Solubilities of Hexadecanoic and Octadecanoic Acids in Supercritical CO2 With and Without Cosolvents

The solubilities of hexadecanoic acid (palmitic acid) and octadecanoic acid (stearic acid) in supercritical carbon dioxide without cosolvents and with two cosolvents, namely, ethanol and 3-methyl-1-butanol, were determined at (308 and 318) K at pressures varying from (12.8 to 22.6) MPa. The solubility data, in both the absence and presence of cosolvents, were correlated by a model proposed by Mendez-Santiago and Teja.

Acylation of lysolecithin in the intestinal mucosa of rats

1. The presence of an active acyl-CoA–lysolecithin (1-acylglycerophosphorylcholine) acyltransferase was demonstrated in rat intestinal mucosa. 2. ATP and CoA were necessary for the incorporation of free [1-14C]oleic acid into lecithin (phosphatidylcholine). 3. The reaction was about 20 times as fast with [1-14C]oleoyl-CoA as with free oleic acid, CoA and ATP. 4. With 1-acylglycerophosphorylcholine as the acceptor, both oleic acid and palmitic acid were incorporated into the β-position of lecithin; the incorporation of palmitic acid was 60% of that of oleic acid. 5. Of the various analogues of lysolecithin tested as acyl acceptors from [1-14C]oleoyl CoA, a lysolecithin with a long-chain fatty acid at the 1-position was most efficient. 6. The enzyme was mostly present in the brush-border-free particulate fraction of the intestinal mucosa. 7. Of the various tissues of rats tested for the activity, intestinal mucosa was found to be the most active, with testes, liver, kidneys and spleen following it in decreasing order.

Purification and partial characterization of acyl carrier proteins from developing oil seeds of pisa (Actinodaphne hookeri) and ground nut (Arachis hypogaea)

Acyl carrier proteins (ACP) were purified to homogeneity in the active form from developing seeds of pisa (Actinodaphne hookeri) which synthesizes exclusively trilaurin and from ground nut (Arachis hypogaea) which synthesizes triacylglycerols containing long chain fatty acids. Two major isoforms of ACPs were purified from developing pisa seeds using DEAE-cellulose, Superose-6 FPLC and C-4 reversed phase HPLC chromatographic methods. In contrast, only a single form of ACP was present in ground nut seeds which was purified by anion-exchange and activated thiol-Sepharose 4B affinity chromatography. The two isoforms of ACPs from pisa showed nearly the same specific activity of 6,706 and 7,175 pmol per min per mg protein while ground nut ACP showed a specific activity of 3,893 pmol per min per mg protein when assayed using E. coli acyl-ACP synthetase and [1-C-14]palmitic acid. When compared with E. coli ACP, the purified ACPs from both the seeds showed considerable difference in their mobility in native PAGE, but showed similar mobility in SDS-PAGE under reducing conditions. In the absence of reducing agents formation of dimers was quite prominent. The ACPs from both the seed sources were acid- and heat-stable. The major isoform of pisa seed ACP and the ground nut ACP contain 91 amino acids with M(r) 11,616 and 1,228 respectively. However, there is significant variation in their amino acid composition. A comparision of the amino acid sequence in the N-terminal region of pisa and ground nut seed ACPs showed considerable homology between themselves and with other plant ACPs but not with E. coli ACP.

Bioremediation and lipid synthesis through mixotrophic algal consortia in municipal wastewater

Algae grown in outdoor reactors (volume: 10 L and depth: 20 cm) were fed directly with filtered and sterilised municipal wastewater. The nutrient removal efficiencies were 86%, 90%, 89%, 70% and 76% for TOC, TN, NH4-N, TP and OP, respectively, and lipid content varied from 18% to 28.5% of dry algal biomass. Biomass productivity of similar to 122 mg/l/d (surface productivity 24.4 g/m(2)/d) and lipid productivity of similar to 32 mg/l/d were recorded. Gas chromatography and mass spectrometry (GC-MS) analyses of the fatty acid methyl esters (FAME) showed a higher content of desirable fatty acids (bearing biofuel properties) with major contributions from saturates such as palmitic acid C16:0; similar to 40%] and stearic acid C18:0; similar to 34%], followed by unsaturates such as oleic acid C18:1(9); similar to 10%] and linoleic acid C18:2(9,12); similar to 5%]. The decomposition of algal biomass and reactor residues with an exothermic heat content of 123.4 J/g provides the scope for further energy derivation. (C) 2014 Elsevier Ltd. All rights reserved.

