Penicillin and the corresponding penicilloic acid are extracted by chloroform from an acidified sample of urine which has been partly saturated by ammonium sulfate. A portion of the extract is dried and redissolved in a small volume of acetone. A measured aliquot is chromatographed on a silica g...

Phenoxymethylpenicilloic acid monohydrate was titrated with 12 different brands of Karl Fischer reagent. It was shown that only the four pyridine-containing reagents gave correct results for water content, providing that the sample solution was cooled in an ice bath or that the delay time of the...

A label-free surface-enhanced Raman scattering (SERS) strategy based on silver-coated gold nanoparticles ([email protected] NPs) was developed for rapid detection of penicilloic acid (PA) in milk products. It has been demonstrated that core size and shell thickness of [email protected] NPs are t...

A simple, fast and sensitive method for determination of the degradation products of penicillin (penicilloic acid and penilloic acid) in milk samples has been developed by combining selective surface molecularly imprinted matrix solid-phase dispersion and high performance liquid chromatography (...

Trace penicilloic acid allergen frequently leads to various fatal immune responses to many patients, but it is still a challenge to directly discriminate and detect its residue in penicillin by a chemosensing way. Here, we report that silver-coated gold nanoparticles ([email protected] NPs) exhi...

Elucidation and quantitative determination of some of commonly used penicillins (ampicillin, penicillin G and carbenicillin) in the presence of their main degradation product (penicilloic acid) were developed. Forced acidic and basic degradation processes were applied at different time intervals...

Gymnemic acids, the triterpene saponins from the leaves of the asclepiad vine Gymnema sylvestre, act as feeding deterrents to a caterpillar, Prodenia eridania. The effect is demonstrable with sugar-free diets, suggesting that the acids do not act, as they do in mammals, by suppressing the sweetn...

Two major active components of gymnemic acids were isolated in pure state. Their chemical structures were established as D-glucuronide of 3β,16β,21β,22α,23,28-hexahydroxyolean-12-ene which is esterified with tiglic acid or 2-methylbutyric acid at 21-C hydroxy group, respectively. The antiswe...

The effects of gymnemic acid (GA) treatment of the tongue of the hamster were studied in a brief exposure two-bottle preference test which paired 0.04 M sucrose with distilled water. Sucrose preference was significantly reduced following GA compared to preference following a control treatment. T...

A method was derived to isolate gymnemic acid A1, a main component of gymnemic acid A, for preparative purpose. Acids esterified in the genin of gymnemic acid A1 were determined to be 1 mole of acetic, 2 moles of isovaleric and 1 mole of tiglic acids. Gymnemic acid A1 was converted into A2, and ...

Elicitation is one of the few strategies that find commercial application in the improvement of secondary metabolite production from plants as well as cell and organ culture systems. Gymnema sylvestre is an important medicinal plant which bears bioactive compound namely gymnemic acid that finds ...

Objective To determine the structure (disease) modifying effect of a glycosaminoglycan polypeptide association complex (GP-C; Rumalon®) in patients with knee and hip osteoarthritis (OA).Methods Double-blind, randomized, placebo-controlled five-year study. Primary assessment criterion was change ...

A spontaneous rough (Rg) mutant of M. avium ATCC 15769 was mutagenized using N-methyl-N-nitro-nitrosoguanidine (MNNG). Out of 54 clones initially chosen on the basis of their morphological appearance on the 7H11 agar, seven Rg clones were selected on the basis of their response to current bioche...

The structure of the monosaccharide isolated from mycoside G, a specific glycolipid of Mycobacterium marinum, is established as follows: demethylation experiments show that the monosaccharide is a methyl ether of l-rhamnose. Spectra (mass and n.m.r.) of the derived, acetylated methyl glycoside s...

RésuméMycoside C2 from Mycobacterium avium is a mixture of two homologous peptidoglycolipids: C2a (Formula III) and C2b (Formula IV). Both have the following partial structure: The C-terminal molecule of D-alanine esterifies the pseudoaldehydic function of 6-deoxy-L-talose in mycoside C2a and ...

The structure of the aglycone of mycoside G isolated from Mycobacterium marinum (balneï) has been established by mass spectrometry and confirmed by degradation.This aglycone is a phenol with a long aliphatic glycolic side chain, the hydroxyle functions of which are esterified with normal and bra...

Mycoside B, a specific glycolipid found in bovine strains of Mycobacterium tuberculosis is shown to be a mixture of homologous compounds differing by the nature of the fatty acids. The principal constituent of this mixture is a mycoside B having the molecular formula C84H156O10; it contains one ...

C-mycosides are superficial type-specific glycopeptidolipids of mycobacterial origin. In the present work, we have shown that field desorption mass spectrometry using the cationization method is a useful method for the molecular weight determination of such compounds. Complementary structural in...

The first synthetic approach towards D-Phe-D-allo-Thr-D-Ala-L-Alanilol-O-(3,4-di-O-Me-Rhap), the glycolipid of C-mycoside is described.

Nuclear magnetic resonance spectroscopy, fast-atom bombardment mass spectrometry, gas chromatography-mass spectrometry, as well as chemical degradations were used to elucidate the structure of the major glycolipids of Mycobacterium fortuitum. Three main glycoconjugates were detected and their st...