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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Composition of cuticular wax on the leaves of kalanchoe daigremontiana

van Maarseveen, Clare Susan 11 1900 (has links)
Analysis of cuticular wax from Kalanchoe daigremontiana leaves was performed to identify the constituent components within the wax, determine how these changed during leaf ontogenesis, and discover how they were distributed within the cuticle. Analysis of extracted cuticular wax by gas chromatography, mass spectrometry, and comparison with authentic standards led to the identification of triterpenoids including glutinol, friedelin, germanicol, epifriedelanol, glutinol acetate and β-amyrin as well as very long chain fatty acid (VLCFA) derivatives including alkanes, primary alcohols, aldehydes, fatty acids, and alkyl esters. Cuticular wax composition in young K. daigremontiana leaves was dominated by triterpenoids, which made up over 70% of the lipid soluble compounds. During leaf ontogenesis, wax composition changed to include a higher proportion of VLCFA derivatives, which made up approximately 50% of cuticular wax in mature leaves. The most abundant triterpenoids in the wax were glutinol and friedelin, both fairly uncommon pentacyclic triterpenoids with a complex proposed biosynthetic mechanism. Tritriacontane (C33 alkane) was the most abundant compound within the VLCFA derivatives. Cuticular wax accumulation was found to correspond well to leaf growth, with both processes slowing at the same time. Variations in the ratio of friedelin-like compounds to glutinol-like compounds during leaf ontogenesis suggest the presence more than one active triterpenoid synthase enzyme in the leaves of K. daigremontiana. VLCFA compounds were found mainly in the epicuticular wax on both the adaxial and abaxial surfaces, while triterpenoids were relatively more abundant in the intracuticular layer. Two different epicuticular wax crystal forms were observed by scanning electron microscopy (SEM) which can be described as platelets with sinuate margins and twisted ribbons. Based on SEM and chemical data as well as previous reports of crystal composition, it is hypothesized that each crystal type has a unique composition, with the platelets containing one or more triterpenoids and the twisted ribbons containing alkanes and other VLCFA derivatives. Confirmation of this hypothesis will have to await further investigation. This research provides information that will aid in the larger goals of characterizing a glutinol or friedelin synthase and understanding the gradients established within epicuticular and intracuticular wax layers.
12

Composition of cuticular wax on the leaves of kalanchoe daigremontiana

van Maarseveen, Clare Susan 11 1900 (has links)
Analysis of cuticular wax from Kalanchoe daigremontiana leaves was performed to identify the constituent components within the wax, determine how these changed during leaf ontogenesis, and discover how they were distributed within the cuticle. Analysis of extracted cuticular wax by gas chromatography, mass spectrometry, and comparison with authentic standards led to the identification of triterpenoids including glutinol, friedelin, germanicol, epifriedelanol, glutinol acetate and β-amyrin as well as very long chain fatty acid (VLCFA) derivatives including alkanes, primary alcohols, aldehydes, fatty acids, and alkyl esters. Cuticular wax composition in young K. daigremontiana leaves was dominated by triterpenoids, which made up over 70% of the lipid soluble compounds. During leaf ontogenesis, wax composition changed to include a higher proportion of VLCFA derivatives, which made up approximately 50% of cuticular wax in mature leaves. The most abundant triterpenoids in the wax were glutinol and friedelin, both fairly uncommon pentacyclic triterpenoids with a complex proposed biosynthetic mechanism. Tritriacontane (C33 alkane) was the most abundant compound within the VLCFA derivatives. Cuticular wax accumulation was found to correspond well to leaf growth, with both processes slowing at the same time. Variations in the ratio of friedelin-like compounds to glutinol-like compounds during leaf ontogenesis suggest the presence more than one active triterpenoid synthase enzyme in the leaves of K. daigremontiana. VLCFA compounds were found mainly in the epicuticular wax on both the adaxial and abaxial surfaces, while triterpenoids were relatively more abundant in the intracuticular layer. Two different epicuticular wax crystal forms were observed by scanning electron microscopy (SEM) which can be described as platelets with sinuate margins and twisted ribbons. Based on SEM and chemical data as well as previous reports of crystal composition, it is hypothesized that each crystal type has a unique composition, with the platelets containing one or more triterpenoids and the twisted ribbons containing alkanes and other VLCFA derivatives. Confirmation of this hypothesis will have to await further investigation. This research provides information that will aid in the larger goals of characterizing a glutinol or friedelin synthase and understanding the gradients established within epicuticular and intracuticular wax layers. / Science, Faculty of / Chemistry, Department of / Graduate
13

