Domino carbocationic rearrangement of aryl-2-(1-N-methyl/benzyl-3-indolyl)cyclopropyl ketones: a serendipitous route to 1H-cyclopenta[c]carbazole framework

Aryl-2-(N-methyl/benzyl-3-indolyl)cyclopropyl ketones 2a-m are shown to undergo a novel unexpected domino carbocationic rearrangement in the presence of SnCl(4)/CH(3)NO(2) yielding 2-aroyl-3-aryl-1H-cyclopenta[c]carbazoles 3a-m in good yields. The possible mechanistic pathway for this interesting transformation involves a series of cascade events, (a) electrophilic ring opening of cyclopropyl ketone, (b) intermolecular enol capture of the resulting zwitterionic intermediate, (c) electrophilic dimerization of indole moieties to give tetrahydrocarbazole intermediate and its subsequent aromatization by elimination of an indole moiety and dehydrogenation, and (d) intramolecular aldol condensation of the side chain to give a cyclopentene ring. The overall transformation involves formation of three carbon-carbon bonds along with a fused benzene and a substituted cyclopentene ring in one-pot operation from simple indole precursors.     

Solid phase radioimmunoassay for testosterone in human serum using antibodies coupled to magnetizable cellulose

Summary A simple user-friendly, solid phase radioimmunoassay for testosterone in human serum based on magnetic particles is described. IgG fractions precipitated from polyclonal testosterone antiserum were coupled to magnetizable cellulose particles using carbonyl diimidazole. The prepared antibody solid phase was stable for one year when stored at 4 °C. The optimized assay involves the incubation of 50 ml of testosterone standards (0.3-10 ng/ml), 100 ml of magnetizable cellulose particle coupled antibody suspension and 100 ml of ¹²⁵I-testosterone derivative for 4 hours at 37 °C. At the end of the incubation, the tubes were placed on a magnetic rack for 10 minutes after the addition of wash buffer and decanted. The sensitivity of the assay is 0.2 ng/ml. The intra-assay variation was <15% throughout the assay range. The recovery varied from 88 to 115%. On dilution of samples having high levels of testosterone, linearity ranged between 87 and 125%. Correlation coefficient of 0.978 was obtained when the developed solid phase assay was compared to the earlier established liquid phase assay.     

Olefin copolymerization via reversible addition-fragmentation chain transfer

Successful statistical copolymerization of an alpha-olefin (1-octene) with an acrylate (butyl acrylate, BA) and with a methacrylate (methyl methacrylate, MMA), employing reversible addition-fragmentation chain transfer (RAFT) mediated polymerization has been accomplished     

Fast electrochromic response of porous-structured cobalt oxide (Co<Subscript>3</Subscript>O<Subscript>4</Subscript>) thin films by novel nebulizer spray pyrolysis technique

Electrochromic effect of cobalt oxide thin films was studied as a function of substrate temperature (573–673 K). Tricobalt tetraoxide (Co₃O₄) thin films were deposited on glass and fluorine-doped tin oxide (FTO) substrates by nebulized spray technique using cobalt nitrate as precursor material. The XRD patterns indicated (311) plane was dominant for all the films irrespective of the deposition temperature. Williamson-Hall (W-H) analysis was made to understand the strain variation in the prepared Co₃O₄ films under different deposition temperature by employing uniform deformation model (UDM). Scanning electron microscopy images revealed porous morphology for the film prepared at 623 K. The optical parameters such as refractive index (n), extinction coefficient (k), and band gap were derived from UV-visible spectra of Co₃O₄ films. The electrochromic performance of the deposited Co₃O₄ films was analyzed through cyclic voltammetry, chronocoulometry, chronoamperometry, and iono-optical studies.     

