Argusides B and C, two new cytotoxic triterpene glycosides from the sea cucumber Bohadschia argus Jaeger

Two new triterpene glycosides, argusides B and C (1 and 2, resp.), have been isolated from the sea cucumber Bohadschia argus Jaeger collected in the South China Sea. Their structures have been established by spectral analysis (2D-NMR and ESI-MS) and chemical evidence. Compounds 1 and 2 both possess a holostane-type triterpene aglycone with a C(9)==C(11) bond and a OH group at C(12), but differ in their substituents at C(17) and the hexasaccharide moiety. The two glycosides exhibited significant cytotoxicities against four human tumor cell lines (A549, HCT-116, HepG2, and MCF-7). In comparison with the positive control V-16 (etoposide), 1 and 2 showed higher cytotoxicities to A549 and HCT-116 cell lines.     

Argusides D and E, two new cytotoxic triterpene glycosides from the sea cucumber Bohadschia argus Jaeger

Two new triterpene glycosides, argusides D and E (1 and 2, resp.), have been isolated from the sea cucumber Bohadschia argus Jaeger collected in the South China Sea. Their structures have been established by spectral analysis (ESI-MS, and 1D- and 2D-NMR) and chemical evidence. Compounds 1 and 2 both possess an holostane-type triterpene aglycone with a C(9)=C(11) bond, an OH group at C(12), and tetrasaccharide moieties, but differ in the side chains. The two glycosides exhibited significant cytotoxicities against four human tumor cell lines, A549, HCT-116, HepG2, and MCF-7.     

Two New Cytotoxic Disulfated Holostane Glycosides from the Sea Cucumber Pentacta quadrangularis

Two new disulfated triterpene glycosides, pentactasides B and C ( 1 and 2 , resp.), were isolated from the sea cucumber Pentacta quadrangularis collected from the South China Sea. Their structures were elucidated by extensive spectral analysis (2D‐NMR and MS) and chemical methods. The compounds 1 and 2 possess the same tetrasaccharide moieties with two sulfated groups, but are different in the side chains of the triterpene aglycone. Pentactasides B and C ( 1 and 2 , resp.) showed significant cytotoxicities (IC₅₀ 0.09–2.30 μM ) against different human tumor cell lines.     

Cytotoxic sulfated triterpene glycosides from the sea cucumber Pseudocolochirus violaceus

Bioassay-guided fractionation of the active BuOH extract of the sea cucumber Pseudocolochirus violaceus resulted in the isolation of three new sulfated triterpene glycosides, i.e., violaceusides I, II, and III (1-3, resp.), as active compounds causing morphological abnormality of Pyricularia oryzae mycelia. Their structures were elucidated by spectroscopic methods including 2D-NMR and MS experiments, as well as chemical evidence. Compounds 1-3 exhibit the same structural features, i.e., the presence of a 16-oxo group in the holostane-type triterpene aglycone with the C(7)=C(8) bond, but differ in the side chains and the tetrasaccharide moieties. Compound 1 possesses one sulfate group, while 2 and 3 are disulfated glycosides. All the glycosides showed significant in vitro cytotoxicities against human gastric cancer MKN-45 and human colon cancer HCT-116 cells.     

Antitrypanosomal cycloartane glycosides from Astragalus baibutensis

Baibutoside (5), a new cycloartane-type triterpene glycoside, has been isolated from the roots of Astragalus baibutensis along with four known glycosides, acetylastragaloside I (1), and astragalosides I, II, and IV (2-4, resp.). The structure elucidation of the compounds were achieved by a combination of one- and two-dimensional NMR techniques (DQF-COSY, HSQC, HMBC, and ROESY), and mass spectrometry (ESI-MS), where all the compounds were shown to have cycloastragenol (=(20R,24S)-3beta,6alpha,16beta,25-tetrahydroxy-20,24-epoxy-9,19-cyclolanostane) as aglycone. All compounds were tested for in vitro antiprotozoal activity. Compounds 1-4 displayed notable activity vs. Trypanosoma brucei rhodesiense, with acetylastragaloside I (1) being the most potent (IC50 9.5 microg/ml). Acetylastragaloside I (1) was also lethal to T. cruzi (IC50 5.0 microg/ml), and it is the first cycloartane-type triterpene with remarkable trypanocidal activity against both T. brucei rhodesiense and T. cruzi. However, it exhibits some cytotoxicity on mammalian cells.     

Triterpene Glycosides in the Leaves of Acanthopanax giraldii

Five triterpene glycosides have been isolated from the leaves of Acanthopanax giraldii Harms (Araliaceae), which are elucidated as: hederagenin-3-O-α-L-rhamnopyranosyl (1→2) -α-L-arabinopyranoside ( Ⅰ ), hederagenin-28-α-L-rhamnopyranosyl- (1→4) -β -D-glu- copyranosyl-(1→6)-β -D-glucopyranosylester ( Ⅱ ), 3-O-α-L-arabinopyranosyl-hederagenin- 28-β -D-glucopyranosyl- ( 1→6 ) -β -D-glucopyranosylester ( Ⅲ ), 3-O-α-L-arabinopyranosyl- hederagenin-28-α-L-rhamnopyranosyl- ( 1→4 ) -β -D-glucopyranosyl- ( 1→6 ) -β -D-glucopyra-nosylester ( Ⅳ ) and 3-O-α-L-rhamnopyranosyl- (1→2) -α-L-arabinopyranosyl-hederagenin-28-α-L-rhamnopyranosyl-( 1→4 )-β -D-glucopyranosyl-( 1→6 )-β -D-glucopyranosylester ( Ⅴ ). All of them are reported in this genus for the first time. Perhaps the findings are valuable for chemotaxonomy of Acanthopanax genus.     

