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At least 19 recordsLinked to original sources
PubMed2026

Functional characterization of SHC-like triterpene cyclase genes in azole response and virulence-related traits of Aspergillus fumigatus.

Aspergillus fumigatus is a major opportunistic fungal pathogen, and increasing azole resistance poses a challenge for aspergillosis treatment. Squalene is an upstream precursor of ergosterol biosynthesis and may also be utilized by SHC-like triterpene cyclases, suggesting a potential link between squalene-associated metabolism, membrane adaptation, and azole response. However, the roles of SHC-like triterpene cyclase genes in A. fumigatus remain unclear. Here, we characterized three candidates, shc1, shc2, and shc3, using comparative bioinformatic analysis, gene deletion, phenotypic assays, azole susceptibility testing, transcriptomics, and host-interaction models. Sequence, genomic-context, phylogenetic, and structural analyses suggested divergence among the three candidates. Individual shc deletion caused limited effects on vegetative growth, whereas loss of shc1 mildly reduced susceptibility to voriconazole and posaconazole, as reflected by twofold MIC increases and lower inhibition rates. Transcriptomic analysis revealed distinct remodeling patterns, with Δshc3 showing the broadest transcriptional changes despite no detectable MIC shift. Targeted metabolite profiling and PI uptake analysis further supported an association between shc deletion, sterol/hopane-type triterpenoid balance, and membrane-associated properties. shc deletion also altered epithelial cell interaction phenotypes, while Δshc1 showed reduced lethality in Galleria mellonella. In clinical isolates, elevated shc transcription was associated with azole-resistant backgrounds. These findings suggest functional diversification among SHC-like triterpene cyclase genes and indicate that shc1 may contribute to azole-associated adaptation and virulence-related traits in A. fumigatus.

Aspergillus fumigatus↗
PubMed1979

[Effect of triterpene glycosides on plasma membrane permeability for UV-absorbing substances in Saccharomyces carlsbergensis yeast cells].

The effect of triterpene glycosides of cauloside C from Caulophyllum robustum M, stichoposide A from Stichopus japonicus S. and theasaponine from Thea sinensis Z. on permeability of plasmic membranes of Saccharomyces carlsbergensis for UV-absorbing substances was studied. It was found that incorporation of 14C-uridine from the endocellular pool into the yeast acid-insoluble fraction decreased under the effect of the triterpene glycosides as a result of the precursor leakage from the cell into the medium. It was found that the triterpene glycosides stimulated the leakage of the UV-absorbing substances with an absorption maximum at 260 nm from the cells. The maximum membranotropic effect was observed at 30--40 degrees C and in the presence of monovalent potassium, sodium, ammonium and lithium ions in the medium. Cauloside C and theasaponine, pentacyclic glycosides had the highest effect on the permeability at pH 4.8--5.6, while stichoposide A, a tetracyclic glycoside, had the highest effect at pH 7.0.

Cell Membrane Permeability↗
PubMed1976

Triterpenes of toxic and non-toxic taxa of Lantana camara.

The taxa of Lantana camara toxic to animals contain lantadene A lantadene B, whereas in two non-toxic taxa other triterpenes predominate. Several new triterpenes have been characterized. Contrary to earlier claims, lantadene A and to a lesser extent lantadene B are toxic when administered intraruminally to sheep.

Animal Feed↗
PubMed1991

Triterpenes from Mucuna birdwoodiana.

Methanolic extracts of the stalks of Mucuna birdwoodiana on acid hydrolysis and subsequent methylation with diazomethane provided four triterpene sapogenols. On the other hand, investigation of glycosides after methylation of the same extract led to the isolation of four triterpene glycosides. On the basis of chemical and spectral evidence, their structures were characterized as methyl asiatate, methyl maslinate, two new sapogenols, methyl 1 beta,2 alpha,3 beta,23-tetrahydroxyolean-12-en 28-oate (mucunagenin a), its urs-12-en isomer (mucunagenin b), 3-O-(6-O-methyl-beta-D-glucuronopyranosyl) methyl asiatate 3-O-[alpha-L-arabinopyranosyl(1----2)]-6-O-methyl-beta-D-glucur onopyranosyl methyl maslinate, 3-O-[alpha-L-arabinopyranosyl(1----2)]-6-O-methyl-beta-D-glucur onopyranosyl methyl asiatate and 3-O-(6-O-methyl-beta-D-glucuronopyranosyl) asiatic acid 28-O-beta-D-glucopyranoside.

