The glutamic acid E396, aspartic acid D409 and glutamic acid E411 residues of the Escherichia coli penicillin-binding protein 3 were each converted into an alanine residue. As deduced from penicillin-binding and complementation experiments, none of these dicarboxylic acid residues is involved in the mechanism of acylation by penicillin and none of them is essential for the in vivo functioning o...

Papilistatin has been isolated recently and found to have good anticancer and antibacterial activity. Papilistatin is a unique phenanthrene-1,10-dicarboxylic acid. The first total synthesis of papilistatin is described here with radical cyclisation as the key step.

The biochemical mechanisms mediating the rapid distribution of valproic acid across placenta are not precisely known. We have characterized valproic acid transport by the human trophoblast using the human choriocarcinoma cell line, BeWo. The uptake of [14C]valproic acid by BeWo cells was found to be saturable and blocked by pre-exposure to the metabolic inhibitors, sodium azide and 2,4-dinitrop...

The data presented in this paper indicate operation of different mechanisms for acetate oxidation by A. aerogenes, depending on the carbon source used for growth. The mechanism for citrate-grown cells appears to involve a conventional citric acid cycle, whereas acetate-grown cells appear to incorporate acetate carbon more readily via a dicarboxylic acid cycle.

The polymeric title compound, [Ca(C(6)H(2)N(2)O(4))(H(2)O)](n), was synthesized from pyrazine-2,3-dicarb-oxy-lic acid and calcium dichloride under hydro-thermal conditions. The Ca(2+) cation is seven-coordinated by five O atoms and one N atom of four pyrazine-2,3-dicarboxyl-ate anions, and one water mol-ecule. The complete deprotonated pyrazine-2,3-dicarboxyl-ate anion adopts a μ(4)-coordinatio...

The analysis of mixed acid streams plays an important role in the control of processes for the production of acetic acid and the determination of dicarboxylic and ketoacids, such as succinic (butane-dioic acid) and levulinic acids (4-oxypentanoic acid), can present particular problems to the analyst, In process streams at high temperatures these components are fully soluble but at ambient tempe...

In this study, the effect of crocin, a substance found in Crocus sativus L. stigmata on nervous system development and regeneration was investigated. Crocin is a glycosyl ester of the polyene dicarboxylic acid crocetin and is one of the few families of carotenoids found in nature, which are freely soluble in water. In the first experiment, the effect of crocin (30 microM, 60 microM and 120 micr...

The structure of the side chain of the 3 alpha, 7 alpha, 12 alpha-trihydroxy-5 beta-C29 dicarboxylic bile acid occurring in body fluids of infants with coprostanic acidemia was investigated by means of mass spectrometry and nuclear magnetic resonance spectroscopy. The findings identified this bile acid as 3 alpha, 7 alpha, 12 alpha-trihydroxy-27a, 27b-dihomo-5 beta-cholestane-26,27b-dioic acid ...

The transport of succinate was studied in bacteroids of an effective, streptomycin-resistant strain (GF160) of Rhizobium leguminosarum. High levels of succinate transport occurred, and the kinetics, specificity, and sensitivity to metabolic inhibitors were similar to those previously described for free-living cells. The symbiotic properties of two transposon (Tn5)-mediated C4-dicarboxylate tran...

The micro-alga Chlorella pyrenoidosa expresses an enzymatic activity that cleaves the 13-hydroperoxide derivatives of linoleic acid [13-hydroperoxy-9(Z),11(E)-octadecadienoic acid, 13-HPOD] and linolenic acid [13-hydroperoxy-9(Z),11(E),15(Z)-octadecatrienoic acid, 13-HPOT] into volatile C(5) and non-volatile C(13) oxo-products. This enzymic activity initially was attributed to a hydroperoxide l...