3-氧,11α-羟基、Δ~(12)-齐墩果烯及其类似化合物的~(13)C NMR分析

化合物１－８属于近似结构的齐墩果烷型三萜，它们分别为：β－ａｍｙｒｉｎ（１）；３－氧，Δ１１，１３（１８）－齐墩果二烯（２）；３β－羟基，Δ１１，１３（１８）－齐墩果二烯（３）；３β，２４－二羟基，Δ１１，１３（１８）－齐墩果二烯（４）；３，１１－二氧，Δ１２－齐墩果烯（５）；３－氧，Δ９（１１），１２－齐墩果二烯（６）；３－氧，１１α－羟基，Δ１２－齐墩果烯（７）；３β，１１α－二羟基，Δ１２－齐墩果烯（８）．它们的１３ＣＮＭＲ化学位移归属已确定，并通过了ＤＥＰＴ谱的验证．按结构特点分为三组：２～４为第一组，１，５，７，８为第二组，６为第三组．本文重点讨论了它们的１３ＣＮＭＲ化学位移由其结构特点引起的变化，得到了化学位移与结构相关的有意义的结果．     

Triterpene glycosides from <Emphasis Type="Italic">Astragalus</Emphasis> and their genins. LXXVII. Cyclomacrogenin B,a new cycloartane triterpenoid

Ten pure compounds, three of which were identified as β-sitosterol, β-sitosterol β-D-glucopyranoside, and D-3-O-methyl-chiro-inositol, were isolated from roots of Astragalus macropus Bunge (Leguminosae). The structure of the new cycloartane triterpenoid cyclomacrogenin B was established as 24R-cycloartan-1α,3β,7β,24,25-pentaol. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 502–504, September-October, 2008. Original article submitted May 26, 2008.     

HPLC method for the determination and pharmacokinetic studies of four triterpenoids in rat plasma after oral administration of Ganoderma lucidum extract

Four major triterpenoids (ganoderic acids C(2), B, K and H) in rat plasma after oral administration of G. lucidum extract were analyzed quantitatively by high-performance liquid chromatography (HPLC). Plasma samples taken from rats were acidified with hydrochloric acid and extracted with dichloromethane-ethyl acetate (90:10). The chromatographic separation was achieved on an Agilent Zorbax SB-C(18) column (250 x 4.6 mm, 5 microm) at 35 degrees C, with a linear gradient of acetonitrile and 0.03% aqueous phosphoric acid (v/v), at a flow rate of 1.0 mL/min. The four triterpenoids and internal standard (hydrocortisone) were detected at a wavelength 252 nm. All calibration curves showed good linearity (r(2) > 0.99) within test ranges. The relative deviation of this method was less than 10% for intra- and inter-day assays, and the accuracy ranged from 89 to 108%. The extract recovery for the four triterpenoids and internal standard ranged from 95 to 67%, and the QC samples were found to be stable according to the results of the stability study. This is the first report on determination of the major triterpenoids in rat plasma after oral administration of G. lucidum extract and the results provided a firm basis for clarifying the pharmacological effect of G. lucidum and evaluating the clinical applications of this medicinal fungus.     

Triterpenoids from Eugenia grandis: structure elucidation by NMR spectroscopy

A new pentacyclic triterpenoid, 2alpha,3beta-dihydroxylup-12-en-28-oic acid (1) and a rarely encountered pentacyclic triterpenoid, 3beta-hydroxylup-12-en-28-oic acid (2), together with five known compounds, friedelin (3), 3beta-friedelinol (4), betulinic acid (5), oleanolic acid (6) and beta-sitosterol (7) were isolated from the chloroform extract of stem bark of Eugenia grandis (Syn: Syzygium grande). The structure and stereochemistry of the new compound (1) and the rarely encountered compound (2) were established by 1D and 2D NMR spectroscopic techniques. All the above isolated compounds from this plant are reported for the first time.     

Structural determination of seven new triterpenoids from Kadsura heteroclita by NMR techniques

Seven new triterpenoids, namely heteroclitalactones G-M (1-7), were isolated from the ethanol extract of the stems of Kadsura heteroclita. Structures of these compounds were characterized by extensive 1D and 2D NMR spectroscopic analyses.     

Highly Oxygenated Triterpenoids and Diterpenoids from Fructus Rubi (Rubus chingii Hu) and Their NF-kappa B Inhibitory Effects

