Panax ginseng produces triterpene saponins called ginsenosides, which are classified into two groups by the skeleton of aglycones, namely dammarane type and oleanane type. Dammarane-type ginsenosides dominate over oleanane type not only in amount but also in structural varieties. However, their sapogenin structure is restricted to two aglycones, protopanaxadiol and protopanaxatriol. So far, the genes encoding oxidosqualene cyclase (OSC) responsible for formation of dammarane skeleton have not been cloned, although OSC yielding oleanane skeleton (b-amyrin synthase) has been successfully cloned from this plant. In this study, cDNA cloning of OSC producing dammmarane triterpene was attempted from hairy root cultures of P. ginseng by homology based PCR method. A new OSC gene (named as PNA) obtained was expressed in a lanosterol synthase deficient (erg7) Saccharomyces cerevisiae strain GIL77. LC-MS and NMR analyses identified the accumulated product in the yeast transformant to be dammarenediol-II, demonstrating PNA to encode dammarenediol-II synthase.

Olive (Olea europaea) is a well-known evergreen tree native to the Mediterranean coast, whose fruits and oil have been used for foods and cooking. Olive contains large quantity of triterpene acids including oleanolic acid (6) as a major one.1,2) Recently, much attention has been paid for triterpene acids from pharmaceutical viewpoints because of their anti-HIV, 3) anti-inflammatory, 4) anti-tumor-promoting 5) activities and antagonist activity for an endothelin receptor, 6) etc. Wax of olive fruits contains predominantly oleanolic acid, 1) whereas that of the leaves contains a mixture of oleanolic acid and betulinic acid (16) in a ratio of 7 : 2.2) In addition to these triterpene acids, triterpene-diols, such as erythrodiol (8: oleanane type) and uvaol (15: ursane type) are also contained, even though in less quantity than the corresponding acids. 2)Successful production of triterpene acids by plant cell cultures has been documented. Production of bryonolic acid (17), an anti-allergic triterpene acid, by cultured cells of several cucurbitaceous plants 7) is a good example. Cell cultures of plants, however, do not always produce the same secondary metabolites as those in the mother plants. Some callus cultures produce no trace of the metabolites found in the mother plants but produce those metabolites that are not produced by the mother plants. This situation is exemplified by Glycyrrhiza glabra cell cultures, which did not produce glycyrrhizin (18), a major triterpene saponin of the mother plant, but produced betulinic acid (16) 8) and soyasaponin I (19).9) It is quite interesting to know what kinds and how much of triterpenes cultured cells produce. If they produce any particular ones in large quantity, such production system would benefit the supply of triterpene acids for clinical use, since purification and isolation of triterpenes from complex mixtures are generally laborious. Thus we induced cell cultures of O. europaea and investigated the production of triterpene metabolites.Triterpenes are biosynthesized from a common precursor, (3S)-oxidosqualene (1). Over one hundred of diverse triterpene skeletons reported from nature 10) are constructed at the cyclization step of oxidosqualene catalyzed by oxidosqualene cyclase (OSC). Thus, the studies on their product specificity, in particular, would lead to better understanding of the structural diversity of natural triterpenes. As a continuation of our studies on OSCs 11) in this direction, cDNA clonig of OSCs from Olive cell cultures was also conducted.In this paper, we report induction of cell cultures, isolation Olive (Olea europaea) contains large quantity of triterpene acids including oleanolic acid (6) as a major one. Varieties of biological activities exhibited by triterpene acids attracted our attentions, especially from pharmaceutical viewpoints. Cell culture of olive plant was induced and its triterpene constituents were studied. From the cell suspension cultures, six ursane type triterpene acids; ursolic acid (9), pomolic acid (10), rotundic acid (11)...

The whole plant extract of Eclipta prostrata and its isolated compounds were tested for their antiinflammatory effects against lipopolysaccharide (LPS)-induced nitric oxide (NO), prostaglandin E2 (PGE2 ) and tumor necrosis factor-alpha (TNF-α) release in RAW264.7 cells, as well as for the antiinflammatory mechanism of the active compound on mRNA expression. Among the isolated compounds, orobol (5) exhibited the highest activity against NO release with an IC50 value of 4.6 μm, followed by compounds 1, 2 and 4 with IC50 values of 12.7, 14.9 and 19.1 μm, respectively. The IC50 value of compound 5 against PGE2 release was found to be 49.6 μm, whereas it was inactive towards TNF-α (IC50 > 100 μm). The mechanism of orobol (5) was found to down-regulate iNOS and COX-2 mRNA expression in a concentration-dependent manner. The present study may support the traditional use of Eclipta prostrata for the treatment of inflammatory-related diseases.

No abstract

No abstract