Two triterpenoids and other constituents from Petasites tricholobus

Two migrated ursane skeleton triterpenoids, one is D:B-friedoursane-3alpha,16alpha-dihydroxy-7alpha,8alpha-epoxy-5(10)-ene, named petatrichol A (1) and the other one represents a novel triterpenoid carbon framework, named petatrichol B (2), along with 10 known compounds were isolated from the rhizome of Petasites tricholobus. Their structures were elucidated on the basis of spectroscopic methods (IR, EIMS, HRMS, 1D and 2D NMR). The triterpenoids were assayed against Escherichia coli, Staphylococcus aureus and Bacillus subtilis. Compounds 1 and 2 exhibited significant antibacterial activity against B. subtilis.     

Cycloartane type triterpenoids from the rhizomes of Polygonum bistorta

Two new compounds, 24(E)-ethylidenecycloartanone (1) and 24(E)-ethylidenecycloartan-3alpha-ol (2) were isolated from the rhizomes of Polygonum bistorta, together with seven known compounds viz., cycloartane-3,24-dione (3), 24-methylenecycloartanone (4), gamma-sitosterol (5), beta-sitosterol (6), beta-sitosterone (7), friedelin (8) and 3beta-friedelinol (9). All the cycloartane type triterpenoids, compounds 7 and 8 are reported for the first time from this plant. A combination of 1D and 2D NMR spectroscopy and MS were mainly used to elucidate the structures of the new compounds 1 and 2.     

Miscellaneous terpenoid constituents of Abies nephrolepis and their moderate cytotoxic activities

Three monoterpenoids and two triterpenoids were isolated from Abiesnephrolepis together with 53 known terpenoids. The structures of the compounds were established by 1D and 2D NMR spectroscopy. The absolute configuration of 3-hydroxycamphane-2-carboxylic acid was established as (1S,2R,3S,4R) by Cu-Kα X-ray crystallography. All 58 isolates were tested for cytotoxic activity against four tumor cells viz. A549 (human lung adenocarcinoma), Colo205 (colon adenocarcinoma), QGY-7703 (human hepatoma) and THP-1 (human monocytic leukemia). α-Cadinol exhibited the best effects on A549, Colo205 and QGY-7703 with IC₅₀ values of 8.6, 8.1 and 4.6 μg/mL, respectively.     

Pentacyclic triterpenoids from Embelia schimperi

Five oleanane-type pentacyclic triterpenoids were isolated by chromatographic separation of a chloroform extract of the stem bark of Embelia schimperi. Three of these compounds have a methyleneoxy bridge. Two compounds, embelinone and schimperinone, are reported here for the first time from a natural source (they have been synthesized previously during chemical transformations). Their structures were determined by spectroscopic techniques, among which 2-D NMR was useful for complete characterization. Three of the triterpenoids exhibited mild antibacterial properties against the gram-positive bacterial strain Rhodococcus sp.     

Anti-HIV-1 protease triterpenoids from Stauntonia obovatifoliola Hayata subsp. intermedia

Three triterpenoids, 16beta-hydroxy-2,3-seco-lup-20(29)-ene-2,3-dioic acid (1), 3beta,21beta,24-trihydroxy-30-noroleana-12,20(29)-dien-28-oic acid (2) and 16beta-hydroxylupane-1,20(29)-dien-3-one (3), along with eleven known triterpenes were isolated from stems of Stauntonia obovatifoliola Hayata subsp. intermedia (Y.C. Wu) T. Chen. Their structures were determined by analysis of HR-EI/FAB-MS and 1D and 2D NMR spectroscopic data and comparison with those in the literature. Ten of the compounds showed inhibitory activity against HIV-1 protease.     

Cytotoxic cycloartanes from the fruits of Caloncoba glauca

Two new cycloartane-type triterpenoids, glaucartanoic acids A (1) and B (2), together with five known compounds were isolated from the fruits of Caloncoba glauca. Their structures were elucidated by spectroscopic methods including extensive 1D and 2D NMR techniques, by chemical evidence and by comparison with literature data. The new compounds were evaluated for their in vitro cytotoxicity against five human cancer cell lines.     

