958 resultados para opioid peptided esters
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BACKGROUND: Obesity and substance use are major concern in young people. This study explored the bidirectional longitudinal relationships between the body mass index (BMI) of young men and their use of: 1) four classes of non-medical prescription drugs; 2) alcohol; 3) tobacco; and 4) cannabis. METHODS: Baseline and follow-up data from the Cohort Study on Substance Use Risk Factors were used (n=5,007). A cross-lagged panel model, complemented by probit models as sensitivity analysis, was run to determine the bidirectional relationships between BMI and substance use. Alcohol was assessed using risky single-occasion drinking (RSOD); tobacco, using daily smoking; and cannabis, using hazardous cannabis use (defined as twice-weekly or more cannabis use). Non-medical prescription drugs use (NMPDU) included opioid analgesics, sedatives/sleeping pills, anxiolytics and stimulants. RESULTS: Different associations were found between BMI and substance use. Only RSOD (β= -.053, p=.005) and NMPDU of anxiolytics (β=.040, p=.020) at baseline significantly predicted BMI at follow-up. Baseline RSOD predicted a lower BMI at follow-up while baseline NMPDU of anxiolytics predicted higher BMI at follow-up. Furthermore, BMI at baseline significantly predicted daily smoking (β=.050, p=.007) and hazardous cannabis use (β=.058, p=.030). CONCLUSIONS: Our results suggest different associations between BMI and the use of various substances by young men. However, only RSOD and NMPDU of anxiolytics predicted BMI, whereas BMI predicted daily smoking and hazardous cannabis use.
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This paper describes variations in the profile of the main volatile organic compounds present in Brazilian sugar cane spirits distilled in copper and stainless steel distillers. The main organic compounds: aldehydes, ketones, carboxylic acids, alcohols and esters, were determined through High Performance Liquid Chromatography (HPLC) and High Resolution Gas Cromatography (HRGC). The spirits produced in copper distillers exhibit higher contents of aldehydes with respect to the ones produced in stainless steel. The inverse is true with respect to the higher alcohol and ester contents. No significant variation has been observed for the carboxylic acids.
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Six Brazilian commercial mangoes were analysed by HRGC-O-AEDA-MS, viz., Carlota, Haden, Espada, Coração de boi, Rubi and Tommy Atkins. All them showed ethyl butanoate as the main aroma character impact compound by AEDA evaluation. The ethyl esters of 2 and 3-methylbutanoic acids are also important, the main contribution in Carlota variety being 2(S) enantiomer. In Rubi variety, both 2(R) enantiomer and 3-methyl isomer contributes to the caprylic fruity note observed. In four varieties, viz., Haden, Espada, Rubi and Tommy Atkins, d-3-carene showed to be the second impact aroma compound presented. In Tommy Atkins variety, a-pinene also has a significant contribution, mainly due to its (1R,5R)(+)-enantiomer.
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The hexane extract of leaves of B. microphylla afforded a mixture of triterpenes esterified with fatty acids. Analyses of spectral data of the mixture and of the derivatives obtained by a transesterification reaction with NaOMe/MeOH permitted to identify the composition of the mixtures as being 24-hydroxy-urs-12-enyl 3b-eicosanate, estearate and palmitate as well as of the 24-hydroxy-olean-12-enyl 3b-eicosanate, estearate and palmitate. From the choroform and ethyl acetate extracts were isolated the oleanolic and 3b,24-dihydroxy-urs-12-en-28-oic acids, quercetin and methyl galic ester, respectively. The compounds were identified through analysis of their spectral data.
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The phase diagram formation of microemulsion-based gels composed of an anionic surfactant aerosol-OT sodium bis (2-ethylhexyl)-sulphosuccinate), water, gelatin and an organic solvent is presented for heptane. The stability of this organo- gel, when an enzyme is immobilized is discussed in terms of its reutilization in various esters synthesis.
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The hexane and methanolic extracts from pheromonal glands of Castnia licus (Drury) virgin females have been studied. Analyses by gas chromatography and mass spectrometry allowed us to determine the major constituents present in the hexane extract as n-alkanes C21 to C30, (Z)-9-hexadecenoic acid (C16), and (Z)-9-octadecenoic acid (C18) and hexadecanoic acid (C16). Aldehyds, alkenes and acetates were also detected in low concentrations in the extracts. Female pheromone glands were analysed for pheromone precursors using the methanolic extract. In addition to the compounds methyl hexadecanoate and methyl (Z)-9-octadecenoate, the glandular tissue contains a homologous series of methyl esters from C12 to C24. The hexane extract of the female abdomenal glands elicited activity from males in a behavioural bioassay.
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Phytochemical investigation of the fruits of Rheedia gardneriana led to the isolation of sesquiterpenes mixture, methyl esters of fatty acids (palmitate, estearate, oleate, linoleate, linolenate), sugars (galactose, glucose, fructose), triterpene (oleanolic acid), steroids mixture (stigmasterol and sitosterol) and the new tetraprenylated benzophenone 7-epiclusianone.