Isolation and Structure Elucidation of Antiproliferative Agents From Madagascar Rainforests

Karkare, Sampada S. 31 October 2007 (has links)
Through our continuing search for anticancer agents from Madagascar rainforests as a part of International Cooperative Biodiversity Group (ICBG), we received two extracts which were active against the A2780 human ovarian cancer cell line and hence were selected for further fractionation. Six compounds were isolated from these extracts. The structure elucidation and characterization of these compounds was carried out using mass spectrometry and 1D and 2D NMR techniques. The bioassay-guided fractionation of Roupellina (Strophanthus) boivinii yielded three new and one known cardenolide glycosides. The structure of the known cardenolide glycoside was determined after comparison of NMR data to that found in literature for digitoxigenin 3-O-β-D-glucopyranosyl-(1â 4)-α-L-acofriopyranoside. All four compounds exhibited good antiproliferative activity on the A2780 bioassay. The fractionation of the extract of Grewia sp. led to the isolation of one new and one known triterpenoid. The known triterpenoid was identified as 7β-hydroxy-23-deoxojessic acid and its structure was confirmed by comparison of its 1D and 2D NMR data to that found in literature. / Master of Science
14

Compositional variation in aged and heated Pistacia resin found in Late Bronze Age Canaanite amphorae and bowls from Amarna, Egypt

Heron, Carl P., Corr, L., Serpico, M., Stern, Ben, Bourriou, J. January 2003 (has links)
No / This study examines resinous deposits from the interior surfaces of sherds of imported Canaanite amphorae and locally produced bowls from the 18th Dynasty site of Tell el-Amarna, Egypt. Archaeological evidence indicates that the Canaanite amphorae were used for resin transport, whilst the bowls are associated with burning resin as incense. A number of characteristic triterpenoids identify all the resinous deposits from both vessel types as Pistacia spp. No other resins were observed and there was no evidence of mixing with oils or fats. The composition of the archaeological resins is more complex than that of modern pistacia resin, due to degradation and generation of new components. Experimental heating alters the relative abundance of the triterpenoid composition of modern pistacia resin. One component, the triterpenoid 28-norolean-17-en-3-one, is produced by such heating; however, an increase in its relative abundance in ancient samples is not matched by the archaeological evidence for heating. It is therefore not possible to use this component reliably to identify heated resin. However, additional unidentified components with a mass spectral base peak at m/z 453 have been associated with seven (out of 10) bowls and are not observed in resins associated with Canaanite amphorae. It is proposed that these components are more reliable molecular indicators of heating.
15

The impact of storage time and seasonal harvesting on biomarker levels of Lessertia frutescens

