Next Article in Journal
Synthesis and Antiviral Bioactivities of α-Aminophosphonates Containing Alkoxyethyl Moieties
Previous Article in Journal
Application of the Solid-Phase Julia–Lythgoe Olefination in Vitamin D Side-Chain Construction
 
 
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Communication

A Novel Triterpene from Centella asiatica

1
College of Pharmaceutical Sciences and Biotechnology, Tianjin University, Tianjin 300072, P.R. China
2
School of Agronomy, Hebei Normal University of Science & Technology, Hebei Cangli, 066600, P.R. China
3
School of Pharmacy, Tianjin Medical University, Tianjin 300070, P.R. China
4
Faculty of Pharmaceutical Sciences, University of Tokushima, 770-8505, Japan
*
Author to whom correspondence should be addressed.
Molecules 2006, 11(9), 661-665; https://doi.org/10.3390/11090661
Submission received: 28 July 2006 / Revised: 11 August 2006 / Accepted: 30 August 2006 / Published: 4 September 2006

Abstract

:
A novel triterpene, 2α,3β,20,23-tetrahydroxyurs-28-oic acid (1), was isolated from the aerial part of Centella asiatica. Its structure was elucidated by spectroscopic methods, including 2D-NMR spectra. It displayed no activity against Hela and A549 cell lines at concentrations of 10 and 30 μg/mL, respectively.

Introduction

The perennial subshrub Centella asiatica (L.) Urban (Umbelliferae/Apiaceae family, commonly known as Gutu kola, Asiatic pennywort, Indian pennywort or Spadeleaf) has been widely cultivated as a vegetable or spice in China, Southeast Asia, India, Sri Lanka, Africa and Oceania. It has been used in Southeast Asia for the treatment of a wide variety of afflictions such as skin diseases, rheumatism, inflammation, syphilis, mental illness, epilepsy, hysteria, dehydration and diarrhea [1]. It was also used in Europe for treatment of wounds and ulcers. Earlier work on this plant has led to the isolation of more than 70 constituents, such as triterpenoid saponins [2,3,4], polyacetylenes [5], flavones [6], sterols and lipids [7]. A systematic study of the chemical constituents and antitumor activities of C. asiatica led us to isolate a new urs-type triterpene compound 1, together with ten known compounds, namely asiatic acid, madecassic acid, indocentoic acid, bayogenin, kaempferol, quercetin, euscaphic acid, terminolic acid, 3β-6β-23-tri-hydroxyolean-12-en-28-oic acid, and 3β-6β-23-trihydroxyurs-12-en-28-oic acid. This paper deals with the structural elucidation of the new triterpene 1.

