Cinnamoyl-(trans)-L-phenylalanine

Solvent isotope effects have been examined for the action of the zinc-containing metalloenzyme carboxypeptidase A on ester and peptide substrates. The kinetic parameters for the carboxypeptidase-catalyzed hydrolysis of an ester, O-(trans-cinnamoyl)-L-beta-phenyllactate, in 0.05 M Tris-DCl buffer containing 0.5 M NaCl at pD 8.07 and 25 degrees were compared with those obtained from measurements done in 0.05 M Tris-HCl buffer containing 0.5 M NaCl at pH 7.52 and 25 degrees . A (k(cat))(H2O)/(k(cat))(D2O) ratio of approximately 2 was obtained. The value of the Michaelis constant K(m) was unaffected by the change in solvent as was the inhibition constant, K(i), found for the product, L-beta-phenyllactate, which is a competitive inhibitor. These results indicate that a catalytic step involving general base catalysis is probably important in the carboxypeptidase-catalyzed hydrolysis of an ester. A similar set of experiments carried out on the peptide substrate, N-(N-benzoylglycyl)-L-phenylalanine gave ambiguous results. The role of the zinc ion in the catalytic action of carboxypeptidase A can be considered in the light of these findings.

Larrea tridentata (Sesse and Moc. ex DC.) Coville (family: Zygophyllaceae) is an aromatic evergreen shrub with resin-covered leaves, known to use in traditional medicine for diverse ailments. It also has immense pharmacological significance due to presence of powerful phenylpropanoids antioxidant, nordihydroguaiaretic acid (NDGA). The RNA sequence/transcriptome analyses connect the genomic information into the discovery of gene function. Hence, the acquaint analysis of L. tridentata is in lieu to characterize the transcriptome, and to identify the candidate genes involved in the phenylpropanoid biosynthetic pathway. To gain molecular insight, the bioinformatics analysis of transcriptome was performed. The total bases covered 48,630 contigs of length greater than 200 bp and above came out to 21,590,549 with an average GC content of 45% and an abundance of mononucleotide, SSR, including C3H, FAR1, and MADS transcription gene families. The best enzyme commission (EC) classification obtained from the assembled sequences represented major abundant enzyme classes e.g., RING-type E3 ubiquitin transferase and non-specific serine/threonine protein kinase. The KEGG pathway analysis mapped into 377 KEGG different metabolic pathways. The enrichment of phenylpropanoid biosynthesis pathways (22 genes i.e., phenylalanine ammonia-lyase, trans-cinnamate 4-monooxygenase, 4-coumarate-CoA ligase, cinnamoyl-CoA reductase, beta-glucosidase, shikimate O-hydroxycinnamoyl transferase, 5-O-(4-coumaroyl)-D-quinate 3'-monooxygenase, cinnamyl-alcohol dehydrogenase, peroxidase, coniferyl-alcohol glucosyltransferase, caffeoyl shikimate esterase, caffeoyl-CoA O-methyltransferase, caffeate O-methyltransferase, coniferyl-aldehyde dehydrogenase, feruloyl-CoA 6-hydroxylase, and ferulate-5-hydroxylase), and expression profile indicated antioxidant, anti-arthritic, and anticancer properties of L. tridentata. The present results could provide an important resource for squeezing biotechnological applications of L. tridentata.

An amino acid derivative, L-(-)-(N-trans-cinnamoyl)-arginine, was isolated from the whole plant of Glinus oppositifolius (L.) Aug. DC. along with kaempferol 3-O-galactopyranoside, isorhamnetin 3-O-beta-D-xylopyranosyl-(1-->2)-beta-D-galactopyranoside, vitexin, vicenin-2, adenosine and L-phenylalanine. The structure determinations were based on analyses of chemical and spectroscopic methods.