Cycloartane Triterpene Research Articles

Secondary metabolites from the roots of Astragalus zahlbruckneri.

Four new phenolic glycosides, beta-apiofuranosyl-(1-->2)-beta-glucopyranosides (1-4), along with the cycloartane triterpenes 20(R),25-epoxy-3beta,6alpha,16beta,24alpha-tetrahydroxycycloartane (5) and 20(R),24(S)-epoxy-3beta,6alpha,25-trihydroxycycloartan-16-one (6) were isolated from roots of Astragalus zahlbruckneri. The structure elucidation of all compounds was based on their (1)H and (13)C NMR spectral data including 1D-TOCSY, DQF-COSY, HSQC, and HMBC experiments.

Studies on the constituents of Cimicifuga species

The chemical constituents of Cimicifuga simplex and its related species were reexamined using HPLC and high resolution spectral analysis. From C. simplex, C. acerina and C. japonica, a new alkaloid, 59 new cycloartane triterpene glycosides and 11 new aromatic constituents were isolated with the previously reported compounds. The latter aromatic constituents were identified in HPLC analysis of the extracts from crude drugs due to C. dahurica, C. heracleifolia and C. foetida. Several interesting topics in this study are reviewed about separation of unstable and closely related compounds by HPLC, rearrangement reactions, chemical conversion for confirmation of absolute configuration, isomerism in NMR solutions, X-ray crystal analysis, spectral analysis of complicated structures, isolation of glycoside malonates, high yield of enzymatic hydrolysis, specific CD curve due to a cycloart-7-ene system, and so on. Biological activities of a major glycoside, cimicifugoside, a modified triterpene, acerinol, and benzyltartaric acid derivatives such as fukinolic acid and cimicifugic acids were also mentioned.

New cycloartane triterpenoids from Passiflora edulis.

Three cycloartane triterpenes, cyclopassifloic acids E (1), F (2), and G (3), and their saponins, cyclopassiflosides VII (4), VIII (5), IX (6), X (7), and XI (8), were isolated from the leaf and stem parts of Passiflora edulis. The structures of 1-8 were elucidated on the basis of extensive NMR experiments and by chemical methods.

Four cycloartane triterpenoids and six related saponins from Passiflora edulis.

Four cycloartane triterpenes, cyclopassifloic acids A (1), B (2), C (3), and D (4), and six related saponins, cyclopassiflosides I (5), II (6), III (7), IV (8), V (9), and VI (10), were isolated from the leaves and stems of Passiflora edulis, and their structures were elucidated on the base of extensive NMR experiments and chemical methods. Cyclopassifloic acids A-D were assigned as 22(R), 24(S)-1alpha,3beta,22,24,31-pentahydroxy-24-methylcycloartan -28-oic acid; 24(S)-1alpha,3beta,24, 31-tetrahydroxy-24-methylcycloartan-28-oic acid; 20(S),24(S)-1alpha, 3beta,21,24,31-pentahydroxy-24-methylcycloartan-28-oic acid; and 22(R)-1alpha,3beta,22-trihydroxy-24-oxocycloartan-28-oic acid, respectively. Cyclopassiflosides I-VI, in turn, were established as the 28-O-beta-D-glucopyranosides of cyclopassifloic acids A-D. Finally, cyclopassiflosides III and V were demonstrated as the 28, 31-bis-O-beta-D-glucopyranosides of cyclopassifloic acids B and C, respectively. Also obtained in this investigation were the known compounds passiflorin (11) and passifloric acid (12).

Constituents and bioactivity of the tubers of Euphorbia sessiliflora

The diterpene ent-12-hydroxy-12[ R]-abieta-8(14),13(15)-dien-16,12-olide was isolated from the tubers of Euphorbia sessiliflora Roxb., together with four known ent-abietadienolides, four known cycloartane triterpenes and ellagic acid-β- D-glucopyranoside. Two of these metabolates displayed moderate antibacterial activities.

Antialgal compounds from zantedeschia aethiopica

Two cycloartane triterpenes and 10 sterols present in Zantedeschia aethiopica along with three lignans and 10 phenylpropanoids were identified by spectroscopic means. 3-(4-hydroxy-3-methoxy)-phenyl-1,2-propandiol and 1-(4-hydroxy-3-methoxy)-phenyl-2- [4, 2, 3, 2]-phenoxy-1,3-propandiol have been isolated for the first time. Antialgal assays show good activity for some aromatic compounds.

Cycloartane triterpenes from Combretum quadrangulare

In addition to two known flavonoids, kumatakenin and isokaempferide, three new cycloartane triterpenes were isolated from the leaves of Combretum quadrangulare. Their structures were established by the means of 1D and 2D NMR techniques and physical data (MS, IR) as 1α,3β-dihydroxy-cycloart-24-ene-30-carboxylic acid, 1α,3β-dihydroxy-cycloart-24-ene-30-carboxylic acid methyl ester and (20ξ)-1α,3β,25-trihydroxy-cycloart-21-al-23-ene-30-carboxylic acid methyl ester.

