Научная статья на тему 'Megastigmane, iridoids and phenyl propanoids glycosides from the Nepalese sandalwood Osyris wightiana Wall ex Wight'

Megastigmane, iridoids and phenyl propanoids glycosides from the Nepalese sandalwood Osyris wightiana Wall ex Wight Текст научной статьи по специальности «Биологические науки»

CC BY
81
17
i Надоели баннеры? Вы всегда можете отключить рекламу.
Ключевые слова
БИОЛОГИЧЕСКИ АКТИВНЫЕ СОЕДИНЕНИЯ / OSYRIS WIGHTIANA / ХРОМАТОГРАФИЯ / СТРУКТУРА / САНДАЛОВОЕ ДЕРЕВО / SANDALWOOD / СПИРТОВАЯ ЭКСТРАКЦИЯ / BENZYL ALCOHOL / PHENYL PROPANOID / IRIDOID / MEGASTIGMANE

Аннотация научной статьи по биологическим наукам, автор научной работы — Sajan L. Shyaula, Mohammad I. Choudhary, Mangala D. Manandhar.

The crude ethanolic extract of the Nepalese sandalwood Osyris wightiana Wall. ex Wight, was analyzed for its bioactive chemical constituents by chromatographic and spectroscopic methods. Phenyl propanoid, benzyl alcohol, iridoid and megastigmanes, were isolated from the butanolic fraction by the successive use of column chromatography and HPLC. They were isolated as the new source from the genus Osyris. The structures of syringin (1) and diO -methylcrenatin (2), 8-epideoxyloganic acid (3), citroside B (4) and roseoside (5) were characterized on the basis of extensive spectroscopic data analysis of NMR, mass and other spectroscopic techniques.

i Надоели баннеры? Вы всегда можете отключить рекламу.
iНе можете найти то, что вам нужно? Попробуйте сервис подбора литературы.
i Надоели баннеры? Вы всегда можете отключить рекламу.

Текст научной работы на тему «Megastigmane, iridoids and phenyl propanoids glycosides from the Nepalese sandalwood Osyris wightiana Wall ex Wight»

УДК

ИССЛЕДОВАНИЕ БИОЛОГИЧЕСКИ АКТИВНЫХ ГЛИКОЗИДОВ ПОЛУЧЕННЫХ СПИРТОВОЙ ВЫТЯЖКОЙ ИЗ НЕПАЛЬСКОГО САНДАЛОВОГО ДЕРЕВА OSYRIS WIGHTIANA (НЕТРАДИЦИОННОЕ НАЗВАНИЕ WALL EX WIGHT)

Саджа Л. Шейаула1, Мухамед И. Чоудари2, Мангала Д. Манандахар1

(1 Факультет науки, Непальской академии наук и технологий 2Хуссейн Ибрахим Джамал исследовательский институт химии, Международный центр химических и биологических наук, университет Карачи; e-mail: shyaulasajan@gmail.com)

Спиртовые фракции сырой древесины непальского сандалового дерева Osyris wightiana (непальское название Wall ex Wight) проанализированы с помощью хроматографических и спектральных методов на наличие биологически активных химических компонентов. С помощью колоночной хроматографии и ВЭЖХ из бутанольной фракции экстрактов выделены новые классы гликозидов. Структуры нескольких соединений охарактеризованы на основе применения комплекса физико-химических методов: спектроскопических методик, ЯМР и масс-спектрометрических исследований.

Ключевые слова: биологически активные соединения, Osyris wightiana, хроматография, структура, сандал.

Introduction

Osyris wightiana Wall. ex Wight is a shrub about 2-3 m tall. It is widely distributed in the tropical and temperate zones at the altitudes of 900 to 2,500 m from Simla to Bhutan, Myanmar, India, Nepal and China [1]. The different species of the genus Osyris are used for the gynecological complaints of menorrhagia and infertility in Africa. The root bark boiled in water, is given to women after childbirth to stop bleeding and to boost energy. The leaves, roots, woods, barks and fruits have been used medicinally in the traditional healing system, mostly in Asia and Africa [2]. The dried leaves of Osyris are commonly used as a substitute of tea in the central part of Nepal. Despite of its important potential uses, there are the limited phytochemical studies of the genus Osyris. These facts inspired us to undertake the present phytochemical investigation.

