نتایج جستجو برای: triterpene mass fragmentation pattern

تعداد نتایج: 842418  

2011
Beata Jasiewicz Elżbieta Wyrzykiewicz

The unpublished in the literature FAB mass spectral fragmentation of seven oxosparteines (i.e., 2-oxosparteine, 15-oxosparteine, 17-oxosparteine, 2,17-dioxosparteine, 2,13-dioxosparteine, 2-oxo-13-hydroxysparteine, and 2-oxo-17-hydroxysparteine) is investigated. Fragmentation pathways, elucidation of which was assisted by FAB/collision-induced dissociation (CID) mass spectra measurements, are d...

2014
Kapendra Sahu Anees A. Siddiqui Mohammad Shaharyar Shikha Sahu

Piracetam was subjected to the hydrolytic, oxidative, thermal and photolytic stress, according to ICH guideline Q1A (R2). The drug depicted degradation only in basic conditions, while it was stable to other stress conditions (acidic, neutral hydrolysis, thermal and photolytic conditions). A total of one degradation product was formed, which were separated on a BEH column employing an isocratic ...

2016
R. Yarahmadi R. Bagherpour A. Khademian H. Mirzaie R. Kakaie

Various geological processes such as tectonic activities develop fractures and discontinuities in the rock mass body; these, in turn, form blocks with different shapes and sizes in the rock mass body. Accurate understanding of these blocks' geometry is essential in different domains of rock and mine engineering such as determination of yield in quarries, optimization of fragmentation energy, th...

2004
William Shaw Ellen Kassen Enrique Chaves

A marked Increase in analogs of Krebs cycle metabolites was found in the urine of two brothers with autistic features. These metabolites included citramalic, tartaric (3-OH-malic), and 3-oxoglutaric acids and compounds tentatively identified as a citric acid analog and partially identified as a phenylcarboxylic acid by the fragmentation pattern of the trimethylsilyl (TMS) derivatives of the com...

Journal: :Journal of mass spectrometry : JMS 1996
Y H Kim J S Yoo C H Lee Y M Goo M S Kim

O-Demethylabierixin, a new polyether antibiotic, was isolated from a Streptomyces spp. Its structure elucidation was carried out with fast atom bombardment mass spectrometry (FAB-MS) and fast atom bombardment mass spectrometry-mass spectrometry (FAB-MS/MS) by comparing spectral patterns with those of structurally similar polyether compounds, nigericin and abierixin. The collision-induced dissoc...

Journal: :Molbank 2022

We herein report on the synthesis of a pentacyclic triterpene functionalized through derivation betulinic acid with hydroxybenzotriazole. The compound was fully characterized by proton (1H-NMR), carbon-13 (13C-NMR), heteronuclear single quantum coherence (HSQC) and distortionless enhancement polarization transfer (DEPT-135 DEPT-90) nuclear magnetic resonance. Ultraviolet (UV), Fourier-transform...

Journal: :Journal of mass spectrometry : JMS 2011
Jian-Long Zhang Julia Kubanek Mark E Hay William Aalbersberg Wen-Cai Ye Ren-Wang Jiang

Tydemania expeditionis Weber-van Bosse (Udoteaceae) is a weakly calcified green alga. In the present paper, liquid chromatography coupled with photodiode array detection and electrospray mass spectrometry was developed to identify the fingerprint components. A total of four triterpenoid sulfates and three hydroxy fatty acids in the ethyl acetate fraction of the crude extract were structurally c...

Journal: :Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy 2006
M A Zayed M F Hawash M A Fahmey

Codeine is an analgesic with uses similar to morphine, but it has a mild sedative effect. It is preferable used as phosphate form and it is often administrated by mouth with aspirin or paracetamol. Therefore, it is important to investigate its structure to know the active groups and weak bonds responsible for its medical activity. Consequently in the present work, codeine was investigated by ma...

Journal: :Journal of animal science 2008
M Lourenço P W Cardozo S Calsamiglia V Fievez

Four different plant secondary metabolites were screened for their effect on rumen biohydrogenation of forage long-chain fatty acids, using dual-flow continuous culture fermenters. Treatments were as follows: control (no additive), positive control (12 mg/L of monensin), and plant extracts (500 and 1,000 mg/L of triterpene saponin; 250 and 500 mg/L of quercetin; 250 mg/L of eugenol; 500 mg/L of...

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