Three‐Arm,Biotin‐Tagged Carbazole–Dicyanovinyl–Chlorambucil Conjugate: Simultaneous Tumor Targeting,Sensing, and Photoresponsive Anticancer Drug Delivery

The design, synthesis, and in vitro biological studies of a biotin–carbazole–dicyanovinyl–chlorambucil conjugate (Bio‐CBZ‐DCV‐CBL; 6 ) are reported. This conjugate ( 6 ) is a multifunctional single‐molecule appliance composed of a thiol‐sensor DCV functionality, a CBZ‐derived phototrigger as well as fluorescent reporter, and CBL as the anticancer drug, and Bio as the cancer‐targeting ligand. In conjugate 6 , the DCV bond undergoes a thiol–ene click reaction at pH<7 with intracellular thiols, thereby shutting down internal charge transfer between the donor CBZ and acceptor DCV units, resulting in a change of the fluorescence color from green to blue, and thereby, sensing the tumor microenvironment. Subsequent photoirradiation results in release of the anticancer drug CBL in a controlled manner.     

Developments in Titanium-Based Alkali and Alkaline Earth Metal Oxide Catalysts for Sustainable Biodiesel Production: A Review

Biodiesel represents a biodegradable, environmentally friendly, and renewable alternative to fossil fuels. Despite more than three decades of research, significant obstacles still hinder the widespread production of biodiesel. This current review elucidates both the potential and the existing challenges associated with homogeneous and heterogeneous catalysts in catalyzing biodiesel production, with a particular focus on alkali analogues, alkaline earth metal oxides, and titania-based catalysts. In particular, a comprehensive analysis is presented concerning alkali and alkaline earth-based titania (TiO₂) catalysts. Among these, the alkaline earth metal oxides, including lithium, calcium, and strontium when combined with titanium-based catalysts, exhibit superior catalytic activity compared to other metal oxides, owing to their heightened basicity. Consequently, this review offers a thorough and up-to-date insight into the potential of titania-based heterogeneous catalysts for advancing biodiesel production.     

Isolation of Taraxerol from Coccinia grandis,and its Standardization

JPC – Journal of Planar Chromatography – Modern TLC - Coccinia grandis (L). Voigt (family: Cucurbitaceae) is widely used in the Indian system of medicine for various skin diseases,...     

Practicality of Tetragonal Nano-Zirconia as a Prospective Sorbent in the Preparation of 99Mo/99mTc Generator for Biomedical Applications

The feasibility of using tetragonal nano-zirconia (t-ZrO₂) as an effective sorbent for developing a ⁹⁹Mo/^99mTc chromatographic generator was demonstrated. The structural characteristics of the sorbent matrix were investigated by different analytical techniques such as XRD, BET surface area analysis, FT-IR, TEM etc. The material synthesized was nanocrystalline, in tetragonal phase with an average particle size of ~7 nm and a large surface area of 340 m² g^?1. The equilibrium sorption capacity of t-ZrO₂ is >250 mg Mo g^?1. The present study indicates that ⁹⁹Mo is both strongly and selectively retained by t-ZrO₂ at acidic pH and ^99mTc could be readily eluted from it, using 0.9% NaCl solution. A 9.25 GBq (250 mCi) t-ZrO₂ based chromatographic ⁹⁹Mo/^99mTc generator was developed and its performance was repeatedly evaluated for 10 days. ^99mTc could be eluted with >85% yield having acceptable radionuclidic, radiochemical and chemical purity for clinical applications. The compatibility of the product in the preparation of ^99mTc labeled formulations such as ^99mTc-EC and ^99mTc-DMSA was evaluated and found to be satisfactory.     

Modeling shear modulus distribution in magnetic resonance elastography with piecewise constant level sets

Magnetic resonance elastography (MRE) is designed for imaging the mechanical properties of soft tissues. However, the interpretation of shear modulus distribution is often confusing and cumbersome. For reliable evaluation, a common practice is to specify the regions of interest and consider regional elasticity. Such an experience-dependent protocol is susceptible to intrapersonal and interpersonal variability. In this study we propose to remodel shear modulus distribution with piecewise constant level sets by referring to the corresponding magnitude image. Optimal segmentation and registration are achieved by a new hybrid level set model comprised of alternating global and local region competitions. Experimental results on the simulated MRE data sets show that the mean error of elasticity reconstruction is 11.33% for local frequency estimation and 18.87% for algebraic inversion of differential equation. Piecewise constant level set modeling is effective to improve the quality of shear modulus distribution, and facilitates MRE analysis and interpretation.