The liver is an essential organ in the body for detoxification drugs and toxic substances. present study was designed to investigate hepatoprotective effects of L-Cysteine, Ursodeoxycholic acid (Ursoflor), Silymarin against carbon tetrachloride-induced injury rats. Twenty adult male rats were used this work; they randomly divided into five groups (4 rats/group). first group served as control re...

Under anaerobic conditions an exponentially growing culture of Escherichia coli K-12 was exposed to hydrogen peroxide in the presence of various compounds. Hydrogen peroxide (0.1 mM) together with 0.1 mM L-cysteine or L-cystine killed the organisms more rapidly than 10 mM hydrogen peroxide alone. The exposure of E. coli to hydrogen peroxide in the presence of L-cysteine inhibited some of the ca...

b a c k g r o u n d & aim: the aim of the current study was to investigate the advantages of bayesian method in comparison to traditional methods to detect best antioxidant in freezing of human male gametes. methods  &  materials:   semen  samples  were  obtained  from  40  men  whose  sperm  had  normal criteria. a part of each sample was separated without antioxidant  as fresh and the remaini...

Despite antibiotic therapy, acute and long-term complications are still frequent in pneumococcal meningitis. One important trigger of these complications is oxidative stress, and adjunctive antioxidant treatment with N-acetyl-l-cysteine was suggested to be protective in experimental pneumococcal meningitis. However, studies of effects on neurological long-term sequelae are limited. Here, we inv...

Simultaneous separation of 37 proteinogenic D/L-amino acids excluding proline with HPLC is generally difficult. In this study, two sets o-phthalaldehyde (OPA)-based fluorescent diastereomers were formed using chiral thiols N-acetyl-L-cysteine (NAC) and N-isobutyryl-L-cysteine (NIBC) independently. It expected that obtained OPA-derivatized D/L show different retention selectivity in reversed pha...

Among the L-amino acids, only L-cysteine was oxidized by isolated washed membranes of group B Neisseria meningitidis SD1C. The cysteine oxidase in the membrane obeyed Michaelis-Menten kinetics and was heat labile. The pH optimum for the maximum velocity of the reaction was 9.8. Specific activity of the enzyme increased as cell growth progressed through the exponential phase toward the stationar...

S-Alk(en)yl-L-cysteine sulfoxides are pharmaceutically important secondary metabolites produced by plants that belong to the genus Allium. Biosynthesis of S-alk(en)yl-L-cysteine sulfoxides is initiated by S-alk(en)ylation of glutathione, which is followed by the removal of glycyl and γ-glutamyl groups and S-oxygenation. However, most of the enzymes involved in the biosynthesis of S-alk(en)yl-L-...

Cell-free extracts of Bacillus megaterium form beta-cyanoalanine (beta-CNA)-(14)C from Na(14)CN and l-cysteine, O-acetyl-l-serine or, to a lesser extent, l-serine. However, the presence of cyanide in the growth medium does not increase the capacity of cell extracts to catalyze the formation of beta-CNA from cysteine and cyanide. The formation of beta-CNA is readily detected in extracts of cells...

Tyrosinase, the enzyme responsible for melanin biosynthesis in normal tissues and malignant melanomas, has been reported to be a vital respiratory enzyme of melanizing tissue. In the present study, S-91 mouse melanoma expiant growth inhibition in vitro was evaluated quantitatively for 7 substrate analogs of tyrosine, alone and in the presence of L-cysteine. i>L-j3-Phenyllactate (PLA) was the mo...

A number of arylcysteine derivatives, which are metabolites of polycyclic aromatic hydrocarbons, have been synthesized. These amino acid analogs were tested for their ability to act as substrates for aminoacyl-RNA synthetases in an in vitro system using enzyme fractions of bakers' yeast. These studies have shown that 5-(p-chlorophenyl)-L-cysteine, 5-(9 ,10 dihydro-9-hydroxy-l 0-phenanthryl)-L-c...