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gamma-Hydroxy-alpha-diazo-beta-ketoesters are key intermediates in the chemistry of penicilin-based antibiotics and natural products. The method developed here for the synthesis of ethyl 2-diazo-4-hydroxy-3-oxo-butanoate 17 (in two steps from the diazo mercurial 2) compares very favorably with those reported in the literature for similar compounds. The Rh2(OAc)4-mediated intramolecular OH-insertion reaction of the diazo hydroxy ester 17 was investigated, furnishing the oxetan-3-one-2-carboxilate 18 in good yield. When the diazo ester lacks a free hydroxyl group as in the case of the phenoxy diazo ester 11 an intramolecular CH-insertion takes place, affording the 2H-chromene 20 in almost quantitative yield. The behavior of other functionalized diazo esters towards Rh2(OAc)4 was also investigated.
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BACKGROUND AND PURPOSE Kyotorphin (KTP; L-Tyr-L-Arg), an endogenous neuropeptide, is potently analgesic when delivered directly to the central nervous system. Its weak analgesic effects after systemic administration have been explained by inability to cross the blood-brain barrier (BBB) and detract from the possible clinical use of KTP as an analgesic. In this study, we aimed to increase the lipophilicity of KTP by amidation and to evaluate the analgesic efficacy of a new KTP derivative (KTP-amide - KTP-NH 2). EXPERIMENTAL APPROACH We synthesized KTP-NH 2. This peptide was given systemically to assess its ability to cross the BBB. A wide range of pain models, including acute, sustained and chronic inflammatory and neuropathic pain, were used to characterize analgesic efficacies of KTP-NH 2. Binding to opioid receptors and toxicity were also measured. KEY RESULTS KTP-NH 2, unlike its precursor KTP, was lipophilic and highly analgesic following systemic administration in several acute and chronic pain models, without inducing toxic effects or affecting motor responses and blood pressure. Binding to opioid receptors was minimal. KTP-NH 2 inhibited nociceptive responses of spinal neurons. Its analgesic effects were prevented by intrathecal or i.p. administration of naloxone. CONCLUSIONS AND IMPLICATIONS Amidation allowed KTP to show good analgesic ability after systemic delivery in acute and chronic pain models. The indirect opioid-mediated actions of KTP-NH 2 may explain why this compound retained its analgesic effects although the usual side effects of opioids were absent, which is a desired feature in next-generation pain medications
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This review is about the aliphatic, alicyclic and aromatic compounds (non-heterocyclic compounds) that are present in the volatile fractions of roasted coffees. Herein, the contents, aroma precursors and the sensorial properties of volatile phenols, aldehydes, ketones, alcohols, ethers, hydrocarbons, carboxylic acids, anhydrides, esters, lactones, amines and sulphur compounds are discussed. Special attention is given to the compounds of these groups that are actually important to the final aroma of roasted coffees.
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Analysis of alcohols, esters and carbonyl compounds were performed using HRGC and HPLC techniques in samples of fusel oils from three different Brazilian alcohol distilleries. High content of isoamyl alcohol (390 g.L-1), isobutyl alcohol (158 g.L-1), ethyl alcohol (28,4 g.L-1), methyl alcohol (16,6 g.L-1) and n-propyl alcohol (11,9 g.L-1) were found. These compounds represent 77 ± 8 % of the approximated weight of a liter of fusel oils. The obtained results show the feasibility of using fusel oils as low-cost raw material for the synthesis of chemicals.
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The main purpose of this work was the qualitative study of organic compounds in landfill leachate. The samples were collected from a sanitary landfill located at Gravataí, a southern Brazilian city, that receive both, industrial and domestic refuse. The samples were submitted to solid phase extraction (SPE) with XAD-4 resin as the stationary phase. The instrumental analysis was performed by Gas Chromatography with a Mass Spectrometry Detector (GC/MSD). The compounds achieved in the SPE extracts were tentatively identified by the GC/MS library. It was found several oxygen and nitrogen compounds like carboxylic acids, ketones, amines and amides. Sulfur compounds and phthalate esters are also identified.
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A monoterpene, 3beta,6beta-dihydroxy-p-menth-1-ene has been isolated from the seeds of Xylopia sericea along with four kaurane, one beyerene, one atisene and four trachylobane diterpenoids, including the trachyloban-18- and 19-methyl esters. The X-ray crystal structure of methyl ent-trachyloban-18-oate was determined in order to make an unambiguous distinction between the 18- and 19-esters. The 13C NMR data for ent-15alpha-hydroxy-trachyloban-19-oic acid has been revised.
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The fractionation column with SiO2 of the hexane extract of Sebastiania argutidens (Euphorbiaceae) yielded fractions containing hydrocarbons, carboxylic acids, sterols and pentacyclic triterpenes. Besides, one fraction showed the presence of several methyl esters, including four uncommon long chain palmitate esthers as minor components. The characterization of these chemical constituents have been done by High Resolution Gas Chromatography (HRGC) and HRGC coupled to Mass Spectrometry (GC/MS). Campesterol, stigmasterol, b-sitosterol, glutin-5-en-3-ol were identified by HRGC co-injection with standards.
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Despite the fact that boranes are frequently used in amide reductions, the reaction mechanisms of the involved are note well known. This work presents the results of a bibliographic search on probable amide reduction mechanisms and an analysis of the existing literature. Steric and electronic effects were considered in light of reactivity since it could be concluded that the formation of intermediates and products depends mainly on the substitution patterns of both the boron and nitrogen atoms. Otherwise, results described in the literature for the reactions of boranes, sodium borohydride, lithium aluminum hydride, alkylboranes or haloboranes with others functional groups such as carboxylic acids, esters, ketones and alkenes were analysed with the aim to obtain something about the N-substituted amide reactions employing boranes.