Prompted by results of molecular modeling performed on the seco-d-ring-vitamins D, we turned our attention to such analogs, having reversed configurations at C-13 and C-14, as the next goals of our studies on the structure-activity relationship for vitamin D compounds. First, we developed an eff...

The flash pyrolysis of d-glucose was investigated by the use of isotopic labeling with 13C, in conjunction with GC/MS. Co-pyrolysis of uniformly labeled and unlabeled d-glucose established the extent of unimolecular formation of each of the pyrolysis products. A complete set of singly labeled d-...

Stereochemistry of reduction of the diastereomerically pure N-tosyl 2-benzoyl-1,3-oxazines prepared from D-glucose was investigated with various reducing agents. It was found that the stereochemical outcome is consistent with the Cram's chelation model where the ring oxygen atom is involved...

Oil derived from fast pyrolysis of biomass (or bio-oil) is a candidate renewable feedstock for producing hydrogen (H2). In this work, the steam reforming of model oxygenates present in the bio-oil aqueous fraction was studied in a fixed-bed reactor. Using Ni/Al2O3 catalyst, the reactions with 2-...

Raman spectra of 1-isothiocyanato-4-(trans 4-propylcyclohexyl)benzene (3CHBT) were studied in the region, 1450–2300 cm− 1 at twenty two different temperatures in the range, 83–293 K in cooling and heating cycles. All bands in this region were critically evaluated in term of linewidth, peak pos...

Two neuropeptides with adipokinetic activity in Locusta migratoria and hypertrehalosaemic activity in Periplaneta americana were purified by high-performance liquid chromatography from the corpus cardiacum of the lubber grasshopper, Romalea microptera. The sequences of both peptides, designated ...

1.1. The corpus cardiacum/corpus allatum complex (CC/CA) of the beetle, Tenebrio molitor, contains a factor which elicits hyperlipaemia in migratory locusts and hypertrehalosaemia in American cockroaches. Appreciable amounts of this factor are found only in the CC/CA.2.2. The lipid and carbohydr...

Haemolymph of various insect species (four cockroaches, one tenebrionid beetle and one stick insect) was purified by isocratic high performance liquid chromatography on an amino-phase support. The purified sugars were detected and quantified using a refractive index monitor. Injection of 10 pmol...

The structure of the hypertrehalosemic neuropeptide of the German cockroach, Blattella germanica, was found to be identical to that of the cockroach species, Blaberus discoidalis and Nauphoeta cinerea (Glp-Val-Asn-Phe-Ser-Pro-Gly-Trp-Gly-Thr-NH2). Since Blattella germanica is not closely related...

Hypertrehalosaemic peptides from the corpora cardiaca of 14 different species were compared with respect to phylogenetic relationships within the insect suborder Blattaria (cockroaches). Gland extracts from members of the family Blattidae (Periplaneta americana, P. brunnea, P. australasiae, P. f...

The hypertrehalosaemic factor from the cockroach Nauphoetacinerea, a decapeptide, has been assigned the structure Glu-Val-Asn-Phe-Ser-Pro-Gly-Trp-Gly-Thr-Nh2. The structure was assigned from its high-resolution fast atom bombardment mass spectrum and metastable studies on the M + H ion and confi...

A high-performance liquid chromatographic method is described for the determination of a fluoroquinolone, rufloxacin, and its N-desmethyl metabolite in plasma, urine and bile. Samples are chromatographed on a poly(styrene—divinylbenzene) column, the eluate being monitored with a fluorescence de...

An adsorptive stripping voltammetric method with a hanging mercury drop electrode was developed for the determination of the fluoroquinolone rufloxacin in tablets, human plasma and urine. Measurements were obtained in differential pulse mode and a multivariate strategy was used to optimize the v...

The presence of copper(II) in the micromolar range modulates the photodegradation rate of the fluoroquinolone Rufloxacin (RFX), both under air and in nitrogen saturated aqueous solution. The photodegradation rate of RFX under aerobic conditions decreases in the presence of metal ions, and no cha...

A simple and rapid fluorimetric method for the determination of 9-fluoro-10-[N-(4′-methyl)piperazinyl]-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-d,e][1–4]benzothyazin-6-carboxylic acid hydrochloride (MF 934), in serum and in pharmaceutical formulations, has been developed based on its strong fluoresce...

A simple, specific and sensitive high-performance liquid chromatographic method has been developed for the simultaneous determination of rufloxacin, fenbufen and felbinac in human plasma. Plasma, spiked with internal standard, was vortex-mixed for 1 min with a mixture of dichloromethane-diethyl ...

Rufloxacin (RFX) is an antibacterial fluoroquinolone that exhibits UVA photosensitization properties. Photosensitization reactions lead to the formation of oxidative damage, mainly via singlet oxygen. Here we explore the phototoxic and photomutagenic potency of RFX using a panel of yeast (Saccha...

A simple and rapid capillary electrophoresis method with UV detection was developed and validated for the determination of rufloxacin hydrochloride in coated tablets. An experimental design strategy (Doehlert design and desirability function) allowed the analytical parameters to be simultaneousl...

Enhydroxylaminones—2,2-dimethyl-2,4-dihydro-3H-pyrrol-3-on-1-oxides were shown to give various chlorinated products in the Vilsmeier–Haack reaction. The general sequence of the reaction steps is determined and the extent of the reaction was shown to be strongly dependent on the substrate struc...

Designed novel imidazo[1,2-a]pyrazine based inhibitors, synthesized by condensing α-aminopyrazines with α-halocarbonyl compounds followed by electrophilic substitutions. Cytotoxic effects on four cancer cell lines evaluated. Based on preliminary data, imidazo[1,2-a]pyrazine template redesigned...