T. Kowalska and J. Sherma (Eds) Thin-Layer Chromatography in Chiral Separations and Analysis xvi + 420 pp., Chromatographic Science Series,Vol. 98, CRC Press,Boca Raton,New York, 2007. ISBN 978-0-8493-4369-8.

JPC – Journal of Planar Chromatography – Modern TLC -     

Cycloaddition von Heterocumulenen an CN-Bindungssysteme. 1. Mitteilung. Perhydro-s-triazindione und Perhydro-s-triazinyl-harnstoffe aus N,N,N′-trisubstituieten Formamidinen und Isocyanaten

The addition of methyl isocyanate to N,N-dimethyl-N′-arylformamidines 4d – 4r leads to the perhydro-s-triazine-diones 5d – 5o and to the s-triazinylureas 10a – 10k . The mechanism of formation is discussed. The addition of the arylisocyanates 18a – 18p to the N,N,N′-trialkylformamidines 9 and 27a – 27i furnishes the expected 1,4-cycloaddition products 26 and 27 in good yields. The N,N-di-isopropyl-N′-alkylformamidines 27j – 271 , however, do not undergo 1,4-dipolar cycloadditions and react with the arylisocyanate 18b to yield the alkyl isocyanates 31a – 31c and N,N-diisopropyl-N′-(p-chlorphenyl)-formamidine 32 exclusively.     

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...     

Steroid total synthesis. 3. 9 , 10 -testosterone

The total synthesis of 9β, 10α-testosterone via a BCD-tricyclic intermediate is described. The latter compound – 17β-hydroxy-des-A-androst-9-en-5-one – was obtained in optically active form by our previously reported scheme, using an efficient resolution step early in the synthesis. New results regarding the asymmetric induction step are also discussed.     

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...     

Neue β-Lactam-Antibiotika. Über Derivate der 3-Hydroxy-7-amino-ceph-3-em-4-carbonsäure. Modifikationen von Antibiotika, 10. Mitteilung [1]

3-Hydroxy-ceph-3-em-esters 5 a – c , versatile intermediates for the preparation of new β-lactam antibiotics, were obtained by ozonolysis of the corresponding 3-methylidene-esters 3 a – c . Reduction and elimination gave the 3-unsubstituted ester 13 ; derivatives 16 a – c and 20 – 22 resulted from O-alkylation. The 3-methoxy-esters 16 a – c were converted into the corresponding acids 23 a – d . Several other transformations of the β-ketoester system are described.     

Validated HPTLC Method for Quantification of Myricetin in the Stem Bark of Myrica esculenta Buch. Ham. Ex D. Don,Myricaceae

JPC – Journal of Planar Chromatography – Modern TLC - A simple, rapid, and precise high-performance thin-layer chromatographic method has been established for quantitative analysis of...     

Quantitative Analysis of Corosolic Acid,a Type-II Anti-Diabetic Agent,in Different Parts of Lagerstroemia speciosa Linn.

JPC – Journal of Planar Chromatography – Modern TLC - An HPTLC method has been established for rapid and simple quantitative determination of corosolic acid, a type-II (non-insulin...     

A Simple and Rapid Estimation of Major Bioactive Arnebin-1 from the Natural Dye Plant,Arnebia nobilis Reichb. f.

JPC – Journal of Planar Chromatography – Modern TLC - Arnebia nobilis has gained an increasing popularity for the recently recognized various pharmacological activities. The root part...     

Two New Metabolites,Epoxydine A and B,from Phoma sp.

The new compounds, epoxydines A and B ( 1 and 2 , resp.), along with the known and related metabolites, 3 – 6 , were isolated from the fungal endophyte Phoma sp. The structures of the new compounds were elucidated by detailed spectroscopic analysis, and the relative configuration of 1 was confirmed by ROESY experiments. Preliminary studies indicated that compounds 2 – 5 possess good antibacterial, antifungal, and algicidal properties. Similarly, compound 1 showed antifungal and algicidal, and compound 6 antibacterial and algicidal properties.     

Professor Dr. Siegfried Ebel, 03/02/1934–29/07/2019

JPC – Journal of Planar Chromatography – Modern TLC -     

Validated High-Performance Thin-Layer Chromatographic Method for the Simultaneous Determination of Quercetin,Rutin, and Gallic Acid in Amaranthus tricolor L.

