Six New Triterpenoid Saponins from the Leaves of Ilex oblonga and Their Inhibitory Activities against TMV Replication

Abstract

Ilex (Aquifoliaceae) species are distributed widely in the People's Republic of China, and some are used extensively in folk medicine. For example, I. rotunda is an antipyretic and antidote and used for the treatment of the common cold, tonsillitis, and stomach and intestinal ulcers. I. pubescens is used for the treatment of coronary disease, myocardial infarction, dysentery, and erysipelas. I. cornuta and I. latifolia are used for the treatment of headache, toothache, bloodshot eyes, and tinnitus. Many reports indicate that saponins are the major constituents of Ilex species.1-5) The occurrence of flavonoids, 6) xanthines, 7) aldehydes, 8) hemiterpene glycosides, 9,10) triterpenes and alkanes, 11) anthocyanins, 12) pentyl esters, hexyl esters, and other lipophilic compounds 13) were reported. Several biological activities were related to the compounds isolated from Ilex species, including hypocholesterolemic 14) and antioxidant 15,16) activities. In a continuation of our study on the constituents of the medicinal plants of the Aquifoliaceae family. 17,18) We investigated the water-soulble fraction of Ilex oblonga. This plant is a well-known endemic herb to treat gumboil, eczema, rheumatism, scald and bruise in Guangxi province of China. 19) No previous phytochemical investigation on I. oblonga has been reported. In this paper, we describe the isolation and structure elucidation of ten triterpenoid saponins designated as oblonganoside A (1) (7) 22) from the leaves of I. oblonga. Results and DiscussionThe leaves of I. oblonga were extracted with MeOH under reflux. The MeOH extract was subjected to Diaion HP-20 column chromatography to give H 2 O, MeOH, and acetoneeluted fractions. The MeOH eluted fraction was subjected to ordinary and reversed phase silica gel column chromatography and finally HPLC to furnish triterpenoid saponons 1-10.Compound 1 was obtained as a white powder and exhib- Ministry of Education, Fujian Agriculture and Forestry University; Fuzhou, Fujian, 350002, P. R. China: and b Department of Bio-engineering & Technology, Huaqiao University; Quanzhou, Fujian, 362011, P. R. China. Received November 3, 2006; accepted December 21, 2006 Six new triterpenoid saponins of the ursane types were isolated from the MeOH extract of the leaves of Ilex oblonga. They were oblonganoside A (1), oblonganoside B (2), oblonganoside C (6), oblonganoside D (8), oblonganoside E (9), and oblonganoside F (10), together with three known triterpenoid saponins. The structures of these compounds were elucidated on the basis of spectroscopic analysis, and compound 1 showed appreciable inhibitory activity against TMV replication with EC 50 value 0.074 mM.

Antiviral activity and interaction mechanisms study of novel glucopyranoside derivatives

“…Recently, a large number of natural glycosides were found to exhibit outstanding antiviral activities against TMV. [15][16][17][18][19][20][21] Moreover, a number of synthetic glycosides derivatives were found to exhibit antiviral activities against TMV. For example, Dai and co-workers synthesized a series of glycosides derivatives containing 1,5-diacetyl-2,4-dioxohexahydro-1,3,5-triazine moiety with good antiviral activity against TMV.…”

Structure-Activity Relationship of Triterpenes and Triterpenoid Glycosides against Tobacco Mosaic Virus

“…According to the structures of the compounds, we had also found that with the same main structure, but with transformation of substituent groups, the anti-TMV activity of the compounds varied over a wide range [8], [9]. Here, the structure-activity relationship of 47 triterpenes and triterpenoid glycosides, isolated and purified from plants by our laboratory during the past years, most of which have initially been reported by us, were studied according to their anti-TMV activity against TMV replication in vivo by indirect ELISA.…”

LC-MS/MS Determination and Pharmacokinetic Study of Pedunculoside in Rat Plasma after Oral Administration of Pedunculoside and Ilex rotunda Extract

“…Previous phytochemical studies on the barks and leaves of Ilex rotunda have resulted in the isolation of triterpenes [9], triterpene saponins [10,11], phenylpropanoids [12], and hemiterpene glycosides [13]. Triterpene saponins are commonly recognized as major constituents of the Ilex species and have been proven to be major active constituents closely related to the pharmacological cardiovascular protection activities [14,15,16,17]. Pedunculoside (PDC, Figure 1A), a triterpene saponin, is a representative and abundant component of Ilex rotunda [18,19].…”