The filamentous fungus Byssochlamys fulva strain IMI 40021 produces (+)-byssochlamic acid 1, its novel dihydroanalogue 2 and four related secondary metabolites. Agnestadrides A, 17 and B, 18 constitute a novel class of seven-membered ring, maleic anhydride-containing (hence termed heptadride) natural products. The putative maleic anhydride precursor 5 for both nonadride and heptadride biosynthe...

The aim of this study was to investigate the effects of different acid catalysts and pretreatment factors on the hydrolysis of biomass compounds over a range of thermochemical pretreatments; maleic, oxalic, and sulfuric acids were each used under different pretreatment conditions. The most influential factor for fermentable sugar production in the dicarboxylic acid-pretreated mixed hardwood was...

BACKGROUND To evaluate the effect of EDTA, Maleic acid, Citric acid and MTAD Irrigating Solutions on the shear bond Strength of A-H plus sealer. MATERIALS & METHODS Forty mandibular single rooted premolar teeth with straight roots were taken, decoronated and instrumented using Protaper rotary instruments to size #F3, 0.09 taper, at the working length, with 3 mL of 2.6% sodium hypochlorite in ...

Four polyesters were prepared by stepwise condensation of isopbthalic acid, cblorendic acid and maleic anhydride with propylene glycol using p-toluenesulpbonic acid as catalyst and xylene as entrainer. The quantities of maleic anbydride and propylene glycol used were 1 and 2.2 moles respectively and tbe molar ratios of cblorendic acid to isopbtbalic acid were 0.2: 0.8. 0.4: 0.6, 0.6: 0.4 and 0....

1. It has been shown that Penicillium charlesii continues to synthesize galactocarolose when l-malic acid, malonic acid, succinic acid, fumaric acid, maleic acid or oxaloglycollic acid is substituted for dl-tartaric acid in the Raulin-Thom nutrient medium. 2. The quantity of galactocarolose synthesized per g. of mycelia was markedly decreased by substitution of l-malic acid, malonic acid, succi...

The dipotassium salts of maleic, fumaric and acetylenedicarboxylic acids were electrooxidized and the reaction products were analyzed qualitatively and quantitatively by UV/VIS and FT-IR spectroscopy. Acetylene, carbon dioxide and carbon monoxide, along with polyynes, are the products obtained from maleic and fumaric acids. The best acetylene yields are obtained from fumaric acid and not from m...

A number of polycarboxylic acids butane tetracarboxylic acid BTCA, polyacrylic-co-maleic acid PAMA, citric acid, maleic-itaconic MA-IA were examined, in combination with sodium hypophosphite SHP in order to give a similar high fabric crease recovery performance and whiteness index to traditional formaldehyde based crease agents. BTCA showed to be the best crease resist agent for crosslinking co...

An ion chromatographic method was developed which is able to separate five unsubstituted and hydroxy C4 dicarboxylic acids, succinic, malic, tartaric, maleic and fumaric acid, besides the other unsubstituted C2-C5 dicarboxylic acids, oxalic, malonic and glutaric acids, as well as inorganic ions in samples extracted from atmospheric particulate matter. By the application of this method it was fo...

Abstract The structure of model compounds for the amphiphilic copolymer poly(diisobutylene‐ alt ‐maleic acid), DIBMA, is investigated with (gas phase) B3LYP/6‐31G** and PM7 calculations. It found that in monoprotonated state repeating unit strong (about 70 kJ mol −1 ) ionic hydrogen bonds are formed within succinate rings, which impart partial structural rigidity on backbone copolymer. Based li...