JPC – Journal of Planar Chromatography – Modern TLC - A simple, rapid, quantitative, and validated high-performance thin-layer chromatographic (HPTLC) method has been developed for the...     

High-Performance Thin-Layer Chromatographic Analysis for the Simultaneous quantification of Gallic Acid,Vanillic Acid,Protocatechuic Acid,and Quercetin in the Methanolic Fraction of Limonia acidissima L. Fruits

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

Ein neuer Reaktionsweg zu 1, 3-Dicarbonylderivaten. Modelluntersuchungen am A/B-Teil von 3-Oxo-5α-steroiden

A New Route to 1, 3-Dicarbonyl Derivatives, Model Investigations on the A/B-Part of-3-Oxo-5α-steroids Starting from 1 the 1, 3-dicarbonyl compounds 4a – d were synthetized via the enynes 2a – e and the relatively unstable epoxides 3a – d . The latter were reacted with 95% formic acid to gave 4a – d ; small amounts of the furane derivatives 5a – c were identified as by-products in this last step. In the presence of catalytic amounts of HgSO₄ the epoxides 3a – c yielded with 95% formic acid the furanes 5a – c , but no detectable amounts of 4a – c .     

A Sensitive HPTLC Method for Estimation of Amentoflavone,a Bioactive Principle from Biophytum sensitivum (Linn.) DC. and Putranjiva roxburghii Wall.

JPC – Journal of Planar Chromatography – Modern TLC - A sensitive high-performance thin-layer chromatographic (HPTLC) method has been developed for estimation of amentoflavone, an...     

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...     

Metallcarbonyl-Synthesen,XIV. Neuartige Vanadium-, Niob- und Tantal-Komplexe mit Wasserstoff-Brücken

Syntheses of Metal Carbonyls, XIV. Novel Vanadium, Niobium, and Tantalum Complexes Having Hydrido Bridges The novel homo- and heterodinuclear organometallic μ-hydrido compounds 3a – c of vanadium, niobium, and tantalum have been synthesized by light-induced reactions of the hydridoniobium complex (η⁵-C₅H₅)₂NbH₃ ( 1 ) with the half-sandwich complexes (η⁵-C₅H₅)M(CO)₄ ( 2a : M = V; 2b : M = Nb; 2c : M = Ta). These compounds have the general composition L_xM – H – Nb(CO)(η⁵-C₅H₅)₂. The formation of the M – H – Nb moieties is a dark-reaction preceded by two photoreactions that are independent from each other elimination of CO from 2a – c and elimination of H₂ from 1 , with the extruded carbon monoxide being transfered to the (η⁵-C₅H₅)₂NbH fragment; subsequent fixation of the species (η⁵-C₅H₅)₂Nb(CO)H thus generated to the photogragments (η⁵-C₅H₅)M(CO)₃ results in donor stabilization of these latter groups. The structural architecture of the derivatives 3a und b was established by X-Ray diffraction. The hydrogen bridges are to be considered as three-center two-electron functions that are responsible for a serious lengthening of the otherwise by at least 40 pm shorter metal-to-metal distances amounting to 371.3 pm in 3a and 373.3 pm in 3b (mean values).     

Photochemische Umwandlungen, 42 [1] Photoisomerisierungen im 5-Isopropyliden-tetracyclo-[4.3.0.02,4.03,7]non-8-en-System. Vorläufige mitteilung

Direct photochemical excitation of the tetracyclo[4.3.0.0.^2,4.0^3,7]non-8-enes 7a – d leads to a mixture of the isomers 8a – d and 10a – d , with the former being the main products. On sensitization by acetone the formation of 10a – d is clearly favored. The cis-bishomobenzenes 9a – d are the postulated intermediates. Spectral data and some thermal reactions are described.     

A Sensitive HPTLC method for Estimation of Swertiamarin in Enicostemma littorale Blume,Swertia chirata (Wall) Clarke,and in formulations containing E. littorale

JPC – Journal of Planar Chromatography – Modern TLC - Swertiamarin is a secoiridoid glucoside present in members of the Gentianaceae family, including Swertia chirata (Wall) Clarke, S....     

TLC and HPLC Analysis of the Phenolic Acids in Silphium perfoliatum L. Leaves,Inflorescences and Rhizomes

JPC – Journal of Planar Chromatography – Modern TLC - TLC and HPLC have been used for preliminary evaluation of the phenolic acids occurring in the leaves, inflorescences, and rhizomes...