From the genus Osyris, phenyl propanoid, benzyl alcohol, iridoid and megastigmane, were isolated from the butanolic fractions as the new source. Volatile constituents of the genus Osyris have been mostly analysed due to its fragrance. Previous studies in the genus Osyris led to isolation of hexyl and hexenyl derivatives, sesquiterpenes, phenolic acids, flavonoids, pyrrolizidine and quinolizidine alkaloids, long chain hydrocarbons and fatty acids, triterpenes, dihydro-P-agarofuran sesquiterpenes, lignans and phenolics [3-13]. Syringin (1)

belongs to phenyl propanoids and di-O-methylcrenatin (2) is benzyl alcohol derivative. They are shikimic acid derived products and have significant biological activities. 8-Epideoxyloganic acid (3) is iridoid belonging to the subclass of terpenoidal metabolites. Megastigmanes like citroside B (4) and roseoside (5) form a noriso-prenoid class of compounds formed by the enzymatic degradation of carotenoids in plants biosynthesis. These compounds contribute to flavors of the fruits and wines. Here the detail reports of isolation and structure elucidation of megastigmanes, iridoid, benzyl alcohol and phenyl propanoid from the new source, O. wightiana, are presented.

Experimental

Plant Material

The aerial parts of O. wightiana were collected from Kavre district, Nepal, in August 2005 at the altitudes of 1,600 m to 1,700 m. It was identified by comparing with herbarium specimen at the National Herbarium laboratory, Department of Plant Resources, Godawari, Nepal.

Column Chromatography

Diaion HP-20 resin was used for fractionation of the crude n-butanolic extract. Polyamide was further used for preparing sub-fractions. Final purifications of com-

pounds were achieved by preparative recycling HPLC (LC-908, JAI) and the columns L-80 (YMC. Co. Ltd.). It was eluted with MeOH and H2O system. Precoated silica gel TLC plates (E. Merck, F254) were used for checking the purity of compounds.

UV and IR Spectrophotometer

Shimadzu UV 240 spectrophotometer was used for determination of Xmax for isolated compounds. The IR spectra of pure compounds were recorded by using JASCO A-320 spectrophotometre.

H NMR and 13C NMR

XH NMR spectra were recorded on Bruker AC-300 and AMX-500 MHz instrument, while 13C NMR spectra were recorded at 100 and 125 MHz. 1H-NMR

13

and C-NMR chemical shifts were reported here in d (ppm) and coupling constant values (J) were measured in Hz. Multiplicities of carbon signals were determined by DEPT 90o and 135o experiments. 2D NMR spectra were recorded on a Bruker Avance AMX 500 NMR spectrometer.

Mass Spectrometry

The EI MS spectra were recorded on mass spectrometer Varian MAT 312. FAB MS and HREI MS experiments were performed on Jeol HX 110 mass spectrometer. The ion peaks are presented in m/z (%).

Extraction and Isolation

The air dried aerial parts of the plant (6.3 Kg) was first extracted with 80% ethanol/water. Then it was successively extracted by «-hexane, dichloromethane, ethyl acetate and «-butanol. The «-butanol fraction (64.5 g) was first fractionated by column chromatography (Diaion HP-20, 200 g) by using H2O/MeOH as the solvent system. Five sub-fractions were obtained by gradual elu-tion with increasing methanol in H2O/MeOH system. The sub-fraction OB-52 (15 g, eluted with 5% to 10% of MeOH in H2O) and OB-53 (11 g, eluted with 10% to 20% MeOH in H2O) were further subjected to the polyamide column chromatography with CHCl3-MeOH as the solvent. 8-Epideoxyloganic acid (3) was obtained from the sub-fraction OB-52, on eluting through recycling HPLC (using L-80 column) at 1:1 MeOH: H2O solvent system. Syringin (1), di-O-methylcrenatin (2), citroside B (4) and roseoside (5) were isolated from sub-fraction OB-53 on eluting through recycling HPLC (using L-80 column) at 1:1 MeOH: H2O solvent system.