Estrogenic activity of triterpene glycosides in yeast two-hybrid assay

Estrogenic potency of six triterpene glycosides, Holothurin A, Holotoxin A₁, Frondoside A, Cucumarioside A₂-2 and Cauloside C, that are natural products and semi-synthesized Ginsenoside-Rh₂, were examined with yeast two-hybrid system, including expressed genes of human estrogen receptor, hER, the co-activator TIF2 and lacZ as a reporter gene. Only Ginsenoside-Rh₂ exhibited significant moderate estrogenic activity in the concentration range of 10⁻⁷ to 10⁻⁶ M. Its effect was approximately 30% of the activity of 17β-estradiol applied at half-effective concentration. This indicates Ginsenosides-Rh₂ is a weak phytoestrogen. The sea cucumber triterpene glycosides, Holothurin A, Holotoxin A₁, Cucumarioside A₂-2 and Frondoside A, and plant glycoside Cauloside C had no appreciable estrogenic activity. Data obtained by yeast two-hybrid assay reflect structure–activity relationship between tested compounds and 17β-estradiol. Only Ginsenoside-Rh₂ has some similarity in chemical structure with 17β-estradiol that might explain affinity of this glycoside to the hER receptor.     

A Novel Sulfated Holostane Glycoside from Sea Cucumber Holothuria leucospilota

A new sulfated holostane glycoside, leucospilotaside B ( 1 ), together with the two related structurally known compounds holothurin B₂ ( 2 ) and holothurin B ( 3 ), was isolated from sea cucumber Holothuria leucospilota collected from the South China Sea. The structure of 1 was elucidated by spectral analysis (¹H‐, ¹³C‐, and 2D‐NMR, ESI‐MS, and HR‐ESI‐MS) and chemical methods. The compounds 1 – 3 possess the same disaccharide moiety, but were different in the side chains of the triterpene aglycone. Compound 1 showed significant cytotoxicities against four human tumor cell lines, HL‐60, MOLT‐4, A‐549, and BEL‐7402.     

Arguside A: a new cytotoxic triterpene glycoside from the sea cucumber Bohadschia argus Jaeger

A new holostane-based triterpene glycoside, arguside A (1), was isolated from the sea cucumber Bohadschia argus, collected in the South China Sea. The structure of the new compound was elucidated by spectroscopic and mass-spectrometric analyses, in combination with chemical transformations. Compound 1 exhibited significant cytotoxicity against different human tumor cell lines, being more active towards HCT-116 cells (IC50 = 0.14 microM) than 10-hydroxycamptothecin (HCP) used as positive control.     

Structure and cytotoxicity of a new lanostane-type triterpene glycoside from the sea cucumber Holothuria hilla

A new triterpene glycoside, hillaside C (1), was isolated from the sea cucumber Holothuria hilla Lesson, which is found in the South China Sea, and its structure has been elucidated by spectral analysis (ESI-MS and NMR) and chemical transformations. Four known compounds, holothuria A, thymine, uracil, and cholesterol, were also obtained. Compound 1 exhibited significant cytotoxicity against eight human tumor cell lines (A-549, MCF-7, IA9, CAKI-1, PC-3, KB, KB-VIN, and HCT-8) with IC50 values in the range of 0.15-3.20 microg/ml.     

Patagonicosides B and C, two antifungal sulfated triterpene glycosides from the sea cucumber Psolus patagonicus

Two new triterpene glycosides, patagonicosides B and C (2 and 3, resp.), together with the known patagonicoside A (1), have been isolated from the EtOH extract of the sea cucumber Psolus patagonicus. The structures of the new compounds were established on the basis of extensive NMR spectroscopic analysis ((1)H- and (13)C-NMR, (1)H,(1)H-COSY, HMBC, HSQC, TOCSY, and NOESY), HR-ESI-MS data, and chemical transformations. Compounds 1-3 and their desulfated analogs showed antifungal activities against the phytopathogenic fungus Cladosporium cladosporoides in a dose-dependent fashion.     

Triterpene glycosides with in vitro anti-inflammatory activity from Cyclamen repandum tubers

A new triterpene glycoside, repandoside (1) was isolated together with six known saponins (2-7) from the methanol extract of Cyclamen repandum tubers. The isolated saponins were characterized by high resolution mass spectrometry and both 1D and 2D NMR experiments. The in vitro effect of saponins on LPS-induced IL-8 and TNF-α mRNA level (by quantitative RT-PCR) and protein release (by ELISA) was evaluated in human THP-1 macrophages. We found that compounds 1 (repandoside), 2 (deglucocyclamin) and 4 (anagalloside B) at 100 μM inhibited the LPS-induced IL-8 and TNF-α expressions.     

