Cumulative CAMAG Bibliography Service CCBS

Our CCBS database includes more than 11,000 abstracts of publications. Perform your own detailed search of TLC/HPTLC literature and find relevant information.

The Cumulative CAMAG Bibliography Service CCBS contains all abstracts of CBS issues beginning with CBS 51. The database is updated after the publication of every other CBS edition. Currently the Cumulative CAMAG Bibliography Service includes more than 11'000 abstracts of publications between 1983 and today. With the online version you can perform your own detailed TLC/HPTLC literature search:

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      129 002
      Imaging high-performance thin-layer chromatography as powerful tool to visualize metabolite profiles of eight Bacillus candidates upon cultivation and growth behavior
      S. KRUSE, F. PIERRE, Gertrud E. MORLOCK* (*Institute of Nutritional Science, and Interdisciplinary Research Centre for Biosystems, Land Use and Nutrition, Justus Liebig University Giessen, Giessen, Germany; gertrud.morlock@uni-giessen.de)

      J Chromatogr A, 1640, 461929 (2021). Study of the impact of different strains, culture media and parameters (temperature, time, rotational speed, and glucide and amino-acid supply) on the metabolite profile of bacteria. Samples were cultivation broths of Bacillus subtilis, B. licheniformis, B. pumilus and B. amyloliquefaciens, as well as their respective supernatant liquid-liquid extracts (apolar solvents only or QuEChERS method with acetonitrile and MgSO4 – NaCl mixture 4:1). HPTLC on silica gel (normal phase and RP-18), either as bands (for small volumes of extracts) or as areas for supernatants and bigger volumes of extracts. Extract areas were focused with a three-step procedure (up to 20mm with acetone, and twice with methanol); unextracted supernatants were focused twice with methanol and once with tetrahydrofuran, but the application zone of the plate had to be cut before development, due to the high matrix load. Development with ethyl acetate – methanol – water at different ratios after activation of the plate surface with magnesium chloride (33% relative humidity), evaluation in white light and UV. Detection of antibacterial compounds with Aliivibrio fischeri bioassay. Derivatization with primuline (for lipophilic substances) and diphenylamine aniline sulfuric acid reagent (for saccharides). This method allowed a fast comparison: A) of the patterns of the different strains (presence /absence and intensity of detected or antibacterial bands); B) of cultivation parameters: the number of metabolites increased with time, rotational speed (oxygen level), and at 37°C (vs. 30°C), whereas a minimal medium allowed the detection of more metabolites, due to the lower matrix load; C) of the impact of the extraction parameters: choice of the solvents (QuEChERS method had no advantage here), solvent – supernatant ratio (1:3 showed richer patterns than 1:1); D) of the HPTLC parameters used (better separation and resolution with normal phase vs. RP18 layers).

      Classification: 3a, 10a, 11c, 27
      129 013
      A bioimaging system combining human cultured reporter cells and planar chromatography to identify novel bioactive molecules
      I. KLINGELHOEFER, L. PHAM NGOC, B. VAN DER BURG, Gertrud E. MORLOCK* (*Chair of Food Sci., Inst. of Nutrit. Sci. & TransMIT Center for Effect-Directed Anal., Justus Liebig Univ. Giessen, Heinrich-Buff-Ring26-32, 35392, Giessen, Germany, Gertrud.Morlock@uni-giessen.de)