Chemical ecology fatty acids of mollusks dominant species in intertidal zone of Chabahar Bay

Chemical ecology is the science of study and analysis of natural chemical products in result of biochemical processes in organisms and their reactions to variations of ecological and environmental parameters. In marine chemical ecology the existence of natural products in aquatic organisms and their ecological roles in marine animals and their reactions to environmental parameters variations will be studied. Among them, fatty acids are the most various and abundant ones in natural products which had been extracted from many marine organisms such as mollusks and algae. In this study selected animals were the dominant species of mollusks in intertidal zone of chabahar bay including gastropods, bivalves and polyplacophora classes. Nerita textilis and Turbo coronatus species are among gastropoda, Saccostrea cucullata is from bivalve, and Chiton lamyi is from polyplacophora. After seasonal sampling, separation and identification of natural products of these species, fatty acids had been isolated and identified by GC mass chromatography and their seasonal variations had been identified. In addition environmental factors of the location including pH, salinity temperature, dissolved oxygen, chlorophyll a and nutrients were measured monthly. Then the effect of seasonal variations of environmental factors on fatty acids had been studied by applying statistical analysis. GC/MS resulted thirteen fatty acids, which the most importants were myristic, stearic, oleic, palmitoleic, arachidonic and eicosapentaenoic acids. In majority of species palmitic acid was most abundant than the others and saturatedes had the most percentage levels than unsaturated ones. Although seasonal variations of identified fatty acids was not similar in species, but the majority of unsaturated ones had their maximum during winter, while saturated acids reached their maximum in summer. Statistical Analysis showed the strong correlations between Environmental factors and some fatty acids and temperature, nitrate, silicate and pH had strong correlations in all species. The species was studied from the point of lipid content and the results showed a good quality of lipid content in the selected species in the intertidal zone of Chabahar bay.

Influence of cold storage time on the protein changes and fatty acids deterioration of (Rutilus frisi kutum) during frozen storage

The main aim of this research was to identify fatty acids composition of Caspian sea of White fish Rutilus frisi kutum tissue and their changes during one year cold storage (-18Ċ).The secondary aim was to determine the changes of moisture, ash, protein, fat, and to investigate the effects of storage time on peroxide, TBAi, FFA, and extractability of myofibrillar proteins of the fish tissue during one year cold storage (-18 Ċ). 10 samples of (Rutilus frisi kutum) were randomly collected from Anzali landings. The samples were frozen at -30 Ċ and kept in cold storage at -18Ċ for one year. According to time table, the samples were examined. The results showed that 27 fatty acids were identified. The unsaturated fatty acids (UFA) and saturated fatty acids (SFA) were 74/09 and 21/63 %, respectively, in fresh tissue. So that DHA (C22:6) oleic acid (C18:1c) had high amounts (15/07 ,20/57 ) among the UFA and palmitic acid (C16:0) was the most (13/09 %) among the SFA. The effects of freezing and cold storage on fish tissue showed that UFA and SFA contents have reached to 58/79 and 22/17 %, respectively, at the end of cold storage. It indicated that these compound change to each other during frozen storage. Also ω-3 and ω-6 series of fatty acids was 24/22 and 15/56% in fresh tissue, but their contents decreased to 8/68 and 5/11% at the end of period. Among the fatty acids C22:6, C18:1c and C16:0 had the most changes. The changes of fatty acids were significantly at 95% level expected for C18:0. Results showed that moisture, ash, protein, and fat contents were 75/9±0/03, 1/28±0/012, 21/8±0/2, and 4/1±0/01 % respectively, in fresh tissue. The moisture, ash, protein, and fat contents were 72/3±0/04, 1/83±0/05, 1/91±0/01 and 19/9±0/01 % respectively, at the end of storage period. Lipid damage was measured on the basis of free fatty acids (FFA), peroxide value (PV), and Thiobarbituric acid index (TBA-i). PV, TBARS and FFA concentration of frozen Caspian Sea white fish stored at -18 Ċ the temporal variation of these three variables were statistically significant (p<0.001). Results of White fish myofibrillar proteins showed aggregation of bound reduced for stored at 12 months. SDS-PAGE analysis revealed that, the intensity of the myosin heavy chain and actin bound was reduced with increasing storage time. SDS-PAGE patterns showed that myosin heavy chain was much more susceptible to hydrolysis than actin. Key words: Rutilus frisi kutum, frozen storage, ω-3, ω-6, protein myofibrillar

