Xylanase and Ultrasound Assisted Pulping of Wheat Straw

In the present work, a novel approach to pretreat wheat straw pulping was investigated with ultrasound and xylanase to achieve maximum reduction in lignin content. Sequential xylanase pretreatment and alkaline pulping was found to reduce kappa number by 0.31 to 4.84?% compared with only alkaline pulping alone at different pulping conditions. Although Klason lignin of ultrasound-treated straw was found to be 7.37?% less compared with untreated straw, sequential ultrasound pretreatment and alkaline pulping could not show any significant reduction in kappa number compared with alkaline pulping alone. Also, sequential xylanase and ultrasound pretreatment could not show any significant reduction in kappa number. Total yield of the pulp was found to be less in ultrasound-assisted processing compared with both alkaline pulping alone and sequential xylanase pretreatment and alkaline pulping.     

Influence of Cr and Fe on magnetic phase transition and magnetocaloric effect in Co2(Cr1-xFex)Al, (x ≤ 0 ≤ 1) soft magnetic Heusler alloys

The structural measurement indicates that the system possesses A2 to B2 phase transformation at the extent of A2 phase at room temperature. The present system shows first order magneto-structural transformation (FOMST). The substitution of Cr by Fe causes a vital role for an increase in magnetocaloric properties. The change in magnetic entropy (ΔS_M) and relative cooling power (RCP) are evaluated under an applied field of 20 KOe that shows drastic changes near the blocking temperature under the specific temperature regime. In the vicinity of these observed properties, critical exponent parameters such as, β, ? and δ were also observed using field dependence magnetic entropy change.     

Determination of gatifloxacin and ornidazole in tablet dosage forms by high-performance thin-layer chromatography.

A simple and sensitive high-performance thin-layer chromatography (HPTLC) method has been developed for the quantitative estimation of gatifloxacin and ornidazole in its combined dosage forms. Gatifloxacin and ornidazole were chromatographed on silica Gel 60 F(254) TLC plate using n-butanol:methanol:ammonia (6 M) (8:1:1.5 v/v) as the mobile phase and scanned at 302 nm using a Camag TLC Scanner 3. The R(f) value of gatifloxacin and ornidazole was found to be 0.21 +/- 0.02 and 0.76 +/- 0.04, respectively. The linearity of gatifloxacin and ornidazole were in the range of 100 - 500 ng/spot and 250 - 1250 ng/spot, respectively. The limit of detection was found to be 40 ng/spot for gatifloxacin and 100 ng/spot for ornidazole. The proposed method was applied for the determination of gatifloxacin and ornidazole in combined dosage forms.     

Organ-based chemo-profiling of Echinops echinatus Roxb. using high-performance thin-layer chromatography (HPTLC) technique

JPC – Journal of Planar Chromatography – Modern TLC - Plants contain different classes of secondary metabolites that have different levels of solubility in solvents, based on their...     

Synthesis and properties of covalently linked BF2–oxasmaragdyrin–porphyrin dyads and triad

Two covalently linked diphenyl ethyne bridged unsymmetrical dyads containing porphyrin and BF₂–oxasmaragdyrin and Zn(II)porphyrin and BF₂–oxasmaragdyrin units and one covalently linked triad containing Zn(II)porphyrin, porphyrin and BF₂–oxasmaragdyrin units were synthesized by coupling appropriate functionalized macrocycles under Pd(0) coupling reaction conditions. The dyads and triad were freely soluble in common organic solvents and confirmed by ES-MS spectra. 1D and 2D NMR techniques were used to characterize the dyads and triad. Absorption and electrochemical studies of dyads and triad showed the overlapping features of the constituted macrocycles indicating that the macrocycles retain their basic features in the dyads and triad. The BF₂–oxasmaragdyrin absorbs at lower energy and emits strongly in the visible region compared to porphyrin/Zn(II)porphyrin. Thus, BF₂–oxasmaragdyrin acts as energy acceptor and porphyrin/Zn(II) porphyrin act as energy donor in dyads and triad. The steady state and time-resolved fluorescence studies supported an efficient energy transfer from porphyrin/Zn(II)porphyrin to BF₂–oxasmaragdyrin unit in dyads and triad.     

Simultaneous Quantification of Aliskiren, Valsartan and Sitagliptin by LC with Fluorescence Detection: Evidence of Pharmacokinetic Interaction in Rats

A sensitive, precise and simple LC method for the simultaneous quantification of aliskiren, valsartan and sitagliptin in rat plasma has been developed and validated. The chromatographic separation was achieved on a C₁₈ column (250 mm × 4.6 mm, 5 μm) maintained at room temperature, using isocratic elution with acetonitrile/20 mM ammonium acetate buffer (35:65, v/v), pH adjusted to 4.85 with glacial acetic acid, and detected using a fluorescence detector. Liquid–liquid extraction of the aliskiren, valsartan and sitagliptin from the rat plasma with t-butyl methyl ether resulted in their high recoveries. LC calibration curves based on the extracts from the rat plasma were linear in the range of 25–2,000 ng mL^?1 for aliskiren and sitagliptin and 50–4,000 ng mL^?1 for valsartan. The limits of quantification were 25 ng mL^?1 for aliskiren and sitagliptin and 50 ng mL^?1 for valsartan. The precision and accuracy of the method were well within the generally accepted criteria for biomedical analysis. The described method was successfully applied to study the pharmacokinetics of aliskiren, valsartan and sitagliptin following oral administration, individually as well as in combination in Sprague–Dawley rats. The results of the study implied the occurrence of pharmacokinetic interaction upon the co-administration of these three drugs.     

Masked mercapto acid-driven MCR in task-specific ionic liquid: a new sterocontrolled entry into bicyclic 1,3-thiazines

An unprecedented multi-component reaction for the synthesis of thiosugar-annulated 1,3-thiazines is reported. The envisaged synthetic strategy involves the reaction of d-glucose/d-xylose and 2-methyl-2-phenyl-1,3-oxathiolan-5-one with AcONH₄/RNH₂ in task specific ionic liquid (TSIL), [bmim]SCN which afforded thiosugar annulated 1,3-thiazines in excellent yields (83–93%). The reaction is effected via ionic liquid promoted Michael addition followed by mercaptoacetylative ring transformation in a one-pot procedure and the ionic liquid, [bmim]OH could be easily recycled for further use without any loss of efficiency and be used for the synthesis of [bmim]SCN, thus allowing recycling of the TSIL for further use.     

Sensitive HPTLC Method for Monitoring Dissolution Profiles of Diclofenac from Different Tablets Containing Combined Diclofenac and Acetaminophen

JPC – Journal of Planar Chromatography – Modern TLC - Two fundamentally different analytical methods have been validated and used to monitor release of diclofenac and acetaminophen...     

Microwave Assisted,Solvent-Free, “Green” Synthesis of Novel Indole Analogs as Potent Antitubercular and Antimicrobial Agents and Their Molecular Docking Studies

A rapid, efficient and environmentally benign synthesis of novel indole analogs bearing thiazolidinone attached to substituted thiazolyl coumarin scaffolds are synthesized. Conventional and microwave-assisted (MW) approaches are studied. Structures of the products are confirmed by FT-IR, NMR (¹H and ¹³C) and Mass spectra. The in vitro antitubercular and antimicrobial activities are evaluated. Several screened compounds demonstrate promising anti-TB and antimicrobial properties. The structure activity relationship (SAR) study reveal that the compounds containing halogens are most potent. Docking of the potent compounds inside the active site of a target enzyme mycobacterial enoyl reductase (InhA)(PDB code 4TZK) is performed.