Showing papers on "Triterpene published in 1992"
115 citations
85 citations
TL;DR: A new ring-A secotriterpene, koetjapic acid, and five known compounds, 3-oxo-olean-12-en-29-oic acid [2] (a novel natural product), katonic acid [3], (-)-alloaromadendrene, (-)-caryophyllene oxide, and (+)-spathulenol, have been isolated and characterized from a cytotoxic Et2O-soluble extract
Abstract: A new ring-A secotriterpene, koetjapic acid [1], and five known compounds, 3-oxo-olean-12-en-29-oic acid [2] (a novel natural product), katonic acid [3], (-)-alloaromadendrene, (-)-caryophyllene oxide, and (+)-spathulenol, have been isolated and characterized from a cytotoxic Et2O-soluble extract of Sandoricum koetjape stems. Of these compounds, 2 and 3 demonstrated significant cytotoxic activity against cultured P-388 cells (ED50 values of 0.61 and 0.11 microgram/ml, respectively). Significant, albeit less intense, cytotoxicity was also observed with a variety of cultured human cancer cells. The 13C-nmr chemical shifts of these triterpenes were assigned unambiguously using selective INEPT nmr experiments. Aside from compounds 2 and 3, these substances were not toxic with cultured cells.
77 citations
TL;DR: Five new triterpenoids were isolated from the fruit galls of Actinidia polygama on the basis of chemical and spectral evidence and were determined to be 2α,3α,23,24-tetrahydroxyurs-12-en-28-oic acid and 3β-( trans - p -coumaroyloxy)-2 α,23-dihydroxy-urs- 12-en -28-Oic acid.
71 citations
TL;DR: Five new oleanane saponins named arganine A, B, D, E and F and two known sap onins: arganines C and mi-saponin A were isolated from the kernel of Argania spinosa.
67 citations
51 citations
TL;DR: A new o Leanane-glucoside was isolated from the leaves of three Rubus species collected in Yunnan, southern China, along with several known ursane- and oleanane-type triterpene glucosides.
48 citations
TL;DR: From the leaves of Bencomia caudata and Dendriopoterium menendezii a new triterpenoid glycoside has been isolated and its structure was determined as 3-O-galloyl-23-hydroxytormentic acid 28-O -β- d -glucopyranoside mainly from the NMR spectra.
48 citations
TL;DR: Differentiation-inducing activity of over 180 extracts of crude drugs and plants was tested using mouse myeloid leukemia cell line (M1), and methanol extracts of clove showed remarkable induction of differentiation of M1 cells into macrophage-like cells.
Abstract: Differentiation-inducing activity of over 180 extracts of crude drugs and plants was tested using mouse myeloid leukemia cell line (M1). The methanol extracts of clove (Syzygium aromaticum Merrill et Perry, Myrtaceae) showed remarkable induction of differentiation of M1 cells into macrophage-like cells. From the extract, oleanolic acid (1) and crategolic acid (2) were isolated as the active components. We also tested other triterpenes, such as oleananes, ursanes and dammaranes, to investigate the structure-activity relationship. Some triterpene aglycones showed differentiation-inducing activity, but triterpene glycosides showed little activity. Furthermore, the differentiation-inducing activity of these triterpene compounds was tested against human acute promyelocytic leukemia cell line (HL-60).
41 citations
TL;DR: The asymmetric dihydroxylation of squalene was studied using the new ligand (DHQD) 2 -PHAL in this paper, where moderate positional selectivity was observed with high % ee.
41 citations
TL;DR: In this article, triterpene glucosides, cumingianosides A-F (1-6), trisnor-and tetranortriterpene (TTRP) glucoside, cumindysosides B (7) and C (8), with 14,18-cycloapoeuphane-type skeleton have been isolated from Dysoxylum cumingiansum as antileukemic principles.
Abstract: Six new triterpene glucosides, cumingianosides A-F (1-6) as well as trisnor- and a tetranortriterpene glucoside, cumindysosides A (7) and B (8), wiht a 14,18-cycloapoeuphane-type skeleton have been isolated from Dysoxylum cumingianum as antileukemic principles. The structures were established on the basis of chemical and spectroscopic evidence. Among them, compounds 1 and 3 exhibited potent selective cytotoxicity against MOLT-4 human leukemia cell with ED 50 of <0.00625 and <0.0045 μg/mL, respectively
TL;DR: In this paper, a clerodane-type diterpene with a 6,7-oxirane group has been isolated from Croton megalocarpus and structure elucidation has been achieved by a combination of spectroscopic measurements including 2D NMR and NOE experiments.