Identification and measurement of fatty acids, amino acids in roe of tuna fish (Thunnus tonggol) and its TVB and peroxide value during cold storage

The first aim of this research was to identify fatty acids, amino acids composition of Thunnus tonggol roe and their changes during cold storage (-18'C). The second aim was to determine the changes of moisture, protein, fat and ash contents of the roe during one year cold storage (-18'C). 60 samples of longtail tuna (Thunnus tonggol) ovaries were randomly collected form Bandar-e-Abbas landings. The samples were frozen at-30'C and kept in cold store at -18'C for one year. According to a time table, the samples were examined for identification of fatty acids, amino acids, moisture, protein, fat, ash, peroxide and T.V.N. and their changes were evaluated during this time. The results showed that 26 fatty acids were identified. The unsaturated fatty acids (UFA) and saturated fatty acids (SFA) were 62.33 and 37.6%, respectively, in fresh roe. So that, DHA (C22:6) and oleic acid (C18:1) had high amounts (24.79 and 21.88%) among the UFA and palmitic acid (C16:0) was the most content (22.75%) among the SFA. The PUFA/SFA was 0.91. Also, 17 amino acids were identified that essential amino acids (EAA) and nonessential amino acids (NE) were 10478 and 7562 mg/100g, respectively, and E/NE was 1.38. Among the EAA and NE, lysine (2110mg/100g) and aspartic acid (1924 mg/100g) were the most contents. Also, results showed that moisture, ash, protein and fat contents were 72.74, 1.8, 19.88 and 4.53%, respectively, in fresh roe. The effects of freezing and cold storage on the roes showed that UFA and SFA contents have reached to 49.83 and 48.07%, respectively, at the end of cold storage. It indicated that these compounds change to each other during frozen storage. Also, n-3 and n-6 series of fatty acids were 32.75 and 1.61% in fresh roe. But their contents decreased to 22.96 and 1.25% at the end of period. Among the fatty acids, 22:6 and C16:0 had the most changes. The changes of fatty acids were significantly at 95% level except for C15:1, C18:3(n-3) and C20:4(n-6). All of the amino acids decreased in frozen storage and their changes were significantly (P<0.05). EAA was 7818 mg/100g and E/NE was 1.27 at the end of storage period. Among the amino acids, leucine and lysine had the most changes. Moisture, ash, protein and fat contents were 70.13, 1.82, 19.4 and 6.51%, respectively, at the end of storage period. The peroxide value and T.V.N. increased during storage. So that, their contents have reached to 5.86 mg/kg and 26.37 mg/100 g, respectively, at the end of frozen storage. The best shelf life of Thunnus tonggol roe was 6 or 7 months, because of lipid oxidation and increasing of peroxide.

