Browsing by Subject "Duftstoff"

Now showing 1 - 2 of 2

Determination of potentially hazardous oxidation products in cosmetics containing lanolin or 1-(1,2,3,4,5,6,7,8-octahydro-2,3,8,8-tetramethyl-2-naphthalenyl)ethanone (OTNE)
(2019) Schrack-Belschner, Sonja Miriam Irmgard; Schwack, Wolfgang
Cosmetic products are important consumer goods in the "non-food" sector, which should not have negative effects of the human health. Critical compounds, however, can be formed by the oxidation of an unsaturated organic compound.Thereby formed oxidation products with potentially adverse properties are well known from the food sector. As the oxidation of cosmetic ingredients, however, has less been studied, the oxidation of selected cosmetic ingredients with respect to the formation of potentially critical compounds was investigated within the framework of this thesis.The oxidation of cholesterol to various cholesterol oxidation products (COPs) was investigated in a first step.COPs are known from the food sector and are suspected of causing certain diseases such as arteriosclerosis.Cosmetic products have not yet been tested for COPs, although a versatile ingredient used only in cosmetic products, lanolin, contains above-average levels of the cholesterol, which is the precursor.Total COPs contents in cosmetics containing lanolin, namely lip care products, fat creams and ointments for nursing women were in the low percent range (up to 3 %) and were thus several orders of magnitudes higher than the contents found in food.The oxidation of fragrances was studied in the second part of this work.The subject is not new as the oxidation of terpenes to contact allergens has been studied in earlier studies. The oxidation of other fragrances was hardly investigated. In order to extend our knowledge in this field, the oxidation of a synthetic fragrance frequently used in perfumes, octahydro tetramethyl naphthalenyl ethanone (OTNE) was studied. Obtained results indicated that peroxides of OTNE were formed during oxidation.It was found out that the OTNE oxidation even occurs, when perfumes are stored indoors under normal temperature and light conditions. An in-vivo test showed that OTNE oxidation can be expected on the skin after application of a perfume.
Molecular elements involved in locust olfaction : gene families in the desert locust Schistocerca gregaria
(2018) Jiang, Xingcong; Breer, Heinz
Locusts are remarkable insects due to their unique and potentially devastating phenotypic plasticity based on the local population density. While “solitarious” phase locusts avoid one another, “gregarious” locusts can form dense and highly mobile swarms, which have been feared as agricultural pests since ancient history. For this reason alone, locust biology has long been the object of intense scientific studies; moreover, from a purely scientific perspective it is of great interest to unravel the mystery underlying the phenotypic plasticity. The unique phase transition including the behavioral plasticity heavily relies on chemical communication by means of critical volatiles. It is therefore important to elucidate the mechanisms underlying locust chemosensory communication, including the identification of molecular elements involved in recognizing odorous compounds. Towards this goal, the desert locust Schistocerca gregaria, as a representative locust species, was investigated in this study. One of the key elements for recognizing odorous compounds are odorant binding proteins (OBPs). To gain insight into the repertoire of locust OBPs, genomic sequences encoding candidate OBPs from Schistocerca gregaria together with those from three other locust species were subjected to thorough comparative analyses. The results indicated that locust OBPs could be classified into several categories, namely, “classic OBPs”, “plus-C OBPs”, “minus-C OBPs” and “atypical OBPs” which reside in four major phylogenetic families (I to IV). With the aim to uncover distinct features of the various OBP types, the initial studies were concentrating on the conserved subfamilies I-A and II-A which comprise “classic OBPs”. The sequence analyses provided evidence for both common and subfamily-specific motifs as well as evolutionary clues based on the calculation of coden substitution rates, which suggested the effect of purifying selection pressure. The subfamily I-A comprised a much higher number of orthologous OBPs than subfamily II-A, which resulted in a distinct re-clustering patterns for subfamily I-A and subfamily II-A. Exploring the topographic expression pattern on the antennae revealed that OBPs of subfamily I-A were selectively expressed in sensilla basiconica and sensilla trichodea, whereas OBPs of subfamily II-A were restricted to sensilla coeloconica. Furthermore, cells expressing the subtype OBP1 were present in almost all sensilla basiconica and trichodea, whereas other subtypes were only present in subpopulations. The OBPs of subfamily II-A, were expressed in distinct subpopulations of sensilla coeloconica. Analyses of representative OBPs from the remaining phylogenetic subfamilies revealed that representative subtypes from subfamily III-A and III-B were expressed in sensilla chaetica, similarly the two representatives of subfamily I-B were also expressed in this sensillum type. The selective expression of these OBPs in sensilla chaetica was substantiated by analyzing the antennal tip, which comprises numerous sensilla chaetica. The “atypical OBP” OBP12, a representative of subfamily IV-A was found to be selectively expressed in a distinct subpopulation of sensilla coeloconica, while “plus-C OBP” OBP9, from subfamily IV-B, showed a unique expression pattern and seemed to be associate with all four sensillum types. The diversity and complex sensilla- and cellular-specific distribution implies distinct functional implications of OBP subtypes in the process of chemoreception.