Cinnamic Series Research Articles

Alkoxycarbonylphenyl 4-alkoxycinnamate liquid crystals with antiparallel packing

ABSTRACT A series of cinnamates with two flexible chains, one as alkoxy and the other as alkoxycarbonyl, has been synthesised to investigate mesomorphic behaviour. Single crystal X-ray measurements demonstrated the crystalline structure and a dimer packing was predicted due to H-bonding interactions. Most of the compounds show SmA phase only on cooling. Only the member with shortest chains exhibited nematic along with SmA phase. A monotropic SmC phase was observed for compounds with octyloxy group. However, X-ray diffraction studies demonstrated that the SmA to SmC phase transition is not accompanied by a significant interlayer spacing reduction, which was associated to strong intermolecular interactions within the layers. In all the compounds, the mesophase supercools prior to crystallisation.

Cinnamic Acid Esters as Potent Inhibitors of Fungal 17β‐Hydroxysteroid Dehydrogenase — A Model Enzyme of the Short‐Chain Dehydrogenase/Reductase Superfamily

AbstractFor Abstract see ChemInform Abstract in Full Text.

Cinnamic acid esters as potent inhibitors of fungal 17β-hydroxysteroid dehydrogenase––a model enzyme of the short-chain dehydrogenase/reductase superfamily

We present the synthesis of a new family of nonsteroidal inhibitors of 17β-hydroxysteroid dehydrogenase, designed from flavones and chalcones. Their inhibitory potential was screened on 17β-hydroxysteroid dehydrogenase from the fungus Cochliobolus lunatus (17β-HSDcl), a model enzyme of the short-chain dehydrogenase/reductase superfamily. In a series of cinnamates and related coumarin-3-carboxylates, a number of compounds proved to be potent inhibitors of both the oxidative and reductive reactions catalyzed by 17β-HSDcl, with IC 50 values in the low micromolar range.

POLYPHENOLIC SUBSTRATES OF CATIONIC AND NEUTRAL/ANIONIC PEROXIDASES FROM BARLEY AND MALT USING A CHRONOMETRIC METHOD FOR THE DETERMINATION OF POD ACTIVITY

4-methylcatechol, phenolic acids from the benzoic and cinnamic series, flavan 3-ols and L-tyrosine were tested to determine the catalytic behavior of barley peroxidases (POD) at the expense of hydrogen peroxide. A chronometric assay using L-ascorbic acid was described for determining the peroxidatic activity of basic and neutral/anionic enzymatic fractions. The effects of hydrogen donors H2O2, and Ca++ ion concentrations and pH were studied to set maximal conditions for POD measurement. The sensitivity to endogenous phenolic compounds (ferulic and p-coumaric acids, (+) catechin) along with caffeic acid for POD fractions was investigated and compared with their response versus guaiacol. Under the conditions tested, syringic and sinapinic acids as well as L-tyrosine were very weakly oxidized by POD from barley, whereas ferulic and caffeic acids were rapidly transformed. Levels of POD activity extracted from barley, green malt and kilned malt crude extracts were thereafter compared.

Inhibition of chemiluminescence in human PMNs by monocyclic phenolic acids and flavonoids.

Flavonoids are metabolized in vivo to monocyclic phenolic acids. We investigated whether 18 phenolic acids of the benzoic, phenylacetic, phenylpropanoic or cinnamic series-known or potential metabolites of flavonoids-inhibit reactive oxygen species (ROS) released by human polymorphonuclear neutrophils (PMNs). Chemiluminescence was measured after PMN stimulation with three agents (N-fMetLeuPhe, phorbol myristate acetate (PMA), or opsonised zymosan) using two probes (lucigenin or luminol) with or without horseradish peroxidase (HRP) in order to derive specificity profiles for each test compound. The profiles of the phenolic acids and flavonoids were compared by a multivariate (correspondence) factor analysis. Overall, the phenolic acids were less specific than the flavonoids and, with a few exceptions, less potent. Phenolic acids had virtually no effect on the chemiluminescence related to O2- formation that is measured by lucigenin but inhibited luminol luminescence. Inhibition for all but two phenolic acids was sensitive to HRP and might be explained by a scavenger mechanism. Few structure-activity relationships emerged suggesting that simple properties such as radical scavenging and/or redox activity rather than overall structure might be the key determinants of chemiluminescence inhibition. Whatever the mechanism, however, we conclude that part of the in vivo pharmacological activity of flavonoids may readily be accounted for by phenolic acids.