3,5,7,3′,5′-Pentahydroxyflavan and 3α-methoxyfriedelan from Humboldtia laurifolia

The leaf, bark and timber extractives of Humboldtia laurifolia were investigated and the following compounds have been isolated: O-acetyloleanolic aldehyde, a sitosteryl ester, lupeol, sitosterol, a fatty acid, 5,7,4′-trihydroxyflavone (apigenin), (2R,3R)-3,5,7,3′,5′-pentahydroxyflavan and 3α-methoxyfriedelan. The latter two compounds are new natural products.     

Sapogenins from Guaiacum officinale

Acid hydrolysis of the saponins from the stem bark of Guaiacum officinale yielded the new sapogenin 3β,20η-dihydroxy-30-norolean-12-en-28-oic acid and the artifacts 3β-hydroxy-30-norolean-12,19-dien-28-oic acid and its methyl ester. Larreagenin, sitosterol and oleanolic acid were also isolated.     

Triterpenoid taxonomic markers for Stemonoporus and other genera of the dipterocarpaceae

The bark and/or timber extracts of Stemonoporus affinis, S. cordifolius, S. elegans, S. lancifolius, S. oblongifolius and S. petiolaris have been studied. The following compounds have been isolated: α-amyrin, δ-amyrenone, ursolic acid, sitosterol, sitosteryl-o-methoxybenzoate, ursonic acid, acetylursolic acid, 4-hydroxybenzaldehyde, methyl 2,4-dihydroxybenzoate, 2α-hydroxyursolic acid and bergenin. TLC examination of extracts of S. petiolaris, S. canaliculatus and S. reticulatus is reported. Triterpenoid taxonomic markers are summarized for Dipterocarpus, Doona, Shorea and Stemonoporus.     

A furanoeremophilane from Vitex negundo

Acetyl oleanolic acid, sitosterol and a new furanoeremophilane characterized as 3-formyl-4,5-dimethyl-8-oxo-5H-6,7-dihydronaphtho(2,3-b)furan have been isolated from the roots of Vitex negundo.     

Trietrpenoides d'Agauria salicifolia

3-acetylmorolic acid, 3-acetylmoradiol, 3-acetylmoraldehyde, taraxerol, taraxerone, sitosterol and agauriasterone, an isomer of nor-31-lanosterone, have been isolated from the methanolic extract of the bark of Agauria salicifolia.     

Distribution of some triterpenes and phenolic compounds in the extractives of endemic dipterocarpaceae species of Sri Lanka

Extractives of bark and/or timber of 11 species belonging to the genera Cotylelobium, Hopea, Shorea, Vateria and Vatica yielded a fatty-acid ester, a sitosteryl ester, β-amyrin acetate, β-amyrin, dipterocarpol, ursolic acetate, lupeol, sitosterol, ursolic acid, betulinic acid, hexamethyl-coruleoellagic acid, tetramethylellagic acid, chrysophanol and scopoletin. The distribution of these compounds in 18 other species was examined by TLC screening.     

3-acetylmaslinic acid from the root bark of Terminalia alata

A new triterpene acid, 3-acetylmaslinic acid, has been isolated from the root bark of Terminalia alata together with oleanolic acid, arjunic acid, arjunolic acid and arjunetin.     

Distribution and expression characteristics of triterpenoids and OSC genes in white birch (<Emphasis Type="Italic">Betula platyphylla</Emphasis> suk.)

Betulin and oleanolic acids (pentacyclic triterpenoid secondary metabolites) have broad pharmacological activities and can be potentially used for the development of anti-cancer and anti-AIDS drugs. In this study, we detected the accumulation and the distribution characteristics of betulin and oleanolic acid in various organs of white birch at different ages. We also determined the expression of 4 OSC genes (LUS, β-AS, CAS1 and CAS2) involved in the triterpenoid synthesis pathways by real time RT-PCR. The result showed that the 1-year old birch can synthesize betulin and oleanolic acid. In addition, betulin and oleanolic acids were mainly distributed in the bark, while the content in the root skin and leaf was very low. The content of betulin and oleanolic acid in birch varied in different seasons. The content of betulin and oleanolic acid and their corresponding LUS and β-AS gene expression were very low in 1-year old birch. With increasing age of birch, betulin content was increased, while oleanolic acid was decreased. Similar changes were also observed for their corresponding synthesis genes LUS and β-AS. In the leaf of 1-year old plant, the highest expression of CAS1 and CAS2 occurred at end of September, while expression of LUS and the β-AS was low from June to October. In the stem skin,high expression of β-AS and the LUS genes occurred from the end of July to September. In the root, high expression of the β-AS gene was observed at the end of October. These results indicated that triterpenoid gene expression was similar to the triterpene accumulation. Expression of LUS gene and β-AS gene in birch with different ages were corresponding to the betulinic and oleanolic acid accumulation. Expression of CAS1 and CAS2 genes were elevated with increasing age of birch. This study provides molecular mechanisms of triterpenes synthesis in birch plants.     

Xanthones and 4-phenylcoumarins of Mesua thwaitesii

The constituents of the bark, timber and seeds of Mesua thwaitesii were examined by column chromatography and GC-MS. 1,5-Dihydroxyxanthone, 1,7-dihydroxyxanthone (euxanthone), 1,3-dimethoxy-5-hydroxyxanthone, 1,5,6-trihydroxyxanthone, mammeisin, (4-phenylcoumarin) and sitosterol have been characterized. Nine 4-phenylcoumarins including mammeigin, mesuagin, mammeisin, mesuol, or its isomers, have been identified in the seed extract. One coumarin has not been previously reported.     