Results and Discussion

Compound 1 was a white powder, Molecules 11 00661 i001 +26.6 (c 0.1, MeOH). Its HRFABMS showed a [M-H2O]+ peak at m/z 489.7028, corresponding to the molecular formula C30H50O6 (calcd. 489.7033). Its IR spectrum showed absorption bands at 3433 and 1722 cm-1, ascribable to hydroxyl and carboxyl functions, respectively. 13C- and DEPT 135°NMR spectra showed six signals for Me carbons, ten methylenes, seven methines, and six quaternary carbons, together with a carboxyl group. A total of 30 carbon resonances were observed, which confirmed its triterpenic nature. The following NMR data suggested the structural features of urs-28-oic acid for compound 1: a methyl doublet (δ 1.03, d, J = 6.9 Hz, Me-29), and the carbonyl carbon resonance at δ 180.1 (C-28). The spectrum also showed signals at δ 3.68 and 3.34 (J = 9.4 Hz) ascribable to the 2β- and 3α-protons on carbons bearing a hydroxyl function, respectively. An AB doublet, δ 3.50 (J = 11.0 Hz) and 3.26 (J = 11.0 Hz), indicated the presence of a –CH2OH function. The chemical shifts of C-4 and Me-24 led to placement of the -CH2OH at the C-23 position. The A and B ring proton and carbon signals matched those reported for asiatic acid (2α,3β,23-trihydroxyurs-12-en-28-oic acid) [8], but the 1H-NMR spectrum of 1, compared with that of asiatic acid, lacked a methyl doublet (Me-30) and contained a signal corresponding to a methyl singlet at δ 1.32 in the 1H-NMR, as well as a quaternary hydroxylated carbon (δ 86.2) in the 13C-NMR spectrum. The carbon signals of the E ring were in agreement with those reported for 3β-O-(β-D-xylopyranosyl-(1-3)-α-L-arabinopyranosyl)-2α,20β,23-trihydroxyurs-12-en-28-O-[β-D-glucopyranosyl-(1-6)-β-D-glucopyranosyl] ester [9]. The 1H- and 13C-NMR spectra were completely assigned by detailed 2D-NMR experiments (Table 1), which showed the HMBC correlations between H-30 and C-19, C-20, C-21, H-29 and C-18, C-19, C-20, H-3 and C-2, C-4, C-23, C-24. NOESY correlation of H-2 and H-25, H-3 and H-23 further corroborated the above conclusions. In summary, compound 1 was identified as 2α,3β-20,23-tetrahydroxyurs-28-oic acid (Figure 1).
Figure 1. Structure of Compound 1.
Figure 1. Structure of Compound 1.
Molecules 11 00661 g001
Table 1. 1H-NMR (300 MHz), and 13C-NMR (75 MHz) data of 1 (CD3OD, TMS, δ ppm).
Table 1. 1H-NMR (300 MHz), and 13C-NMR (75 MHz) data of 1 (CD3OD, TMS, δ ppm).
Carbon No.δHδC
1 48.3 (t)
23.68 (1H, m)70.0 (d)
33.34 (1H, d, J = 9.4 Hz)78.2 (d)
4 44.2 (s)
5 48.5 (d)
6 19.1 (t)
7 34.6 (t)
8 41.7 (s)
9 51.9 (d)
10 39.3 (s)
11 22.4 (t)
12 28.6 (t)
13 44.5 (d)
14 42.4 (s)
15 28.1 (t)
16 33.2 (t)
17 49.7 (s)
18 49.5 (d)
19 43.5 (d)
20 86.2 (s)
21 28.5 (t)
22 26.4 (t)
233.50 (1H, d, J = 11.0 Hz) 66.3 (t)
3.26 (1H, d, J = 11.0 Hz)
240.67 (3H, s)13.8 (q)
250.95 (3H, s)18.5 (q)
260.96 (3H, s)16.3 (q)
270.98 (3H, s)14.7 (q)
28 180.1 (s)
291.03 (3H, d, J = 6.9 Hz)19.0 (q)
301.32 (3H, s)24.4 (q)

Biological Activity

The EtOH extract of C. asiatica and the individual compounds were screened for anti-cancer activity against Hela and A549 cell lines. The MTT method was used to determine cytotoxic activity. No activity was observed at concentrations of 10 and 30 μg/mL, respectively.

Experimental

General

NMR spectra were run on a Bruker AVANCE 300 instrument using TMS as internal standard. MS data was obtained on a JEOL JMS D-300 instrument. Column chromatography was performed on silica-gel (Qingdao Haiyang Chemical Co., Ltd), and Toyopearl HW-40 (Tosoh). The HPLC instrument was a JASCO Gulliver Series equipped with a PU-1580 (pump), RI-1530 and UV-1575 (detectors). Semi-Preparative HPLC was performed using a YMC-Pack ODS-A, SH-343-5 column. IR spectra were recorded on a Nicolet 380 FT-IR spectrophotometer (Thermo Electron Corporation). Optical rotation was measured with a MC 241 digital polarimeter (Perkin-Elmer).