      Anal Chim Acta 1183 (2021) 338956. Demonstration of first on-surface adherent cell assays by investigating growth and viability of modified adherent human osteosarcoma U2OS cells (Cytotox CALUX® cell system) as a biodetector for the cytotoxicity evaluation of e.g. mycotoxins, cytostatics and plant extracts, on HPTLC plates. In the planar bioassay, the cytotoxicity of sample extracts was measured with the luciferase activity in the Cytotox CALUX® reporter cells. For direct bioresponse testing on the HPTLC plate, the U2OS cell suspension was pipetted along the the sample track. RP-HPTLC-CALUX® bioassays of Saussurea costus and Ginseng extracts on HPTLC RP-18 W with n-hexane - toluene - tetrahydrofuran 25:7:15 to 6 cm. After drying, immersion in citrate phosphate buffer pH 12, and several drying and moistening steps the cytotoxic zones were detected by bioluminescence inhibition. Two different test procedures proved Cytotox CALUX® cell viability on surface and in microtiter plate assay. The isolated cytotoxic zone was analyzed by HPTLC on RP-18 W with n-hexane - toluene - tetrahydrofuran 10:1:1 and one part of the  chromatogram cut in half was derivatized with sulfuric acid reagent and evaluated under white light, while the other part was subjected to the new planar Cytotox-CALUX® bioassay. The cytotoxic zone had the same hRF as standards costunolide and dehydrocostus lactone.

      Classification: 32e
      129 012
      Nanomole-scaled high-throughput chemistry plus direct bioautography on the same chromatography plate for drug discovery
      I. YÜCE, Gertrud E. MORLOCK* (*Chair of Food Sci., Inst. of Nutrit. Sci. & TransMIT Center for Effect-Directed Anal., Justus Liebig Univ. Giessen, Heinrich-Buff-Ring26-32, 35392, Giessen, Germany, Gertrud.Morlock@uni-giessen.de)

      Anal Chim Acta 1182 (2021) 338950. On-surface synthesis and effect-directed analysis for quantitative nanomole-scaled high-throughput chemistry and biological response on a single HPTLC plate for up to 68 on-surface synthesis reactions. For generic on-surface synthesis, 1 mL or 15 nmol each of malononitrile and benzaldehyde candidates were automatically sprayed as 3-mm bands  on an HPTLC plate, dried, and oversprayed with  diketoester on the same zones, followed by drying. Development in anti-parallel with chloroform - tetrahydrofuran 6:1 up to 5 cm and detection in UV 254 nm, 366 nm and  white light. For yield calculation, four-point calibration with the preparatively synthesized standard ethyl 6-amino-5-cyano-2-methyl-4-(4-nitrophenyl)-4H-pyran-3-carboxylate, derivatization with ninhydrin collidine reagent, heating at 110°C, detection in UV 254 nm, 366 nm and white light and densitometric absorbance measurement at 430 nm. Online elution of the synthesis product zones with methanol to high-resolution mass spectroscopy and analysis by electrospray ionization MS. For the HPTLC-Bacillus subtilis bioassay 3 mm bands of ciprofloxacin solutions were developed in ethanol - water - hydrochloric acid 9:10:1, sprayed with the bacterial suspension, incubated at 37°C for 2 h, sprayed with phosphate buffered saline (PBS)-buffered thiazolyl blue tetrazolium bromide (MTT) solution, incubated at 37°C for 30 min, followed by drying. Detection of colorless (bright) inhibition zones in white light and by absorbance measurement of the blue-violet formazan background of the biodensitogram at 546 nm.

      Classification: 4e, 32
      129 011
      High-performance thin-layer chromatography combined with effect-directed assays and high-resolution mass spectrometry as an emerging hyphenated technology: A tutorial review
      Gertrud E. MORLOCK (Chair of Food Sci., Inst. of Nutrit. Sci. & TransMIT Center for Effect-Directed Anal., Justus Liebig Univ. Giessen, Heinrich-Buff-Ring 26-32, 35392, Giessen, Germany, Gertrud.Morlock@uni-giessen.de)