尼泊尔水东哥、水麻、木姜冬青和青荚叶的化学成分研究

活性筛选中发现尼泊尔水东哥 (Saurauia napaulensis DC.) 树皮95%乙醇提取物具有α-淀粉酶抑制活性、水麻(Debregeasia orientalis) 枝叶95%乙醇提取物显示血管紧张素转化酶(ACE)抑制活性、青荚叶(Helwingia japonica (Thunb.) Dieter.) 95%乙醇提取物的中小极性部分显示蛋白酪氨酸磷酸酯酶(PTP)1B抑制活性。为全面了解它们的成分及相关活性成份，主要运用硅胶柱层析方法从这三个植物分离得到39个化合物，通过波谱分析或与已知品对照的方法对其进行了鉴定。对木姜冬青(Ilex litseaefolia Hu et Tang)的成分做了进一步的研究，取得了如下结果。 1. 从尼泊尔水东哥树皮的95%乙醇提取物分离并鉴定12个化合物： auranamide、aurantiamide benzoate、齐墩果酸、β-谷甾醇、β-胡萝卜甙、乌苏酸、2α,3α-二羟基-12-烯-28-乌苏酸、2α,3β,24-三羟基-12-烯-28-乌苏酸、(2S,3S,4R,10E)-2-[(2'R)-2' -hydroxytetracosanoylamino] -10-octadecene -1,3,4-triol、 2α,3α,24-三羟基-12-烯-28-齐墩果酸、2α,3β-二羟基-12-烯-28-乌苏酸和2α,3α,24-三羟基-12-烯-28-乌苏酸。 2. 从水麻枝叶的95%乙醇提取物分离并鉴定了18个化合物：棕榈酸、二十烷酸、二十烷酸甲酯、β-谷甾醇、Monogynol A、桦木酸、Hederagenin、β-胡萝卜甙、18αH-19(29)-烯-3-酮-乌苏烷、3，4-开环-20(30)-烯-乌苏烷-3-酸、Pomolic acid，表儿茶素、儿茶素、槲皮素、槲皮素-3-O-β-D-吡喃葡萄糖苷、紫丁香苷、紫丁香酚苷和山萘酚-3-O-芸香糖。儿茶素、槲皮素和槲皮素-3-O-β-D-吡喃葡萄糖苷为具有ACE抑制活性的成分。 3. 从木姜冬青95%乙醇提取物的乙酸乙酯部分分离并鉴定了5个化合物： 2-O-β-D-吡喃葡萄糖-6,2´-二羟基-4,4´-二香草酰氧甲基-1,1´-二苯醚（冬青苷）和四个已知化合物：七叶内酯、香草酸、3,4-二甲氧基苯乙酸和vanilloylcalleryanin。冬青苷为新化合物。 4. 从青荚叶95%乙醇提取物的中小极性部分分离并鉴定了9个化合物：β-谷甾醇、β-胡萝卜苷、羽扇豆醇、桦木醇、桦木酸、棕榈酸甘油酯、桂皮酸、6αH-4-烯-3-酮-豆甾醇和6βH-4-烯-3-酮-豆甾醇。 5. 对1985-2006年间天然二苯醚类化合物及活性研究进展进行综述. The in vitro test indicated that the 95% ethanolic extract of the barks of Saurauia napaulensis DC showed α-amylase inhibitory activity, the 95% ethanolic extract of the whole plants of Debregeasia. orientalis showed angiotensin converting enzyme (ACE) inhibitory activity and some fractions of the 95% ethanolic extract of the aerial parts of Helwingia japonica showed protein tyrosine phosphatase (PTP)1B inhibitory activity. In order to investigate components and active compounds of the three plants, they were chemically studied mainly using. Thirty-nine compounds were isolated predominantly by column chromatography identified by spectral methods or comparing them with authentic samples. Further investigation of Ilex litseaefolia Hu et Tang was carried out. Major results are as follows: 1. Twelve compounds were isolation from the 95% ethanolic extract of the barks of S. napaulensis DC. They were identified as auranamide, aurantiamide benzoate, oleanolic acid, β-sitosterol, β-daucosterol, ursolic acid, 2α,3α-dihydroxyurs-12-en-28-oic acid, 2α,3β,24-trihydroxyurs-12-en-28-oic acid, (2S,3S,4R,10E)-2-[(2'R)-2'-hydroxytetracosanoyl amino]-10-octadecene-1,3,4-triol, 2α,3α,24 -trihydroxyolean-12-en-28-oic acid, 2α,3β-dihydroxyurs-12-en-28-oic acid, and 2α,3α,24-trihydroxyurs-12-ene-28-oic acid, respectively, by spectral methods or comparing them with authentic samples. 2. Eighteen compounds were isolation from the 95% ethanolic extract of the whole plants of D. orientalis. They were identified as palmitic acid, henicosanoic acid, henicosanoic acid methyl ester, β-sitosterol, monogynol, betulinic acid, hederagenin, β-daucosterol, 18αH-urs-20(30)-en-3-one, 3,4-seco-urs-20(30)-en-3-oic acid, pomolic acid, (-)-epicatechin, (+)-catechin, quercetin, quercetin 3-O-β-D-glucopyranoside, syringin, syringiaresinol digloside and kaempferol-3-O-rutinose. (+)-Catechin, quercetin and quercetin 3-O-β-D-glucopyranoside were the ACE inhibitory active components. 3. Further phytochemical investigation of the ethyl acetate parts of 95% ethanolic extract of the whole plant of I. litseaefolia afforded 2-O-β-D-glucopyranose-4,4´-di-vanilloyloxymethyl-2,6´-dihydroxy-1,1´-diphenyl ether (ilexiside), esculetin, vanillic acid, 3,4-dimethoxybenzylacetic acid and vanilloylcalleryanin. Ilexiside was new compound. 4. Nine compounds were isolation from the 95% ethanolic extract of the whole plant of H. japonica: β-sitosterol, β-daucosterol, lupeol, betulin, betulinic acid, glycerol monopalmitate, cinnamic acid, stignast-4-en-6β-3-one and stignast-4-en-6α-3-one 5.Diphenyl ether compounds from nature between 1985-2006 were summarized.