Syringin (1). Crystalline needles, M. p.: 192-193oC; UV (EtOH) A. nm: 265, 222; IR (KBr) A. cm-1: 3400

v y max y j v y max

(OH), 1585 (C=C); EI MS m/z (rel. int. %): 210 (100),

196 (2), 182 (20), 167 (22), 154 (7), 139 (4); XH NMR, (500 MHz, MeOH-d4): 5H 6.74 (s, 2H, H-2 and H-6), 6.52 (d, JV2, =15.8 Hz, 1H, H-1'), 6.33 (dt, JTV = 15.8 Hz, J2 ,3, = 5.5 Hz, 1H, H-2 '), 4.21 (d, J3 ,2, = 5.5 Hz, 2H, H-3 '), 4.86 (d, Jr2„ = 7.5 Hz, 1H, H-1' '), 3.85 (s, 6H, 2xOCH3), 3.78 (dd, J6„a6nb = 11.9 Hz, J6„a5„ = 2.2 Hz, 1H, H6 ' ' a), 3.66 (dd, J6 ' 'b '6 ' 'a = 11.9 Hz, J6 ' . ' = 5.1 Hz, 1H, H6' ' b), 3.46 (m, 1H, H-2 ' '), 3.40 (m, 1H, H-4 ' '), 3.39 (m, 1H, H-5''), 3.20 (m, 1H, H-3 ' '); 13C-NMR (125 MHz, MeOH-d4): SC 154.4 (C-3 and C-5), 135.9 (C-4), 135.3 (C-1), 131.3 (C-1' ), 130.1 (C-2 '), 105.5 (C-2 and C-6), 105.4 (C-1' '), 78.3 (C-3' '), 77.8 (C-5 ' '), 75.7 (C-2 ' '), 71.4 (C-4 ' '), 63.5 (C-3 '), 62.6 (C-6 ' '), 57.0 (2xCH3O).

Di-O-methylcrenatin (2). Crystalline needles, M. p.: 175-177oC, EI MS m/z (rel. int. %): 184 (100), 167 (13), 155 (5), 123 (11), 109 (11), 73 (21); XH-NMR (500 MHz, MeOH-d4): 5H 6.69 (s, 2H, H-2 and H-6), 4.83 (d, JV2, = 7.5 Hz, 1H, H-1'), 4.54 (s, 2H, H-1a), 3.84 (s, 6H, 2x OCH3), 3.77 (dd, J6,86t, =119 Hz, J6a,5, = 2.1 Hz, 1H, H-6 'a), 3.66 (dd, J6,,6 ^ = 119 Hz, J61j5, = 5.1 Hz, 1H, H-6 'b), 3.47 (m, 1H, H-2 '), 3.41 (m, 1H, H-4 '), 3.40 (m, 1H, H-5 '), 3.19 (m, 1H, H-3'); 13C-NMR (125 MHz, MeOH-d4): 5C 154.2 (C-3 and C-5), 139.7 (C-1), 135.4 (C-4), 105.8 (C-2 and C-6), 105.5 (C-1'), 78.3 (C-3 '), 77.8 (C-5'), 75.7 (C-2 '), 71.3 (C-4 '), 65.0 (C-1a), 62.5 (C-6 '), 57.0 (2xOCH3).