Campbell, James January 2012 (has links)
<p>In South Africa, it is estimated that approximately 70% of the population frequently make use of traditional medicinal plants for their health care needs. The use of Lessertia frutescens by the&nbsp / various cultural groups in South Africa dates back to the earlier civilizations and continues to be used today to treat a multitude of ailments. To get the best results from a medicinal plant, one&nbsp / &nbsp / would need to ensure that the crude material is of good quality through interventions like being properly grown, well dried and correctly processed. This would add a measure of quality&nbsp / assurance, which will contribute towards the safety and efficacy aspect of herbal medicine. The aim of this study was to investigate what impact a particular season of harvest and the time in&nbsp / storage would have on the flavonoid and triterpenoid marker levels of Lessertia frutescens. To achieve this, the following was investigated: (1) storage variation of Lessertia frutescens leaves&nbsp / by comparing the results obtained from the High Performance Liquid Chromatography (HPLC) analysis of the flavonoids and triterpenoids, (2) seasonal variation of Lessertia frutescens&nbsp / leaves by comparing the results obtained from the HPLC analysis of the flavonoids and triterpenoids, (3) leaf and stem variation of Lessertia frutescens by comparing the results obtained from HPLC analysis of the flavonoids and triterpenoids. The hypotheses were: (1) the stored sample would indicate the same level of the biomarkers for the flavonoids and triterpenoids, as that of&nbsp / the freshly prepared sample, (2) the sample that was harvested during the summer season would indicate higher levels of the biomarkers of&nbsp / flavonoids and triterpenoids than the other three&nbsp / seasons, (3) the leaf sample would indicate the same level of the biomarkers for the flavonoids and triterpenoids, as that of the stem sample. An Agilent 1200 series HPLC was used for the&nbsp / determination of the flavonoids sutherlandin A and sutherlandin D as well as the triterpenoids sutherlandioside B and sutherlandioside D. Results show that for both sutherlandin A (summer:&nbsp / 3.67 &plusmn / 2.88 mg/ml / storage: 4.07 &plusmn / 2.88 mg/ml) and D (summer: 4.10 &plusmn / 1.06 mg/ml / storage: 4.25 &plusmn / 1.06 mg/ml) show significantly (P &lt / 0.0001) higher concentrations in the case of the storage&nbsp / amples. For both sutherlandioside B (summer: 3.01 &plusmn / 0.39 mg/ml / storage: 2.82 &plusmn / 0.39 mg/ml) and D (summer: 5.82 &plusmn / 0.42 mg/ml / storage: 4.66 &plusmn / 0.42 mg/ml) show significantly (P &lt / &nbsp / .0001)&nbsp / higher concentrations in the case of the fresh summer samples.For the seasonal comparison, results show that for sutherlandin A (summer: 3.67 &plusmn / 12.49 mg/ml / autumn: 4.75 &plusmn / &nbsp / 12.49 mg/ml / winter: 4.23 &plusmn / 12.49 mg/ml / spring: 6.56 &plusmn / 12.49 mg/ml) show significantly (P &lt / 0.0001) higher concentrations in the case of the spring sample. For sutherlandin D (summer: 4.10&nbsp / &nbsp / 10.32 mg/ml / autumn: 6.37 &plusmn / 10.32 mg/ml / winter: 5.25 &plusmn / 10.32 mg/ml / spring / 6.08 &plusmn / 10.32 mg/ml) show significantly (P &lt / 0.0001) higher concentrations in the case of the autumn sample. For both sutherlandioside B (summer: 3.01 &plusmn / 7.19 mg/ml / autumn: 2.15 &plusmn / 7.19 mg/ml / winter: 2.89 &plusmn / 7.19 mg/ml / spring: 1.47 &plusmn / 7.19 mg/ml) and D (summer: 5.82 &plusmn / 14.48 mg/ml / autumn: 3.33 &plusmn / 14.48 mg/ml / winter: 4.23 &plusmn / 14.48 mg/ml / spring: 2.50 &plusmn / 14.48 mg/ml) show significantly (P &lt / 0.0001) higher concentrations in the case of the autumn sample. For the summer&nbsp / leaf/stem comparison, results show that for sutherlandin A (leaf: 3.67 &plusmn / 8.18 mg/ml / stem: 4.67 &plusmn / 8.18 mg/ml) show significantly (P &lt / 0.0001) higher concentrations in the case of the stem&nbsp / sample. For the sutherlandin D (leaf: 4.10 &plusmn / 4.81 mg/ml / stem: 3.31 &plusmn / 4.81 mg/ml) show significantly (P &lt / 0.0001) higher concentrations in the case of the summer leaf sample. For both the&nbsp / sutherlandioside B (leaf: 3.01 &plusmn / 4.24 mg/ml / stem: 3.62 &plusmn / 4.24 mg/ml) and D (leaf: 5.82 &plusmn / 0.42 mg/ml / stem: 5.80 &plusmn / 0.42 mg/ml) show significantly (P &lt / 0.0001) higher concentrations in the&nbsp / case of the stem samples. Results demonstrate that the production of secondary metabolites are influenced by&nbsp / &nbsp / environmental factors like seasonal harvesting, as indicated by the variation in the chemical constituent composition of Lessertia frutescens depending on the season collected in. Moreover, the storage of Lessertia frutescens for a period of one year resulted in an&nbsp / increase of two of the four constituents being monitored. There was slight variations in the chemical constituents, depending on whether the leaf or stem material of Lessertia frutescens was being used. Finally, the type of chemical constituent being monitored was also important in the consideration of this study. Therefore, this study can be seen as a starting point to further&nbsp / &nbsp / investigations of these aspects, which are of clinical, pharmacological and economic</p>
16

The impact of storage time and seasonal harvesting on biomarker levels of Lessertia frutescens

