Microbial transformation of ursolic acid by Syncephalastrum racemosum (Cohn) Schroter AS 3.264

Biotransformation of ursolic acid by the filamentous fungus Syncephalastrum racemosum (Cohn) Schroter AS 3.264 yielded five metabolites. Their structures were identified as 3β,21β-dihydroxy-urs-11-en-28-oic acid-13-lactone, 3β,7β,21β-trihydroxy-urs-11-en-28-oic acid-13-lactone, 1β,3β-dihydroxy-urs-12-en-21-one-28-oic acid, 1β,3β,21β-trihydroxy-urs-12-en-28-oic acid and 11,26-epoxy-3β,21β-dihydroxy-urs-12-en-28-oic acid based on NMR and MS spectroscopic analyses. The condensation reactions to form 28-oic acid-13-lactone ring and 11,26-epoxy ring are not frequently seen for the biotransformation of triterpenoids. One compound showed moderate inhibitory activity against protein tyrosine phosphatase 1B (PTP1B).     

Three new oxygenated triterpenoids of the lupane series from Gymnosporia wallichiana

Two new epimeric triterpenoid acids, gymnosporic acid, 3β-hydroxy-(20R)-lupan-29-oic acid, wallichianic acid, 3β-hydroxy-(20S)-lupan-29-oic acid and a new diol wallichianol, (20S)-lupane-3β,29-diol have been isolated from Gymnosporia wallichiana, in addition to β-amyrin, friedelin, 3β-hydroxy-29-norlupan-20-one and dulcitol.     

3β-hydroxy-21β-e-cinnamoyloxyolean-12-en-28-oic acid,a triterpenoid from enterolobium contorstisiliquum

The triterpenes 3β-hydroxy-21β-E-cinnamoyloxyolean-12-en-20-oic acid, 3β,21β-dihydroxyolean-12-en-28-oic acid (machaerinic acid) and its lactone (3β-hydroxyolean-12-en-21β→28-lactone) were isolated from the fruits of Enterolobium contorstisiliquum. Methyl and ethyl esters of 3β,21β-dihydroxyolean-12-en-oic acid were isolated and characterized as artifacts. The structures of these triterpenes have been established by a study of their chemical and spectroscopic (IR, MS and NMR) data.     

Further triterpenoids and 13C NMR spectra of oleanane derivatives from Phytolacca acinosa

In addition to five known triterpenoids, namely acinosolic acid, phytolaccagenin, phytolaccagenic acid, esculentic acid and jaligonic acid, three new oleanane derivatives, designated as phytolaccagenin A, acinosolic acid A and acinosolic acid B, have been isolated and characterized from the defatted berries of Phytolacca acinosa. The new compounds have been identified as 3β-acetoxy-3β-methyloleanate-12-en-2β,23α-diol-28β-oic acid, 3β-acetoxy-28β-methyloleanate-12-en-2β-ol-30β-oic acid and 2β-acetoxy-28β-methyloleanate-12-en-3β-ol-30β-oic acid, respectively.     

Terpenes of Dipterocarpus and Doona species

From the resins of Dipterocarpus hispidus, Dipterocarpus zeylanicus and Doona macrophylla, asiatic (2α,3β,23α-trihydroxyurs-12-en-28-oic) and 2α,3β-dihydroxyurs-12-en-28-oic acids have been isolated. The resin of Doona macrophylla contains ursolic acid and that of Doona congestiflora asiatic acid, 20β-hydroxy-3-oxo dammar-23-ene (Dipterocarpol) and a dihydroxyolean-12-en-28-oic acid. The bark of Dipterocarpus hispidus contains betulinic acid, dipterocarpol, and 3β,20β-dihydroxydammar-23-ene (dammarenediol 20S) whilst the timber contained dipterocarpol and asiatic acid.     

