Chemical constituents and biological activities of the soft corals of genus Cladiella: A review

In this review, structures of natural products isolated from the soft corals of genus Cladiella and their biological activities are described.     

Note floristique et repartition de Rhodophycees rares (Kallymeniacees et Sebdeniacees) de la Mediterranee occidentale

Abstract

Floristic notes and geographical distribution of some rare Rhodophyta (Kallymeniaceae and Sebdeniaceae) of the western Mediterranean. Callophyllis laciniata, Kallymenia requienii and Kallymenia lacerata (Kallymeniaceae) and Sebdenia rodrigueziana (Sebdeniaceae) are recorded for the first time in the bay of Naples. For each species systematic and distribution data are also given.     

Demonstration and Characterization of two Classes of Cardiac Glycoside Binding Sites to Rat Heart Membrane Preparations Using Quantitative Computer Modeling

Abstract

Cardiac glycoside binding to rat heart membrane preparations was measured by rapid filtration technique. The binding data were analyzed using quantitative computer analysis. The experimental results using [³H]-ouabain as the labeled ligand were consistent with a model in which cardiac glycoside specific binding occurs at two independent classes of sites. The high affinity sites were characterized by a dissociation constants of 40 nM, 50 nM, and 61 nM for ouabain, digoxin and digitoxin, respectively, with a binding capacity of 1.3 pmoles/mg protein. The lower affinity sites for ouabain were characterized by dissociation constants of 2.3 µM, 67 nM and 71 nM for ouabain, digoxin and digitoxin, respectively, with a binding capacity of 3 pmoles/mg protein. Potassium ions inhibit [³H]-ouabain binding in a dose dependent manner with an IC₅₀ of 500 µM. Quantitative computer modelling indicated that potassium inhibits ouabain binding at both binding sites.     

Decarboxylation of Oxalic Acid during Ripening of Banana Fruit (Musa sapientum L.)

ABSTRACT

Japanese apricot, Prunus mume Sieb. et Zucc., biosynthesizes the l-phenylalanine-derived cyanogenic glucosides prunasin and amygdalin. Prunasin has biological properties such as anti-inflammation, but plant extraction and chemical synthesis are impractical. In this study, we identified and characterized UGT85A47 from Japanese apricot. Further, UGT85A47 was utilized for prunasin microbial production. Full-length cDNA encoding UGT85A47 was isolated from Japanese apricot after 5?- and 3?-RACE. Recombinant UGT85A47 stoichiometrically catalyzed UDP-glucose consumption and synthesis of prunasin and UDP from mandelonitrile. Escherichia coli C41(DE3) cells expressing UGT85A47 produced prunasin (0.64 g/L) from racemic mandelonitrile and glucose. In addition, co-expression of genes encoding UDP-glucose biosynthetic enzymes (phosphoglucomutase and UTP-glucose 1-phosphate uridiltransferase) and polyphosphate kinase clearly improved prunasin production up to 2.3 g/L. These results showed that our whole-cell biocatalytic system is significantly more efficient than the existing prunasin production systems, such as chemical synthesis.     

Lowering Effect of Phenolic Glycosides on the Rise in Postprandial Glucose in Mice

Glycosides were screened for their lowering effect on the postprandial blood glucose rise in vivo. The effect of phlorizin and other phenolic glycosides on the postprandial blood glucose response to glucose ingestion was evaluated in Std ddY mice. When phlorizin was simultaneously added, the peak blood glucose level was significantly decreased by 51% (p < 0.01) compared to vehicles following glucose ingestion by mice, while the blood insulin responses were generally similar. Screening experiments were conducted with different classes of phenolic glycosides added to a glucose solution. Reductions of 40–52% (p < 0.05) were observed in vehicles containing arbutin, 4-hydroxyphenyl-α-d-glucopyranoside (hydroquinone-α-glucoside) or glycyrrhizin, and of only 15–31% (not significant) in vehicles containing neohesperidin dihydrochalcone, glycyrrhetinic acid monoglucuronide, or 3,4-dimethoxyphenyl-β-d-glucopyranoside. No lowering effect was observed in vehicles containing salicin. Since glycyrrhizin, arbutin, and hydroquinone-α-glucoside blunted to varying degrees the postprandial blood glucose rise following glucose ingestion, they may be useful adjuvants for the treatment of diabetic subjects.     

New Acylated Flavonol Glycosides and a Phenolic Profile of Pritzelago alpina,a Forgotten Edible Alpine Plant

Thirteen acylated flavonoid glycosides, 1 – 13 , including eleven new congeners, 3 – 13 , were isolated from the aerial parts of Pritzelago alpina (Brassicaceae) by a combination of column chromatography on Sephadex LH‐20, and preparative and semi‐preparative HPLC. The structures were established by extensive NMR and MS experiments in combination with acid hydrolysis and sugar analysis by GC/MS. The new compounds were shown to be kaempferol and quercetin glycosides acylated for most of them by a branched short chain fatty acid or a hydroxycinnamic acid residue on the sugar portion. As shown by a HPLC‐DAD analysis of a MeOH extract, these compounds are the main phenolic constituents in the aerial parts of the plant.     

Wheat leaf lipids during heat stress: I. High day and night temperatures result in major lipid alterations

Understanding how wheat (Triticum aestivum L.) plants under high temperature (HT) regulate lipid composition is critical to developing climate‐resilient varieties. We measured 165 glycerolipids and sterol derivatives under optimum and high day and night temperatures in wheat leaves using electrospray ionization‐tandem mass spectrometry. Levels of polar lipid fatty acyl chain unsaturation were lower in both heat‐tolerant genotype Ventnor and susceptible genotype Karl 92 under HT, compared with optimum temperature. The lower unsaturation was predominantly because of lower levels of 18:3 acyl chains and higher levels of 18:1 and 16:0 acyl chains. Levels of 18:3‐containing triacylglycerols increased threefold/more under HT, consistent with their possible role in sequestering fatty acids during membrane lipid remodelling. Phospholipids containing odd‐numbered or oxidized acyl chains accumulated in leaves under HT. Sterol glycosides (SG) and 16:0‐acylated sterol glycosides (ASG) were higher under HT than optimum temperatures. Ventnor had lower amounts of phospholipids with oxidized acyl chains under HT and higher amounts of SG and 16:0‐ASG than Karl 92. Taken together, the data demonstrate that wheat leaf lipid composition is altered by HT, in which some lipids are particularly responsive to HT, and that two wheat genotypes, chosen for their differing physiological responses to HT, differ in lipid profile under HT.