No description available.

Resumo: O licopeno é um carotenóide com poderosa ação antioxidante, encontrado em maior quantidade no tomate, utilizado no combate a inúmeras doenças como vários tipos de câncer, dentre eles o de próstata, e doenças cardiovasculares. Sua ação tópica é pouco explorada e, por isso, a proposta de ser utilizado no combate à aceleração do envelhecimento cutâneo, incorporado em uma emulsão. Um estudo preliminar foi realizado para a escolha do tipo de tomate que apresenta maior concentração de licopeno e/ou maior atividade antioxidante. O método de quantificação do fitoquímico foi validado e, em função dos testes de avaliação antioxidante in vitro, o tomate do tipo salada foi o escolhido para o desenvolvimento do fitocosmético. Além disso, o extrato foi submetido à avaliação da citotoxicidade in vitro que constatou a não ocorrência de toxicidade em fibroblastos e macrófagos. Assim, o cosmético foi desenvolvido contendo fase oleosa constituída de derivados de karité e submetido a testes para avaliar sua estabilidade, identificar as características da emulsão, avaliar seu comportamento reológico e sua atividade cosmética pelos testes de permeação cutânea e verificando a eficácia quanto à ação antioxidante do licopeno incorporado na emulsão. Foi possível observar que o fitocosmético é estável, de acordo com as condições experimentais realizadas neste estudo, permite a retenção do licopeno na epiderme e na derme e apresenta atividade antioxidante, sendo promissor para o combate à aceleração do envelhecimento cutâneo. / Abstract: Lycopene, a carotenoid with high antioxidant activity, is found in greater quantities in tomatoes used to combat many diseases such as various types of cancers, including of the prostate, and cardiovascular diseases. Its topical action is not explored and therefore the proposal to be used to combat aging, incorporated into an emulsion. A preliminary study was conducted to evaluate which tomato had higher concentration of lycopene and/or higher antioxidant activity. The method of quantification of the phytochemical was validated and the lycopene extract was evaluated by testing in vitro antioxidant activity. Tomato salad was chosen for the development of the phytocosmetic. Furthermore, this extract was subjected to the evaluation of cytotoxicity in vitro activity and it was found that the non-occurrence of toxicity in fibroblasts and macrophages. Thus was developed a product containing oily phase consists only derived about shea which was submitted to tests to assess its stability, to identify the characteristics of the emulsion, to evaluate the rheological behavior and cosmetic activity carried out tests such as skin permeation and checking the effectiveness in the antioxidant action of lycopene incorporated into emulsion. Through the results it was possible to observe that the phytocosmetic is stable, allows the retention of lycopene in the epidermis and dermis, shows antioxidant activity and it's promising to combat the acceleration of skin aging / Orientador: Vera Lucia Borges Isaac / Coorientador: Hérida Regina Nunes Salgado / Banca: Marcos Antônio Correa / Banca: Pedro Alves da Rocha Filho / Mestre

The main task of this thesis is to find the ICT activator of a carotenoid spheroidenone in the pigment-protein complex LH1 of Rhodobacter sphaeroides. The ICT state is characterized by a red-shifted positive transient absorption signal around 750 - 800 nm. We hypothesize that the presence of the ICT state is associated with the pigment-protein interaction of a carotenoid keto group and specific amino acid in the protein. To perform the experiment, four mutant complexes with amino acids substitutions, which should result in decreased intensity of the ICT signal due to a weaker or missing pigment-protein interaction, were obtained and measured using femtosecond time resolved pump-probe spectroscopy.

