A new phenolic compound from Crinum asiaticum L.

Qian Sun a, Wei Dong Zhang a,b, Yun Heng Shen a,*,Chuan Zhang a,*, Hui Liang Li a

a Department of Phytochemistry, School of Pharmacy, Second Military Medical University, Shanghai 200433, Chinab School of Pharmacy, Shanghai Jiao tong University, Shanghai 200030, China

Received 15 October 2007

Abstract

A new phenolic compound was isolated from the ethanol extract of the bulbs of Crinum asiaticum L. var. sinicum Baker. Its

structure was defined as 1-(2-hydroxy-4-hydroxymethyl)phenyl-6-O-caffeoyl-b-D-gluco-pyranoside on the basis of spectroscopic

evidences.

# 2008 Chuan Zhang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Keywords: Crinum asiaticum L. var. sinicum baker; Amaryllideae; Phenolic compound; 1-(2-Hydroxy-4-hydroxymethyl)phenyl-6-O-caffeoyl-b-

D-glucopyranoside

The genus Crinum belongs to the family Amaryllideae, including about 120–130 species [1]. Only two species of

this genus: Crinum latifolium L. and C. asiaticum L. var. sinicum Baker, were distributed in China [2]. The bulbs of C.

asiaticum L. var. sinicum Baker have been used to treat abscesses, aching joints and sores in China since ancient times

[3–5]. Crinum species have been reported to contain mainly alkaloids. In addition to the alkaloids, the flavonoids,

chromones and terpenoids, have also been obtained from this species [6–7]. In this paper, we report the isolation and

characterization of a new phenolic compound from C. asiaticum L. var. sinicum Baker.

The bulbs of C. asiaticum L. var. sinicum Baker were collected in September 2005, in Fugong County, Yunnan, P.R.

China, and were authenticated by Prof. Yuanchuan Zhou. A voucher specimen (No. 2005071509) is deposited in

School of Pharmacy, Second Military Medical University.

The dried bulbs of C. asiaticum (30 kg) were extracted with 95% EtOH for three times at room temperature. After

removal of EtOH, the water suspension was partitioned with petroleum ether, CHCl3, EtOAc, and n-BuOH,

respectively. The EtOAc extract (40 g) was repeatedly subjected to silica gel column chromatography. Eluting with

gradient CHCl3/CH3OH (15:1–1:1) gave 4 fractions, and fraction 4 was purified over silica gel and Sephadex LH-20

column to afford 1 (25 mg) (Fig. 1).

Compound 1 was obtained as yellow powder with an optical rotation [a]20D �30 (c 0.27, MeOH). The HRESIMS

gave the molecular formula to be C22H24O11 (m/z 487.1217 [M+Na]+, calcd. 487.1216). The UV spectrum of 1 showed

maximal absorptions at 285 and 330 nm. The IR spectrum suggested the presence of hydroxyl group (3334 cm�1),

carbonyl group (1694 cm�1) and phenyl group (1597 cm�1, 1510 cm�1).

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Chinese Chemical Letters 19 (2008) 447–449

* Corresponding authors.

E-mail address: shenyunheng9217018@yahoo.com.cn (Y.H. Shen).

1001-8417/$ – see front matter # 2008 Chuan Zhang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

doi:10.1016/j.cclet.2008.01.022

The 1H NMR spectrum (Table 1) displayed proton signals at dH 6.29 (d, 1H, J = 16.0 Hz, H-8’’), 7.58 (d, 1H,

J = 16.0 Hz, H-7’’), 7.07 (d, 1H, J = 2.0 Hz, H-2’’), 6.81 (d, 1H, J = 8.5 Hz, H-500) and 6.96 (dd, 1H, J = 8.5, 2.0 Hz, H-

600), together with carbon resonances at dC 127.7 (s), 115.3 (d), 146.8 (s), 149.6 (s), 116.6 (d), 123.0 (d), 147.2 (d),

114.9 (d), and 168.9 (s), suggested the presence of a caffeoyl moiety, while proton resonances at dH 6.87 (d, 1H,

J = 2.0 Hz, H-3), 6.67 (dd, 1H, J = 8.0, 2.0 Hz, H-5), and 7.09 (d, 1H, J = 8.0 Hz, H-6) indicated the presence of a

1,2,4-trisubstituted phenyl. The 13C NMR (Table 1) showed the carbon resonances at dC 104.2 (d), 74.8 (d), 77.5 (d),

71.9 (d), 75.7 (d), 64.6 (t), along with the observation of an anomeric proton at dH 4.76 (d, 1H, J = 7.5 Hz, H-10),revealed a glucose moiety. Compound 1 was carried out alkaline hydrolysis, and then acid hydrolysis to yield a sugar

residue, which was identified as b-D-glucose by co-TLC with standard sugar (EtOAc: MeOH: HAc: H2O 12:3:3:2,

Rf = 0.51) [8–9].