8-Epideoxyloganic acid (3). Colorless crystalline needles, M. p.: 106oC; UV (EtOH) Xmax nm (log e): 235 (4.0); IR (KBr) Xmax cm-1: 3300 (OH), 1(558, 1635 (C=C); EI MS m/z (rel. int. %): 198 (21), 180 (29), 154 (45), 137 (37), 125 (40), 81 (99), 57 (100); XH-NMR (300 MHz, MeOH-d4): ¿H 7.29 (s, 1H, H-3), 5.41 (d, J19 = 5.0 Hz, 1H, H-1), 4.68 (d, J12 ' = 7.8 Hz, 1H, H-1'), '3.91 (br. d, J 6^ = 11.7 Hz, 1H, H-6 'a), 3.63 (dd, J6Wa = 11.7 Hz, J6'b5 ' = 5.8 Hz, 1H, H-6 'b), 3.36 (m, 1H, H-3 ' ), 3.23 (m, 1H, H-4 '), 3.27 (m, 1H, H-5 '), 3.18 (m, 1H, H-2 '), 2.91 (m, 1H, H-5), 2.24 (m, 1H, H-9), 2.17 (m, 1H, H-8), 2.02 (m, 1H, H-6a), 1.77 (m, 1H, H-7a), 1.61 (m, 1H, H-6b), 1.34 (m, 1H, H-7b), 1.06 (d, J108 = 6.3 Hz, 3H, CH3);

C-NMR (125 MHz, MeOH-d4): 5C 173.2 (CO2H), 150.6 (C-3), 115.9 (C-4), 99.6 (C-1'), 95.8 (C-1), 78.3 (C-5 '), 77.9 (C-3 '), 74.8 (C-2'), 71.7 (C-4'), 62.9 (C-6'), 44.4 (C-9), 37.5 (C-8), 34.9 (C-5), 33.4 (C-7), 32.3 (C-6), 16.8 (CH3).

Citroside B (4). Colorless amorphous solid, UV (CHCl3) ^max nm (log e): 230 (4.17); IR (KBr) Vax cm-1: 3400 (OH), 1945 (C=C=C), 1675 (C=O); EI MS m/z (rel. int. %): 206 (36), 191 (48), 173 (89), 162 (16), 147 (39), 119 (60), 91 (100); XH-NMR (500 MHz, MeOH-d4) 5H 5.88 (s, 1H, H-8), 4.52 (d, JV2, = 7.6 Hz, 1H, H-1'), 4.31 (tt, J3™ = 115 Hz, J,^ . = 1.7 Hz, 1H, H-3), 3.81

13

(dd, J6,a6,b = 11.7 Hz, J6,a5, = 2.0 Hz, 1H, H-6 'a), 3.61 (dd,

J6'b,6'a = 11.7 Hz, J6,b5 , = 5.3 Hz, 1H, H-6 'b), 3.34 (m, 1H,

6 ' b,5

H-3'), 3.30 (m, 1H, H-5 '), 3.21 (m, 1H, H-4 '), 3.15 (m, 1H, H-2'), 2.48 (dd, J4a4b = 11.5 Hz, J4a3 =1.6 Hz, 1H, H-4a), 2.18 (s, 3H, H-10), 1.92 (dd, J2a2b = 11.5 Hz, J2a3 = 1.7 Hz, 1H, H-2a), 1.45 (s, 3H, CH3-13), 1.36 (s, 3H, CH3-12), 1.33 (Overlapped, H-4b), 1.30 (Overlapped, H-2b), 1.14 (s, 3H, CH3-11); 13C-NMR (125 MHz, MeOH-d4):

212.9 (C-7), 200.6 (CO), 119.1 (C-6), 101.3 (C-8), 98.6 (C-1'), 78.7 (C-1), 78.6 (C-3'), 77.8 (C-5 '), 75.2 (C-2 '), 71.7 (C-4 '), 63.8 (C-3), 62.9 (C-6 '), 49.9 (C-2), 48.0 (C-4), 37.0 (C-5), 32.5 (CH3-12), 30.6 (CH3-11), 26.7 (CH3-13), 26.6 (CH3-10).

