Spectroscopic properties of protochlorophyll forms in Triton X-100 detergent micelles

Protochlorophyll (PChl) forms were performed in Triton X-100 detergent micelles. The concentration of Triton X-100 was 7·10^?4 M (above the critical micellar concentration); the concentration of PChl varied between 1.6·10^?5 and 1.8·10^?4 M. Absorption, fluorescence and circular dichroism (CD) spectra were registered. The absorption spectra were resolved into Gaussian components by computer analysis. PChl forms with absorption bands at 632–634, 638, 652–654, 663–664, 668 and 676 nm and with fluorescence emission bands at 634–636, 640–644, 652–655, 677–678, 686 and 694–696 nm were observed in micellar solutions of different PChl concentrations. The CD spectra showed a strong dependence on the concentration of PChl: positive CD signals or positive Cotton effects were observed in the vicinity of 650 nm. The intensity of these signals increased in parallel with increasing concentration of PChl. No CD signals were found in the region of the longer wavelength absorption bands. These data show that the PChl exists in many different forms in this system, and the spectroscopic properties of these forms are determined by different molecular interactions viz., interactions of PChl with Triton X-100 or water molecules and/or by the aggregation of PChl.     

Organ-dependent differences in composition and function observed in hepatic and intestinal granulomas isolated from mice with Schistosomiasis mansoni

In murine schistosomiasis mansoni, eggs deposited in the liver and intestines induce a cell-mediated granulomatous reaction. Previous studies have shown that maximal granuloma size differs in the liver and various segments of the gastrointestinal tract. The objective of this investigation was to isolate intestinal granulomas and to determine whether organ-dependent differences in cell composition and granuloma function exist. Intestinal granulomas representative of those in tissue were isolated by a combination of chemical and mechanical techniques. When dissociated by collagenase, these lesions yielded a viable heterogeneous population of inflammatory cells. Granulomas from the liver, colon, and ileum showed differences in cellular composition. Liver lesions contained the largest number of T and B lymphocytes, eosinophils, and mast cells whereas ileal granulomas comprised mostly macrophages. Immunofluorescence studies on frozen tissue sections revealed that T and B lymphocytes also displayed different patterns of distribution within granulomas from different tissues. In contrast to isolated cultured liver granulomas that produced MIF-like substances, isolated colonic and ileal granulomas had weak or no MIF activity. It thus appears that granuloma formation in various organs is influenced by local factors that could affect the ultimate resolution of the lesions.     

Iron-induced lipid peroxidation and inhibition of dopamine synthesis in striatum synaptosomes

Crude striatum synaptosomes (P₂ fraction) from Fisher 344 female rats were incubated in the presence of ADP-chelated Fe³⁺ (0.5–50 M) and ascorbate (250 M). Intrasynaptosomal conversion of tyrosine to dopamine (DA) was measured by¹⁴CO₂ evolution froml-[1-¹⁴C]tyrosine in the absence of added cofactors and DOPA decarboxylase. Malondialdehyde (MDA) was measured as an index of lipid peroxidation. A concentration-dependent inhibition of DA synthesis by ADP-Fe³⁺/ascorbate was found with 50% inhibition occurring at 2.5 M Fe³⁺ concentration. This was accompanied by marked accumulation of MDA. Ascorbate or ADP alone did not affect DA synthesis and ADP-Fe³⁺ in the absence of exogenous ascorbate was effective only above 25 M. Exogenously added MDA did not inhibit DA synthesis. Purified synaptosomes were isolated from peroxidized and control P₂ fractions using sucrose gradients. Membrane microviscosity of the purifled synaptosomes was assessed by nitroxyl spin labels of stearic acid using electron paramagetic resonance techniques. There was a significant increase in membrane microviscosity as a result of ADP-Fe³⁺/ascorbate induced peroxidation. Maleimide nitroxide spin-label binding to protein sulhydryls was significantly modified by peroxidation of striatum synaptosomes. The weakly immobilized component of the sulhydryl spin-label (w) was drastically decreased whereas the strongly immobilized component (s) was modified less, thus leading to a marked reduction of w/s ratio. The exposure of striatum synaptosomes to the peroxidizing system resulted in a significant increase in total iron and in a 25% decrease in protein sulhydryl content. It is concluded that ironinduced damage to the DA synthetic system is mediated by alterations of the structural properties of nerve ending membranes.     

Synthesis of 6-deoxy-5-thio-d-glucose

Three routes were investigated for the conversion of d-glucose into the title compound. In the first approach, reduction of the 5,6-thürane ring of 5,6-dideoxy-5,6-epithio-1,2-O-isopropylidene α-d-glucofuranose (17) as well as that of its 3-O-allyl derivative (13) with lithium aluminium hydride was investigated; 17 afforded the corresponding 6-deoxy derivative besides di-, tri-, and poly-mers, whereas only polymers were formed from 13. In the second approach, the oxirane ring of was reduced by sodium borohydride and the resulting 6-deoxy derivative was converted into the 5-thiobenzoate; the corresponding hex-4-enofuranose was formed as a byproduct. In the third approach partial mesylation of methyl 5-thio-α-d-glucopyranoside was attempted, but the 6-mesylate 27 could be isolated only in modest yield (28%) together with rearranged 2,5-thioanhydromannofuranoside derivatives. The mechanism of this rearrangement is discussed in detail. The 6-mesylate 27 was converted via the 6-iodo derivative into the title compound.     

