Triterpenoids of Akebia quinata callus tissue

From tissue culture of Akebia quinata, three new triterpenes were isolated together with two known triterpenes, oleanolic acid and mesembryanthemoidgenic acid. The new triterpenes were characterized by spectroscopic means as 3β-hydroxy-30-norolean-12,20(29)-dien-28-oic acid, 3-epi-30-norolean-12,20(29)-dien-28-oic acid and 3β-hydroxy-29(or 30)-al-olean-12-en-28-oic acid.     

Antitumour triterpenes of Maytenus diversifolia

The known compounds maytansine and sitosterol-β-D-glucoside as well as the new triterpenes maytenfoliol and maytenfolic acid were isolated as antileukemic agents from Maytenus diversifolia. Other triterpenes isolated included the new maytensifolin-A and -B as well as the known friedelin, canophyllal, β-amyrin, canophyllol, pachysonol, 29-hydroxyfriedelan-3-one and 30-hydroxyfriedelan-3-one.     

Triterpenes from Angelica cartilagino-marginata var. foliata Yuan et Shan and their significance as chemosystematic characters

One new and three known triterpenes were isolated from roots of Angelica cartilagino-marginata var. foliata Yuan et Shan. The structures of the new compounds were determined by modern spectroscopic techniques, including 2D NMR experiments. These triterpenes are important characters in chemosystematics of Umbelliferae.     

Pentacyclic triterpenoids from Prunella vulgaris

Three new pentacyclic triterpenes together with several known triterpenes have been isolated as their methyl esters from the roots of Prunella vulgaris.     

A new triterpene,betulafolienpentaol, from Betula platyphylla

A new triterpene, betulafolienpentaol, 3α,12β,17,20,25-pentahydroxy dammar-23-trans-ene and two other known triterpenes were isolated from Betula platyphylla. The latter compounds were identified as betulafolientetraol and betulafolientetraol-A, respectively.     

Triterpenes from Ferula linkii

Two new natural triterpenes, 3β-acetoxyolean-9,12-diene and 3β-acetoxy-6β-hydroxyolean-9,12-diene, were isolated from Ferula linkii.     

Triterpenoid-biosynthetic UDP-glycosyltransferases from plants

Triterpenoid saponins are naturally occurring structurally diverse glycosides of triterpenes that are widely distributed among plant species. Great interest has been expressed by pharmaceutical and agriculture industries for the glycosylation of triterpenes. Such modifications alter their taste and bio-absorbability, affect their intra?/extracellular transport and storage in plants, and induce novel biological activities in the human body. Uridine diphosphate (UDP)-glycosyltransferases (UGTs) catalyze glycosylation using UDP sugar donors. These enzymes belong to a multigene family and recognize diverse natural products, including triterpenes, as the acceptor molecules. For this review, we collected and analyzed all of the UGT sequences found in Arabidopsis thaliana as well as 31 other species of triterpene-producing plants. To identify potential UGTs with novel functions in triterpene glycosylation, we screened and classified those candidates based on similarity with UGTs from Panax ginseng, Glycine max, Medicago truncatula, Saponaria vaccaria, and Barbarea vulgaris that are known to function in glycosylate triterpenes. We highlight recent findings on UGT inducibility by methyl jasmonate, tissue-specific expression, and subcellular localization, while also describing their catalytic activity in terms of regioselectivity for potential key UGTs dedicated to triterpene glycosylation in plants. Discovering these new UGTs expands our capacity to manipulate the biological and physicochemical properties of such valuable molecules.     

Terpenoids of Rhododendron japonicum

From Rhododendron japonicum were isolated two diterpene glucosides, pieroside B and grayanoside B, and two new triterpenes, 2α,3α,24-trihydroxy     

Triterpenes of Lithocarpus species

The triterpenes of the five Lithocarpus species examined comprised members of the friedo- and unrearranged oleanane groups, viz. friedelin, friedelan-3β-ol, taraxerol and β-amyrin. Glutinol was also present, except in L. harlandi where friedelan-2α,3β-diol was found. In addition, three new cycloartane triterpenes, lithocarpolone (21,24-epoxy-24-hydroxymethyl-cycloartan-3-one), lithocarpdiol (21,24-epoxy-24-hydroxymethyl-cycloartan-3β-ol). and 24-methylenecycloartan-3β,21-diol were found in L. polystachya, and their structures determined.     

Two eudesmanolides from Sonchus macrocarpus

The aerial parts of Sonchus macrocarpus afforded, in addition to known triterpenes, two new eudesmanolides.     

Triterpenoids from Cornus capitata

The structure of two new triterpenes isolated from the stems and stem bark of Cornus capitata has been elucidated as 21,23-epoxytirucalla-7,24-diene-3-one and 3β-acetoxy-21, 23-epoxytirucalla-7,24-diene by physico-chemical methods.     