Oleanane-type glycosides from Weigela x Styriaca and two cultivars of W. florida: “Minor black” and “Brigela”

Sixteen oleanane-type glycosides were extracted from three Weigela hybrids and cultivars: W. x Styriaca, W. florida “Minor black” and W. florida “Brigela”, and four of them were previously undescribed ones: 3-O-β-D-xylopyranosyl-(1→4)-β-D-xylopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranosyloleanolic acid, 3-O-β-D-xylopyranosyl-(1→4)-β-D-xylopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyloleanolic acid, 3-O-β-D-xylopyranosyl-(1→4)-β-D-xylopyranosyl-(1→4)-β-D-xylopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyloleanolic acid, and 3-O-β-D-xylopyranosyl-(1→4)-β-D-xylopyranosyl-(1→4)-β-D-xylopyranosyl-(1→4)-β-D-xylopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyloleanolic acid. Their full structural elucidation required extensive 1D and 2D NMR experiments, as well as mass spectrometry analysis. Six compounds among the known ones were in sufficient amount to be tested for their antifungal activity against Candida albicans, and their antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa.     

Triterpenoids from enkianthus campanulatus

From the leaves of Enkianthus campanulatus were isolated three new triterpenes, 3-oxo-19,23,24-trihydroxyurs-12-en-28-oic acid, 3β,6β, 19,23-tetrahydroxyurs-12-en-28-oic acid and 3β,6β,23-trihydroxyurs-12-en-28-oic acid.     

Metabolic transformations of some ent-kaurenes in Gibberella fujikuroi

The conversion of ent-kaur-16-enes to gibberellic acid in Gibberella fujikuroi is blocked by A-ring modifications. Thus ent-3β-hydroxykaur-16-en-19-yl succinate gives good conversion (46%) to the 7β-hydroxy derivative.* Under the same conditions the 3β-epimer gives 7β- or 6α-hydroxylation and the former occurs for the 3-oxo analogue. The succinoyloxy function acts as a less efficient block and ent-kaur-16-en-19-yl succinate is converted to 7β-hydroxy and 6β,7β-dihydroxy derivatives along with gibberellic acid. Hydrolysis of the succinate block of the metabolities provides the 7β, 19-diol and 6β,7β, 19-triol. Of this pair only the former was effectively metabolized to gibberellic acid in G. fujikuroi.     

Graded-hydrolysis studies on bael (aegle marmelos) gum

Graded hydrolysis of purified bael gum afforded three neutral and two acidic oligosaccharides, together with monosaccharides. These sugars were identified through periodate oxidation, methylation, reduction with lithium aluminum hydride, co-chromatography, and preparation of crystalline derivatives. The neutral oligosaccharides were characterized as 3-O-β-D-galactopyranosyl-L-arabinose, 5-O-β-D-galactopyranosyl-L-arabinose, and 3-O-β-D-galactopyranosyl-D-galactose, and the acidic oligosaccharides as 3-O-(β-D-galactopyranosyluronic acid)-D-galactose and 3-O-(β-D-galactopyranosyluronic acid)-3-O-β-D-galactopyranosyl-D-galactose.     

Diterpenoids from Salvia oxyodon and Salvia lavandulifolia

Three new diterpenoids have been detected in Salvia oxyodon and identified as 3β-hydroxy-dehydroabietic acid, 3β-acetoxy-abieta-8(14)-en-18-oic acid 9α,13α-endoperoxide and 3β-hydroxy-abieta-8(14)-en-18-oic acid 9α,13α-endoperoxide. Salvia lavandulifolia yielded two known compounds ursolic acid and galdosol.     

Isolation and characterization of two saponins from Fagonia indica

Two new bisglycosidic triterpenoid saponins were isolated from the ethanolic extract of the aerial parts of Fagonia indica. They were characterized as 23,28-di-O-β-D-glucopyranosyltaraxer-20-en-28-oic acid and 3β,28-di-O-β-D-glucopyr acid. Furthermore, the conversion of the aglycone to 3β,23-dihydroxy-28,20β-taraxastonolide, nahagenin, during the acidic hydrolysis of the new saponins was studied.     