      Anal Chim Acta 1180 (2021) 338644. Review with 120 references on HPTLC combined with effect-directed assays (EDA) and high-resolution mass spectrometry (HRMS). Brief introduction of status quo of these emerging technologies, involving targeted, untargeted and predictive strategies. Hyphenated HPTLC has great potential for solving pressing analytical questions because it provides information on the effects from individual compounds in complex or natural samples, it allows separation in parallel, and the separation is combined with effect-directed detection using enzymatic or biological assays, capable to select the important compounds in a complex sample for further characterization by HRMS. Overview of emerging hyphenated technologies driven by HPTLC, including non-target high-throughput 8D hyphenation, minimum requirements for sample preparation and comprehensive effect evaluation, agonistic and antagonistic fast effect detection, identifying multi-potent or multi-modulating compounds and simulated on-surface digestion or metabolization for study of biotransformation. HPTLC is a versatile, creative and flexible open-format technique with the benefits of super-hyphenation, minimum requirements for sample preparation, detection of multi-modulating compounds or agonistic versus antagonistic effects, and miniaturization of on-surface metabolization. Discussion of the potential offered by the miniaturized open-source LabToGo system.

      Classification: 1
      129 010
      Open-source all-in-one LabToGo office chromatography
      F. SCHADE, W. SCHWACK, Y. DEMIRBAS, Gertrud E. MORLOCK* (*Chair of Food Sci., Inst. of Nutrit. Sci. & TransMIT Center for Effect-Directed Anal., Justus Liebig Univ. Giessen, Heinrich-Buff-Ring 26-32, 35392, Giessen, Germany, Gertrud.Morlock@uni-giessen.de)

      Anal. Chim. Acta 1174 (2021) 3387022. Presentation of the next generation LabToGo system OCLab2 which was improved and made more robust e.g. by using print and media technologies in chromatography, so-called office chromatography (OC). The first LabToGo methods were developed in the field of food safety and quality for point-of-care or on-site usage. For application volume study,  HPTLC of different methanolic / propanolic Patent Blue V solutions on HPTLC silica gel with ethyl acetate - methanol - water - acetic acid 65:23:11:1 up to 50 mm. Evaluation in white light and  absorption measurement at 635 nm. For performance tests of plate imaging, HPTLC of benzoic acid and sorbic acid acid on HPTLC with ethyl acetate - toluene - acetic acid 25:25:1. For study of the illumination homogeneity, HPTLC of either sorbic acid, 7-hydroxy-4-methylcoumarin, or Patent Blue V on amino phase, evaluation at 254 nm (sorbic acid), 366 nm (7-hydroxy-4-methylcoumarin) and in white light (Patent Blue V), and in the OCLab2 at 278 nm, 365 nm, and white light, respectively, and scanning the plates at 254 nm 366 nm and 635 nm, respectively. For analysis of food dye mixture by OCLab2, HPTLC on silica gel with ethyl acetate - methanol - water - acetic acid 65:23:11:1 up to 5 cm, drying and capturing of plate images by the OCLab2 at 515-525 nm, 620-630 nm and 465-475 nm, video densitometry and evaluation using the open-source quanTLC software. For analysis of Stevia leave samples, the ethanolic extracts and four calibration levels of a steviol glycoside mixture were applied by OCLab2 for the hydrophilic interaction liquid chromatography (HILIC) separation on HPTLC silica gel with acetonitrile - water 5:1. Derivatization with 2-naphthol sulfuric acid reagent at evaluation in white light. For analysis of water and environmental samples, ink-printing the prepared samples on HPTLC silica gel MS-grade, focusing using acetone - water 4:1 up to 13 mm, drying,  developing with ethyl acetate - toluene 1:1 up to 70 mm, drying and capturing the plate images in white light, 254 nm and 366 nm. For biological detection, spraying the plate with A. fischeri bacteria suspension and capturing of images over 36 min with an exposure time of 60 s and a trigger interval of 3.0 min. 