Campbell, James January 2012 (has links)
<p>In South Africa, it is estimated that approximately 70% of the population frequently make use of traditional medicinal plants for their health care needs. The use of Lessertia frutescens by the&nbsp / various cultural groups in South Africa dates back to the earlier civilizations and continues to be used today to treat a multitude of ailments. To get the best results from a medicinal plant, one&nbsp / &nbsp / would need to ensure that the crude material is of good quality through interventions like being properly grown, well dried and correctly processed. This would add a measure of quality&nbsp / assurance, which will contribute towards the safety and efficacy aspect of herbal medicine. The aim of this study was to investigate what impact a particular season of harvest and the time in&nbsp / storage would have on the flavonoid and triterpenoid marker levels of Lessertia frutescens. To achieve this, the following was investigated: (1) storage variation of Lessertia frutescens leaves&nbsp / by comparing the results obtained from the High Performance Liquid Chromatography (HPLC) analysis of the flavonoids and triterpenoids, (2) seasonal variation of Lessertia frutescens&nbsp / leaves by comparing the results obtained from the HPLC analysis of the flavonoids and triterpenoids, (3) leaf and stem variation of Lessertia frutescens by comparing the results obtained from HPLC analysis of the flavonoids and triterpenoids. The hypotheses were: (1) the stored sample would indicate the same level of the biomarkers for the flavonoids and triterpenoids, as that of&nbsp / the freshly prepared sample, (2) the sample that was harvested during the summer season would indicate higher levels of the biomarkers of&nbsp / flavonoids and triterpenoids than the other three&nbsp / seasons, (3) the leaf sample would indicate the same level of the biomarkers for the flavonoids and triterpenoids, as that of the stem sample. An Agilent 1200 series HPLC was used for the&nbsp / determination of the flavonoids sutherlandin A and sutherlandin D as well as the triterpenoids sutherlandioside B and sutherlandioside D. Results show that for both sutherlandin A (summer:&nbsp / 3.67 &plusmn / 2.88 mg/ml / storage: 4.07 &plusmn / 2.88 mg/ml) and D (summer: 4.10 &plusmn / 1.06 mg/ml / storage: 4.25 &plusmn / 1.06 mg/ml) show significantly (P &lt / 0.0001) higher concentrations in the case of the storage&nbsp / amples. For both sutherlandioside B (summer: 3.01 &plusmn / 0.39 mg/ml / storage: 2.82 &plusmn / 0.39 mg/ml) and D (summer: 5.82 &plusmn / 0.42 mg/ml / storage: 4.66 &plusmn / 0.42 mg/ml) show significantly (P &lt / &nbsp / .0001)&nbsp / higher concentrations in the case of the fresh summer samples.For the seasonal comparison, results show that for sutherlandin A (summer: 3.67 &plusmn / 12.49 mg/ml / autumn: 4.75 &plusmn / &nbsp / 12.49 mg/ml / winter: 4.23 &plusmn / 12.49 mg/ml / spring: 6.56 &plusmn / 12.49 mg/ml) show significantly (P &lt / 0.0001) higher concentrations in the case of the spring sample. For sutherlandin D (summer: 4.10&nbsp / &nbsp / 10.32 mg/ml / autumn: 6.37 &plusmn / 10.32 mg/ml / winter: 5.25 &plusmn / 10.32 mg/ml / spring / 6.08 &plusmn / 10.32 mg/ml) show significantly (P &lt / 0.0001) higher concentrations in the case of the autumn sample. For both sutherlandioside B (summer: 3.01 &plusmn / 7.19 mg/ml / autumn: 2.15 &plusmn / 7.19 mg/ml / winter: 2.89 &plusmn / 7.19 mg/ml / spring: 1.47 &plusmn / 7.19 mg/ml) and D (summer: 5.82 &plusmn / 14.48 mg/ml / autumn: 3.33 &plusmn / 14.48 mg/ml / winter: 4.23 &plusmn / 14.48 mg/ml / spring: 2.50 &plusmn / 14.48 mg/ml) show significantly (P &lt / 0.0001) higher concentrations in the case of the autumn sample. For the summer&nbsp / leaf/stem comparison, results show that for sutherlandin A (leaf: 3.67 &plusmn / 8.18 mg/ml / stem: 4.67 &plusmn / 8.18 mg/ml) show significantly (P &lt / 0.0001) higher concentrations in the case of the stem&nbsp / sample. For the sutherlandin D (leaf: 4.10 &plusmn / 4.81 mg/ml / stem: 3.31 &plusmn / 4.81 mg/ml) show significantly (P &lt / 0.0001) higher concentrations in the case of the summer leaf sample. For both the&nbsp / sutherlandioside B (leaf: 3.01 &plusmn / 4.24 mg/ml / stem: 3.62 &plusmn / 4.24 mg/ml) and D (leaf: 5.82 &plusmn / 0.42 mg/ml / stem: 5.80 &plusmn / 0.42 mg/ml) show significantly (P &lt / 0.0001) higher concentrations in the&nbsp / case of the stem samples. Results demonstrate that the production of secondary metabolites are influenced by&nbsp / &nbsp / environmental factors like seasonal harvesting, as indicated by the variation in the chemical constituent composition of Lessertia frutescens depending on the season collected in. Moreover, the storage of Lessertia frutescens for a period of one year resulted in an&nbsp / increase of two of the four constituents being monitored. There was slight variations in the chemical constituents, depending on whether the leaf or stem material of Lessertia frutescens was being used. Finally, the type of chemical constituent being monitored was also important in the consideration of this study. Therefore, this study can be seen as a starting point to further&nbsp / &nbsp / investigations of these aspects, which are of clinical, pharmacological and economic</p>
17