Two new saponins from Paronychia capitata

Two new oleanane-type triterpene glycosides, 3˗O˗β˗D˗glucopyranosyl˗28˗O˗[β˗D˗glucopyranosyl˗(1→2)˗β˗D˗xylopyranosyl˗(1→6)˗β˗D˗glucopyranosyl]medicagenic acid (1) and 3˗O˗β˗D˗glucopyranosyl˗28˗O˗[β˗D˗glucopyranosyl˗(1→6)˗β˗D˗glucopyranosyl˗(1→2)˗ β˗D˗xylopyranosyl]oleanolic acid (2), named capitatosides A and B respectively, were isolated from the butanol extract of Paronychia capitata (L.) Lam., along with seven known compounds. The structures of the isolated compounds were established by spectroscopic methods, mainly HRMS, 1D and 2D NMR (¹H, ¹³C, COSY, HSQC, HMBC and NOESY) techniques, whereas those of the known compounds were identified by spectral comparison with reported literature data.     

Triterpene glycosides from red ginseng marc and their anti-inflammatory activities

Three new triterpene glycosides ursan-3β,19α,22β-triol-3-O-β-d-glucopyranosyl (2′→1″)-β-d-glucopyranoside (1), ursan-3α,11β-diol-3-O-α-d-glucopyranosyl-(6′→1″)-α-d-glucopyranosyl-(6″→1‴)-α-d-glucopyranosyl-(6‴→1‴′)-α-d-glucopyranoside (2) and lanost-5,24-dien-3β-ol-3-O-β-d-glucopyranosyl-(6′→1″)-β-d-glucopyranosyl-(6″→1‴)-β-d-glucopyranoside (3), together with one known compound were isolated and identified from the marc of red ginseng. Their structures were elucidated by spectroscopic data analysis. Compounds (1–3) were investigated for anti-inflammatory effects using the RAW 264.7 macrophage cell line. In the cell proliferation assay, lipopolysaccharide stimulation decreased cell proliferation of RAW 264.7 macrophage cells, but the suppression of cell proliferation was significantly protected by treatment with compounds 2 and 3. Compounds 2 and 3 had a suppressive effect on the production of nitric oxide (NO), and they inhibited mRNA expression of proinflammatory mediators such as inducible nitric oxide synthase, and cyclooxygenase-2, and proinflammatory cytokines such as two interleukins and tumor necrosis factor-α. These findings suggest that compounds 2 and 3 have potential anti-inflammatory activities.     

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.     

Triterpene saponins from Salsola imbricata

Continuing our investigations on medicinal plants of the Egyptian desert, two new triterpene glycoside derivatives, along with three known compounds have been isolated from the roots of Salsola imbricata, a shrub widely growing in Egypt. Their structures have been established as 3-O-β-d-xylopyranosyl-(1 → 2)-O-β-d-glucuronopyranosyl-akebonic acid 28-O-β-d-glucopyranoside and 3-O-β-d-xylopyranosyl-(1 → 2)-O-β-d-glucuronopyranosyl-29-hydroxyoleanolic acid 28-O-β-d-glucopyranoside on the basis of spectroscopic methods including 1D- (¹H, ¹³C) and 2D-NMR (DQF-COSY, HSQC, HMBC) experiments as well as mass spectrometry analysis.     

Membranotropic effect of some triterpene glycosides possessing immunostimulating properties

The peculiarities of the interaction between cell membrane lipids and triterpene glycosides from holothurians Apostichopus japonicus S. and Cucumaria japonica (holotoxin A1 and cucumarioside A2-2, respectively) were studied in comparison with plant saponins from Quillaja saponaria, known as hemolytic, adjuvant, and structure-forming components of immunostimulating complexes. Similar to Quillaja saponins, the sea glycosides, holotoxin A1 and cucumarioside A2-2 were shown to possess a high hemolytic activity (2.6 and 3 microg/ml, respectively) and sterol-depending membranotropic effect mediated by the formation of nonbilayer sterol-lipid-glycoside complexes. At the same time, cucumarioside A2-2 bound exogenic cholesterol only in the presence of membrane lipids, such as phosphatidylcholine or monogalactosyldiacylglycerol, in contrast to Quillaja saponins and holotoxin A1, which bound cholesterol in the molar ratios 1:2 and 1:8, respectively. Moreover, in all cases, tree-component complexes containing cholesterol, lipid, and glycoside exhibited a lower hemolytic activity compared with two-component sterol-glycoside complexes. It was concluded that the hydrophobic medium of cell membranes performs a potentiative role in the effective interaction between triterpene glycosides and "sterol receptors". A method for decreasing the toxicity of membranotropic holothurian glycosides possessing the immunomodulating properties was suggested.     

Two triterpenoid glycosides from leaves of Ilex cornuta

Two new triterpene glycosides, a diglycoside (as the corresponding methyl ester) and a bis-desmoside were isolated from leaves of Ilex cornuta. The