Chemical synthesis of 3β-sulfooxy-7β-hydroxy-24-nor-5-cholenoic acid: An internal standard for mass spectrometric analysis of the abnormal Δ-bile acids occurring in Niemann-Pick disease

In Niemann-Pick disease, type C1, increased amounts of 3β,7β-dihydroxy-5-cholenoic acid are reported to be present in urinary bile acids. The compound occurs as a tri-conjugate, sulfated at C-3, N-acetylglucosamidated at C-7, and N-acylamidated with taurine or glycine at C-24. For sensitive LC-MS/MS analysis of this bile acid, a suitable internal standard is needed. We report here the synthesis of a satisfactory internal standard, 3β-sulfooxy-7β-hydroxy-24-nor-5-cholenoic acid (as the disodium salt). The key reactions involved were (1) the so-called “second order” Beckmann rearrangement (one-carbon degradation at C-24) of hyodeoxycholic acid (HDCA) 3,6-diformate with sodium nitrite in a mixture of trifluoroacetic anhydride and trifluoroacetic acid, (2) simultaneous inversion at C-3 and elimination at C-6 of the ditosylate derivatives of the resulting 3α,6α-dihydroxy-24-nor-5β-cholanoic acid with potassium acetate in aqueous N,N-dimethylformamide, and (3) regioselective sulfation at C-3 of an intermediary 3β,7β-dihydroxy-24-nor-Δ⁵ derivative using sulfur trioxide-trimethylamine complex. Overall yield of the desired compound was 1.8% in 12 steps from HDCA.     

Microbial transformation of acetyl-11-keto-β-boswellic acid and their inhibitory activity on LPS-induced NO production

The capabilities of 20 strains of fungi to transform acetyl-11-keto-β-boswellic (AKBA) were screened. And biotransformation of AKBA by Cunninghamella blakesleana AS 3.970 afforded five metabolites (1–5), while two metabolites (6, 7) were isolated from biotransformation of Cunninghamella elegans AS 3.1207. The chemical structures of these metabolites were identified by spectral methods including 2D NMR and their structures were elucidated as 7β-hydroxy-3-acety-11-keto-β-boswellic acid (1), 21β-dihydroxy-3-acety-11-keto-β-boswellic acid (2), 7β,22α-dihydroxy-3-acety-11-keto-β-boswellic acid (3), 7β,16α-dihydroxy-3-acety-11-keto-β-boswellic acid (4), 7β,15α-dihydroxy-3-acety-11-keto-β-boswellic acid (5); 7β,15α,21β-trihydroxy-3-acety-11-keto-β-boswellic acid (6) and 15α,21β-dihydroxy-3-acety-11-keto-β-boswellic acid (7). All these products are previously unknown. Their primary structure–activity relationships (SAR) of inhibition activity on LPS-induced NO production in RAW 264.7 macrophage cells were evaluated.     

Synthesis, aggregation behavior and cholesterol solubilization studies of 16-epi-pythocholic acid (3α,12α,16β-trihydroxy-5β-cholan-24-oic acid)

Synthesis, aggregation behavior and in vitro cholesterol solubilization studies of 16-epi-pythocholic acid (3α,12α,16β-trihydroxy-5β-cholan-24-oic acid, EPCA) are reported. The synthesis of this unnatural epimer of pythocholic acid (3α,12α,16α-trihydroxy-5β-cholan-24-oic acid, PCA) involves a series of simple and selective chemical transformations with an overall yield of 21% starting from readily available cholic acid (CA). The critical micellar concentration (CMC) of 16-epi-pythocholate in aqueous media was determined using pyrene as a fluorescent probe. In vitro cholesterol solubilization ability was evaluated using anhydrous cholesterol and results were compared with those of other natural di- and trihydroxy bile acids. These studies showed that 16-epi-pythocholic acid (16β-hydroxy-deoxycholic acid) behaves similar to cholic acid (CA) and avicholic acid (3α,7α,16α-trihydroxy-5β-cholan-24-oic acid, ACA) in its aggregation behavior and cholesterol dissolution properties.     