A cycloartane triterpene 3β, 16β diglucoside from Astragalus trigonus and its non natural 6-hydroxy epimer

The detailed investigation of Astralagus trigonus DC roots, led to the isolation of a new cycloartan-3β, 16β diglucoside, whose structure was elucidated by extensive use of 1D- and 2D- high field (600 MHz) NMR techniques. The NaBH 4 reduction of the natural 6-oxo 3β, 16β diglucoside, previously isolated from the same plant, afforded the 6-epi-derivative of the new compound. The conformational preference of both these compounds has been investigated by high field 1H NMR spectroscopy and molecular modeling techniques.

Cycloartane triterpene glucosides from Corchorus depressus

Depressoside A and B, two new cycloartane triterpene glucosides were isolated from Corchorus depressus. The structures of depressoside A and B were elucidated as 9,19-cyclolanosta-22( R),25-epoxy-3β,16β,24(S)-triol-3-O-β- d-glucopyranoside and 9,19-cyclolanosta-22( R),25-epoxy-24(S)-acetoxy-3β,16β-diol-3-O-β- d-glucopyranoside respectively on the basis of 1D and 2D spectroscopic studies and chemical analysis.

Phytochemistry of Illicium dunnianum and the systematic position of the illiciaceae

Detailed chemical investigation of a dichloromethane extract of Illicium dunnianum yielded six phenylpropanoids (two of which, 1-[(3-methylbut-2-enyl)oxy]-2-methoxy-4-(prop-1-en-3-ol)benzene and 1,2-(methylenedioxy)-4-(propan-1,2-diol)benzene, were novel), five known neolignans, three known cycloartane triterpenes and a novel ring-A cleaved cycloartane, 3,4- seco-(24 Z)-cycloart-4(28),24-diene-3,26-dioic acid 3-methyl ester. The significance of these chemical findings is assessed in the context of the historical debate concerning the systematic position and phylogenetic relationships of the genus.

A novel cycloartane glycoside fromThalictrum uchiyamai

A new cycloartane glycoside (1) was isolated from the aerial part ofThalictrum uchiyamai Nakai (Ranunculaceae). On the basis of chemical and physicochemical evidence, the aglycone structure of this compound was characterized as 16,25-dihydroxy-3,24-diacetoxy-9, 19-cycloartane-29-oic acid, a new derivative of cycloartane triterpene. Also, the oligosaccharide moiety of this glycoside were determined as 29-O-α-L-rhanmnopyranosyl-(1→2)-[β-D-xylofuranosyl-(1→6)]-β-D-glucopyranosy by application of HMBC technique. Consequently, the structure of compound 1 was elucidated as 29-O-α-L-rhanmnopyranosyl-(1→2)-[β-D-xylofuranosyl-(1→6)]-β-D-glucopyranosyl-16, 25-dihydroxy-3,24-diacetoxy-9,19-cycloartane-29-oic acid ester.

Biosynthesis of triterpenoids in cultured cells, and regenerated and wild plant organs of Taraxacum officinale

Undifferentiated cultured cells of Taraxacum officinale produced oleanolic and ursolic acids as major triterpenoids in addition to triterpenols composed mainly of α- and β-amyrins. Regenerated and wild plants contained additional triterpenols, i.e. taraxasterol and lupeol, but negligible quantities of triterpene acids. [2- 14C]Mevalonic acid was fed to callus cells, wild plant organs, and shoot and root segments of plants redifferentiated from callus. After 48 hr incubation, triterpenols, phytosterols and triterpene acids were equally labelled in callus cultures; in contrast, triterpene acids were strongly labelled in the differentiated tissues. The incorporation of radioactivity into α- and β-amyrins was highest in the callus where taraxasterol and lupeol were not labelled substantially; the latter were labelled in differentiated organs, agreeing with the accumulation patterns. A time course experiment with shoot segments showed a different production pattern of cycloartane triterpenes from other classes of triterpenoids. The results are discussed in relation to organ-specific biosynthesis of specific triterpenoids.

Cycloartane triterpene glycosides from Astragalus alexandrinus

Alexandroside I, a new cycloartane triterpene glycoside was isolated from Astragalus alexandrinus. Its structure was established as 3- O-β- d-glucopyranosyl-9β,19-cyclolanost-3β,6α,16β,24( R),25 pentaol on the basis of spectroscopic and chemical methods. Four known glycosides, astraversianins VI, X, XIV and XV, were also isolated.

Sericeol, a cycloartane triterpene from Neolitsea sericea

Sericeol, a new cycloartane triterpene, and other known compounds have been isolated from the heartwood of Neolitsea sericea. Their structures were established by spectral analyses.

Uvariastrol, a novel cycloartane triterpene from the stem bark of Uvariastrum zenkeri

Uvariastrol, a cycloartane triterpene with a novel tetrahydrofuran/furanone side-chain, has been isolated from the stem bark of Uvariastrum zenkeri and characterized using spectral characteristics, notably high-field 1H NMR and 13C NMR spectroscopy.

Acid-catalyzed isomerization of cycloartane triterpene alcohols. The formation of cucurbitane- and lanostane-type isomers

Acid-catalyzed isomerization of cycloartane triterpene alcohols. The formation of cucurbitane- and lanostane-type isomers

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.