Use of a Water-in-Oil Microemulsion as Mobile Phase in Complexation TLC of Amino Acids on Silica Layers Impregnated with Metal Cations

JPC – Journal of Planar Chromatography – Modern TLC - A water-in-oil microemulsion has been used for the first time as a mobile phase in thin-layer chromatography of amino acids. A new...     

Development of a validated high-performance thin-layer chromatography method for the standardization of an Ayurvedic formulation using berberine and ursolic acid

Giloy Tulsi tablet is an Ayurvedic preparation containing Tinospora cordifolia (Giloy) and Ocimum sanctum (Tulsi) and it is recommended for boosting the body’s immune response. This research work is about the marker-based standardization of this Ayurvedic preparation using high-performance thin-layer chromatography method. Standardization is based on the determination and quantification of the phytoconstituents berberine and ursolic acid present in Giloy Tulsi tablets. Separation was performed on pre-coated silica gel 60 F₂₅₄ plate as the stationary phase, with chloroform‒acetone‒formic acid (6:3.5:0.5, V/V) as the mobile phase. Identification and quantification were conducted densitometrically at 330 nm. The developed method resulted in good quality peak shape and enabled high-quality resolution of biomarkers. The R_F value for berberine (0.46 ± 0.02) and for ursolic acid (0.68 ± 0.02) in both reference standard and formulation were found to be comparable. The method was validated for specificity, linearity, limit of detection, limit of quantification, intra-day and inter-day precisions, accuracy, and robustness. The limit of detection values were 91 and 153 ng/band for berberine and ursolic acid, respectively. The limit of quantification values were 175 and 465 ng/band for berberine and ursolic acid, respectively. Regression analysis of the calibration data revealed a good linear relationship between peak area response and concentration in the range 200‒1000 ng/band for berberine (r² = 0.995) and 500‒2500 ng/band for ursolic acid (r² = 0.9968). The accuracy of the method, determined by measurement of recovery at three different levels, was in the range 98‒102% for both markers. These results are indication of reliability, reproducibility, accuracy, and precision of the method.

     

Synthesis of some new mesoionic heterocycles

The synthesis of various substituted 1-hydroxy-2-chloroacetyl-6-thia-10b-aza-2a-azoniaaceanthrylene hydroxide inner salt, 1-hydroxy-6-thia-10b-aza-2a-azoniaaceanthrylene hydroxide inner salt, 1-hydroxy-2-piperidinoacetyl-6-thia-10b-aza-2a-azoniaaceanthrylene hydroxide inner salt is described. The ir is also included.     

Vibrational and gravimetric analysis of polyaniline/polysaccharide composite materials

In this paper, we present a comparative study of polyaniline/polysaccharide composites (starch, carboxymethyl cellulose, cellulose acetate, and chitosan) by FTIR, UV-visible, SEM and electrochemical analysis. We propose that simultaneously three different phenomena happen while formation of composite system that may be listed as degradation of polysaccharide, polymerization of aniline, formation of polyaniline- polysaccharide composite. Effects of hydrochloric acid and oxidizing agent (ammonium peroxydisulphate) on the structure of polysaccharides were also investigated. We obtained dissimilar product yield and variable polyaniline and polysaccharide ratio in the composite system even though experimental conditions were same. The possible reasons responsible for the observed differences as well as characteristics and morphology of protonated and deprotonated composite materials are discussed.     

Thin-Layer Chromatography of Anions — Separation of Coexisting Hexacyanoferrate(II), Hexacyanoferrate(III) and Thiocyanate with a New Mobile Phase

JPC – Journal of Planar Chromatography – Modern TLC - The thin-layer chromatography of eighteen anions has been performed on silica layers with mixed aqueous–organic mobile...     