Carbohydrate Sequence↗
PubMed1992

Triterpene saponins from the roots of Ampelozizyphus amazonicus.

A new triterpene saponin was isolated from the roots of Ampelozizyphus amazonicus together with the known 3-O-beta-D-glucopyranosyl-20-O-alpha-L-rhamnopyranosyljujubogenin and the known triterpenes melaleucic acid, 3 beta,27 alpha-dihydroxylup-20(29)-en-28 beta-oic acid, betulinic acid, betulin, lupeol. The structure of this saponin was elucidated as 3-O-[beta-D-glucopyranosyl(1----2)alpha-L-arabinopyranosyl]- 20-O-alpha-L-rhamnopyranosyljujubogenin by spectral analysis and chemical transformations.

Carbohydrate Sequence↗
PubMed1976

Proton magnetic resonance spectra of tetracyclic triterpene alcohols under the influence of a lanthanide shift reagent.

The proton magnetic resonance spectra were measured for four series of tetracyclic triterpen-3beta-ols, i.e. 5alpha-lanostane, 5alpha-euphane, 5alpha-tirucallane, and 5alpha-dammarane series, in the presence of a molar equivalent of tris (dipivalomethanato) europium, a lanthanide shift reagent. The spectral pattern measured in the presence of the shift reagent was found useful for distinguishing each series and also for characterizing each skeletal isomer of tetracyclic triterpene alcohols.

Alcohols↗
PubMed1977

The oral toxicity for sheep of triterpene acids isolated from Lantana camara.

Toxic Lantana camara taxa growing in Queensland all contain the triterpene acids lantadene A, reduced lantadene A and lantadene B. These when dosed as pure compounds orally to sheep were similarly toxic at 65 to 75, 42 to 80 and 200 to 300 mg/kg body weight respectively, causing jaundice, photosensitisation, kidney and liver lesions typical of natural and experimental lantana poisoning. Because of its comparative toxicity and abundance lantadene A is the most significant toxic principle in the plant. Reduced lantadene A because of its low concentration in the leaves (5% of lantadene A) and lantadene B because of its significantly lower toxicity are thus unlikely to be of much importance in the poisoning of ruminants following consumption of the plant. In addition, the structural features of both lantadene A and B molecules given to sheep by the oral route do not conform to the chemical structures previously reported to be required for liver damaging action of the verbenaceous triterpenes administered to rabbits by the intraperitoneal route.

Animals↗
PubMed1992

Antilipoxygenase activity of amyrin triterpenes.

Triterpenes--alpha-amyrin acetate, beta-amyrin acetate and beta-amyrin were tested for their effects on the synthesis of 5-lipoxygenase products in human neutrophils. All the triterpenes reduced 5-HETE synthesis without effect on LTB4 synthesis. The relative effects suggest that 5-HETE inhibition can explain the antiarthritic activity possessed by these compounds.

Female↗
PubMed1979

[Antimicrobial action spectrum of triterpene and steroid glycosides].

Antimicrobial activity of 9 triterpene glycosides of the plant and animal origin was studied. It was found that saponins inhibited the fungal growth to different extents and had no activity against grampositive and gramnegative bacteria. Triterpene glycosides of the animal origin, i.e. holoturins A and B, stichoposids A and C had the most pronounced antifungal activity as compared to the saponins isolated from plants. Changes in the length of the carbon chain from 2 to 6 monosugars had no significant effect on the activity of the triterpeneglycosides studied.

Animals↗
PubMed1977

[Effect of triterpene glycosides on RNA biosynthesis in a yeast cell culture of Saccharomyces carlsbergensis].

