نتایج جستجو برای: esims
تعداد نتایج: 139 فیلتر نتایج به سال:
Pyrenophoric acids B and C, two new phytotoxic sesquiterpenoids produced by Pyrenophora semeniperda.
Two new phytotoxic sesquiterpenoid acids, named pyrenophoric acids B and C, were isolated together with the related pyrenophoric and abscisic acids from solid Bromus tectorum (cheatgrass) seed culture of the seed pathogen Pyrenophora semeniperda. This fungus has been proposed as a mycoherbicide for biocontrol of cheatgrass (Bromus tectorum), a Eurasian annual grass that has become invasive in r...
use by the OPCW inspectorate. Use of GC with one or more spectrometric technique such as mass spectrometry is required to conRrm the presence of chemical warfare agents. For this reason many analyses are carried out by GC-MS under electron impact or chemical ionization conditions. For analyses involving low levels of chemical warfare agents in the presence of high levels of interfering chemical...
Four new triterpene glycosides, variegatusides C-F (1-4), together with three structurally known triterpene glycosides, variegatusides A and B (5, 6), and holothurin B (7), were isolated from the sea cucumber Stichopus variegates Semper (Holothuriidae), collected from the South China Sea. Their structures were elucidated on the basis of extensive spectral analysis (nuclear magnetic resonance (N...
Escherichia coli tmRNA functions uniquely as both tRNA and mRNA and possesses structural elements similar to canonical tRNAs. To test whether this mimicry extends to post-transcriptional modification, the technique of combined liquid chromatography/ electrospray ionization mass spectrometry (LC/ESIMS) and sequence data were used to determine the molecular masses of all oligonucleotides produced...
In the course of our continuing search for novel antimicrobial agents,1-5) we have isolated a novel antibacterial anthracycline, micromonomycin (1), from culture Micromonospora sp. Micromonomycin was identified as a new anthracycline using high resolution ESIMS and extensive NMR spectroscopic analyses. In this paper, we describe the isolation and structure elucidation of 1. The biological activ...
Introduction The fast development of genetic engineering and biotechnology has made possible to obtain proteins naturally expressed at so low concentrations that it makes hard to be isolated. The recombinant DNA technology allows inserting a gene coding for a protein of interest into the genome of a host microorganism by means of an appropriate genetic construct. Then, the recombinant protein i...
Eremostachys pulvinaris (family: Labiatae), one of the 60 species of the genus Eremostachys, occurs mainly in central Asian countries, e.g. Iran, Armenia, Ashgabad and the USSR. The rhizomes of this plant were collected from Tabriz in Azarbaijan province during September-October 2003. There is no report on any previous phytochemical investigation on E. pulvinaris available todate, phytochemical...
Study was made of host-guest complexation of neutral crown ethers with fiveand six-membered Nheteroaromatic cations and purinium cation. Complexation of tetraphenylborate with selected Nheteroaromatic cations and tropylium cation also was studied. Crown ether complexes were characterized by mass spectrometric and 1H NMR spectrometric methods and by X-ray crystallography. Fast atom bombardment m...
The present study aimed to analyze sera proteins in females with cervical intraepithelial neoplasia, grade III (CIN III) and in healthy control females, in order to identify a potential biomarker which detects lesions that have a greater probability of cervical transformation. The present study investigated five sera samples from females who were Human Papilloma Virus (HPV) 16+ and who had been...
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