Roseoside (5). Colorless amorphous soild, UV (MeOH) ^max nm (log s): 237 (4.06), 316 (2.55); IR (KBr) ^max cm-1: 3390 (OH), 1648 (enone); EI MS m/z (rel. int. %): 387 (3), 225 (13), 207 (57), 191 (5), 150 (100), 124 (71), 95 (21); HREI MS m/z: 386.4367 (C19H30O8); 'H-NMR (500 MHz, MeOH-d4): SH 5.86 (Overlapped, H-8), 5.85 (Overlapped, H-7), 5.84 (s, 1H, H-4), 4.41 (m, 1H, H-9), 4.34 (d, Jr2, = 7.8 Hz, 1H, H-1'), 3.84 (dd, J6 , a 6 b = 11.8 Hz, J6,a 5 , = 1.7 Hz, 1H, H6 'a), 3.62 (dd, J6,a 6 , b = 11.8 Hz, J6,b5, = 5.4 Hz, 1H, H6 'b), 3.31 (Overlapped, H-5'), 3.30 (Overlapped, H-3'), 3.23 (m, 1H, H-4 '), 3.16 (m, 1H, H-2 '), 2.52 (d, J2a2b = 16.8 Hz, 1H, H2a), 2.15 (d, J2b2a =16.8 Hz, 1H, H2b), 1.91 (s, 3H, CH3-13), 1.27 (d, J1()9 = 6.4 Hz, 3H, CH3-10), 1.03 (s, 3H, CH3-12), 1.02 (s, 311, CH3-11); 13C-NMR (125 MHz, MeOH-d4): SC 201.1 (CO), 167.2 (C-5), 135.2 (C-8), 131.5 (C-7), 127.2 (C-4), 102.7 (C-1'), 80.0 (C-6), 78.1 (C-3 '), 78.0 (C-5'), 77.2 (C-9), 75.2 (C-2 '), 71.6 (C-4 '), 62.8 (C-6 '), 50.7 (C-2), 42.4 (C-1), 24.6 (CH3-12), 23.4 (CH3-11), 21.1 (CH3-10), 19.5 (CH3-13).

Result and Discussion

Spectral data of compounds 1-5 are given in the experimental section. The spectral data of compounds were compared with the reported data for the identification.

Phenyl propanoid

The phenyl propanoid glycoside, syringin (1) was isolated as the crystalline needles (Fig. 1). The mass spectrum showed its base peak at m/z 210.1 (C11H14O4) due to cleavage of glycoside moiety from the C-4 (OH). The 13C NMR spectrum contains 17 carbon signals. It includes 2 methyl, 2 methylene, 9 methine, and 4 quaternary carbons. The downfield signals at dC 105.5 (C-2 and C-6), 154.4 (C-3 and C-5) and 57.0 (two methoxy groups) were equivalent. The downfield singlet at 5H 6.74 (H-2 and H-6) corresponds to two equivalent aromatic protons. It showed that the aromatic ring was tetrasubstitut-

Fig. 1. Syringin (1) ed. The methyl singlet at 5H 3.85 was assigned to meth-

1 H 13

oxy groups. The H NMR and C NMR spectra contain characteristic signals for glucose moiety. The anomer-ic proton signal appeared at 5H 4.86 (d, Jv ,2,, = 7.5 Hz, H-1' ' ). The signals for remaining protons of glucose moiety appeared at 5H 3.46 (m, H-2 ' ' ), 3.20 (m, H-3' ' ), 3.40 (m, H-4 ' '), 3.39 (m, H-5' '), 3.78 (dd, J6, ,a6, ,b = 11.9 Hz, J6a, , ,5 , , = 2.2 Hz, H6 ' ' a), and 3.66 (dd, J6 , , b,6 , , a = 11.9 Hz, J6 , ,b5 , , = 5.1 Hz, H6 ' 'b). The downfield doublet at 5H 6.52 (Jr2, = 15.8 Hz, H-1') and doublet of triplet at 5H 6.33 (J2 , v = 15.8 Hz, J3,2 , = 5.5 Hz, H-2 ' ) were assigned to olefinic protons which are in trans disposition, what is evident from their J values. The downfield methylene doublet at 5H 4.21 (J3,2 , = 5.5 Hz) was assigned to H-3' geminal to hydroxyl group [14, 15].