TL;DR: A new triterpene 1 has been isolated from the extract of Stautonia hexaphylla callus tissues and the structure was elucidated as 3α-hydroxy-11α, 12α-epoxyoleanan- 28, 13β-olide by 1 H-nmr, 13 C-nmR, and ms spectroscopc studies.
Abstract: A new triterpene 1 has been isolated from the extract of Stautonia hexaphylla callus tissues. The structure was elucidated as 3α-hydroxy-11α, 12α-epoxyoleanan- 28, 13β-olide [1] by 1 H-nmr, 13 C-nmr, and ms spectroscopc studies. Two known compounds, 28-norolean-12-ene-3β, 17β-diol [2] and 11α-hydroxy-β-amyrin [3], were also isolated
TL;DR: The roots of Sanguisorba alpina yielded 18 compounds of which five were novel, including four triterpenoid saponins and one new triterphenoid acid.
TL;DR: Two new pentacyclic triterpene acids, bellericagenin A and bellericaide B and their glycosides were isolated from the stem-bark of Terminalia Bellerica and were respectively defined as 2α, 3β, 7α, 23-tetrahydroxyolean-12-en-28-oic acid and β-D-glucopyranosyl based on their spectroscopic properties and some chemical transformations as discussed by the authors.
TL;DR: A new triterpene saponin was isolated from the roots of Ampelozizyphus amazonicus together with the known triterpenes and the structure was elucidated as 3-O-[beta-D-glucopyranosyl(1----2)alpha-L-arabinopyrnosyl]- 20-O-alpha- L-rhamnopyranoyljujubogenin by spectral analysis and chemical transformations.
TL;DR: The structures of four new 4α-methylsterols and triterpene alcohols isolated from an extract of the stems and branches of Neolitsea aciculata were shown in this paper.
TL;DR: In this article, four new methyl ester derivatives of oleanene glycosides (3-6) were isolated from the seeds of Astragalus complanatus R. BR.
Abstract: Four new methyl ester derivatives of oleanene glycosides (3-6) were isolated from the seeds of Astragalus complanatus R. BR. together with two known triterpene glycosides, astragaloside VIII methyl ester (1) and soyasaponin I methyl ester (2) after treatment with diazonethane during separation procedure. The structures of 3-6 were elucidated as 3-O-α-L-rhamnopyranosyl(1→2)-β-D-xylopyranosyl(1→2)-6-O-methy-β-D-glucuronopyranosyl-soyasapogenol B 22-O-β-D-glucopyranosede, 3-O-α-L-rhamnopyranosyl(1→2)-β-D-galactopyranosyl(1→2)-6-O-methyl-β-D-glucuronopyranosyl-soyasapogenol B 22-O-β-D-glucopyranoside, 3-O-α-L-rhamnopyranosyl(1→2)-β-D-xylopyranosyl(1→2)-6-O-methyl-β-D-glucuronopyranosyl 3β, 22β, 24-trihydroxy-11-oxo-olean-12-ene and 3-O-α-L-rhamnopyranosyl (1→2)-β-D-galactopyranosyl(1→2)-6-O-methyl-β-D-glucuronopyranosyl 3β, 22β, 24-trihydroxy-11-oxo-olean-12-ene, respectively.
TL;DR: From the roots of Glycyrrhiza yunnanensis, collected in Yunnan, China, six new oleanane-type triterpene glycosides named yunganosides A1, B1, C1, D1, E2 and F2 were isolated together with hypaphorine.
TL;DR: A new triterpene and its glycosides were isolated from the bark of Schefflera octophylla together with asiatic acid andAsiaticoside, and for the first time asiaticsoside was isolated from a plant other than Centella asoatica.
TL;DR: From the seeds of Astragalus sinicus L. (Leguminosae), seven triterpene glycosides were isolated and identified as soyasaponin I-III methyl esters, unambiguously characterized and designated as complogenin.