Concentriols B,C and D,three squalene-type triterpenoids from the ascomycete Daldinia concentrica

Three squalene-type triterpenoids named concentricols B, C and D (1-3) were isolated from the ethyl acetate extract of fruiting bodies of the xylariaceous ascomycete Daldinia concentrica. Their absolute structures were elucidated by analysis of 2D NMR, MS, IR and UV spectra, and the modified Mosher's method.     

A new iridoid and effect on the rat aortic vascular smooth muscle cell proliferation of isolated compounds from Buddleja officinalis

A new iridoid, named methylscutelloside (1) together with 19 known compounds belonging to the iridoids (2-4), monoterpenoids (5), flavonoids (6-8), triterpenoids (9-14), and phenylethanoids (15-20) were isolated from the flowers of Buddleja officinalis. Their chemical structures were elucidated on the basis of physicochemical properties, and by spectroscopic methods including 1D, 2D NMR, and MS. All isolated compounds were tested in vitro for their effects on the proliferation of rat aortic vascular smooth muscle cells (VSMCs). Among them, iridoids were the main active components and showed significant inhibitory effects on PDGF-BB-induced proliferation in rat aortic VSMCs.     

Triterpenoids from Gentiana scabra

Five triterpenoids, (20S)-dammara-13(17),24-dien-3-one, (20R)-dammara-13(17),24-dien-3-one, chirat-16-en-3-one, chirat-17(22)-en-3-one and 17beta,21beta-epoxyhopan-3-one, were isolated from the rhizomes and roots of Gentiana scabra together with five known ones, chiratenol, hop-17(21)-en-3-one, hop-17(21)-en-3beta-ol, lupeol and alpha-amyrin. The structures of new compounds were elucidated on the basis of spectroscopic studies.     

Triterpenoids from the orchids Agrostophyllum brevipes and Agrostophyllum callosum

Agrostophyllinol and agrostophyllinone, two new triterpenoids, were isolated from the orchid Agrostophyllum brevipes. Agrostophyllinone was also isolated from another orchid Agrostophyllum callosum. The structures of agrostophyllinol and agrostophyllinone were established as 24-methylene-lanosta-9(11)-en-3beta-ol (5a) and 24-methylene-lanosta-9(11)-en-3-one (5c), respectively, from spectral and chemical evidence. The above triterpenoids are of considerable biogenetic importance.     

Bangangxanthone A and B, two xanthones from the stem bark of Garcinia polyantha Oliv

Two xanthones, bangangxanthone A (1) [1,5,8-trihydroxy-6'-methyl-6'-(4-methylpent-3-enyl)- pyrano[2',3':3,4]xanthone] and B (2) [1,4,8-trihydroxy-2-prenylxanthone], along with two known xanthones, 1,5-dihydroxyxanthone, 2-hydroxy-1,7-dimethoxyxanthone and the pentacyclic triterpenoids, friedelin, oleanolic acid and lupeol were isolated from the chloroform extract of the stem bark of Garcinia polyantha. The structures of these compounds were assigned by spectroscopic analysis. Compounds 1-4 showed antioxidant DPPH radical scavenging activities.     

Triterpenoids from the bark of Ruptiliocarpon caracolito

Five spirocaracolitone triterpenoids were isolated from the dichloromethane-soluble fraction of the bark of Ruptiliocarpon caracolito, and their structures were determined mainly by application of 1D and 2D NMR spectroscopy. Two known CD-spirotriterpenoids were also isolated from the same source. This brings the total number of known CD-spirotriterpenoids from this source to 17. The discovery of such a large number of closely-related compounds in a single species represents an excellent example of phytochemical redundancy as a defense mechanism.     