<i>Hevea brasiliensis </i>latex contains a large quantity of high molecular weight rubber and is thus the primary commercial source of natural rubber. Rubber and other non-rubber isoprenoids in <i>Hevea </i>latex are synthesised from isopentenyl diphosphate (IPP) generated from the cytoplasmic mevalonate (MVA) pathway and the plastidic methyl erythritol phosphate pathway (MEP). This study utilised two rubber tree clones (RRIM600 and PB235) that show visibly contrasting levels of yellow carotenoids for the measurement of latex isoprenoids (carotenoids, rubber and isoprenoid intermediates) and transcript levels of the genes involved in isoprenoid biosynthesis. Metabolite extraction and analysis showed that four major carotenoids namely lutein, zeaxanthin, α-carotene and β-carotene were consistently present in both RRIM600 and PB235 latex. β-carotene was found to be the major carotenoid, at 1.2 μg/g in PB235 and 0.8 μg/g in RRIM600 fresh latex samples. However, the analytical method developed to measure isoprenoid intermediates needed to be further optimised to increase extraction efficiency. To enable accurate measurement of transcript levels of key genes involved in the isoprenoid biosynthetic pathway, a set of reference transcripts was constructed by merging short-reads (RNA-seq) and long-reads (Iso-seq and full-length cDNA sequences) data from <i>Hevea brasiliensis</i>. This produced a comprehensive set of 193,997 transcript sequences with good level of coverage of predicted transcripts and highly conserved core plant genes. Not only did the reference transcriptome update the annotation of rubber gene models, additional transcript variants were also discovered. Manual curation of gene models for key steps associated with rubber and carotenoids resulted in a repertoire of 115 genes, with 151 corresponding transcript variants. Subsequently, differential expression analysis on the basis of mapping RRIM600 and PB235 RNA-seq reads to the reference transcriptome revealed isoform-specific expression of genes for biosynthesis of carotenoids (PSY isoform 2), IPP (AACT2 and HMGR1) and rubber (REFSRPP gene members). In addition, the levels of these genes correlated positively with the carotenoid and rubber content measurements from the same latex of PB235 and RRIM600 used for metabolite extraction. Finally, the utility of the reference transcript catalogue was demonstrated by the characterisation of the REFSRPP gene family, which is involved in rubber elongation steps. REFSRPP gene family showed a local expansion which appear to be unique to <i>Hevea</i>. A pilot study has demonstrated there is considerable diversity of the genomic region containing the duplicated REFSRPP genes.

No description available.

The photophysics of pigments is influenced, to an extent depending on its structure, by the properties of the environment. Proteins represent a very specific environment at least in two aspects: i) they are native to most of the pigments in living systems; ii) they facilitate modifications of pigment configuration, leading to changes not only in its spectroscopic properties, but also in its functional abilities. In studies presented in this thesis, femtosecond pump-probe spectroscopy was used to study predominantly the photosynthetic antenna complexes of bacteria and algae. Based on spectroscopic evidence, the structural modifications of pigments imposed by the protein were deduced or hypothesized, together with their functional relevance.

Our research has shown the carotenoid pigment to be found in the cell membrane of C. poinsettiae. These results suggest that the pigment is bound to protein and that protein tertiary structure is important in the binding.

The purpose of this investigation was to determine the site of the carotenoid pigments in C. spp. strain 7E1C as a step towards resolving the role of the pigment in the cell.

Information regarding the structure and function of living tissues and cells is instrumental to the advancement of cell biology and biophysics. Nonlinear optical microscopy can provide such information, but only certain biological structures generate nonlinear optical signals. Therefore, structural specificity can be achieved by introducing labels for nonlinear optical microscopy. Few studies exist in the literature about labels that facilitate harmonic generation, coined "harmonophores". This thesis consists of the first major investigation of harmonophores for third harmonic generation (THG) microscopy. Carotenoids and chlorophylls were investigated as potential harmonophores. Their nonlinear optical properties were studied by the THG ratio technique. In addition, a tunable refractometer was built in order to determine their second hyperpolarizability (γ). At 830 nm excitation wavelength, carotenoids and chlorophylls were found to have large negative γ values however, at 1028 nm, the sign of γ reversed for carotenoids and remained negative for chlorophylls. Consequently, at 1028 nm wavelength, THG signal is canceled with mixtures of carotenoids and chlorophylls. Furthermore, when such molecules are covalently bonded as dyads or interact within photosynthetic pigment-protein complexes, it is found that additive effects with the γ values still play a role, however, the overall γ value is also influenced by the intra-pigment and inter-pigment interaction. The nonlinear optical properties of aggregates containing chlorophylls and carotenoids were the target of subsequent investigations. Carotenoid aggregates were imaged with polarization-dependent second harmonic generation and THG microscopy. Both techniques revealed crystallographic information pertaining to H and J aggregates and β-carotene crystalline aggregates found in orange carrot. In order to demonstrate THG enhancement due to labeling, cultured cells were labeled with carotenoid incorporated liposomes. In addition, Drosophila melanogaster larvae muscle as well as keratin structures in the hair cortex were labeled with β-carotene. Polarization-dependent THG studies may be particularly useful in understanding the structural organization that occurs within biological structures containing carotenoids and chlorophylls such as photosynthetic pigment-protein complexes and carotenoid aggregates in plants and alga. Further, artificial labeling with carotenoids and chlorophylls may be useful in clinical applications since they are nontoxic, nutritionally valuable, and they can aid in visualizing structural changes in cellular components.