Terpenes of Podocarpus lambertius

Sitosterol and the following terpenic compounds have been isolated from the bark of Podocarpus lambertius: 3β-hydroxytotarol, 4β-carboxynortotarol, and macrophyllic and lambertic acids. The leaves yielded sitosterol, stigmastan-3β,5α-diol-6-one, isopimaric acid, phyllocladene, isophyllocladene, 8,9-abieten-15-ol and 17-isophyllocladenol.     

Sterol and triterpenoid glycosides from the roots of Patrinia scabiosaefolia

From the roots of Patrinia scabiosaefolia, oleanolic acid, hederagenin, 3-O-α-l-arabinopyranosyl-oleanolic acid, 3-O-α-l-arabinopyranosyl-hederagenin, 2′-O-acetyl-3-O-α-l-arabinopyranosyl-hederagenin and a mixture of sitosterol and campesterol-d-glucosides were isolated.     

Triterpenes from Gymnosporia emarginata

Triterpene quinone-methides, lupenone, β-amyrin, dulcitol, and sitosterol have been isolated from the timber, root and leaf extracts of Gymnosporia emarginata. Their chemotaxonomic significance is discussed.     

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.     

Terpenoids of Canarium zeylanicum

The following terpenoids were identified in the oleoresin, bark and timber of Canarium zeylanicum: 3β-hydroxyurs-12-en-11-one, 3β-hydroxyolean-12-en-11-one, olean-12-en-3,11-dione, urs-12-en-3,11-dione, α- and β-amyrin, α- and β-amyrenone, taraxerol, sitosterol, canaric acid, elemene, elemol, α-pinene, α- and β-phellandrene, limonene, terpineol and carvone.     

Naphthoquinones and triterpenes from african Diospyros species

Investigation of the bark and/or wood of seventeen African species of Diospyros has revealed the presence of a number of triterpenes and naphthoquinones. The triterpenes lupeol, betulin and betulinic acid were detected in all samples but three other triterpenes were each found in only one species; betulinaldehyde in D. canaliculata, cerin in D. iturensis, and glutinol in D. zenkeri. Naphthoquinones were detected in fourteen of the seventeen species and the common dimeric compounds diospyrin, isodiospyrin and diosindigo-A were isolated. D. canaliculata differed from all other species in producing derivatives of plumbagin including its reduced form, isoshinanolone (1R,2R) and a novel stereoisomer which was given the trivial name epiisoshinanolone (1S,2R).     

An anthraquinone 3-neohesperidoside from Cassia sophera root bark

A new anthraquinone diglycoside has been isolated from Cassia sophera root bark and characterized as 1,8-dihydroxy-2-methylanthraquinone 3-neohesperidoside along with sitosterol, chrysophanol and physcion.     

Antimicrobial constituents of Thompson seedless raisins (Vitis vinifera) against selected oral pathogens

As a part of a project directed toward the discovery of oral antimicrobial compounds from plants, eight known compounds, oleanolic acid (1), oleanolic aldehyde (2), linoleic acid (3), linolenic acid (4), betulin (5), betulinic acid (6), 5-(hydroxymethyl)-2-furfural (7), and β-sitosterol were isolated from an hexane-soluble partition of a methanol extract of Thompson seedless raisins (Vitis vinifera). From an EtOAc-soluble partition rutin (8) and β-sitosterol glycoside were isolated. In an attempt to increase the resultant antimicrobial activity of oleanolic acid (1), a series of acylation and etherification reactions were performed on oleanolic acid to obtain derivatives 1a–1f. All the compounds isolated and the derivatives 1a–1f were evaluated for their antimicrobial activity against two oral pathogens, Streptococcus mutans and Porphyromonas gingivalis associated with caries and periodontal disease, respectively. Compounds 1, 2, 7 and 1f inhibited the growth of the test bacteria with concentrations ranging from 3.9 to 500 μg/mL. Derivative 1f showed greatly enhanced antimicrobial activity when compared with oleanolic acid (1).     

Lupeol long-chain fatty acid esters and other triterpenoid constituents from Plumeria obtusifolia

From the bark of Plumeria obtusifolia was isolated a series of lupeol fatty esters with the carbon numbers 16, 18,20 and 21–28 in the fatty acid part. Furthermore, lupeol, lupeol acetate, sitosterol, stigmasterol and campesterol were also identified.     

Alkaloidal and other constituents of Uncaria elliptica and canthium dicoccum

A new alkaloid roxburghine X, along with roxburghine D, formosanine and mitraphylline, has been isolated from the bark of Uncaria elliptica. Sitosterol, quinovaic acid, acetylquinovaic acid and scopoletin were isolated from the bark of Canthium dicoccum.     

Cytotoxic naphthoquinones,molluscicidal saponins and flavonols from Diospyros zombensis

7-Methyljuglone, isodiospyrin and three glucuronides of oleanolic acid were isolated from the lipophilic and the methanol extracts, respectively, of the root bark of Diospyros zombensis. Cytotoxic activities of the naphthoquinones and strong molluscicidal activity of 3-O-[O-α-L-rhamnopyranosyl-(1 → 3)-β-D-glucuronopyranosyl]-oleanolic acid were shown. In addition hyperoside, quercitrin and quercetin-3-O-β-D-glucuronopyranoside were isolated from a methanol extract of the leaves.