Chemical constituents of leaves and stem bark of Plumeria obtusa

The continued studies on the constituents of the fresh leaves and stem bark of Plumeria obtusa Linn. have led to the isolation and characterization of four new triterpenoids, dammara-12,20(22)Z-dien-3-one (1), dammara-12,20(22)Z-dien-3beta-ol (2), olean-12-en-3beta,27-diol (3), and 27-hydroxyolean-12-en-3-one (4) and 12 known compounds, which included eight triterpenoids; dammara-3beta,20(S),25-triol (5), urs-12-en-3beta-hydroxy-27-Z-feruloyloxy-28-oic acid (6), 3beta-hydroxyolean-12-en-28-oic acid (7), 3beta,27-dihydroxylupan-29-ene (8), 3beta-hydroxylupan-29-en-28-oic acid (9), 3beta-hydroxyursan-12-en-28-oic acid (11), 3beta-hydroxy-27-p-coumaroyloxy-olea-12-en-28-oic acid (12) and urs-12-en-3-one (15); an iridoid 1alpha-plumieride (10); a cardenolide 3alpha,14beta-dihydroxy-17beta-card-20(22)-enolide (13); a fatty acid ester methyl n-octadecanoate (14) and a steroid 3beta-hydroxy-delta5-stigmastane (16). The new constituents were characterized through spectroscopic studies including 1D (1H and 31C NMR) and 2D (COSY-45, NOESY, J-resolved, HMQC and HMBC) NMR and chemical transformations. This is the first report on the isolation of dammarane triterpenoids from P. obtusa. Compounds 5 and 6 are hitherto unreported from P. obtusa. The known compounds were identified by comparison of their spectral data with those reported in the literature.     

Flavaglines and triterpenoids from the leaves of Aglaia forbesii

Three structurally complex flavaglines of the cyclopenta[bc]benzopyran type, named desacetylpyramidaglains A, C, D (1-3), and the triterpene 23, 24, 25-trihydroxycycloartan-3-one (4) were isolated from the leaves of Aglaia forbesii together with the two rare pregnane steroids 2beta,3beta-dihydroxy-5alpha-pregn-17(Z)-en-16-one and 2beta,3beta-dihydroxy-5alpha-pregn-17(E)-en-16-one, as well as the bisamide pyramidatine, the sesquiterpene spathulenol, and the widespread triterpenoids lupeol, lupenone, and a mixture of beta-sitosterol and stigmasterol. Their structures were elucidated by 1D and 2D NMR spectroscopy and mass spectrometry. Compounds 3, 4, 5, and 6 were tested for antituberculosis and antiviral activity.     

Immunomodulatory triterpenoids from the oleogum resin of Boswellia carterii Birdwood

The immunomodulatory bioassay-guided fractionation of the oleogum resin of frankincense (Boswellia carterii Birdwood) resulted in the isolation and identification of 9 compounds; palmitic acid and eight triterpenoids belonging to lupane, ursane, oleanane, and tirucallane skeleta were isolated form the resin. These triterpenoids are lupeol, beta-boswellic acid, 11-keto-beta-boswellic acid, acetyl beta-boswellic acid, acetyl 11-keto-beta-boswellic acid, acetyl-alpha-boswellic acid, 3-oxo-tirucallic acid, and 3-hydroxy-tirucallic acid. The structures of the isolated compounds were deduced based on spectroscopic evidences. The lymphocyte transformation assay of the isolated compounds proved that the total extract retained more activity than that of any of the purified compounds.     

Lanostane triterpenoids from the inedible mushroom Fomitopsis spraguei

Investigation of the methanolic extract of the inedible mushroom Fomitopsis spraguei (Polyporaceae) led to the isolation of five lanostane-type triterpenoids (1-5): three new compounds named fomitopsins A-C (2-4), and two known compounds, quercinic acid C (1) and 3alpha-carboxyacetyl-12beta-hydroxyquercinic acid (5). Their structures were determined by 2D NMR, MS, IR, UV spectra, and X-ray crystallographic analyses. An X-ray crystal structure analysis of quercinic acid C (1) established its stereochemistry as 3R,12R-dihydroxy-24R-methyl-23-oxo-25S-lanost-8-en-26-oic acid.     

