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1.
Molecules ; 28(2)2023 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-36677891

RESUMO

Interest in cultivating cannabis for medical and recreational purposes is increasing due to a dramatic shift in cannabis legislation worldwide. Therefore, a comprehensive understanding of the composition of secondary metabolites, cannabinoids, and terpenes grown in different environmental conditions is of primary importance for the medical and recreational use of cannabis. We compared the terpene and cannabinoid profiles using gas/liquid chromatography and mass spectrometry for commercial cannabis from genetically identical plants grown indoors using artificial light and artificially grown media or outdoors grown in living soil and natural sunlight. By analyzing the cannabinoids, we found significant variations in the metabolomic profile of cannabis for the different environments. Overall, for both cultivars, there were significantly greater oxidized and degraded cannabinoids in the indoor-grown samples. Moreover, the outdoor-grown samples had significantly more unusual cannabinoids, such as C4- and C6-THCA. There were also significant differences in the terpene profiles between indoor- and outdoor-grown cannabis. The outdoor samples had a greater preponderance of sesquiterpenes including ß-caryophyllene, α-humulene, α-bergamotene, α-guaiene, and germacrene B relative to the indoor samples.


Assuntos
Canabinoides , Cannabis , Alucinógenos , Canabinoides/análise , Cannabis/química , Terpenos/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Alucinógenos/análise , Agonistas de Receptores de Canabinoides/metabolismo
2.
J Am Chem Soc ; 138(39): 12861-12867, 2016 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-27666433

RESUMO

Here, we compare analogous cyclic and acyclic π-conjugated molecules as n-type electronic materials and find that the cyclic molecules have numerous benefits in organic photovoltaics. This is the first report of such a direct comparison. We designed two conjugated cycles for this study. Each comprises four subunits: one combines four electron-accepting, redox-active, diphenyl-perylenediimide subunits, and the other alternates two electron-donating bithiophene units with two diphenyl-perylenediimide units. We compare the macrocycles to acyclic versions of these molecules and find that, relative to the acyclic analogs, the conjugated macrocycles have bathochromically shifted UV-vis absorbances and are more easily reduced. In blended films, macrocycle-based devices show higher electron mobility and good morphology. All of these factors contribute to the more than doubling of the power conversion efficiency observed in organic photovoltaic devices with these macrocycles as the n-type, electron transporting material. This study highlights the importance of geometric design in creating new molecular semiconductors. The ease with which we can design and tune the electronic properties of these cyclic structures charts a clear path to creating a new family of cyclic, conjugated molecules as electron transporting materials in optoelectronic and electronic devices.

3.
Biomacromolecules ; 15(11): 4214-27, 2014 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-25316187

RESUMO

Diacetylated lactonic sophorolipids (polyLSL[6'Ac,6″Ac]), a biosurfactant, can be efficiently polymerized by ring-opening metathesis polymerization (ROMP). In this paper, enzyme-mediated chemical transformations are developed to regioselectively modify LSL[6'Ac,6″Ac] at sophorose primary hydroxyl positions (6' and 6″). The resulting modified LSLs were polymerized to expand polyLSL structural diversity, that is, polyLSL[6'OH,6″Ac], polyLSL[6'OH,6″OH], polyLSL[6'Bu,6″Ac], polyLSL[6'N3,6″Ac], and polyLSL[6'MA,6″Ac]. Controlled placement of azide and methacrylate at sophorolipid moieties enables the use of "click" reactions to introduce bioactive groups. Thermal analyses of polyLSLs showed that the acylation pattern at sugar moieties has a remarkable effect on chain stiffness and crystallinity. Films of polyLSL[6'Ac,6″Ac], polyLSL[6'OH,6″Ac], and polyLSL[6'Bu,6″Ac] exhibited nonbrittle behaviors with compressive elastic moduli ranging from ∼1.5 to ∼4.9 MPa. PolyLSLs were cytocompatible with human mesenchymal stem cells (h-MSCs), and examination of material-induced osteogenic cell lineage progression uncovered a dependence on polyLSL substitution at sophorose 6'-sites. This research reveals opportunities to regulate polyLSL physical properties and cell response behaviors by variation in substituents at polyLSL sophorolipid moieties.


