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INTRODUCTION: Depending on their terpenoid and phenolic constituents plant resins can be classified as diterpenoid, triterpenoid or phenolic resins; thereby the profile of diterpenes and triterpenes is considered as genus- or even species-specific. OBJECTIVES: We aimed to develop a simple, rapid, inexpensive, sensitive and specific method for the identification of resin-specific triterpenoid and phenolic compounds in plant resins using (HP)TLC [(high-performance) thin-layer chromatography] combined with APCI-MS (atmospheric pressure chemical ionisation mass spectrometry) and post-chromatographic detection reactions. METHODS: Twenty resin samples from different plant species were analysed. Different extraction procedures, post-chromatographic detection reagents as well as various sorbents and solvents for planar chromatography were tested. To evaluate the potential of the optimised (HP)TLC-APCI-MS methods, parameter such as limit of detection (LOD) was determined for selected marker compounds. RESULTS: Our protocol enabled qualitative analyses of chemotaxonomic molecular markers in natural resins such as dammar, mastic, olibanum and benzoin. For the first time, the application of thionyl chloride-stannic chloride reagent for a specific post-chromatographic detection of triterpenes is reported, sometimes even allowing discrimination between isomers based on their characteristic colour sequences. For triterpene acids, triterpene alcohols and phenolic compounds, detection limits of 2-20 ng/TLC zone and a system precision with a relative standard deviation (RSD) in the range of 3.9%-7.0% were achieved by (HP)TLC-APCI-MS. The applicability of the method for the analysis of resin-based varnishes was successfully tested on a mastic-based varnish. Thus, the method we propose is a helpful tool for the discrimination of resins and resin-based varnishes with respect to their botanical origin.

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In this study, cocoons and degummed silk samples of Bombyx mori and twenty Saturniidae species of the genera Actias, Attacus, Argema, Antheraea, Caligula, Callosamia, Cricula, Epiphora, Hyalophora, Loepa, Samia and Saturnia are studied to gain an insight into their morphology, chemical composition and physical structure. For this purpose, silk samples are characterized by optical microscopy and FTIR spectroscopy in attenuated total reflection mode (ATR-FTIR spectroscopy). Furthermore, degummed silk samples are analyzed for their amino acid (AA) composition by GC-FID. In the course of method development, various degumming methods are tested using alkalis, citric acid, enzymes and detergents. A mixture of 0.1% sodium carbonate and 2.5% ethylenediamine proves to be an effective agent for degumming Saturniidae and B. mori cocoons. After hydrolysis of the fibroin filaments with 6 N hydrochloric acid and derivatization with propyl chloroformate, fifteen AAs are identified and qualified. This method shows a satisfactory overall analytical performance with an average recovery rate of 95% at the medium concentration level. The chemical composition of the different silks was considered comparatively. Within a genus, the analyses usually show a high degree of similarity in AA composition and the resulting structural indices, whereas differences are found between genera.

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Cannabis products have been used in various fields of everyday life for many centuries, and applications in folk medicine and textile production have been well-known for many centuries. For traditional textile production, hemp fibers were extracted from the stems by water retting in stagnant or slow-moving waters. During this procedure, parts of the plant material' among them phytocannabinoids' are released into the water. Cannabinol (CBN) is an important degradation product of the predominant phytocannabinoids found in Cannabis species. Thus, it is an excellent indicator for present as well as ancient hemp water retting. In this study, we developed and validated a simple and fast method for the determination of CBN in sediment samples using high-performance thin-layer chromatography (HPTLC) combined with electrospray ionization mass spectrometry (ESI-MS), thereby testing different extraction and cleanup procedures' as well as various sorbents and solvents for planar chromatography. This method shows a satisfactory overall analytical performance with an average recovery rate of 73%. Our protocol enabled qualitative and quantitative analyses of CBN in samples of a bottom sediment core' having been obtained from a small lake in Northern India, where intense local retting of hemp was suggested in the past. The analyses showed a maximum CBN content in pollen zone 4 covering a depth range of 262-209 cm, dating from approximately 480 BCE to 1050 CE. These findings correlate with existing records of Cannabis-type pollen. Thus, the method we propose is a helpful tool to track ancient hemp retting activities. Graphical Abstract.

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Organic dyes of animal and plant origin have often been used by our ancestors to create textiles with polychromic ornamental patterns, and dyestuff analyses reveal how ancient cultures used these natural colorants. Mass spectrometry can characterize ancient colorants from these textiles, but its combination with separation techniques such as liquid chromatography requires the destruction of the pattern to extract organic dyes from the fabrics. In this study we applied mass spectrometry imaging (MS imaging) on colorful patterned textiles to show the spatial distribution of indigo-type and anthraquinone-type dyes. We evaluated different sample preparation techniques for matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF)-MS imaging, e.g. the production of imprints in TLC (thin layer chromatography) aluminum sheets and the embedding of the material in Technovit7100 to produce thin sections. Our protocol enabled the detection of indigo-type dyes directly on a historic textile of more than 2,000 years old embedded in Technovit7100. This is the first-time application of MALDI-TOF-MS imaging to map different organic dyestuffs on archeological remains.

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In this study, we explore the cytotoxic activity of four natural abenquines (2a-d) and fourteen synthetic analogues (2e-j and 3a-h) against a panel of six human cancer cell lines using a SRB assay. It was found that most of the compounds revealed higher levels of cytotoxic activities than naturally occurring abenquines. The analogues carrying ethylpyrrolidinyl and ethylpyrimidinyl with either an acetyl group (2h-i) or a benzoyl group (3f-g), were the most potent against all human cancer cell lines and displayed EC50 between a range of 0.6-3.4µM. Notably, of the compounds tested, compound 2i proved the most cytotoxic against both ovarian (A2780) and breast (MCF7) cells, showing EC50=0.6 and 0.8µM respectively. Likewise, the analogues 2i, 3f and 3g showed strong activity against cell HT29 with EC50=0.9µM for these compounds.

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Triterpenoic acids 1-6 exhibited very low or no cytotoxicity at all, but their corresponding 2,3-di-O-acetyl-piperazinyl amides 13-18 showed low EC50 values for several human tumor cell lines. Their cytotoxicity, however, was also high for the non-malignant mouse fibroblasts NIH 3T3. A significant improvement was achieved by preparing the rhodamine B derivatives 19-24. While rhodamine B is not cytotoxic (up to a concentration of 30µM - cut-off of the assay), the triterpenoid piperazine-spacered rhodamine B derivatives were cytotoxic in nano-molar concentration. Compound 24 (a diacetylated maslinic acid derivative) was most toxic for several human tumor cell lines but less toxic for mouse fibroblasts NIH 3T3. Staining and double-staining experiments revealed 24 to act as a mitocan.

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We present a method requiring no sample preparation for the direct identification of indigoid colorants in tiny amounts in ancient historic fabrics using ASAP®-MS. Exact determinations were completed in less than 1 min. Copyright © 2015 John Wiley & Sons, Ltd.