Triterpene saponins of Genista ulicina Spach

From the n-BuOH extract of the aerial parts of Genista ulicina, six triterpene saponins, 3-O-β-d-glucopyranosyl-olean-12-ene-3β,27,28,30-tetraol, 3-O-β-d-glucopyranosyl-olean-12-ene-3β,27,28,29-tetraol, 3,29-di-O-β-d-glucopyranosyl-olean-12-ene-3β,27,28,29-tetraol, 3-O-β-d-glucopyranosyl-olean-12-ene-3β,28,29-triol-27-oic acid, 3-O-β-d-glucopyranosyl-olean-12-ene-3β,27,28-triol-29-oic acid, and 3-O-β-d-glucopyranosyl-14-H-27-nor-olean-12-ene-3β,28,29-triol, were isolated together with eight known triterpene saponins and six flavonoids. Their structures were established mainly by means of spectroscopic methods (1D and 2D-NMR as well as HR-ESI-MS). The n-BuOH extract, investigated for its antitumor growth inhibition of human colon cancer HT-29 cells, presented no significant activity (IC₅₀ > 100 μg).     

Triterpenoids from guettarda angelica

From the root bark of Guettarda angelica were isolated 3-O-β-d-glucopyranosyl-quinovic acid and its aglycone. The root wood gave the same glucoside, rotundic acid, hederagenin and 3β,23-dihydroxyurs-12-en-28-oic acid.     

Terpenoid and biflavonoid constituents of Calophyllum calaba and Garcinia spicata from Sri Lanka

A new bark acid, isochapelieric acid (cis-chapelieric acid), chapelieric acid, friedelin, friedelan-3β-ol, canophyllal, canophyllol, friedelan-3β,28-diol, canophyllic acid and amentoflavone have been isolated and characterized from leaf extractives of Calophyllum calaba. ¹³CNMR spectra of methyl chapelierate and methyl isochapelierate have been recorded and interpreted. Leaf extractives of Garcinia spicata afforded an unidentified long chain carboxylic acid, friedelin, friedelan-3β-ol, sitosterol and the biflavanones GB-1, GB-1a, GB-2a and morelloflavone. Chemotaxonomic significance of the occurrence of some of the above foliar constituents in Calophyllum and Garcinia species is discussed.     

Periandrin II and IV,triterpene glycosides from Periandra dulcis

Investigation of the natural sweeteners of Periandra dulcis afforded new sweet triterpene glycosides, periandrin II (3-β-O-[β-d-glucuronopyranosyl-(1→-2)-β-d-glucuronopyranosyl]-25-formyl-olean-12(13)-en-30-oic acid) and periandrin IV (3-β-O-[β-d-glucuronopyranosyl-(1→2)-β-d-glucuronopyranosyl]-25-hydroxyolean-12(13)-en-30-oic acid). Evidence for the structures was obtained by correlation of their derivatives with known compounds.     

Arjunolitin,a triterpene glycoside fromTerminalia arjuna

Arjunolic acid diglycoside, which we have named arjunolitin, has earlier been reported fromTerminalia arjuna. Its structure has now been established as 3-O-β-d-glycopyranosyl 2α,3β-23-tri-hydroxyolean-12-en-28-oic acid 28-O-β-d-glucopyranoside by chemical and spectral data.     

Structures of 3,28-O-bisglycosidic triterpenoid saponins of Fatsia japonica

Four novel 3,28-O-bisglycosidic triterpenoid saponins were isolated from the mature fruits of F. japonica. They were characterized as the 28-O-α-l-rhamnopyranosyl-(1 → 4)-β-d-glucopyranosyl-(1 → 4)-β- d-glucopyranosides of 3-O-α-l-arabinopyranosyl echinocystic acid, 3-O-α-l-arabinopyranosyl hederagenin, 3-O-β-d-glucopyranosyl-(1 → 2)-α-l-arabinopyranosyl oleanolic acid and 3-O-β- d-glucopyranosyl-(1 → 2)-α-l-arabinopyranosyl hederagenin respectively.