Abstract: From the seeds of Astragalus sinicus L. (Leguminosae), seven triterpene glycosides were isolated and identified as soyasaponin I-III methyl esters (1-3) which were treated with CH2N2 during the separation procedure, soyasaponin IV (4), soyasapogenol B 3-O-beta-D-glucuronopyranoside (5), 3-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D-xylopyranosyl(1-->2)-beta-D- glucuronopyranosyl 3 beta, 22 beta, 24-trihydroxy-11-oxoolean-12-ene (6), whose sapogenol (8) was obtained by enzymatic hydrolysis using glycyrrhizinic acid hydrolase, unambiguously characterized and designated as complogenin, and 3-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D-galactopyranosyl(1-->2)-beta-D - glucuronopyranosyl complogenin (7).
TL;DR: Single-crystal X-ray analysis of polacandrin pentahydrate verified the complete structure and stereochemistry and showed potent cytotoxicities against KB, P-388, and RPMI-7951 tumor cells.
Abstract: A new dammarane triterpene, polacandrin [1], has been isolated from Polanisia dodecandra. The structure of 1 was established as 1 beta, 3 alpha, 12 beta, 25-tetrahydroxy-20(S),24(S)-epoxydammarane by chemical and spectroscopic methods, which included the concerted application of a number of 2D nmr techniques that involved 1H-1H COSY, HETCOR, NOESY, and long-range HETCOR. Single-crystal X-ray analysis of polacandrin pentahydrate verified the complete structure and stereochemistry. Polacandrin showed potent cytotoxicities against KB (ED50 = 0.60 microgram/ml), P-388 (ED50 = 0.90 microgram/ml), and RPMI-7951 (ED50 = 0.62 microgram/ml) tumor cells.
TL;DR: The stem bark of Caloncoba glauca has yielded three friedelane triterpenes of which two are characterized by the loss of C-30 and the presence of a C-27, C-15 lactone as discussed by the authors.
TL;DR: A single crystal X-ray diffraction analysis performed on the p -iodobenzoate derivative enabled the assignment of the absolute configuration of the new triterpene metabolite with an oleanane skeleton.
TL;DR: Three novel degraded triterpenoids are described which were isolated from the neutral fraction of the ethanolic extract of the fresh, undried uncrushed ripe neem fruit coats of Azadirachta indica.
TL;DR: The triterpenes 3β,28,30 lup-20(29)ene-triol and 28,30 dihydroxy lup 20(29)-en-3-one have been isolated from Maytenus canariensis and their structures determined by means of spectral studies and chemical correlations.
TL;DR: In this article, the tragopogonosides A-I and B-I were isolated from the whole plants of Tragopus pratensis, together with five known triterpenic glycosides.
TL;DR: Two triterpene dimers, 7 and 8, were isolated from Maytenus umbellata and proved to be oxidized structures of tingenone from which they could also be synthesized.
TL;DR: Another six components of Astragalus tragacantha Habl have been identified on the basis of spectral characteristics and chemical transformations as mentioned in this paper, including cyclocanthagenin and its 3-0-β-D-xylopyranoside.
Abstract: Another six components ofAstragalus tragacantha Habl have been identified on the basis of spectral characteristics and chemical transformations We have previously described cyclocanthagenin and its 3-0-β-D-xylopyranoside — cyclocanthoside A — as products of the acid hydrolysis of cyclocanthoside D Cyclocanthosides B, C, E, and G are here described for the first time and are (24S)-cycloartane-3β,6α,16β,24,25-pentol 3-O-(4-O-acetyl-β-D-xylopyranoside) 6-O-β-D-glucopyranoside, (24S)-cycloartane-3β,6α,16β,24,25-pentol 6-O-(6-O-acetyl-β-D-glucopyranoside) 3-O-β-D-xylopyranoside, (24S)-cycloartane-3β,6α, 16β,24,25-pentol 6-O-β-D-glucopyranoside, and (24S)-cycloartane-3β, 6α, 16β, 24, 25-pentol 6-O-β-D-glucopyranoside 3-O-[O-β-D-glucopyranosyl-(1→2)-β-D-xylopyranoside], respectively
TL;DR: An unusual C-18 isoursane pentacyclic triterpene isolated from the root bark of Calotropis procera is assigned structure 1 on the basis of spectral and chemical studies.