二萜生物碱植物的化学成分研究

本论文由三个部分组成。第一部分是综述性文章-天然C19-二萜生物碱的结构及其核磁共振波谱。这篇综述参考160余篇文献，将迄今为止发表的230余个天然C19-二萜生物碱按其结构和波谱特征，分为10个类型。重点叙述了每个类型的结构和核磁共振波谱，对一些立体构型与13C-NMR化学位移的关系进行了讨论。最后以表格的形式报导了每个天然C19-二萜生物碱的结构及其植物来源，并把其中170余个收集到的13C-NMR化学位移数据整理成表，作为手册，对鉴定此类化合物大有帮助。第二部分是实验论文--弯啄乌头的化学成分研究。重点报导了弯啄乌头(Aconitum campylorrhynchun Hand-Nazz.)中分离到的一个新生物碱--8-乙酰都啦碱(8-acetyldolaconine)的结构鉴定，并根据DEPT、COSY、COLO等对1H-NMR和13C-NMR的所有信号归属都进行了指定。通过各种图谱还发现这个生物碱的A环同时存在着椅式和船式两种构象导购体。另外还报导了从同一植物的生物碱部分分离到的两个二萜生物碱，它们都是嘟啦碱和aconosine.在非生物碱部分还分离到三个化合物，经鉴定证明是β-谷甾醇、棕榈酸和香豆酸。第三部分也是实验论文--展毛翠雀花中生物碱成分的研究。报导了从展毛翠雀花(Delphinium Kamaonense Var.glabrescens W. T. Wang)中初步分离到的两个生物碱。经IR、NS、1H-NMR和13C-NMR等方法确定结构，证明其中一个是新化合物，命名为展毛翠雀碱(glabredelphinine)。另外一个是前几年发现的二萜生物碱tatsiensine。这两个化合物的A环上都有碳-碳不饱和键，这在天然C19-二萜生物碱中还比较少见。This master's thesis consists of three parts. The first part is a review: The relationship between the chemical structures of natural C19-diterpene alkaloids and their NMR chemical shift data. The C19-diterpene alkaloids were divided into ten types according to their structures and NMR data. Some relationaships between configuration and NMR chemical shift have been discussed. The structures and distributions of more than 230 known C19-diterpene alkaloids and the assignments of 13C-NMR data of the 170 alkaloids of them were listed in tables. The second part is an experimental paper, Studies on the chemical constituents of Aconitum campylorrhynchum. Six compounds were isolated from the roots of title plant. One of them is a new alkaloid. It has been elucidaled as 8-acetyldolaconine by means of IR, MS, 1H-NMR,13C-NMR,DEPT,COSY,COLOC and on the basis of identification with aconosine by saponification. Other five compounds were idenfified as dolaconine, aconosine,β-sitosterol, palmitic acid and p-coumaric acid. The third part is also experimental paper: The alkaloids of Delphinium Kamaonense var.glabrescens. Two alkaloids were isolated from the roots of title plant. One of them, C22H22O6N,m.p.201-3℃,named glabredelphinine, was proved to be a new compound. Its structure has been established as 2(3)-dehydro-6-demethyl-18-delcosine by means of IR, MS, 1H-NMR and 13C-NMR.The other one was identified as tatsiensine by comparising of IR, MS, 1H-NMR and 13C-NMR data with that from the literatute.

Exploring the ester-exchange reactions of diester-diterpenoid alkaloids in the aconite decoction process by electrospray ionization tandem mass spectrometry

The chemical components in the decoctions of Chinese herbal medicines are not always the same as those in the crude herbs because of the insolubility or instability of some compounds. In this work electrospray ionization tandem mass spectrometry was used to explore the ester-exchange reactions for aconitine-type diester-diterpenoid alkaloids occurring during the process of decocting aconite root. The aconitines were screened in a diverse range of samples, including crude aconite, decoction of crude aconite, residues from decoction of crude aconite, prepared aconite, decoction of prepared aconite, decoction of prepared aconite with added palmitic acid, and decoction of a mixture of mesaconitine and hypaconitine standards with liquorice root. It was found that diester-diterpenoid aconitines were converted into lipo-alkaloids as well as monoester alkaloids by the decoction of aconite.