      Classification: 4b
      129 009
      Comprehensive bioanalytical multi-imaging by planar chromatography in situ combined with biological and biochemical assays highlights bioactive fatty acids in abelmosk
      N.G.A.S. SUMUDU CHANDANA, Gertrud E. MORLOCK* (*Chair of Food Sci., Inst. of Nutrit. Sci. & TransMIT Center for Effect-Directed Anal., Justus Liebig Univ. Giessen, Heinrich-Buff-Ring 26-32, 35392, Giessen, Germany, Gertrud.Morlock@uni-giessen.de)

      Talanta 223 (2021) 121701. Development of workflow for a bioanalytical multi-imaging screening based on HPTLC-UV/Vis/FLD-EDA-HESI-HRMS and application to 54 bark, leaf and seed extracts of Sri Lankan Abelmoschus moschatus (abelmosk) to find out the most bioactive individual compounds. HPTLC on silica gel with toluene - ethyl acetate - methanol 6:5:2 or toluene - ethyl acetate 7:3 up to 65 mm, evaluation in (A) UV 254 nm, (B) white light, (C) fluorescence 366 nm, and after derivatization with (D) primuline reagent at UV 366 nm, (E) p-anisaldehyde sulfuric acid reagent, (F) vanillin sulfuric acid reagent, (G) p-aminobenzoic acid reagent, (H) the latter in fluorescence evaluation at 366 nm, (I) diphenylamine aniline orthophosphoric acid reagent, (J) ninhydrin reagent, (K) Fast Blue B salt reagent. For (E-K) detection in white light after heating at 140°C for 5 min, and (L) natural product reagent in fluorescence 366 nm after air-drying. For effect-directed profiling, HPTLC on plates prewashed with methanol - water 3:1, drying for 15 min and immersing in the respective assay solution/suspension or spraying with it, then incubating, drying and evaluation in white light (A) for Gram-negative Aliivibrio fischeri bioassay, spraying the bacterial culture onto the chromatogram and recording the instant bioluminescence over a 30 min period with the positive controls of caffeine; (B) for Gram-positive Bacillus subtilis bioassay, dipping the chromatogram in the bacterial suspension for incubation at 37°C for 2 h, then dipping into a 0.2 % PBS-buffered MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenylte-trazolium bromide) solution with positive control tetracycline; (C) for α-glucosidase inhibition assay, spraying with substrate solution, drying, pre-wetting and incubation by spraying with Fast Blue B salt solution with positive control acarbose, absorbance measurement at 546 nm and quantification via peak area; (D) for β-glucosidase inhibition assay, analog to (C), but using β-glucosidase and 2-naphthyl-β-D-glucopyranoside and longer incubation time, with positive control imidazole; (E) for tyrosinase inhibition assay, spraying with substrate solution, after drying with tyrosinase solution, incubated and dried with positive control kojic acid, absorbance measurement at 579 nm; (F) for radical-scavenging assay, immersing the chromatogram into 0.02 % methanolic 2,2-diphenyl-1-picrylhydrazyl solution, air-dried with the positive control ascorbic acid. The workflow provided comprehensive information about multi-potent compounds and sample diversity, which is elementary for product quality control in the field of botanicals, foods and medicinal plants.

      Classification: 4e
      129 007
      High-performance thin-layer chromatography hyphenated to high-performance liquid chromatography-diode array detection-mass spectrometry for characterization of coeluting isomers
      Agnes M. MORICZ*, V. LAPAT, G.E. MORLOCK, P.G. OTT (*Plant Protection Institute, Centre for Agricultural Research, Herman O. Str. 15, 1022, Budapest, Hungary, moricz.agnes@agrar.mta.hu)