Assuntos
Materiais Biocompatíveis/química , Produtos Biológicos/química , Glicolipídeos/química , Células-Tronco Mesenquimais/fisiologia , Polímeros/química , Materiais Biocompatíveis/farmacologia , Produtos Biológicos/farmacologia , Candida , Adesão Celular/efeitos dos fármacos , Adesão Celular/fisiologia , Células Cultivadas , Glicolipídeos/farmacologia , Humanos , Células-Tronco Mesenquimais/efeitos dos fármacos , Polímeros/farmacologia
4.
Angew Chem Int Ed Engl ; 52(17): 4591-4, 2013 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-23568783

RESUMO

Alcohol is the answer! An inactive, air-stable, dimeric molybdenum alkylidyne complex is activated toward ring-opening alkyne metathesis polymerization (ROAMP) by the addition of methanol. The ROAMP is compatible with water and phenol-containing substrates and with the in situ photochemical generation of alkyne monomers from cyclopropenones.

5.
Chem Commun (Camb) ; 49(4): 385-7, 2013 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-23190865

RESUMO

A unique route to perfectly alternating oligopeptides is described. First, AG-OEt was prepared by standard chemical coupling. Then, AG-OEt was converted by papain-catalysis in 30 s to (AG)(x) (80%-yield, x = 9.4 ± 0.3). Extension of this strategy to other alternating peptide compositions as well as the importance of selecting a protease and reaction conditions that avoid competing transamidation and hydrolysis reactions is discussed.


Assuntos
Dipeptídeos/síntese química , Oligopeptídeos/síntese química , Biossíntese Peptídica , Catálise , Papaína/química
6.
Phys Chem Chem Phys ; 13(40): 18115-22, 2011 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-21915411

RESUMO

Nanoparticle organic hybrid materials (NOHMs) have been recently developed that comprise an oligomeric or polymeric canopy tethered to surface-modified nanoparticles via ionic or covalent bonds. It has already been shown that the tunable nature of the grafted polymeric canopy allows for enhanced CO(2) capture capacity and selectivity via the enthalpic intermolecular interactions between CO(2) and the task-specific functional groups, such as amines. Interestingly, for the same amount of CO(2) loading NOHMs have also exhibited significantly different swelling behavior compared to that of the corresponding polymers, indicating a potential structural effect during CO(2) capture. If the frustrated canopy species favor spontaneous ordering due to steric and/or entropic effects, the inorganic cores of NOHMs could be organized into unusual structural arrangements. Likewise, the introduction of small gaseous molecules such as CO(2) could reduce the free energy of the frustrated canopy. This entropic effect, the result of unique structural nature, could allow NOHMs to capture CO(2) more effectively. In order to isolate the entropic effect, NOHMs were synthesized without the task-specific functional groups. The relationship between their structural conformation and the underlying mechanisms for the CO(2) absorption behavior were investigated by employing NMR and ATR FT-IR spectroscopies. The results provide fundamental information needed for evaluating and developing novel liquid-like CO(2) capture materials and give useful insights for designing and synthesizing NOHMs for more effective CO(2) capture.

7.
Forensic Sci Int ; 212(1-3): e40-5, 2011 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-21775083

RESUMO

In forensic evidence, the identification and quantitation of gamma-hydroxybutyric acid (GHB) in "spiked" beverages is challenging. In this report, we present the analysis of common alcoholic beverages found in clubs and bars spiked with gamma-hydroxybutyric acid (GHB) and gamma-butyrolactone (GBL). Our analysis of the spiked beverages consisted of using (1)H NMR with a water suppression method called Presaturation Utilizing Relaxation Gradients and Echoes (PURGE). The following beverages were analyzed: water, 10% ethanol in water, vodka-cranberry juice, rum and coke, gin and tonic, whisky and diet coke, white wine, red wine, and beer. The PURGE method allowed for the direct identification and quantitation of both compounds in all beverages except red and white wine where small interferences prevented accurate quantitation. The NMR method presented in this paper utilizes PURGE water suppression. Thanks to the use of a capillary internal standard, the method is fast, non-destructive, sensitive and requires no sample preparation which could disrupt the equilibrium between GHB and GBL.


