Sorbitan ester niosomes for topical delivery of rofecoxib

The aim of the present investigation is to encapsulate rofecoxib in niosomes and incorporate the prepared niosomes into dermal gel base for sustained therapeutic action. Niosomes were prepared by lipid film hydration technique and were analyzed for size, entrapment efficiency and drug retention capacity. Niosomal vesicles were then incorporated into blank carbopol gel to form niosomal gel. The in vitro permeation study across pig skin was performed using Keshary-Chien glass diffusion cell. The size and entrapment efficiency of the niosomal vesicles increased with gradual increase in HLB value of nonionic surfactants used. Maximum drug entrapment was observed with Span 20 with HLB value of 8.6 and drug leakage from vesicles was less at refrigerated condition than at the room temperature. Higher proportion of cholesterol made the niosomal formulation more stable with high drug retention properties. The niosomal gel showed a prolong drug release behavior compared to plain drug gel. Differential scanning calorimetric study of drug loaded gel and pig skin after permeation study confirmed inertness of carbopol gel base toward rofecoxib and absence of drug metabolism in the skin during permeation study, respectively. The niosomal formulations were successfully prepared by lipid film hydration technique using cholesterol and Span as nonionic surfactant. Presence of cholesterol made niosomes more stable with high drug entrapment efficiency and retention properties. The lower flux value of niosomal gel as compared to plain drug gel across pig skin assured the prolong drug release behavior with sustained action.     

Comparative study of 6-APA production by free and agar immobilized bacteria in nutrient broth culture

In the present study different bacterial samples were isolated from soil of different places of Dibrugarh and screened for biotransformation ability to produce 6-Aminopenicillanic acid. Among ten isolated bacterial samples, three gram positive bacterial samples designated as AKDD-2, AKDD-4 and AKDD-6 showed the production of 6-APA from penicillin G. Assessment of production of 6-APA after incubation in penicillin G (2 mg/ml) by three different samples separately in free and agar immobilization state was done by HPLC analysis. Reusability of immobilized cells was found successful up to 14 days.     

Synthesis and characterisation of ammonium mediated assembly of two neutral nickel(II) Schiff base fragments

The 1:2 condensation of o-phenelenediamine and o-vanilline yields a compartmental N₂O₄ ligand N,N′-(1,2-Phenylene)-bis(3-methoxysalicylideneimine) [H₂L]. When nickel(II) thiocyanate is added to the methanol solution of H₂L, followed by addition of ammonium thiocyanate, an unusual nickel(II) compound, [NH₄(NiL)₂SCN]·H₂O (1), is separated out in which an ammonium ion is sandwiched between two neutral square planner NiL moieties. Hydrogen bonding interactions are observed among the ammonium ion, NiL moieties, the thiocyanate anion and the water of crystallization. The compound is characterized by C, H, N analysis, UV-VIS and IR spectroscopy, room temperature magnetic susceptibility measurement and X-ray crystal diffraction study. The compound crystallizes in monoclinic space group P2_1/n with a = 13.8636(7) Å, b = 14.0267(7) Å, c = 22.2715(10) Å and β = 94.301(3)°.     

Population genetic analyses of Plasmodium falciparum chloroquine receptor transporter gene haplotypes reveal the evolutionary history of chloroquine-resistant malaria in India

Inferring the origin and dispersal of the chloroquine-resistant (CQR) malaria parasite, Plasmodium falciparum, is of academic and public health importance. The Pfcrt gene of P. falciparum is widely known as the CQR gene and two major haplotypes of this gene (CVIET and SVMNT) occur widely across CQR-endemic regions of the globe. In India, studies to date of the Pfcrt gene have indicated the widespread prevalence of the SVMNT haplotype (prevalent in the South America and Papua New Guinea), whereas the CVIET haplotype, primarily found in southeast Asia, was not detected at a high frequency in India. This distribution pattern of the two most common CQR-Pfcrt haplotypes in India is quite surprising. Thus, in order to understand probable evolutionary and migration patterns of the CQR-Pfcrt haplotypes into India, we generated new sequence data of exon 2 of the Pfcrt gene and collected published information on the CQR-Pfcrt haplotype data from India, Papua New Guinea, southeast Asia and South America, and performed several population and evolutionary genetic analyses. Among several interesting findings, statistically significant longitudinal clines for the CVIET and SVMNT haplotypes (in opposite directions) in India, and the clustering of India and Papua New Guinea under the SVMNT-specific clade in the phylogenetic tree, are the two most remarkable aspects of the data. It also appears that both the SVMNT and CVIET haplotypes in India have migrated from southeast Asia. In particular, whereas the Indian CVIET haplotype has a southeast Asian origin, the SVMNT haplotype, prevalent in India, seems to have originated in Papua New Guinea and entered India through southeast Asia.     