Diterpenoids and triterpenoids from Euphorbia guyoniana

Two new compounds with tigliane and cycloartane skeletons: 4,12-dideoxy(4alpha)phorbol-13-hexadecanoate (1) and 24-methylenecycloartane-3,28-diol (2), respectively, in addition of four known diterpenoids and 13 triterpenoids: 3-benzoyloxy-5,15-diacetoxy-9,14-dioxojatropha-6(17),11-diene (4), ent-abieta-8(14),13(15)-dien-16,12-olide (5), ent-8alpha,14alpha-epoxyabieta-11,13(15)-dien-16,12-olide (6), ent-3-hydroxyatis-16(17)-ene-2,14-dione (7), 3beta-hydroxytaraxer-14-en-28-oic acid (8), beta-sitosteryl-3beta-glucopyranoside-6'-O-palmitate (9), multiflorenyl acetate (10), multiflorenyl palmitate (11), peplusol (12), 24-methylenecycloartanol (3), lanosterol (13), euferol (14), butyrospermol (15), cycloartenol (16), obtusifoliol (17), cycloeucalenol (18) and beta-sitosterol (19), were isolated from the roots of Euphorbia guyoniana. Their structures were established on the basis of physical and spectroscopic analysis, including 1D and 2D homo- and heteronuclear NMR experiments (COSY, HSQC, HMBC and NOESY) and by comparison with the literature data.     

锐尖山香圆叶中三萜类成分的研究

从锐尖山香圆(Turpinia arguta (Lindl.) Seem.)叶中分离得到了11个三萜类化合物。通过光谱分析,分别鉴定其结构为熊果酸(1), 3β,6β,23-trihydroxy-12-oleanen-28-oic acid (2), 3β,6β,23-trihydroxyurs-12-en-28-oic acid (3), 3β,6β,19α,23-tetrahydroxyurs-12-en-28-oic acid (4), 1 α, 3β,23-trihydroxy-12-oleanen-28-oic acid (5), arjunglucoside II (6), rosamultin (7), 3β-O-β-D-glucopyranoylcincholic acid (8), cinchonaglycoside C (9), mussaendoside S (10) 和3β-O-β-D-glucopyranosyl quinovic acid 28-O-β-D-glucopyranosyl ester (11)。除化合物1和6,其它化合物均为首次从山香圆叶中分离得到。     

A new macrolide and six cycloartane triterpenoids from the tubers of Bletilla striata

A new 12-membered macrolide (1) along with two known C-31 and four known C-32 cycloartane triterpenoids (2–7) were isolated from the tubers of Bletilla striata. Their structures were determined by spectroscopic analysis, including 1D NMR, 2D NMR, and HRESIMS. The chemotaxonomic significance of these isolates, especially C-31 and C-32 cycloartane triterpenoids, are discussed. To our knowledge, this is the first report on the co-occurrence of the unusual 24-methyl, 24-ethyl, and 24,24-dimethyl cycloartane triterpenoids in the family Orchidaceae.     

A new ecdysteroid with unique 9beta-OH and four other ecdysteroids from Silene italica ssp. nemoralis

A new natural ecdysteroid, 9beta,20-dihydroxyecdysone (1) and four related compounds 5alpha-20-hydroxyecdysone (2), 5alpha-2-deoxy-integristerone A (3), integristerone A (4) and 22-deoxy-integristerone A (5) were isolated from the herb of Silene italica ssp. nemoralis. Compound 1 is the C-9 epimer of the known 9alpha,20-dihydroxyecdysone (6) and represents a peculiar steroid skeleton. The structures of the compounds were elucidated by 1D and 2D NMR, IR and MS spectroscopy.