Synthesis of Some New 2-(4-Methoxybenzothiazol-2′-yl amino)-4-(2-chloro-4-trifluoromethylanilino)-6-(substituted thioureido)-1,3,5-triazine as Antifungal Agents

2,4,6-Trichloro 1,3,5-triazine was selectively reacted with new nucleophilic reagents such as 4-methoxy-2-aminobenzothiazole, 2-chloro-4-trifluoromethyl-aniline, and phenylsubstituted thiourea in alkaline medium to give 2-(4-methoxybenzothiazol-2′-ylamino)-4-(phenylthioureido)-6-(substitutedthioureido)-1,3,5-triazines. The structures of these compounds were confirmed by IR, ¹H NMR, ¹⁹F NMR, mass spectral data, and elemental analysis. The compounds show fungicidal activity against Alternaria alternata, Aspergillus niger, and Macrofomina.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Synthesis of some new fluorophenothiazines

The synthesis of various 3-substituted derivatives of 7-fluorophenothiazin-3-ol and their 5-oxides is described. The ir, uv and mass spectral data are also included.     

Morphology,crystallization and melting behaviour of poly(trimethylene terephthalate)/thermotropic liquid crystalline polymer blends

The miscibility, crystallization and melting behaviour of poly(trimethylene terephthalate)/thermotropic liquid crystalline polymer (LCP) blends were studied using differential scanning calorimetry. The blends were found to form primarily an immiscible system. The addition of LCP accelerated the overall rate of crystallization and caused a depression in equilibrium melting temperature, especially at low LCP content. Lauritzen–Hoffman analysis showed that the addition of LCP caused a reduction in the fold surface energy and increased the regime II to III transition temperature.

     

Studies in fluorinated 1,3-diketones and related compounds Part XII. Synthesis and spectroscopic studies of some new polyfluorinated 1,3-diketones,and their copper 1,3-diketonates

New polyfluorinated 1,3-diketones have been prepared from polyfluorinated acetophenones and appropriate esters in the presence of sodamide. The corresponding copper 1,3-diketonates have been obtained by treating a methanolic solution of polyfluorinated 1,3-diketone with methanolic solution of copper acetate. The polyfluorinated 1,3-diketones have been characterized by elemental as well as by spectral studies, viz: I.R., ¹H N.M.R. and ¹⁹F N.M.R. In I.R., characteristic absorptions observed are: CF stretching bands (1300 ? 1000) cm^?1, CF deformation modes (900 ? 700 cm^?1) and intramolecular hydrogen bonding (3000 ? 2500 cm^?1). In ¹H N.M.R. methine ( = C$\text{H}$) signal is observed at δ 6.2 ? 6.8 ppm and enolic proton resonance signal at δ 13 ? 15 ppm indicating the presence of strong hydrogen bonding in such polyfluorinated 1,3-diketones.     

Marker-based standardization of polyherbal capsule formulation by high-performance thin-layer chromatography (HPTLC)–densitometric method using andrographolide and catechin

Himalaya PartySmart capsule is a polyherbal formulation recommended for its liver-protective properties. As the formulation contains extracts of six different herbs, a large number of markers are present in the same. This research work reports the standardization of Himalaya PartySmart capsule using andrographolide and catechin as therapeutic phytoconstituents to assess its quality and efficacy. A specific, sensitive, precise, and accurate high-performance thin-layer chromatography (HPTLC) method has been developed for the quantitative estimation of andrographolide and catechin. Separation was performed on TLC silica gel 60 F₂₅₄ aluminum plates as the stationary phase using chloroform‒acetone‒formic acid (7:3:0.5, V/V) as the mobile phase with densitometric detection at 259 nm. The developed method was validated as per the recommendations of the International Council for Harmonisation (ICH) Q2(R1) guideline. Each marker phytoconstituent showed a good linear relationship with an average correlation coefficient (r²) = 0.99 in the concentration range studied. The proposed method was found to be specific, precise, and accurate with recovery within the range of 95‒105% and hence can be used for the routine analysis of PartySmart capsule formulation.