Appearance and some neurochemical features of nitrergic neurons in the developing quail digestive tract

Using immunocytochemistry, NADPH-diaphorase (NADPHd) histochemistry and electron microscopy, the appearance of nitrergic enteric neurons in different digestive tract regions of the embryonic, neonatal and adult quail was studied in whole mounts and sections. NADPHd was first expressed by embryonic day 4–5 in two distinct locations, namely the mesenchyme of the gizzard primordium and at the caeco-colonic junction. At embryonic day 6, nitrergic neurons had already begun to form a myenteric nerve network in the wall of the proventriculus, gizzard and proximal part of the large intestine and by embryonic day 9, a myenteric network was visualized along the entire digestive tract of the quail. At the level of the stomach, this network was confined to the area covered by the intermediate muscles. By embryonic day 12–13, the NADPHd-positive myenteric neurons in the wall of the distal parts of the blind-ending paired caeca also became organized into ganglia. From this developmental stage on, a submucous nitrergic nerve network, sandwiched between the lamina muscularis mucosae and the luminal side of the outer muscle layer, became prominent in the proventriculus and intestinal walls. In the adult quail, only a minority of the NADPHd-positive neurons stained for vasoactive intestinal polypeptide (VIP) along the intestine. VIP-immunoreactive (IR) cell bodies were frequent in the myenteric plexus but not in the submucous plexus, whereas there were considerable numbers of NADPHd-positive neurons in both these plexuses. Nitrergic fibres were also observed in the outer muscle layer, but were almost absent from the lamina muscularis mucosa and lamina propria, in contrast to the dense VIP-ergic innervation encircling the bases of the intestinal crypts.     

Chemical Profile and Biological Activities of Fungal Strains Isolated from Piper nigrum Roots: Experimental and Computational Approaches

The current report describes the chemical investigation and biological activity of extracts produced by three fungal strains Fusarium oxysporum, Penicillium simplicissimum, and Fusarium proliferatum isolated from the roots of Piper nigrum L. growing in Vietnam. These fungi were namely determined by morphological and DNA analyses. GC/MS identification revealed that the EtOAc extracts of these fungi were associated with the presence of saturated and unsaturated fatty acids. These EtOAc extracts showed cytotoxicity towards cancer cell lines HepG2, inhibited various microbacterial organisms, especially fungus Aspergillus niger and yeast Candida albicans (the MIC values of 50–100 μg/mL). In α-glucosidase inhibitory assay, they induced the IC₅₀ values of 1.00-2.53 μg/mL were better than positive control acarbose (169.80 μg/mL). The EtOAc extract of F. oxysporum also showed strong anti-inflammatory activity against NO production and PGE-2 level. Four major compounds linoleic acid (37.346 %), oleic acid (27.520 %), palmitic acid (25.547 %), and stearic acid (7.030 %) from the EtOAc extract of F. oxysporum were selective in molecular docking study, by which linoleic and oleic acids showed higher binding affinity towards α-glucosidase than palmitic and stearic acids. In subsequent docking assay with inducible nitric oxide synthase (iNOS), palmitic acid, oleic acid and linoleic acid could be moderate inhibitors.     

Restriction endonuclease analysis of the transducing bacteriophage lambda rif d18

The rif d18 bacteriophage carries essential parts of the E. coli genome which can not be mapped by conventional methods. The phage DNA was analysed with four restriction endonucleases (endo R. BamHI, Sall, HpaI and EcoRI) and a physical map was constructed.     

Effects of Handling or Immobilization on Plasma Levels of 3,4-Dihydroxyphenylalanine, Catecholamines, and Metabolites in Rats

In conscious animals, handling and immobilization increase plasma levels of the catecholamines norepinephrine (NE) and epinephrine (EPI). This study examined plasma concentrations of endogenous compounds related to catecholamine synthesis and metabolism during and after exposure to these stressors in conscious rats. Plasma levels of 3,4-dihydroxyphenylalanine (DOPA), NE, EPI, and dopamine (DA), the deaminated catechol metabolites 3,4-dihydroxyphenylglycol (DHPG), and 3,4-dihydroxyphenylacetic acid (DOPAC), and their O-methylated derivatives methoxyhydroxyphenylglycol (MHPG) and homovanillic acid (HVA) were measured using liquid chromatography with electrochemical detection at 1, 3, 5, 20, 60, and 120 min of immobilization. By 1 min of immobilization, plasma NE and EPI levels had already reached peak values, and plasma levels of DOPA, DHPG, DOPAC, and MHPG were increased significantly from baseline, whereas plasma DA and HVA levels were unchanged. During the remainder of the immobilization period, the increased levels of DOPA, NE, and EPI were maintained, whereas levels of the metabolites progressively increased. In animals immobilized briefly (5 min), elevated concentrations of the metabolites persisted after release from the restraint, whereas DOPA and catecholamine levels returned to baseline. Gentle handling for 1 min also significantly increased plasma levels of DOPA, NE, EPI, and the NE metabolites DHPG and MHPG, without increasing levels of DA or HVA. The results show that in conscious rats, immobilization or even gentle handling rapidly increases plasma levels of catecholamines, the catecholamine precursor DOPA, and metabolites of NE and DA, indicating rapid increases in the synthesis, release, reuptake, and metabolism of catecholamines.