Simultaneous identification of rutin,chlorogenic acid and gallic acid in Moringa oleifera by densitometric high-performance thin-layer chromatography method

JPC – Journal of Planar Chromatography – Modern TLC - An HPTLC (high-performance thin-layer chromatography) method was carried out to develop a feasible, simple and accurate method for...     

Herbal standardization of formulation containing curcuminoids,piperine and ascorbic acid by dual detection mode densitometric analysis

JPC – Journal of Planar Chromatography – Modern TLC - A dual detection mode high-performance thin-layer chromatographic (HPTLC) method has been evolved for the contemporaneous...     

Simultaneous determination of betulinic acid, β-sitosterol and lupeol in fruits,leaves, root and stem bark of Dillenia pentagyna Roxb. by a validated high-performance thin-layer chromatography method

JPC – Journal of Planar Chromatography – Modern TLC - In the present investigation, a simple and effective high-performance thin-layer chromatography (HPTLC) method was developed and...     

A validated quantification of gallic acid and ellagic acid in Triphala using a high-performance thin-layer chromatography method

JPC – Journal of Planar Chromatography – Modern TLC - A well-known Ayurvedic preparation, Triphala, consists of Amla (Emblica officinalis Gaertn.), Baheda (Terminalia bellirica Roxb.)...     

2,2′-Dipyridyl-6,6′-dicarboxylic acid diamides: Synthesis,complexation and extraction properties

New ligands for complexing of the post-transition metals – diamides of 2,2′-bipyridyl-6,6′-dicarboxylic acid were developed, synthesised and characterised. They were proposed to be effective extractants towards americium. The structures of the amides were studied in solid as well as in solution. The extraction of Am and lanthanides depending on diamide structure, chlorinated cobalt dicarbollide (CCD) – diamide ratio, type of diluent was studied. The optimal conditions for Am/REE separation were determined. The properties of new potentiometric sensors on the base of 2,2′-dipyridyl-6,6′-dicarboxylic acid diamides were studied. The correlation structure vs. properties of ionophores (i.e. extractants), their sensitivity and selectivity in sensor analysis and extraction are discussed.     

Mono- and Dialkylation of Derivatives of (1R, 2S)-2-Hydroxycyclopentanecarboxylic Acid and -cyclohexanecarboxylic acid via bicyclic dioxanones: Selective generation of three contiguous stereogenic centers on a cyclohexane ring

Ethyl (1R, 2S)-2-hydroxycyclopentanecarboxylate and -cyclohexanecarboxylate ( 1a and 2a , respectively) obtained in 40 and 70% yield by reduction of 3-oxocyclopentanecarboxylate and cyclohexanecarboxylate, respectively (Scheme 2), with non-fermenting yeast, are converted to bicyclic dioxanone derivatives 3 and 4 with formaldehyde, isobutyraldehyde, and pivalaldehyde (Scheme 3). The Li-enolates of these dioxanones are alkylated (→ 5a – 5i , 5j , 6a – 6g ), hydroxyalkylated (→ 51, m, 6d, e ), acylated (→ 5k, 6c ) and phenylselenenylated (→ 7 – 9 ) with usually high yields and excellent diastereoselectivities (Scheme 3, Tables and 2). All the major isomers formed under kinetic control are shown to have cis-fused bicyclic structures. Oxidation of the seleno compounds 7–9 leads to α, β-unsaturated carbonyl derivatives 10 – 13 (Scheme 3) of which the products 12a – c with the C?C bond in the carbocyclic ring (exocyclic on the dioxanone ring) are most readily isolated (70–80% from the saturated precursors). Michael addition of Cu(I)-containing reagents to 12a – c and subsequent alkylations afford dioxanones 14a – i and 16a – d with trans-fused cyclohoxane ring (Scheme 4). All enolate alkylations are carried out in the presence of the cyclic urea DMPU as a cosolvent. The configuration of the products is established by NMR measurements and chemical correlation. Some of the products are converted to single isomers of monocyclic hydroxycyclopentane ( 17 – 19 ) and cyclohexane derivatives ( 20 – 23 ; Scheme 5). Possible uses of the described reactions for EPC synthesis are outlined. The observed steric course of the reactions is discussed and compared with that of analogous transformations of monocyclic and acyclic derivatives.     

Crystal structures,thermal stabilities,and dissolution behaviours of tinidazole and the tinidazole–vanillic acid cocrystal: insights from energy frameworks

The crystal structures of the antimicrobial drug tinidazole [ TNZ ; systematic name: 1‐(2‐ethylsulfonylethyl)‐2‐methyl‐5‐nitroimidazole, C₈H₁₃N₃O₄S] and the 1:1 cocrystal of TNZ with the naturally occurring compound vanillic acid ( VA ; systematic name: 4‐hydroxy‐3‐methoxybenzoic acid, C₈H₈O₄), namely, the TNZ – VA cocrystal, were determined by single‐crystal X‐ray analysis at 100 K. The supramolecular structure of the TNZ – VA cocrystal is composed of a carboxylic acid dimer and an O—H…N(heterocycle) synthon in the form of layers made up of O—H…N and O—H…O hydrogen bonds. The layers are joined via C—H…O hydrogen bonds, π–π stacking and C—H…π interactions. The energy framework analysis, together with interaction energy calculations using the DLPNO‐CCSD(T) method, indicates that the TNZ – VA cocrystal inherits strong interactions from the TNZ and VA crystals, which accounts for the enhanced thermal stability and reduced dissolution rate. To the best of our knowledge, this is the first example of a cocrystal containing TNZ .     