Chemical constituents from euphorbia wallichii

Eleven known compounds were isolated from the roots of Euphorbia wallichii for the first time. They were elucidated to be three triterpenoids, β-amyrin (1), β-amyrin acetate (2) and 3β-acetoxy-lupenol (3), one nor-triterpene peroxide baccatin (4), two caffeic esters (5a, 5b), palmitic acid-2,3-dihydroxypropanenyl ester (6), palmitic acid (7), scopoletin (8), β-sitosterol (9) and daucosterol (10) on the basis of spectral methods. Among them, compound 5a, 5b were reported firstly in the spurge family. And the NMR assignments of compounds 5a and 5b were given for the first time.

Characterisation and glucoregulatory actions of a novel acylated form of the (Pro(3))GIP receptor antagonist in type 2 diabetes

In this study, we tested the biological activity of a novel acylated form of (Pro(3))glucose-dependent insulinotropic polypetide [(Pro3)GIP] prepared by conjugating palmitic acid to Lys(16) to enhance its efficacy in vivo by promoting binding to albumin and extending its biological actions. Like the parent molecule (Pro(3))GIP, (Pro(3))GIPLys(16)PAL was completely stable to the actions of DPP-IV and significantly (p <0.01 to p <0.001) inhibited GIP-stimulated cAMP production and cellular insulin secretion. Furthermore, acute administration of (Pro(3))GIPLys(16)PAL also significantly (p <0.05 to p <0.001) countered the glucose-lowering and insulin-releasing actions of GIP in ob/ob mice. Daily injection of (Pro(3))GIPLys(16)PAL (25 nmol/kg bw) in 14-18-week-old ob/ob mice over 14 days had no effect on body weight, food intake or non-fasting plasma glucose and insulin concentrations. (Pro(3))GIPLys(16)PAL treatment also failed to significantly alter the glycaemic response to an i.p. glucose load or test meal, but insulin concentrations were significantly reduced (1.5-fold; p <0.05) after the glucose load. Insulin sensitivity was enhanced (1.3-fold; p <0.05) and pancreatic insulin was significantly reduced (p <0.05) in the (Pro(3))GIPLys(16)PAL-treated mice. These data demonstrate that acylation of Lys(16) with palmitic acid in (Pro(3))GIP does not improve its biological effectiveness as a GIP receptor antagonist.

The inhibitor profiling of the caspase family of proteases using substrate-derived peptide glyoxals.

A series of substrate-based a-keto-ß-aldehyde (glyoxal) sequences have been synthesised and evaluated as inhibitors of the caspase family of cysteine proteases. A number of potent inhibitor sequences have been identified. For example, a palmitic acid containing sequence pal-Tyr-Val-Ala-Asp-glyoxal was demonstrated to be an extremely effective inhibitor of caspase-1, inhibiting not only the action of the protease against synthetic fluorogenic substrates (Ki = 0.3 nM) but also blocking its processing of pro-interleukin-1beta (pro-IL-1ß). In addition, the peptide Ac-Asp-Glu-Val-Asp-glyoxal, which is based on the consensus cleavage sequence for caspase-3, is a potent inhibitor of this protease (Ki = 0.26 nM) yet only functions as a comparatively modest inhibitor of caspase-1 (Ki = 451 nM). Potent inhibitor sequences were also identified for caspases-6 and -8. However, the degree of discrimination between the family members is limited. The ability of Ac-Asp-Glu-Val-Asp-glyoxal to block caspase-3 like activity in whole cells and to delay the development of apoptosis was assessed. When tested against caspase-3 like activity in cell lysates, Ac-Asp-Glu-Val-Asp-glyoxal displayed effective inhibition similar to that observed against recombinant caspase-3. Treatment of whole cells with this potent caspase-3 inhibitor was however, not sufficient to significantly stall the development of apoptosis in-vitro.