The HMBC spectrum of 1 (Table 1) showed the long-correlations of two protons at dH 4.56 (dd, 1H, J = 2.0,

12.0 Hz, H-6’a) and dH 4.36 (dd, 1H, J = 7.0, 12.0 Hz, H-6’b) with carbonyl carbon at dC 168.9 (s) indicating that a

caffeoyl was attached to the C-6 of glucose. The long range correlations from H-1’ at dH 4.76 (d, 1H, J = 7.5 Hz) to C-1

at dC 145.8 (s) was observed, implying that the phenyl group was connected to C-1 of glucose. A hydroxymethyl was

Q. Sun et al. / Chinese Chemical Letters 19 (2008) 447–449448

Fig. 1. The structure and key HMBC correlations of 1.

Table 1

The 1H NMR (500 MHz, CD3OD, d ppm) and 13C NMR (125 MHz, CD3OD, d ppm) spectral data of 1

No. dH (mult., J) dC (mult.) HMBC (H! C) NOESY (H$ H)

1 145.8 (s)

2 148.3 (s)

3 6.87 (d, 1H, J = 2.0 Hz) 116.0 (d) C-1, C-2, C-5 CH2OH

4 138.5 (s)

5 6.67 (dd, 1H, J = 8.0, 2.0 Hz) 119.6 (d) C-3, C-6, C-1 CH2OH, H-6

6 7.09 (d, 1H, J = 8.0 Hz) 118.8 (d) C-1, C-2, C-4 H-5

CH2OH 4.42 (s, 2H) 64.8 (t) C-3, C-4, C-5 H-3, H-5

10 4.76 (d, 1H, J = 7. 5 Hz) 104.2 (d) C-1, C-50, C-30 H-20, H-50

20 3.54 (m, 1H) 74.8 (d) C-30 H-30, H-10

30 3.49 (m, 1H) 77.5 (d) C-40, C-20 H-50, H-20

40 3.43 (m, 1H) 71.9 (d) C-30, C-50, C-60 H-50, H-60 b

50 3.70 (m, 1H) 75.7 (d) C-10 H-60, H-10, H-30, H-40

60 a 4.56 (dd, 1H, J = 2.0, 12.0 Hz) 64.6 (t) C-900 H-60 b, H-50

60 b 4.36(dd, 1H, J = 7.0, 12.0 Hz), C-900, C-50 H-60 a, H-50, H-40

100 127.7 (s)

200 7.07 (d, 1H, J = 2.0 Hz) 115.3 (d) C-6’’,C-300,C-400 H-8’’, H-700

300 146.8 (s)

400 149.6 (s)

500 6.81 (d, 1H, J = 8.5 Hz) 116.6 (d) C-1’’,C-300,C-4’’, C-600 H-600

600 6.96 (dd, 1H, J = 8.5, 2.0 Hz) 123.0 (d) C-2’’,C-400,C-5’’, C-700 H-7’’, H-500, H-800

700 7.58 (d, 1H, J = 16.0 Hz) 147.2 (d) C-1’’,C-200,C-6’’,C-900 H-8’’, H-600,H-200

800 6.29 (d, 1H, J = 16.0 Hz) 114.9 (d) C-1’’, C-700, C-900 H-7’’, H-200, H-600

900 168.9 (s)

located at C-4 of phenyl based on the long-range correlations of hydroxymethyl at dH 4.46 (s, 2H) with C-4, C-3, and

C-5 as well as NOESY (Table 1) correlations of hydroxymethyl with H-3 and H-5. Therefore, 1 was deduced as 1-(2-

hydroxy-4-hydroxymethyl)phenyl-6-O-caffeoyl-b-D-glucopyranoside.

Acknowledgments

This research was partially supported by program for Changjiang Scholars and Innovative Research Team in

University (PCSIRT), the National Natural Science Foundation of China (No. 20402024), and the Scientific

Foundation of Shanghai of China (No. 05DZ19733, 06DZ19717, and 06DZ19005). The authors thank Prof.

Yuanchuan Zhou, Nujiang Institute of Medicinal Plant, for collection and identification of the plant.

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