Benzyl alcohol

Di-O-methylcrenatin (2) was obtained as the needle-like crystalline compound (Fig. 2). Its base peak was observed at m/z 184.0 (C9H12O4) due to cleavage of glycoside moiety from C-4 (OH) in its mass spectrum. The

13

C NMR and its DEPT spectra showed 2 methyl, 2 methylene, 7 methine, and 4 quaternary carbons. The chemical shift values of 1H NMR and 13C NMR were similar to those in syringin (1), however, signals for olefinic protons are absent and singlet signal at dH 4.54 (2H, H-1a) was observed for methylene protons [16].

Fig. 2. Di-O-methylcrenatin (2)

Iridoids

8-Epideoxyloganic acid (3) was obtained as the colorless crystalline compound. (Fig. 3) The EI MS showed a prominent peak at m/z 198.1 (C10H14O4) due to the cleavage of glycoside moiety from C-1 (OH). The molecular composition of compound (3) was deduced from FAB ve (m/z 361) and FAB ve (m/z 359) MS. The 13C NMR (broad-band decoupled) spectrum of compound (3) showed a total 16 carbon signals, including 1 methyl, 3 methylene, 10 methine, and 2 quaternary carbons. The downfield singlet at SH 7.29 (H-3) was assigned to ole-phinic proton. It was showed by HMQC correlation with methine carbon at SC 150.6 (C-3). The H-3 proton showed HMBC correlations with carbons at 5C 95.8 (C-1), 115.9 (C-4), 34.9 (C-5), and 173.2 (CO2H). The downfield doublet at dH 5.41(J19 = 5.0 Hz) was assigned to H-1 acetal proton. The H-1 proton showed COSY coupling network to H-9 (m, 2.24), H-8 (m, 2.17), H-7a (m, 1.77), H-7b (m, 1.34), H-6a (m, 2.02), H-6b (m, 1.61) and H-5 (m, 2.91). It indicated the cyclopentane ring fused to six-membered heterocyclic ring system. The upfield methyl doublet signal at SH 1.06 (J108 = 6.3 Hz, CH3-10) was attached to C-8 (8C 37.5) according to its HMBC correlation. The stereochemistry was confirmed by comparing with the literature [17]. A doublet at 8H 4.68 (J12, = 7.8 Hz) was assigned to anomeric proton H-1' of glucose. Remaining proton signals of glucose were at SH 3.18 (m, H-2 '), 3.36 (m, H-3 ' ), 3.23 (m, H-4 ' ), 3.27 (m, H-5 ' ), 3.91 (br. d, J6,a6 ,b = 11.7 Hz, H-6 'a), and 3.63 (dd, J6 , b6 , a = 11.7 Hz, J6 , b ^ = 5.8 Hz, H-6 'b).

Megastigmanes

Citroside B (4) was obtained as the colorless amorphous powder (Fig. 4). A prominent peak at m/z 206.1 (C13H18O2) was observed in EI MS, due to the cleavage of glycoside moiety from the C-1 position. The 13C NMR and its DEPT spectra showed 4 methyl, 3 methylene, 7

Fig. 3. 8-Epideoxyloganic acid (3)

Fig. 4. Citroside B (4)