During a phytochemical investigation of the unripe fruits of Rubus chingii Hu (i.e., Fructus Rubi, a traditional Chinese medicine named “Fu-Pen-Zi”), a number of highly oxygenated terpenoids were isolated and characterized. These included nine ursane-type (1, 2, and 4–10), five oleanane-type (3, 11–14), and six cucurbitane-type (15–20) triterpenoids, together with five ent-kaurane-type diterpenoids (21–25). Among them, (4R,5R,8R,9R,10R,14S,17S,18S,19R,20R)-2,19α,23-trihydroxy-3-oxo-urs-1,12-dien-28-oic acid (rubusacid A, 1), (2R*,4S*,5R*,8R*,9R*,10R*,14S*,17S*, 18S*,19R*,20R*)-2α,19α,24-trihydroxy-3-oxo-urs-12-en-28-oic acid (rubusacid B, 2), (5R,8R,9R,10R, 14S,17R,18S,19S)-2,19α-dihydroxy-olean-1,12-dien-28-oic acid (rubusacid C, 3), and (3S,5S,8S,9R, 10S,13R,16R)-3α,16α,17-trihydroxy-ent-kaur-2-one (rubusone, 21) were previously undescribed. Their chemical structures and absolute configurations were elucidated on the basis of spectroscopic data and electronic circular dichroism (ECD) analyses. Compounds 1 and 3 are rare naturally occurring pentacyclic triterpenoids featuring a special α,β-unsaturated keto-enol (diosphenol) unit in ring A. Cucurbitacin B (15), cucurbitacin D (16), and 3α,16α,20(R),25-tetrahydroxy-cucurbita-5,23- dien-2,11,22-trione (17) were found to have remarkable inhibitory effects against NF-κB, with IC₅₀ values of 0.08, 0.61, and 1.60 μM, respectively.     

The Identification of New Triterpenoids in Eucalyptus globulus Wood

Eight polyhydroxy triterpenoid acids, hederagenin, (4α)-23-hydroxybetulinic acid, maslinic acid, corosolic acid, arjunolic acid, asiatic acid, caulophyllogenin, and madecassic acid, with 2, 3, and 4 hydroxyl substituents, were identified and quantified in the dichloromethane extract of Eucalyptus globulus wood by comparing their GC-retention time and mass spectra with standards. Two other triterpenoid acids were tentatively identified by analyzing their mass spectra, as (2α)-2-hydroxybetulinic acid and (2α,4α)-2,23-dihydroxybetulinic acid, with 2 and 3 hydroxyl substituents. Two MS detectors were used, a quadrupole ion trap (QIT) and a quadrupole mass filter (QMF). The EI fragmentation pattern of the trimethylsilylated polyhydroxy structures of these triterpenoid acids is characterized by the sequential loss of the trimethylsilylated hydroxyl groups, most of them by the retro-Diels-Alder (rDA) opening of the C ring with a π-bond at C12-C13. The rDA C-ring opening produces ions at m/z 320 (or 318) and m/z 278 (or 277, 276, 366). Sequential losses of the hydroxyl groups produce ions with m/z from [M - 90] to [M - 90*y], where y is the number of hydroxyl substituents present (from 2 to 4). Moreover, specific cleavage in ring E was observed, passing from m/z 203 to m/z 133 and conducting other major fragments such as m/z 189.     

Lanostane-type triterpenoids from Kadsura coccinea

Systematic phytochemical investigation on the stems of Kadsura coccinea resulted in the isolation of eleven new lanostane-type triterpenoids, named kadcoccinones G–Q (1–11), together with two known structural analogues, kadpolysperin M (12) and abiesatrine D (13). Their structures were characterized on the basis of comprehensive spectroscopic methods, and the absolute configuration of 1 was ascertained by single-crystal X-ray diffraction. Structurally, compounds 1/2, 4/5, and 6/7 were three pairs of C-12 epimers, respectively. Additionally, compounds 1–11 were evaluated for their in vitro cytotoxicity against the human tumor HL-60, SMMC-772, A-549, MCF-7, SW-480, and HeLa cell lines using the MTS viability assay.     

Self‐assembly of Renewable Nano‐sized Triterpenoids

Studies on plant metabolites have gained renewed interest in recent years because these can serve as renewable chemicals for the development of a sustainable society. Among various plant secondary metabolites, terpenoids constitute the major component and triterpenoids are the 30C subset of it. In recent years, triterpenoids have drawn the attention of scientific community due to many of its potential and realized applications in medicine, drug delivery, thermochromic materials, pollutant capture, catalysis, liquid crystals, etc. In this personal review, we have discussed our computational results carried out on sixty representative naturally occurring triterpenoids demonstrating that all the triterpenoids are renewable functional nano‐entities. Study of the self‐assembly of several triterpenoids such as betulin, betulinic acid, oleanolic acid, glycyrrhetinic acid and arjunolic acid and their derivatives in different liquids have also been discussed. Moreover, the utilization of the resulting supramolecular architectures such as vesicles, spheres, flowers and fibrillar networks of nano‐ to micrometer dimensions and gels have also been discussed in the perspective of green, renewable and nanos.     

Nordammarane Triterpenoids from Sanguisorba officinalis

Three new nordammarane triterpenoids, 12β‐O‐acetyl‐3β,22‐dihydroxy‐23,24,25,26,27‐pentanordammarane ( 1 ), 12β,22‐dihydroxy‐3‐oxo‐23,24,25,26,27‐pentanordammarane ( 2 ), and 3β,12β‐dihydroxy‐23,24,25,26,27‐pentanordammarane‐22‐carbaldehyde ( 3 ), were isolated from the EtOH extract of the roots of Sanguisorba officinalis. Structural elucidation of these new triterpenoids on the basis of spectroscopic analyses, including including 1D‐ and 2D‐NMR, and HR‐ESI‐MS, is reported