      Talanta 219 (2020) 121306. Development of a workflow for compound characterization of coeluting compounds: employing an HPTLC-UV/Vis/FLD-EDA screening, followed by the characterization and identification of the most potent compounds by multi-imaging, heated electrospray ionization high-resolution mass spectrometry (HESI-HRMS) and hyphenated HPTLC-UV/Vis/FLD-HPLC-DAD-ESI-MS. HPTLC of methanolic Lemon balm leaf extract and standards oleanolic acid and ursolic acid on silica gel with n-hexane - ethyl acetate 7:3 up to 70 mm, drying for 2 min, evaluation in UV 254 nm (UV), UV 366 nm (FLD) and white light (Vis) after derivatization with a solution of vanillin (40 mg) and sulfuric acid (200 μL) in 10 mL ethanol and heating at 110°C for 5 min. Three additional chromatograms were prepared for the antibacterial assays (1) against B. subtilis, (2) A. fischeri and  (3) the α-glucosidase assay. (1) immersing in B. subtilis suspension, detectioon by immersion in aqueous 3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide solution after incubation, followed by incubation until bright zones against a violet background appear, (2) immersing in Aliivibrio fischeri suspension and instantly monitoring in real-time for 30 min using 1 min exposure time in 5-min intervals and indicating the dark (or bright) active zones against the bioluminescent background, (3) immersing in α-glucosidase solution (10 units/mL) and 0.1 M sodium acetate buffer adjusted to pH 7.5 for incubation and immersing into substrate solution (1.2 mg/mL 2-naphthyl-α-D-glucopyranoside in ethanol) for further incubation at room temperature for 10 min and detection by immersion in aqueous Fast Blue Salt B solution (1 mg/mL) and drying, this revealed the enzyme inhibitors as bright zones against a violet background in white light. Online elution of zones of interest with methanol into the MS and full scan recording in the range of m/z 50–750 with a resolution of 280,000 in both negative and positive ionization modes. Expanding the HPLC-DAD-ESI-MS system by installing a TLC-MS interface enabling direct elution of HPTLC zones into the HPLC eluent.

      Classification: 4d, 32
      129 005
      Quantitative inkjet application on self-printed, binder-free HPTLC layers for submicromole-scaled analytical 1H NMR spectroscopy
      I. YÜCE, M. MAYR, Gertrud E. MORLOCK* (*Chair of Food Sci., Inst. of Nutrit. Sci. & TransMIT Center for Effect-Directed Anal., Justus Liebig Univ. Giessen, Heinrich-Buff-Ring 26-32, 35392, Giessen, Germany, Gertrud.Morlock@uni-giessen.de)

      Anal Chim Acta 1087 (2019) 131-139. Presentation of versatile devices for quantitative inkjet application on self-printed, binder-free HPTLC layers for submicromole-scaled analytical 1H NMR spectroscopy, providing the freedom to influence the composition of the slurry and directly access to control the printed quantity of HPTLC silica gel adsorbent to be constant, thus pledging the quality of the layer. To make spectroscopy reveal the cleanest proton spectra with the lowest background signals and most pronounced analyte signals, and to enable the identification of a compound from one 80-mm band on a single HPTLC layer by a 1H NMR spectrum in the full spectral range, the plate quality was improved by pre-developing silica gel plates twice with formic acid - methanol 1:10, then once with acetonitrile -  methanol 2:1. Silica gel particles for self-printed plates were puryfied under solvent pressure using a HPLC pump. For HPTLC,  the homogeneous slurry prepared by stirring 5 g cleaned-up/pre-eluted silica gel particles in 15 mL water - 2-propanol 2:1 was printed on 10 cm x 10 cm glass plates purified with 2-propanol and methanol, and the wet layers were heated to 80°C until dry. Inkjet printing of the solutions as 80-mm band and sample application using a 3-hydroxy-2-naphthoic acid solution (10 mg/mL water – methanol 1 : 9), spraying a methanolic 3-hydroxy-2-naphthoic acid solution (5 mg/mL) as 80-mm band (20mL/band) on the HPTLC plate. After plate drying and chamber pre-conditioning for 7 min with 2 N ammonia solution (10 mL), development with methanol - ethyl acetate - toluene 2:7:1 (5 mL). The deuterated methanol solution of the samples extracted from the analyte area scraped off the analytical plate was measured by NMR with the methanol signal as reference, documentation at UV 366 nm and data evaluation with an open-source video densitometry software (quan TLC). The results showed that HPTLC separated zones had better resolution and less matrix interference with the NMR analyte signal, and thus opened the avenue for submicromole-scaled analytical 1H NMR spectroscopy, which allows a faster structure elucidation of unknown compounds and easier signal interpretation.

      Keywords: HPTLC
      Classification: 4d
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