Cyclotriterpenes from the heartwood of Pterospermum heyneanum

The new triterpenes, 30-norcyclopterospermone, cyclopterospermol and 30-norcyclopterospermol isolated from the heartwood of Pterospermum heyneanum and their structures were established as 30-nor-22-methylene-9,19-cyclolanostan-3-one, 22-methylene-9,19-cyclolanostan-3β-ol and 30-nor-22-methylene-9,19-cyclolanostan-3β-ol, respectively. In addition n-octacosanol, 3-hydroxy-5-methoxy-2-methylbenzoquinone, sitosterol and its glucoside were also isolated.     

Triterpenes from periandra dulcis roots

Two new triterpenes from the root of Periandra dulcis were found to be 3,25-dioxoolean-12(13)-en-30-oic acid and 3,25-dioxoolean-18(19)-en-30-oic acid.     

Cytotoxic triterpenes with diverse skeletons from Amoora tsangii

Two new 29-nor-cycloartane triterpenes, amooratsanols A and B (1, 2) along with nine known compounds including two 29-nor-cycloartane triterpenes (3, 9), two lupane triterpenes (4, 5), two cycloartane triterpenes (6, 10), two dammarane triterpenes (7, 8), as well as one dinorcycloartane triterpene (11) were isolated from the leaves and twigs of Amoora tsangii (Merr.) X. M. Their structures were established by spectroscopic methods (IR, HRESIMS, and NMR). The cytotoxicity of 1–11 was evaluated against the human fibro sarcoma HT1080, esophageal cancer TE, and non-small cell lung cancer A549 cell lines by the CCK8 assay. Cycloartanes (1–3, 6, and 9–11) displayed significant cytotoxic activity with IC₅₀ values ranging from 2.56 to 19.05 μM. Among these triterpenes, mooratsanol A (1) showed the most potent cytotoxic activity, with IC₅₀ values ranging from 2.56 to 5.10 μM.     

A guaian-5,12-olide from Hypochoeris cretensis

Hypochoeris cretensis afforded, in addition to triterpenes and isoalantolactone, a new guaian-5, 12-olide and the corresponding precursor.     

A guaianolide and other constituents from Lychnophora species

A new guaianolide, 11 β,13-dihydroeremanthine, together with a caryophyllene derivative and pentacyclic triterpenes, has been isolated from Lychnophora species.     

Deltoidin A and B,two new germacrolides from Eupatorium deltoideum

Investigation of E. deltoideum provided two new germacrolide-type sesquiterpene lactones, deltoidin A and B, besides the known guaianolide ligustrin, and diterpenes and triterpenes.     

Chemical constituents from Salacia amplifolia

The present phytochemical investigation on Salacia amplifolia led to the isolations of 13 triterpenes, including quinonemethides, friedelanes, oleananes and ursanes triterpenes, three simple phenolics, one polyol and one chromanone. All of them were isolated from this plant for the first time. The presences of quinonemethide triterpenoids might be employed as the common characteristic constituents of both Hippocrateaceae and Celastraceae families.     

Hopane triterpenes as chemotaxonomic markers for the scale insect pathogens Hypocrella s. lat. and Aschersonia

The scale insect pathogens Hypocrella s. lat. and their Aschersonia anamorphs, collected at various locations in Thailand, were surveyed for their productivity of three hopane triterpenes, zeorin (6α,22-dihydroxyhopane), dustanin (15α,22-dihydroxyhopane), and 3β-acetoxy-15α,22-dihydroxyhopane, when cultured in a liquid medium (potato-dextrose broth) under static conditions. Among 53 strains of Aschersonia species, 48 strains (91 %) produced at least one of these compounds. Hypocrella and Moelleriella species (43 strains) also frequently produced these triterpenoids; only two strains lacked all of these triterpenes. The results demonstrate that hopane triterpenes may be suitable for use as chemotaxonomic markers for Hypocrella and Moelleriella species and their Aschersonia anamorphs.     

Composition of epicuticular wax layer of two species of Mandevilla (Apocynoideae,Apocynaceae) from Rio de Janeiro,Brazil

The chemical composition of epicuticular waxes of Mandevilla guanabarica and Mandevilla moricandiana was comparatively analyzed by extraction in n-hexane and chloroform. The mean wax content per unit of leaf area in the n-hexane extract was about 13–30 μg cm⁻² for M. guanabarica, containing 20–28% n-alkanes and 55–63% triterpenes; for M. mori-candiana, the mean content was 19 μg cm⁻², containing 73% n-alkanes and 14% triterpenes. In the chloroform extract, the wax yield was 40–80 μg cm⁻² for M. guanabarica, with about 9–11% n-alkanes and 75–82% triterpenes; while for M. moricandiana, the wax yield was 110 μg cm⁻², with 52% n-alkanes and 14% triterpenes. The major compounds identified were lupeol, pentacyclic triterpenes of the α- and β-amyrin class, and n-alkanes such as nonacosane, hentriacontane and tritriacontane. These results indicate that the quantitative chemical profiles of epicuticular waxes of M. guanabarica and M. moricandiana are distinct and could be used as an additional feature in taxonomic identification.