Analysis of the organic matter associated to sea salt : definition of potential molecular markers based on the volatile composition and presence of glycosidic derivatives and polysaccharides

Sea salt is a natural product obtained from the evaporation of seawater in saltpans due to the combined effect of wind and sunlight. Nowadays, there is a growing interest for protection and re-valorisation of saltpans intrinsically associated to the quality of sea salt that can be evaluated by its physico-chemical properties. These man-made systems can be located in different geographical areas presenting different environmental surroundings. During the crystallization process, organic compounds coming from these surroundings can be incorporated into sea salt crystals, influencing their final composition. The organic matter associated to sea salt arises from three main sources: algae, surrounding bacterial community, and anthropogenic activity. Based on the hypothesis that sea salt contains associated organic compounds that can be used as markers of the product, including saltpans surrounding environment, the aim of this PhD thesis was to identify these compounds. With this purpose, this work comprised: 1) a deep characterisation of the volatile composition of sea salt by headspace solid phase microextraction combined with comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (HS-SPME/GCGC–ToFMS) methodology, in search of potential sea salt volatile markers; 2) the development of a methodology to isolate the polymeric material potentially present in sea salt, in amounts that allow its characterisation in terms of polysaccharides and protein; and 3) to explore the possible presence of triacylglycerides. The high chromatographic resolution and sensitivity of GC×GC–ToFMS enabled the separation and identification of a higher number of volatile compounds from sea salt, about three folds, compared to unidimentional chromatography (GC–qMS). The chromatographic contour plots obtained revealed the complexity of marine salt volatile composition and confirmed the relevance of GC×GC–ToFMS for this type of analysis. The structured bidimentional chromatographic profile arising from 1D volatility and 2D polarity was demonstrated, allowing more reliable identifications. Results obtained for analysis of salt from two locations in Aveiro and harvested over three years suggest the loss of volatile compounds along the time of storage of the salt. From Atlantic Ocean salts of seven different geographical origins, all produced in 2007, it was possible to identify a sub-set of ten compounds present in all salts, namely 6-methyl-5-hepten-2-one, 2,2,6-trimethylcyclohexanone, isophorone, ketoisophorone, β-ionone-5,6-epoxide, dihydroactinidiolide, 6,10,14-trimethyl-2-pentadecanone, 3-hydroxy-2,4,4-trimethylpentyl 2-methylpropanoate, 2,4,4-trimethylpentane-1,3-diyl bis(2-methylpropanoate), and 2-ethyl-1-hexanol. These ten compounds were considered potential volatile markers of sea salt. Seven of these compounds are carotenoid-derived compounds, and the other three may result from the integration of compounds from anthropogenic activity as metabolites of marine organisms. The present PhD work also allowed the isolation and characterisation, for the first time, of polymeric material from sea salt, using 16 Atlantic Ocean salts. A dialysis-based methodology was developed to isolate the polymeric material from sea salt in amounts that allowed its characterisation. The median content of polymeric material isolated from the 16 salts was 144 mg per kg of salt, e.g. 0.014% (w/w). Mid-infrared spectroscopy and thermogravimetry revealed the main occurrence of sulfated polysaccharides, as well as the presence of protein in the polymeric material from sea salt. Sea salt polysaccharides were found to be rich in uronic acid residues (21 mol%), glucose (18), galactose (16), and fucose (13). Sulfate content represented a median of 45 mol%, being the median content of sulfated polysaccharides 461 mg/g of polymeric material, which accounted for 66 mg/kg of dry salt. Glycosidic linkage composition indicates that the main sugar residues that could carry one or more sulfate groups were identified as fucose and galactose. This fact allowed to infer that the polysaccharides from sea salt arise mainly from algae, due to their abundance and composition. The amino acid profile of the polymeric material from the 16 Atlantic Ocean salts showed as main residues, as medians, alanine (25 mol%), leucine (14), and valine (14), which are hydrophobic, being the median protein content 35 mg/g, i.e. 4,9 mg per kg of dry salt. Beside the occurrence of hydrophobic volatile compounds in sea salt, hydrophobic non-volatile compounds were also detected. Triacylglycerides were obtained from sea salt by soxhlet extraction with n-hexane. Fatty acid composition revealed palmitic acid as the major residue (43 mol%), followed by stearic (13), linolenic (13), oleic (12), and linoleic (9). Sea salt triacylglycerides median content was 1.5 mg per kg of dry salt. Both protein and triacylglycerides seem to arise from macro and microalgae, phytoplankton and cyanobacteria, due to their abundance and composition. Despite the variability resulting from saltpans surrounding environment, this PhD thesis allowed the identification of a sea salt characteristic organic compounds profile based on volatile compounds, polysaccharides, protein, and triacylglycerides.

Chromatographic analysis and comparison of chemical composition of the samples between olive oils in Europe and some chinese oils

Dissertação de mest., Qualidade em Análises, Faculdade de Ciências e Tecnologia, Univ. do Algarve, 2013