The effect of triterpen glycosides of cauloside C from Caulophyllum robustum, theasaponine from Thea sinensis ahd stichoposide A from Stichopus japonicus on multiplication and biosynthesis of RNA in the cells of a 7-hour culture of Saccharomyces carlsbergensis was studied. It was shown that cauloside C, theasaponine and stichoposide A in concentrations of 7.5 gamma/ml inhibited multiplication of the yeast cells by 65, 10 and 90 per cent respectively. The summation RNA of the yeast cells is divided into 3 zones on Sephadex G-100. The glycosides induced no pronounced changes in the chromotographic profile of RNA. Biosynthesis of the transport and ribosomal RNA were inhibited to the same extent. Triterpen glycosides inhibited the biosynthesis of RNA at the stage of 14C-uridine in corporation into the nucleotide pool of the yeast cells.

Cells, Cultured↗
PubMedDate not supplied

Triterpenes from the button cactus, Epithelantha micromeris.

Ethanolic extracts of the title plant were toxic to mice. Acid hydrolysis of the toxic extracts permitted the isolation of six crystalline compounds. The known triterpenes oleanolic acid and methyl machaerinate and the common plant sterol, beta-sitosterol, were identified. The structures of two other isolated compounds, named epithelanthic acid and methyl epithelanthate, were postulated to be new delta9(11)-12-oxooleanenes, and another trace compound was incompletely categorized as a triterpene lactone.

Animals↗
PubMed1991

Triterpene glycosides from Schefflera octophylla.

In addition to 3-epi-betulinic acid, three triterpene glycosides were isolated from leaves of Schefflera octophylla. The structures of the glycosides have been determined as 28-O-[alpha-L-rhamnopyranosyl(1----4)-O-beta-D-glucopyranosyl(1----6)-be ta-D- glucopyranosides of 3 alpha-hydroxy-lup-20(29)-ene-23,28-dioic acid, 3 alpha,11 alpha- dihydroxy-lup20(29)-ene-23,28-dioic acid and 3-epi-betulinic acid by spectroscopic data and chemical transformations. The last two compounds were found for the first time in the plant kingdom.

Carbohydrate Sequence↗
PubMed1975

24-Methylenedammarenol: a new triterpene alcohol from shea butter.

A new triterpene alcohol was isolated from shea butter and its structure was shown to be 24-methylenedammarenol (24-methylene-5alpha-dammar-20[21]-en-3beta-o1). Dammaradienol (5alpha-dammara-20[21],24-dien-3beta-o1) also was isolated from shea butter.

Chemical Phenomena↗
PubMed1976

A 1,2,3,4-tetrahydroxy pentane-substituted pentacyclic triterpene from Bacillus acidocaldarius.

A long-chained polyalcohol (polyol) was isolated from the glycolipid fraction of the extreme thermoacidophile Bacillus acidocaldarius. The polyol and its Smith degradation products, as well as the alkanes derived from these compounds were characterized by mobility on thin-layer and gas-liquid chromatography, and by infrared and mass spectrometry. The polyol is proposed to be a fully saturated pentacyclic tetrol (C35H62O4, Mr 546) containing a 1,2,3,4-tetrahydroxy pentane substituted to a hopane-derived pentacyclic triterpene nucleus.

Bacillus↗
PubMed1992

Triterpene glycosides from the seeds of Astragalus sinicus L.

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).

Glycosides↗
PubMed1978

[Effect of triterpene glycosides on the plasma membrane permeability for amino acids in Saccharomyces carlsbergensis yeast cells].

The effect of triterpen glycosides, such as cauloside C from Caulophyllum robustum, stichoposide A from Stichopus japonicus S and the asaponine from Thea sinensis L on permeability of the plasmic membranes for amino acids was studied. It was shown that the glycosides induced higher levels of liberation of the amino acids with positively or negatively charged molecules from the cells of Saccharomyces carlsbergensis as compared to the control. The transport of the non-polar amino acids was least affected by addition of the saponines to the incubation medium.

Amino Acids↗