Chemistry

A new liquid chromatography (LC)-negative ion electrospray ionization (ESI)–tandem mass spectrometry (MS/MS) method with post-column addition of ammonia in methanol has been developed for the analysis of acid herbicides: 2,4-dichlorophenoxy ace- tic acid, 4-chloro-o-tolyloxyacetic acid, 2-(2-methyl-4-chlorophenoxy)butyric acid, mecoprop, dichlorprop, 4-(2,4-dichlorophenoxy) butyric acid, 2,4,5-trichlorophenoxy propionic acid, dicamba and bromoxynil, along with...

A Matlab implemented computer code for spectral resolution is presented. The code enables the user to resolve the UV-visible absorption spectrum of a mixture of up to 3 previously known components, to the individual components, thus, evaluating their quantities. The resolving procedure is based on searching the combination of the...

The present study employs time of flight mass spectrometry for quantitative analysis of the local anesthetic drugs ropivacaine and bupivacaine in authentic, pharmaceutical and spiked human plasma as well as in the presence of their impurities 2,6-dimethylaniline and alkaline degradation product. The method is based on time of flight electron...

Two sensitive and validated methods were developed for determination of a racemic mixture citalopram and its enantiomer S-(+) escitalopram. The first method was based on direct measurement of the intrinsic fluorescence of escitalopram using sodium dodecyl sulfate as micelle enhancer. This was further applied to determine escitalopram in spiked human...

New simple spectrofluorimetric method with enhanced sensitivity has been developed and validated for the determination of the antidepressant paroxetine (PXT) in its dosage forms and plasma. The method was based on nucleophilic substitution reaction of PXT with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole in an alkaline medium (pH 8) to form a highly fluorescent derivative...

The aim of this study is to adopt the approach of metabolic fingerprinting through the use of Fourier Transform Infrared (FTIR) technique to understand changes in the chemical structure in Padina tetrastromatica (Hauck). The marine brown alga under study was grown in two different environmental conditions; in natural seawater (P....

The enzymatic synthesis of capsaicin glycosides and 8-nordihydrocapsaicin glycosides was investigated using almond β-glucosidase and cyclodextrin glucanotransferase (CGTase). Capsaicin and 8-nordihydrocapsaicin were converted into their β-glucoside and β-maltooligosaccharide (amylose conjugate), i.e. β-maltoside and β-maltotrioside, by sequencial glycosylation with almond β-glucosidase and CGTase. The β-glucoside and β-maltoside of capsaicin and β-glucoside...

The stereoselective reduction of an aromatic α-keto amide with actinomycete strains was investigated. It was found that 2-chlorobenzoylformamide was reduced to the corresponding 2-chloromandelamide by mesophilic and thermophilic strains of actinomycetes. Among the strains tested, the reduction of 2-chlorobenzoylformamide by Streptomyces thermocyaneoviolaceus (one of thermophilic strains) in the presence of...

Erythropoietin (EPO) increases the number of circulating erythrocytes and muscle oxygenation. The recombinant forms of EPO have indiscriminately been used by athletes, mainly in endurance sports to increase their erythrocytes concentration, thus generating a better delivery of oxygen to the muscle tissue. The administration of recombinant human erythropoietin (rHuEPO) except...

Curcumin 4'-O-glucooligosaccharides were synthesized by a two step-enzymatic method using almond β-glucosidase and cyclodextrin glucanotransferase (CGTase). Curcumin was glucosylated to curcumin 4'-O-β-D-glucopyranoside by almond β-glucosidase in 19% yield. Curcumin 4'-O-β-D-glucopyranoside was converted into curcumin 4'-O-β-glucooligosaccharides, i.e. 4'-O-β-maltoside (51%) and 4'-O-β-maltotrioside (25%), by further CGTase-catalyzed glycosylation. Curcumin 4'-O-β-glycosides showed suppressive action...

Mitochondria are subcellular organelles that provide energy for a variety of basic cellular processes in eukaryotic cells. Mitochondria maintain their own genomes and many of their endosymbiont genes are encoded by nuclear genomes. The crosstalk between the mitochondrial and nuclear genomes ensures mitochondrial biogenesis, dynamics and maintenance. Mitochondrial proteins are...

The N1-alkylation of 4-(trichloromethyl)pyrimidin-2(1H)-one, 4-methoxy-4-(trichloromethyl)-3,4-dihydropyrimidin- 2(1H)-one, and 5-bromo-4-methoxy-4-(trichloromethyl)-3,4-dihydropyrimidin-2(1H)-one with selected alkylating agents such as 2-chloroacetamide, diethyl 2-bromomalonate, and 5-bromo-1,1,1-trichloro-4-methoxypent-3-en-2-one, is presented. Further reactions of 1-[5,5,5-trichloro-2-methoxy-4-oxo-penten-2-yl]4-trichloromethyl-pyrimidin-2(1H)-one with primary amines and aminoalcohols furnished a series of unexpected new acyclic nucleoside analogues.

Poly(ADP-ribose) polymerase (PARP) polyADP-ribosylates proteins involved in various physiological processes. Accumulated evidence suggests not only protein-conjugated poly(ADP-ribose) but also protein-free poly(ADP-ribose) function in various physiological processes. There are increasing occasions that require protein-free poly(ADP-ribose) to study the function and dynamics of poly(ADP-ribose) in cells. However, the availability of poly(ADP-ribose) is...

Introductory Editorial by Dr Hafiz Ahmed, University of Maryland Biotechnology Institute, Center of Marine Biotechnology, Baltimore, Maryland, U.S.A.

This paper presents a novel unified theory of the structure activity relationship of opioids and opioid peptides. It is hypothesized that a virtual or known heterocyclic ring exists in all opioids which have activity in humans, and this ring occupies relative to the aromatic ring of the drug, approximately the...

Chaperone therapy is a newly developed molecular approach to lysosomal diseases, a group of human genetic diseases causing severe brain damage. We found two valienamine derivatives, N-octyl-4-epi-β-valienamine (NOEV) and N-octyl-β-valienamine (NOV), as promising therapeutic agents for human β-galactosidase deficiency disorders (mainly GM1-gangliosidosis) and β-glucosidase deficiency disorders (Gaucher disease), respectively. We...

RNA is increasingly recognized for its significant functions in biological systems and has recently become an important molecular target for therapeutics development. Aminoglycosides, a large class of clinically significant antibiotics, exert their biological functions by binding to prokaryotic ribosomal RNA (rRNA) and interfering with protein translation, resulting in bacterial cell...

Pseudomonas tolaasii, P. reactans and Burkholderia gladioli pv. agaricicola, are responsible of diseases on some species of cultivated mushrooms. The main bioactive metabolites produced by both Pseudomonas strains are the lipodepsipeptides (LDPs) tolaasin I and II and the so called White Line Inducing Principle (WLIP), respectively, LDPs which have been...

Integrins have been reported to mediate cell survival, proliferation, differentiation, and migration programs. For this reason, the past few years have seen an increased interest in the implications of integrin receptors in cancer biology and tumor cell aggression. This review considers the potential role of integrins in cancer and also...