13 1

methine, and 5 quaternary carbons. The C NMR and H NMR spectral data showed the presence of signals at 8C 101.3 and singlet at 8H 5.88. It was assigned to methine H-8 of allenic moiety.[18] It showed HMBC correlation with C-7 (8C 212.9), C-9 (8C 200.6), and C-6 (119.1). The proton signal at 8H 2.18 (s, 3H) was assigned to methyl adjacent to carbonyl group. Three more methyl signals were resonated at 1.14 (s, 3H, CH3-11), 1.36 (s, 3H, CH3-12) and 1.45 (s, 3H, CH3-13). The triplet of a triplet at 8H 4.31 (J?,2b/3,4b = 11.5 Hz, J32a/34a = 1.7 Hz) was assigned to carbinol H-3. Two sets of diastereotopic protons appeared at 8H 1.92 (dd, J2a2b = 11.5 Hz, J2a3 = 1.7 Hz, H-2a), 1.30 (overlapped, H-2b), 2.48 (dd, J4a4b = 11.5 Hz, J4a3 = 1.6 Hz, H-4a) and 1.33 (overlapped, H-4b). A doublet at 8H 4.52 (J12 , = 7.6 Hz) was assigned to anomeric H-1'. Remaining glucose proton signals were at 8H 3.15 (m, 1H, H-2 '), 3.34 (m, 1H, H-3'), 3.21 (m, 1H, H-4 '), 3.30 (m, 1H, H-5 '), 3.81 (dd, J6 ,a6,b = 11.7 Hz, J6a5 , = 2.0 Hz, 1H, H-6 'a) and 3.61 (dd, J6 ,b6 ,a = 11.7 Hz, J6,b5 , = 5.3 Hz, 1H, H-6 'b).

Roseoside (5) was obtained as the colorless amorphous powder (Fig. 5). The EI MS showed the peak [M-H+] at m/z 387.3 (C19H30O8). Its UV spectrum showed absorption bands at ^ at 237 and 316 nm. The 13C NMR and

max

its DEPT spectra showed 4 methyl, 2 methylene, 9 methine, and 4 quaternary carbons. The singlet proton signal resonated at 8H 5.84 was assigned to H-4 olefinic proton. The downfield carbon signals 8C at 201.1 (C-3), 127.2 (C-4), and 167.2 (C-5) were characteristics of an enone

т

о

Fig. 5. Roseoside (5)

system [19]. The geminal coupled signals at 8H 2.15 (d, J2a2b = 16.8 Hz, H-2a) and 2.52 (d, J2b2a = 16.8 Hz, H-2b) were assigned to CH2 adjacent to carbonyl group. NMR spectrum revealed overlapped signals assignable to olefinic protons at 8H 5.85 (H-7) and 5.86 (H-8). The side chain was attached to C-6, what was deduced from HMBC correlation of olefinic H-7 with C-5 (8C 167.2) and C-6 (8C 80.0). The four methyl signals were resonat-

ed at 8H 1.27 (d, J10 9 = 6.4 Hz, CH3-10), 1.02 (CH3-11), 1.03 (CH3-12) and 1.91 (CH3-13). The carbinol methine proton appeared at 8H 4.41 (m, H-9). A doublet at 8H 4.34 (Jr 2 , = 7.8 Hz) was assigned to anomeric H-1'. The proton signals for remaining protons of glucose moiety appeared at 8H 3.16 (m, H-2 ' ), 3.30 (Overlapped, H-3'), 3.23 (m, H-4 '), 3.31 (Overlapped, H-5 '), 3.84 (dd, J6,a6,b = 11.8 Hz, J6 a5 ' = 1.7 Hz, H-6 'a) and 3.62 (dd, J6,b6,a = 11.8 Hz, J6 ,b,5 , = 5 .4 Hz, H-6 'b).

Conclusion

Phenyl propanoid 1, benzyl alcohol 2, iridoid 3, and megastigmanes 4 and 5 were for the first time reported from the genus Osyris. These compounds were identified on the basis of spectroscopic data. These classes of compounds are synthesized by different biosynthetic pathways and these results can be supportive to validate its medicinal claims.

Acknowledgement

The ICCBS fellowship from HEJ Research Institute of Chemistry, Pakistan is gratefully acknowledged for financial support to this research work.

REFERENCES

Shu Z.S. Flora of China, Science Press (Beijing) and Missouri Botanical Garden Press (England), 2003.

Shyaula S.L. // J. Nat. Pharm. 2012. 3. N 2. P. 61.

Demirci F., Baser K.H.C. // Flavour Fragr. J. 2004. 19. P. 72.