Plant material and product isolation

Aerial parts of C. asiatica were collected in September 2003, in Hebei province, P.R. China. A voucher specimen, identified by Dr. Wen-Yuan Gao, was deposited under registration No. TJU-03928 at the herbarium of the Department of Natural Products and Traditional Chinese Medicine, Tianjin University. The plant material (3 kg) was refluxed three times with 95% EtOH. The extract was concentrated under reduced pressure to give a residue (700 g) which was partitioned between ethyl acetate and H2O. The EtOAc extract (160 g) was chromatographed on a silica gel column with an eluent of increasing polarity and eluates of similar composition, according to TLC analysis, were pooled to yield 19 fractions. Fraction 16 (7.7 g, Rf = 0.5, eluted with 9:1 CHCl3-MeOH) was chromatographed on Toyopearl HW-40, and then further purified by reverse phase HPLC (8:2 MeOH-H2O) and GPC (MeOH) to give compound 1 (6 mg).

References

  1. Jiang Su New Medical College. Dictionary of Chinese Materia Medica; ShangHai Scientific and Technical Publishing House: Shanghai, P.R. China, 1977; p. 1874. [Google Scholar]
  2. Jiang, Z. Y.; Zhang, X. M.; Zhou, J.; Chen, J. J. New triterpenoid glycosides from Centella asiatica. Helv. Chim. Acta 2005, 88, 297–303. [Google Scholar] [CrossRef]
  3. Matsuda, H.; Morikawa, T.; Ueda, H.; Yoshikawa, M. Masayuki. Medicinal foodstuffs. XXVI. Inhibitors of aldose reductase and new triterpene and its oligoglycoside, centellasapogenol A and centellasaponin A, from Centella asiatica (Gotu Kola). Heterocycles 2001, 55, 1499–1504. [Google Scholar] [CrossRef]
  4. Kuroda, M.; Mimaki, Y.; Harada, H.; Sakagami, H.; Sashida, Y. Five new triterpene glycosides from Centella asiatica. Nat. Med. 2001, 55, 134–138. [Google Scholar]
  5. Schulte, K.E.; Ruecker, G.; Abdul Bary, E. Constituents of medical plants. XXVII. Polyacetylenes from Hydrocotyle asiatica. Arch. Pharm. 1973, 306, 197–209. [Google Scholar] [CrossRef]
  6. Prum, N.; Illel, B.; Raynaud, J. Flavonoid glycosides from Centella asiatica L. (Umbelliferae). Pharmazie 1983, 38, 423. [Google Scholar]
  7. Kapoor, R.; Ali, M.; Mir, S. R. Phytochemical investigation of Centella asiatica aerial parts. Oriental J. Chem. 2003, 19, 485–486. [Google Scholar]
  8. Kojima, H.; Ogura, H. Triterpenoids from Prunella vulgaris. Phytochemistry 1986, 25, 729–733. [Google Scholar] [CrossRef]
  9. Giuseppina, C.; Aurora, B.; Cosimo, P.; Fabio, V.; Nunziatina, D. T. Triterpene Saponins from Tupidanthus calyptratus. J. Nat. Prod. 2001, 64, 750–753. [Google Scholar]
  • Sample availability: Available from the corresponding author.

Share and Cite

MDPI and ACS Style

Yu, Q.-L.; Duan, H.-Q.; Takaishi, Y.; Gao, W.-Y. A Novel Triterpene from Centella asiatica. Molecules 2006, 11, 661-665. https://doi.org/10.3390/11090661

AMA Style

Yu Q-L, Duan H-Q, Takaishi Y, Gao W-Y. A Novel Triterpene from Centella asiatica. Molecules. 2006; 11(9):661-665. https://doi.org/10.3390/11090661

Chicago/Turabian Style

Yu, Quan-Lin, Hong-Quan Duan, Yoshihisa Takaishi, and Wen-Yuan Gao. 2006. "A Novel Triterpene from Centella asiatica" Molecules 11, no. 9: 661-665. https://doi.org/10.3390/11090661

Article Metrics

Back to TopTop