The impact of storage time and seasonal harvesting on biomarker levels of lessertia frutescens

Campbell, James January 2012 (has links)
>Magister Scientiae - MSc / In South Africa, it is estimated that approximately 70% of the population frequently make use of traditional medicinal plants for their health care needs. The use of Lessertia frutescens by the various cultural groups in South Africa dates back to the earlier civilizations and continues to be used today to treat a multitude of ailments. To get the best results from a medicinal plant, one would need to ensure that the crude material is of good quality through interventions like being properly grown, well dried and correctly processed. This would add a measure of quality assurance, which will contribute towards the safety and efficacy aspect of herbal medicine. The aim of this study was to investigate what impact a particular season of harvest and the time in storage would have on the flavonoid and triterpenoid marker levels of Lessertia frutescens. To achieve this, the following was investigated: (1) storage variation of Lessertia frutescens leaves by comparing the results obtained from the High Performance Liquid Chromatography (HPLC) analysis of the flavonoids and triterpenoids, (2) seasonal variation of Lessertia frutescens leaves by comparing the results obtained from the HPLC analysis of the flavonoids and triterpenoids, (3) leaf and stem variation of Lessertia frutescens by comparing the results obtained from HPLC analysis of the flavonoids and triterpenoids. The hypotheses were: (1) the stored sample would indicate the same level of the biomarkers for the flavonoids and triterpenoids, as that of the freshly prepared sample, (2) the sample that was harvested during the summer season would indicate higher levels of the biomarkers of flavonoids and triterpenoids than the other three seasons, (3) the leaf sample would indicate the same level of the biomarkers for the flavonoids and triterpenoids, as that of the stem sample. An Agilent 1200 series HPLC was used for the determination of the flavonoids sutherlandin A and sutherlandin D as well as the triterpenoids sutherlandioside B and sutherlandioside D. Results show that for both sutherlandin A (summer: 3.67 ± 2.88 mg/ml; storage: 4.07 ± 2.88 mg/ml) and D (summer: 4.10 ± 1.06 mg/ml; storage: 4.25 ± 1.06 mg/ml) show significantly (P < 0.0001) higher concentrations in the case of the storage samples. For both sutherlandioside B (summer: 3.01 ± 0.39 mg/ml; storage: 2.82 ± 0.39 mg/ml) and D (summer: 5.82 ± 0.42 mg/ml; storage: 4.66 ± 0.42 mg/ml) show significantly (P < 0.0001) higher concentrations in the case of the fresh summer samples. For the seasonal comparison, results show that for sutherlandin A (summer: 3.67 ± 12.49 mg/ml; autumn: 4.75 ± 12.49 mg/ml; winter: 4.23 ± 12.49 mg/ml; spring: 6.56 ± 12.49 mg/ml) show significantly (P < 0.0001) higher concentrations in the case of the spring sample. For sutherlandin D (summer: 4.10 ± 10.32 mg/ml; autumn: 6.37 ± 10.32 mg/ml; winter: 5.25 ± 10.32 mg/ml; spring; 6.08 ± 10.32 mg/ml) show significantly (P < 0.0001) higher concentrations in the case of the autumn sample. For both sutherlandioside B (summer: 3.01 ± 7.19 mg/ml; autumn: 2.15 ± 7.19 mg/ml; winter: 2.89 ± 7.19 mg/ml; spring: 1.47 ± 7.19 mg/ml) and D (summer: 5.82 ± 14.48 mg/ml; autumn: 3.33 ± 14.48 mg/ml; winter: 4.23 ± 14.48 mg/ml; spring: 2.50 ± 14.48 mg/ml) show significantly (P < 0.0001) higher concentrations in the case of the autumn sample. For the summer leaf/stem comparison, results show that for sutherlandin A (leaf: 3.67 ± 8.18 mg/ml; stem: 4.67 ± 8.18 mg/ml) show significantly (P < 0.0001) higher concentrations in the case of the stem sample. For the sutherlandin D (leaf: 4.10 ± 4.81 mg/ml; stem: 3.31 ± 4.81 mg/ml) show significantly (P < 0.0001) higher concentrations in the case of the summer leaf sample. For both the sutherlandioside B (leaf: 3.01 ± 4.24 mg/ml; stem: 3.62 ± 4.24 mg/ml) and D (leaf: 5.82 ± 0.42 mg/ml; stem: 5.80 ± 0.42 mg/ml) show significantly (P < 0.0001) higher concentrations in the case of the stem samples.Results demonstrate that the production of secondary metabolites are influenced by environmental factors like seasonal harvesting, as indicated by the variation in the chemical constituent composition of Lessertia frutescens depending on the season collected in. Moreover, the storage of Lessertia frutescens for a period of one year resulted in an increase of two of the four constituents being monitored. There was slight variations in the chemical constituents, depending on whether the leaf or stem material of Lessertia frutescens was being used. Finally, the type of chemical constituent being monitored was also important in the consideration of this study. Therefore, this study can be seen as a starting point to further investigations of these aspects, which are of clinical, pharmacological and economic importance.
18

