Capsugenin,a dammarane triterpene from Corchorus capsularis

From the leaves of Corchorus capsularis a new dammarane triterpene glycoside, capsin, has been isolated. Capsin was identified as the 3-glucoside of 20,24-epoxy-3β,12β,25,30-tetrahydroxydammarane from spectral data. Capsin was tentatively assigned the (20S, 24S)-configuration by comparison with data available for similar compounds. One of the oxidation products of the aglycone appears to be a friedo-type derivative, formed by concerted methyl migration on decarboxylation of a C-30 carboxylic acid intermediate.     

A new triterpene glucoside from Cymbidium giganteum

A new triterpene glucoside, cymbidoside, has been isolated from Cymbidium giganteum. Its structure is shown to be 4ξ-(β-d-glucopyranosyloxymethyl)-14α-methyl-22ξ, 24ξ, 25,28-tetrahydroxy-9,19-cyclo-5α,9β-ergostan-3-one.     

A new ursane-type triterpenoid glycoside from Centella asiatica leaves modulates the production of nitric oxide and secretion of TNF-α in activated RAW 264.7 cells

One new ursane-type triterpenoid glycoside, asiaticoside G (1), five triterpenoids, asiaticoside (2), asiaticoside F (3), asiatic acid (4), quadranoside IV (5), and 2α,3β,6β-trihydroxyolean-12-en-28-oic acid 28-O-[α-l-rhamnopyranosyl-(1→4)-β-d-glucopyranosyl-(1→6)-β-d-glucopyranosyl] ester (6), and four flavonoids, kaempferol (7), quercetin (8), astragalin (9), and isoquercetin (10) were isolated from the leaves of Centella asiatica. Their chemical structures were elucidated by mass, 1D- and 2D-nuclear magnetic resonance (NMR) spectroscopy. The structure of new compound 1 was determined to be 2α,3β,23,30-tetrahydroxyurs-12-en-28-oic acid 28-O-[α-l-rhamnopyranosyl-(1→4)-β-d-glucopyranosyl-(1→6)-β-d-glucopyranosyl] ester. The anti-inflammatory activities of the isolated compounds were investigated on lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Asiaticoside G (1) potently inhibited the production of nitric oxide and tumor necrosis factor-α with inhibition rates of 77.3% and 69.0%, respectively, at the concentration of 100 μM.     

The development of a new adjuvant lipid-saponin complex and its use at experimental immunization by bacterial antigen

Immunostimulating complexes (ISCOM) have been modified by replacement of structural components of ISCOM; phosphatidylcholine has been replaced, by glycolipid of monogalactosyldiacylglycerol from sea macrophytes, saponin QuilA has been replaced by triterpene glycoside, Cucumarioside A₂-2. The resultant complex includes morphological structures of two types: the ISCOM-like structures with the characteristic morphology and sizes and also the tubular structures with diameter of about 40 nm and length of 150–400 nm. We have defined these structures as TI-complexes. These TI-complexes exhibit considerably lower toxicity than ISCOM. They may include an amphiphilic protein antigen and provide immunoadjuvant effect during experimental vaccination. Under conditions of the experimental immunization of mice with a weak immunogen (subunit membrane pore protein from Y. pseudotuberculosis), TI-complexes with antigen provided stronger humoral immune response to antigen than the complexes of porin with classical ISCOM, liposomes and Freund’s adjuvant. Thus, the TI-complexes represent a new type of adjuvant carriers for antigens.     

Two New Saponins from Lysimachia capillipes Hemsl.

To investigate the saponins from whole plants of Lysimachia capillipes Hemsl., two new saponins, named capilliposide E (1) and capilliposide F (2), were isolated. The structures of the new sa ponins were elucidated as 3 β, 22α-dihydroxy- 16α-acetat-28→ 13 -lactone-oleanane-3 -O- [β-D-glucopyranosyl(1→2)-α-L-arabinpyranoyl]-22-O-β-D-glucopyranoside (1) and 3 β, 22α-dihydroxy- 16α-acetat-28→ 13-1actone-oleanane-3-O- { [β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-(1→4)]-α-L-arabinpyranoyl }-22-O-βD-glucopyranoside (2). The structures of these compounds were determined by 1D- and 2D-NMR, MS techniques, and chemical methods.     

一年蓬的化学成分研究

利用柱层析、重结晶等分离手段,从菊科飞蓬属植物一年蓬的脂溶性成分中,分离得到5个化合物,经现代波谱手段鉴定它们为2个三萜：齐墩果-12-烯3β,23-丙叉基-28-醇(1)、齐墩果-12-烯3β-醇(2)和3个豆甾醇衍生物：豆甾-5-烯-3β,7a-二醇(3)、豆淄-4-烯3S,6α-二醇(4)、豆甾-7,24-二烯-3β-醇(5)。其中化合物1是苗次自天然界分离得到的化合物,且其^18C NMR数据及质谱数据为首次报道。对化合物1的酸水解反应得到了化合物齐墩果-12-烯-3β,23,28-三醇(1a),从而使化合物1的结构得到进一步确证。     

Lupane-triterpene glycosides from leaves of Acanthopanax koreanum

Two new lupane-triterpene glycosides named acankoreosides C and D, were isolated from the leaves of Acanthopanax koreanum. Based on spectroscopic data, the chemical structures were determined as 3-O-β- -glucopyranosyl 3α,11α-dihydroxylup-20(29)-en-28-oic acid 28-O-α- -rhamnopyranosyl-(1→4)-β- -glucopyranosyl-(1→6)-β- -glucopyranosyl ester and 3α,11α-dihydroxylup-23-al-20(29)-en-28-oic acid 28-O-α- -rhamnopyranosyl-(1→4)-β- -glucopyranosyl-(1→6)-β- -glucopyranosyl ester, respectively.