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 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...     

A Novel Synthesis of 1-Aryl-9-alkyl-2, 3, 3a, 4, 9, 9a-hexahydro-1H-pyrrolo[2, 3-b] quinoxalines by lithium aluminium hydride reduction of N-phenyl-1-benzimidazolyl-succinimides

The N-substituted 1-benzimidazolyl-succinimides 6a – v (Scheme 1, Table 1 and 2) have been prepared by the reaction of benzimidazole and its derivatives with maleimides. Reduction of the N-cyclohexyl and N-cyclo-octyl substituted 1-benzimidazolyl-succinimides 6i – k with lithium aluminium hydride gives the normally expected substituted (N-alkyl-3-pyrrolidinyl)benzimidazoles 14i – k . However by LiAlH₄-reduction of the N-phenyl substituted 1-benzimidazolylsuccinimides 6a – h mainly the 1-aryl-9-alkyl-2, 3, 3a, 4, 9, 9a-hexahydro-1H-pyrrolo[2, 3-b]quinoxalines 7a – h are obtained. The mechanism of this unusual reduction has been elucidated.     

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

JPC – Journal of Planar Chromatography – Modern TLC -     

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,...     

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.     

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,...     

The Motor of Planar Chromatography,Professor R. E. Kaiser,is 75!

JPC – Journal of Planar Chromatography – Modern TLC -     

Analysis of a New Potent Hallucinogen, 25-B-NBOMe,in Blotters by High-Performance Thin-Layer Chromatography

JPC – Journal of Planar Chromatography – Modern TLC -     

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...     

A New TLC Method for Quantification of Paraquat,Diquat, Difenzoquat,Mepiquat and Chloromequat in Water

JPC – Journal of Planar Chromatography – Modern TLC - We report improved separation of the highly toxic contact herbicides paraquat, diquat, difenzoquat, mepiquat, and chloromequat by...     

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...     

Synthesis of Novel Chromene,Pyridine, Pyrazole,Pyrimidine, and Imidazole Derivatives via One‐pot Multicomponent Reaction

New series of chromenes 2 – 4 , pyridines 5 – 8 , and pyranopyrazoles 9a,b were synthesized via one‐pot multicomponent reaction of 4‐tosyloxybenzaldehyde ( 1 ) and malononitrile with phenols, amines or hydrazines, and ethyl acetoacetate, respectively. Compound 9a was reacted with acetic anhydride, formic acid, or formamide to afford N ‐acetyl derivative 10 and pyrazolopyranopyrimidines 11 – 13 , respectively. Imidazole derivatives 14 and 15a – d were obtained by multicomponent reaction between compound 1 with ammonium acetate and benzil or aromatic amines in (1:2:1) or (1:1:1:1) ratio, respectively. The structures of new compounds were elucidated by elemental and spectral analyses.     

Mononuclear Tetraamineplatinum(II) Complexes: Synthesis,Anticancer Activity,DNA Binding,and Cellular Uptake

The synthesis of three bis[(tert‐butoxy)carbonyl]‐protected (tetramine)dichloroplatinum complexes 2a – c of formula cis‐[PtCl₂(LL)] and of their cationic deprotected analogs 3a – c and their evaluation with respect to in vitro cytotoxicity, intramolecular stability, DNA binding, and cellular uptake is reported. The synthesis comprises the complexation of K₂[PtCl₄] with di‐N‐protected tetramines 1a – c to give 2a – c and subsequent acidolysis, yielding 3a – c . The cytotoxicity of the complexes is in direct relation to the length of the polyamine. Complexes 3a – c display a significant higher affinity for CT DNA as well as for cellular DNA in A2780 cells than cisplatin.     

Separation,Identification, and Quantitative Analysis of the Epimers of Cefaclor by TLC-Densitometry

JPC – Journal of Planar Chromatography – Modern TLC - The epimers of cefaclor have been separated, identified, and analyzed quantitatively by TLC. The stationary phase was silica gel 60...     

A New,Convenient Method for Determination of Mangiferin,an Anti-Diabetic Compound,in Mangifera indica L.

JPC – Journal of Planar Chromatography – Modern TLC - A simple, precise, and rapid HPTLC method has been established for quantitative determination of the bioactive marker compound...     

Correction to: A validated high performance thin layer chromatography method for the simultaneous estimation of berberine,berbamine, palmatine,magnoflorine and jatrorrhizine from Berberis aristata

JPC – Journal of Planar Chromatography – Modern TLC -     

Synthesis of Novel 4‐Substituted Coumarins,Docking Studies,and DHODH Inhibitory Activity

Coumarins are the important class of naturally occurring heterocyclic compounds. Activities like antioxidant, antibacterial, anti‐inflammatory, and anticancer have been reported for coumarin derivatives. Present work details the synthesis of substituted coumarin‐4‐pyrrolones as well as coumarin‐4‐acetyl amino acids and their DHODH inhibitory activity, which is a dual target for malaria and cancer. Coumarin‐4‐acetic acids ( 2a – c ) were coupled with different methyl esters of α‐amino acids ( 3 ) giving rise to corresponding coumarin‐4‐acetyl amino acid methyl esters ( 4a – o ), which on hydrolysis under basic condition underwent cyclization forming substituted dihydropyrrole‐2‐ones ( 5a – i ), dihydroindolizine‐3‐ones ( 5j – l ), and dihydropyrrolizin‐3‐one ( 5m – o ). Acidic hydrolysis of the compounds ( 4a – o ) yielded corresponding coumarin‐4‐acetyl amino acids ( 6a – f ). The docking study was performed with the protein 4IGH (obtained from PDB) using Surflex–Dock module. The newly synthesized compounds were tested for DHODH inhibitory activity using Brequinar as the standard. Compound 6b showed remarkable inhibition compared with the standard, and the other compounds with terminal COOH showed moderate inhibition.     

Analysis of 5-Methyltryptamine,l-Tryptophan, 5-Hydroxy-l-Tryptophan,and Melatonin in the Bulbs of Garlic by Thin-Layer Chromatographic Method Coupled with Densitometric Detection

JPC – Journal of Planar Chromatography – Modern TLC - Thin-layer chromatography (TLC) methods coupled with densitometric detection were employed in analyses for the presence of...     

Two-Dimensional Thin-Layer Chromatography of Polyaromatic Hydrocarbons Measured by Absorption,Fluorescence, and Chemiluminescence

JPC – Journal of Planar Chromatography – Modern TLC - A 2D-separation of 16 polyaromatic hydrocarbons (PAHs) according to the Environmental Protecting Agency (EPA) standard was...