Crystal structure and microstructure of cholesteryl oleyl carbonate

The crystal structure as well as the microstructure, i.e., size and strain, of crystallites of cholesteryl oleyl carbonate was determined from X-ray powder diffraction data. The X-ray line broadening was analyzed through the refinement of TCH-pseudo-Voigt function parameters (isotropic effects) and the refinement of multipolar functions, i.e., symmetrized cubic harmonics (anisotropic effects). The crystal structure turns out to be primitive monoclinic, space group Pc, type I monolayer having two molecules per unit cell with parameters: a = 18.921 ± 0.006 Å, b = 12.952 ± 0.003 Å, c = 9.276 ± 0.002 Å and β = 91.32 ± 0.03°. The average size of a well ground specimen of crystallites was 60 nm. The average micro-strain, e.g., 45 × 10⁻⁴ has been tentatively attributed to fatty chain conformational disorder. The unit cell parameters, including the lamellar thickness, of COC crystal is very closely similar to those of another, structurally similar cholesterol ester, e.g., cholesteryl oleate (CO) crystal, space group P2₁, type II monolayer. Type I monolayer structure has been established for COC on the basis of the intensity calculations of the XRD profiles of both CO and COC. The dipolar and structural disorder in a 4:1 molar, binary mixture of CO and COC can be accommodated in an induced smectic phase with a lamellar thickness, which is nearly equal to that of pure CO or pure COC.     

Toxicity of Crude Extracellular Products of <Emphasis Type="Italic">Aeromonas hydrophila</Emphasis> on Rohu, <Emphasis Type="Italic">Labeo rohita</Emphasis> (Ham.)

In the present study the haemolytic and proteolytic activity of extracellular products (ECP) secreted from Aeromonas hydrophila (CAHH14 strain) were studied with respect to temperature and different time of incubation as well as its lethal toxicity on rohu, Labeo rohita. The strain was isolated from Catla catla (showing abdominal dropsy symptom) collected from the pond of Central Institute of Freshwater Aquaculture (CIFA), Bhubaneswar, India and was characterized on the basis of biochemical tests. The highest production of haemolysin was achieved when the bacteria was grown at 35°C for 30 h. The proteolytic activity was found to be highest when the bacterium was grown at 30°C for 36 h. The haemolytic and proteolytic toxin produced by Aeromonas hydrophila was found to be lethal to rohu (LD₅₀ 1.7 × 10⁴ cfu/ml). The lethality of ECP was decreased by heating and completely inactivated by boiling at 100°C for 10 min. This indicates that protease activity and haemolytic activity of A. hydrophila ECP was temperature dependant.     

Effect of Arsenic on Nodulation and Nitrogen Fixation of Blackgram (<Emphasis Type="Italic">Vigna mungo</Emphasis>)

Rhizobium–legume symbiotic interaction is an efficient model system for soil remediation and reclamation. We earlier isolated an arsenic (As) (2.8 mM arsenate) tolerant and symbiotically effective Rhizobium strain, VMA301 from Vigna mungo and in this study we further characterized its efficacy for arsenic removal from the soil and its nitrogen fixation capacity. Although nodule formation is delayed in plants with As-treated composite when the inoculum was prepared without arsenic in culture medium, whereas it attains the significant number of nodules compare to plant grown in As-free soil when the inoculum was prepared with arsenic supplemented medium. Arsenic accumulation was higher in roots than root nodules. Nitrogenase activity is reduced to almost 2 fold in plants with As-treated soil but not abolished. These results suggest that this strain, VMA301, has been able to establish an effective symbiotic interaction in V. mungo in As-contaminated soil and can perform dual role of arsenic bioremediation as well as soil nitrogen improvement.     

Photosynthesis and antioxidative enzyme activities in five Indian mangroves with respect to their adaptability

Five typical mangroves were taken (Bruguiera gymnorrhiza, Excoecaria agallocha, Heritiera fomes, Phoenix paludosa and Xylocarpus granatum) both from Sundarbans (in situ) and grown in a mesophytic environment (ex situ, in the Institute’s premises) for 12–15 years. A comparative account of PAR utilization for maximum photosynthesis, stomatal conductance and production of two antioxidant enzymes (peroxidase and Superoxide dismutase) were done between the in situ and ex situ habitats. The present work revealed that the average net photosynthesis was slightly higher in mangroves from non-saline habitats than that of the native ones. At the same time, stomatal conductances were remarkably reduced under salinity-stressed habitats when compared with those of the mesophytic counterparts, by 25–52%. Salinity imposed increase of antioxidant enzymes was observed. Both the investigated antioxidant enzymes showed considerable increase in saline-grown individuals and proved their efficient scavenging ability to evolve reactive oxygen species (ROS), but these increases were relatively lower in Heritiera and Xylocarpus even though the net photosynthesis was higher. This might be related to their lower adaptability under increased salinity stress than those of the other three species investigated.     

Structural characterization and study of immunoenhancing and antioxidant property of a novel polysaccharide isolated from the aqueous extract of a somatic hybrid mushroom of Pleurotus florida and Calocybe indica variety APK2

A water-soluble polysaccharide was isolated from the aqueous extract of the fruit bodies of somatic hybrid PCH9FB, obtained through intergeneric protoplast fusion between the strains Pleurotus florida and Calocybe indica var. On the basis of total acid hydrolysis, the polysaccharide was found to contain galactose, fucose, and glucose in a molar ratio of nearly 2:1:2. Methylation analysis and NMR experiments ((1)H, (13)C, DEPT-135, DQF-COSY, TOCSY, NOESY, ROESY, HMQC, and HMBC) showed that the structure of the repeating unit present in the polysaccharide was This molecule showed macrophage, splenocyte, thymocyte activation as well as antioxidant property.