnoloside G (5). Amorphous powder (MeOH). Negative HR-FAB-MS m/z 607.2032 (calcd for C29H35O14, –1 1 607.2027). [D]31 D –20.0q (c 0.05, MeOH). IR (KBr, Qmax, cm ): 3380, 2926, 1699, 1604, 1507, 1454. For H NMR (400 MHz, CD3OD), see Table 1; for 13C NMR (100 MHz, CD3OD), see Table 2. Magnoloside H (6). Amorphous powder (MeOH). Negative HR-FAB-MS m/z 607.2030 (calcd for C29H35O14, –1 1 607.2027). [D]31 D –37.2q (c 0.05, MeOH). IR (KBr, Qmax, cm ): 3384, 2928, 1695, 1610, 1517, 1448. For H NMR (400 MHz, CD3OD), see Table 1; for 13C NMR (100 MHz, CD3OD), see Table 2.
ACKNOWLEDGMENT This research was supported by a project from the Academy and Research Institute funded Korea Small and Medium Business Administration (S2091482).
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