Hala I.J., Ibrahim M. M., Abdallah M., Omar M. A. S., Musa H. A. Z. // J. Asian Nat. Prod Res. 2010. 12. N 9. P. 814-820.

Yeboah E. M. O., Majinda R. R. T., Kadziola A., Muller A. // J. Nat. Prod. 2010. 73. N 6. P. 1151.

Hopkins C.Y., Chisholm M.J., Cody W.J. // Phytochemistry. 1969. 8. N 1. P. 161.

Mikolajczak K.L., Earle F.R., Wolf I.A. // J. Am. Oil Chem. Soc. 1963. 40. N 8. P. 342.

Woldemichael G. M., Wink M. // Biochem. Syst. Ecol. 2002. 30. P. 139.

KreiplA.T., Konig W.A. // Phytochemistry. 2004. 65. P. 2045.

Le Scao F., Faugeras G., Paris R.R. // Plantes Medicinales et Phytotherapie. 1978. 12. N 4. P. 315.

KreiplA.T., Konig W.A. // Phytochemistry. 2004. 65. P. 2045.

Iwashina T., Jose A.L.S., Kitajima // J. Biochem. Syst. Ecol. 2008. 36. N 2. P. 146.

Shyaula S.L., Manandhar M.D., Choudhary M.I. // J. Nepal Chem. Soc. 2011. 28. N 2. P. 24.

Malingre S.T.M., Van Os F.H.L. // Phytochemistry. 1978. 17. P. 564.

Dubeler A., Voltmer G., Gora V., Lunderstadt J., ZeeckA. // Phytochemistry. 1997. 45. N 1. P. 51.

Li X.C., Elsohly H.N., Walker L.A., Clark A.M. // Planta Med. 2005. 71. P. 977.

Murai F., Tagawa M., Damtoft S., Jensen S.R., Nielsen B.J. // Chem. Pharm. Bull. 1984. 32. N 7. P. 2809.

Otsuka H., Kijima H., Hirata E., Shinzato T., Takushi A., Bando M., Takeda Y. // Chem. Pharm. Bull. 2003. 51. N 3. P. 286.

Bhakuni D.S., Joshi P.P., Upprety H., Kapil R.S. // Phytochemistry. 1974. 13. P. 2541.

Поступила в редакцию 20.05.13

MEGASTIGMANE, IRIDOID, BENZYL ALCOHOL AND PHENYL PROPANOID GLYCOSIDES FROM THE NEPALESE SANDALWOOD OSYRIS WIGHTIANA WALL. EX WIGHT

Sajan L. Shyaula, Mohammad I. Choudhary, Mangala D. Manandhar

(Faculty of Science, Nepal Academy of Science and Technology, Khumaltar, Lalitpur, Nepal; HEJ Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi-75270, Pakistan)

The crude ethanolic extract of the Nepalese sandalwood Osyris wightiana Wall. ex Wight, was analyzed for its bioactive chemical constituents by chromatographic and spectroscopic methods. Phenyl propanoid, benzyl alcohol, iridoid and megastigmanes, were isolated from the butanolic fraction by the successive use of column chromatography and HPLC. They were isolated as the new source from the genus Osyris. The structures of syringin (1) and di-O-methylcrenatin (2), 8-epideoxyloganic acid (3), citroside B (4) and roseoside (5) were characterized on the basis of extensive spectroscopic data analysis of NMR, mass and other spectroscopic techniques.

Key words: Osyris wightiana, phenyl propanoid, benzyl alcohol, iridoid, megastigmane, sandalwood.

Сведения об авторах: Саджа Л. Шейаула - науч. сотр. факультета науки Непальской академии наук и технологий, Кулмалтар, Лалитпур, Непал; Мухамед И. Чоудари - науч. сотр. Междунар. центра химических и биологических наук, университет Карачи , Карачи 75270, Пакистан; Мангала Д. Манандахар - науч. сотр. факультета науки Непальской академии наук и технологий, Кулмалтар, Лалитпур, Непал.

i Надоели баннеры? Вы всегда можете отключить рекламу.