Masters Research - Master of Philosophy (MPhil) / Gac fruit, Momordica cochinchinensis Spreng contains extraordinarily high levels of carotenoids, especially β-carotene and lycopene, and a comparatively high content of alpha-tocopherol (vitamin E) and of polyunsaturated fatty acids. The aim of this study was therefore to develop an understanding of suitable conditions for the processing of Gac fruit and the preparation of Gac fruit powder. The objectives of this study were to investigate the effect of 1) pre-treatments; blanching, ascorbic acid and bisulfite, and 2) drying techniques; air, vacuum, freeze and spray drying, on the physicochemical and antioxidant properties of powders produced from Gac arils. In addition, Gac arils (mixed with added maltodextrin) and untreated Gac skin and yellow pulp were air-dried and their properties were evaluated. The shelf life of a number of the Gac powder products was periodically evaluated during an extended storage period. The moisture sorption isotherms of various Gac powders were also constructed. Furthermore, the stability of three different types of Gac fruit powders was also tested when used in food and beverage products. Results showed that freeze drying of fresh Gac aril without any pre-treatment produced powders of high quality as determined by colour (hue angle of 33.93, total carotenoid content (TCC) of 7.24 mg/g and total antioxidant activity (TAA) of 0.39 mmole TE/g). However, pre-treatment of fresh Gac fruit aril with 1% (w/v) ascorbic acid or bisulfite solution before vacuum drying at 40 oC for 45 hours was just as effective as freeze drying in preserving colour (hue angle of 34.18 and 36.25, respectively), TCC (7.28 and 6.99 mg/g, respectively) and TAA of 0.36-0.40 mmole TE/g. Pre-treatment with 1% (w/v) ascorbic acid or bisulfite solution before air drying at 40 oC for 48 hours was also effective (TCC of 6.36 and 6.11 mg/g, respectively and TAA of 0.33 mmole TE/g) but not to the extent of vacuum or freeze drying. In respect of the spray drying process, taking into account the dilution effect of the added maltodextrin, the addition of 10% maltodextrin to the feed mixture and drying at 120 oC effectively preserved the physicochemical and antioxidant properties of the powder (hue angle of 66.85, TCC of 2.77 mg/g and TAA of 0.14 mmole TE/g). In addition, in a comparison of fresh and frozen arils, both were found to be equally useful for production of Gac powder in terms of preservation of colour (hue angle of 33.93 and 31.28, respectively), TCC (7.24 and 6.27 mg/g, respectively) and TAA (0.39 and 0.33 mmole TE/g, respectively). However, the dried aril was found to be very difficult to grind due to its stickiness. The addition of maltodextrin (0.5 or 1 g maltodextrin/g of total fruit solids) prior to drying solved this problem and also maintained the quality of the powder (hue angle of 28.04-30.55; TCC of 5.65-6.29 mg/g and TAA of 0.29-0.31 mmole TE/g, respectively). The storage study indicated that the degradation of TCC and TAA of freeze-dried and spray-dried powders for up to 8 and 3 months, respectively, was lowest when samples were packed into laminated bags and stored at temperature of 10 oC (TCC loss of 11% and 5% and TAA loss of 44% and 15%, respectively). The highest losses for freeze-dried and spray-dried powders (TCC of 70% and 42%; and TAA of 88% and 42%, respectively) occurred when stored at conditions of 37 oC. Isotherm curves of all the Gac powders have sigmoid shapes. By comparing different drying methods for aril, the lowest hygroscopicity was observed in SD powder, followed by VD, AD and FD powders. Results also showed that the air-dried skin and yellow pulp powders contained low levels of TCC and TAA compared to the aril powders, but these are still high levels of TCC (0.90 and 0.42 mg/g, respectively) as compared to cherry tomatoes (0.36) and pumpkin (0.14). The skin (18%) and yellow pulp (49%) account for 67% of the total weight of the Gac fruit and as such comprise significantly high components. Therefore, utilisation of these components can prevent environmental pollution due to waste issues, and also enhances the overall value of Gac fruit. Freeze-dried, vacuum-dried and spray-dried Gac fruit aril powders were found to be easily incorporated into cooked glutinous rice, pasteurised Gac juice and pasteurised Gac milk mixtures. The colour, TCC and TAA of the juice and the milk mixtures were maintained after storage for 30 days under refrigeration temperature of 40 oC. Overall the study established that, the quality of Gac aril powders, in terms of colour, TCC and TAA, is most effectively preserved by applying pre-treatments prior to vacuum drying at 40 oC. These powders should be packed in laminated bags and stored at 10 oC for any lengthy storage period. It was also found that the Gac powders can be satisfactorily incorporated into “Xoi Gac”, juice and milk products. Finally, the overall value of Gac fruit could be enhanced through utilisation of all the anatomical components.