Drugs online research references
Biochem Biophys Res Commun. 2002 Mar 1;291(3):593-7.
Substrate specificity of penicillin acylase from Streptomyces lavendulae.
Torres-Guzman R, de la Mata I, Torres-Bacete J, Arroyo M, Castillon MP, Acebal C.
Departamento de Bioquimica y Biologia Molecular, Universidad Complutense, Madrid, 28040, Spain.
The kinetic parameters of several substrates of penicillin acylase from Streptomyces lavendulae have been determined. The enzyme hydrolyses phenoxymethyl penicillin (penicillin V) and other penicillins with aliphatic acyl-chains such as penicillin F, dihydroF, and K. The best substrate was penicillin K (octanoyl penicillin) with a k(cat)/K(m) of 165.3 mM(-1) s(-1). The enzyme hydrolyses also chromogenic substrates as NIPOAB (2-nitro-5-phenoxyacetamido benzoic acid), NIHAB (2-nitro-5-hexanoylamido benzoic acid) or NIOAB (2-nitro-5-octanoylamido benzoic acid), however failed to hydrolyse phenylacetil penicillin (penicillin G) or NIPAB (2-nitro-5-phenylacetamido benzoic acid) and penicillins with polar substituents in the acyl moiety. These results suggest that the structure of the acyl moiety of the substrate is more determinant than the amino moiety for enzyme specificity. The enzyme was inhibited by several organic acids and the extent of inhibition changed with the hydrophobicity of the acid. The best inhibitor was octanoic acid with a K(i) of 0.8 mM. All the results, taking together, point to an active site highly hydrophobic for this penicillin acylase from Streptomyces lavendulae. (c)2002 Elsevier Science (USA).
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11855830&dopt=Abstract
J Pharm Sci. 1983 May;72(5):508-13.
In-beam electron ionization mass spectra of penicillins.
Ohashi M, Barron RP, Benson WR.
The characteristics of in-beam electron ionization mass spectra of 6-aminopenicillanic acid and several penicillins, which yield no detectable molecular ion peaks using a conventional direct-insertion probe, have been established. The spectra of all compounds studied, with the exception of amoxicillin, exhibited molecular ion or (M+1) peaks with spectral features similar to the reported methyl ester or amide derivatives of the compounds. The fragmentation of penicillin G on electron impact under in-beam conditions can be described on the basis of data from mass analyzed ion kinetic energy spectrometry. A desorption technique utilizing polyethylene glycol 4000 was used as a means of obtaining satisfactory spectra of ampicillin and amoxicillin.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6306205&dopt=Abstract
Eur J Clin Pharmacol. 1984;26(2):279-81.
Effect of guar gum, a fibre preparation, on digoxin and penicillin absorption in man.
Huupponen R, Seppala P, Iisalo E.
The effect of guar gum on the absorption of digoxin and phenoxymethyl penicillin was studied in a double blind study in 10 healthy volunteers. Guar gum reduced serum digoxin concentration during the early absorption period, but a similar amount of digoxin was found in 24 h urine whether given with or without guar gum. Both the peak penicillin concentration and the area under the serum curve were significantly reduced by the gum.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6327318&dopt=Abstract
Herbs and Pharmaceuticals Online ||
Hair Million herbal formula for hair loss and hair growth ||
Wellstreet online pharmacy for click-order prescription medications ||
Altace Online Pharmacy ||
Rx Drugs USA, Prescription Drugs Online Pharmacy ||
Insurance plans and information ||
Insurance policies for all purposes ||
Antibiotics and prescription medications online literature ||