Triarylborane-Appended Anils and Boranils: Solid-State Emission,Mechanofluorochromism, and Phosphorescence

Herein, the design, synthesis, optical properties, and mechanofluorochromism characteristics of a series of conjugates having covalently linked triarylborane (TAB) and anil/boranil units (TAB-anil: 1 a – 3 a and TAB-boranil: 1 – 3 ) are reported. The electronic interactions between TAB and anil/boranil in 1 a – 3 a and 1 – 3 were fine-tuned by changing the boryl moiety's position on the phenyl spacer connecting the BMes₂ (Mes=mesityl) and anil/boranil units. A boryl moiety at the meta position ( 1 a ) of the phenyl spacer stabilizes the enolic form (E-OH), whereas a boryl moiety at the para position ( 2 a and 3 a ) stabilizes the keto form (Z-NH) in the solid state. However, in solution 1 a , 2 a , and 3 a exhibit keto–enol tautomerism in both ground and excited states. Compounds 1 a – 3 a and 1 – 3 show red-shifted absorption compared with 4 a and 4 , which are devoid of TAB moieties, which indicate effective participation of an empty p orbital on the boron center in 1 a – 3 a and 1 – 3 . Compounds 1 and 2 showed fluorescence variations in response to external stimuli such as mechanical grinding. Long phosphorescence lifetimes of 18–46 ms were observed for compounds 1 – 3 . The observed optical properties of 1 a – 3 a and 1 – 3 are rationalized in the context of quantum mechanical calculations.     

Densitometric Determination of Naproxen,and of Naproxen Methyl Ester,its Impurity,in Pharmaceutical Preparations

JPC – Journal of Planar Chromatography – Modern TLC - A chromatographic–densitometric method has been established for identification and quantification of...     

Thin-Layer Chromatographic Determination of Diazepam,Phenobarbitone, and Saccharin in Toddy Samples

JPC – Journal of Planar Chromatography – Modern TLC -     

Isolation and Densitometric HPTLC Analysis of Rutin,Narcissin, Nicotiflorin,and Isoquercitrin in Caragana spinosa Shoots

JPC – Journal of Planar Chromatography – Modern TLC - Athin-layer chromatographic (TLC) method was used for the quantification of four dominant flavonoids (rutin, narcissin,...     

Densitometric HPTLC Analysis of Juglone,Quercetin, Myricetin,Rutin, Caffeic Acid,and Gallic Acid in Juglans regia L.

JPC – Journal of Planar Chromatography – Modern TLC - Asensitive, selective, and precise high-performance thin-layer chromatography (HPTLC) method was developed for simultaneous...     

Densitometric Determination of Omeprazole,Pantoprazole, and their Impurities in Pharmaceuticals

JPC – Journal of Planar Chromatography – Modern TLC - A method has been developed for separation of omeprazole and pantoprazole, and their impurities omeprazole sulfone and...     

High-performance thin-layer chromatographic analysis for the simultaneous quantification of lupeol and ursolic acid in the methanolic fraction of four different species of Bauhinia

JPC – Journal of Planar Chromatography – Modern TLC - A high-performance thin-layer chromatography (HPTLC) method for the simultaneous quantitative determination of lupeol and ursolic...     

Videodensitometric HPTLC Determination of Fleroxacin,Sparfloxacin, and Cinoxacin in Tablets

JPC – Journal of Planar Chromatography – Modern TLC - A new, simple, accurate, and rapid high-performance thin-layer chromatographic method has been developed for the determination of...     

Reversed-Phase Pressurized Planar Electrochromatography and Planar Chromatography of Acetylsalicylic Acid,Caffeine, and Acetaminophen

JPC – Journal of Planar Chromatography – Modern TLC - We have investigated the use of pressurized planar electrochromatography (PPEC) and planar chromatography (TLC) for reversed-phase...     

Thin-Layer Chromatographic Separation of Cadaverine and Ornithine,and Spectrophotometric Quantification

JPC – Journal of Planar Chromatography – Modern TLC -     

TLC Retention Behavior of Brodifacoum,Bromadiolone, and Coumatetralyl and their Impurities on Different Adsorbents

JPC – Journal of Planar Chromatography – Modern TLC - The chromatographic behavior of three biocidal technical materials, rodenticide active ingredients brodifacoum, bromadiolone, and...     

Simultaneous Determination of Marmin,Skimmianine, Umbelliferone,Psoralene, and Imperatorin in the Root Bark of Aegle Marmelos by High-Performance Thin-Layer Chromatography

JPC – Journal of Planar Chromatography – Modern TLC - Aegle marmelos (Rutaceae) has gained traditional therapeutic importance owing to their coumarins (umbelliferone, psoralene, marmin,...     

A validated high‑performance thin-layer chromatography method for the simultaneous determination of quercetin and gallic acid in Annona reticulata L.

JPC – Journal of Planar Chromatography – Modern TLC - A sensitive and reliable high-performance thin-layer chromatography (HPTLC) method has been developed to simultaneously estimate...