TARGETING DENDRITIC CELL METABOLISM TO INDUCE IMMUNE TOLERANCE

Wei, Hsi-Ju 01 February 2019 (has links)
No description available.
19

Biological and Chemical Analysis of Small Molecule Activators of Anti-inflammatory and Antioxidant Nrf2-Keap1 Signaling

Gatbonton-Schwager, Tonibelle N. 11 June 2014 (has links)
No description available.
20

Caractérisation de substances naturelles en contexte archéologique : apport des études moléculaires, isotopiques et de la datation au 14C / Characterization of natural substances in an archaeological context : contribution of the molecular and isotopic studies and of the 14C dating

Courel, Blandine 07 September 2016 (has links)
Ces travaux d'archéométrie concernent l’étude moléculaire par GC-MS de marqueurs lipidiques (biomarqueurs) préservés au sein de sols archéologiques et de substances végétales impliquées en tant qu'ingrédients dans la confection d’artefacts. Des analyses complémentaires en isotopie du carbone de composés individuels et des mesures de datation au 14C (AMS MICADAS) de la matière organique totale des sols, d'extraits lipidiques et d'un composé individuel (miliacine) ont également été effectuées. Cette approche a permis:- de montrer l’existence de la culture de millet dès l’âge du Bronze en Alsace, les sols associés à cette culture et leur contenu organique ayant été piégés et préservés dans des silos à grains enterrés datés de l’âge du Fer.- d'identifier la nature de structures archéologiques comme étant d'anciennes latrines et une aire de stabulation de bétail via l'identification de stéroïdes fécaux.- d'établir des critères chimiotaxonomiques fiables basés sur l'analyse des lipides pour l’authentification de résines de styrax et de liquidambars.- d'identifier la nature d'une résine issue de Styrax officinalis ayant été incorporée dans l’enduit organique ornant un crâne décoré (IXème millénaire av. J.-C., site de Nahal Hemar, Israël).- de mettre en évidence l’emploi de brai de bouleau comme agent collant lors de la confection d’un bijou daté du Premier âge du Fer. / In this archaeometric study, lipid biomarkers from archaeological soils and organic substances originating from plants found on artefacts were investigated by GC-MS. In addition, the stable carbon isotopic composition of individual lipids and the 14C age (AMS MICADAS) of soil organic matter, lipid extracts and one isolated compound (miliacin) were determined. Such an archaeometric approach allowed:- the existence of a millet cultivation during the Bronze Age in Alsace to be unveiled for the first time based on preserved molecular remains of this cereal in agricultural soils trapped within grain silos dated from the Iron Age.- the function of uncharacterized archaeological structures to be identified as ancient latrines and a stall area based on the identification of faecal steroidal markers.- reliable chemotaxonomic criteria for the authentication of styrax resins and liquidambar gums to be established using specific organic markers (triterpenoids, notably).- the vegetal component of an organic coating decorating a skull from the 9th millennium BC (Nahal Hemar site, Israel) to be identified as a resin from Styrax officinalis.- the use of birch bark tar as adhesive for the making of a jewellery dated from the Iron Age to be discovered.

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