Assuntos
4-Butirolactona/análise , Bebidas/análise , Toxicologia Forense/métodos , Hidroxibutiratos/análise , Espectroscopia de Ressonância Magnética , 4-Butirolactona/química , Bebidas Alcoólicas/análise , Humanos , Hidroxibutiratos/química , Imageamento por Ressonância Magnética/métodos , Estudos de Amostragem , Sensibilidade e Especificidade , Solventes/análise , Solventes/química
8.
Forensic Sci Int ; 194(1-3): 103-7, 2010 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-19926414

RESUMO

Identification of 3,4-methylenedioxy-N-methylamphetamine (MDMA, ecstasy) in five cases of intoxication using nuclear magnetic resonance (NMR) spectroscopy of human urine is reported. A new water suppression technique PURGE (Presaturation Utilizing Relaxation Gradients and Echoes) was used. A calibration curve was obtained using spiked samples. The method gave a linear response (correlation coefficient of 0.992) over the range 0.01-1mg/mL. Subsequently, quantitation of the amount of MDMA present in the samples was performed. The benefit and reliability of NMR investigations of human urine for cases of intoxication with MDMA are discussed.


Assuntos
Alucinógenos/urina , Espectroscopia de Ressonância Magnética , N-Metil-3,4-Metilenodioxianfetamina/urina , Toxicologia Forense , Humanos , Prótons , Detecção do Abuso de Substâncias/métodos
9.
Org Lett ; 11(7): 1527-30, 2009 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-19254041

RESUMO

In the Rh(2)(OAc)(4)-catalyzed amidoglycosylation of glucal 3-carbamates, anomeric stereoselectivity and the extent of competing C3-H oxidation depend on the 4O and 6O protecting groups. Acyclic protection permits high alpha-anomer selectivity with further improvement in less polar solvents, while electron-withdrawing protecting groups limit C3-oxidized byproducts. Stereocontrol and bifurcation between alkene insertion and C3-H oxidation reflect an interplay of conformational, stereoelectronic, and inductive factors.


Assuntos
Gluconato de Cálcio/química , Carbamatos/química , Hexosaminas/síntese química , Manose/síntese química , Oxazolidinonas/síntese química , Catálise , Técnicas de Química Combinatória , Glicosilação , Hexosaminas/química , Manose/análogos & derivados , Estrutura Molecular , Oxazolidinonas/química , Estereoisomerismo
10.
Chirality ; 20(9): 1053-65, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18655174

RESUMO

The copper/chiral phosphoramidite (L(1))-catalyzed conjugate addition of dimethylzinc to cycloocta-2,7-dienone 4, followed by the methylation of the intermediate enolate, yielded a single isomer of 7,8-dimethylcyclooct-2-enone (+)-5. Compound (+)-5 was subjected to the second conjugate addition with ent-L(1) giving only one stereoisomer of 2,3,7-trimethylcyclooctanone (+)-6, which was converted to 2,3,7-trimethylcyclooctanol 7. To determine the relative and absolute configurations of these compounds, the (1)H NMR anisotropy method using (S)-(+)-2-methoxy-2-(1-naphthyl)propionic acid {(S)-(+)-MalphaNP acid} 1 was applied. Racemic alcohol (+/-)-7 was esterified with (S)-(+)-MalphaNP acid 1 yielding diastereomeric esters, which were efficiently separated by HPLC on silica gel affording the first-eluted MalphaNP ester (-)-10a and the second-eluted one (-)-10b. The relative and absolute configurations of ester (-)-10a were determined to be (S;1R,2S,3R,7S) by analyzing the (1)H and (13)C NMR spectra of (-)-10a and (-)-10b, especially their HSQC-TOCSY and NOESY spectra, and by applying the MalphaNP anisotropy method. The alcohol 7 formed from (+)-6 was similarly esterified with (S)-(+)-MalphaNP acid 1 yielding an MalphaNP ester, which was identical with (-)-10a, and the relative and absolute configurations of 2,3,7-trimethylcyclooctanone (+)-6 were determined to be (2S,3R,7S).

13.
J Am Chem Soc ; 128(46): 14752-3, 2006 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-17105254

RESUMO

The 1H nuclear spin-lattice relaxation time (T1) of H2 and H2@C60 in organic solvents varies with solvent, and it varies proportionally for H2 and for H2@C60. Since intermolecular magnetic interactions are ruled out, the solvent must influence the modulating processes of the relaxation mechanisms of H2 both in the solvent cage and inside C60. The temperature dependence of T1 also is very similar for H2 and H2@C60, T1 going through a maximum by varying the temperature in solvents which allow a wide range of temperatures to be explored. This behavior is attributed to the presence of dipolar and spin-rotation mechanisms which have an opposite dependence on temperature.

14.
J Nat Prod ; 69(3): 429-31, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16562852

RESUMO

Ginkgolide M (GM), which is found only in the roots of the Ginkgo biloba tree and is an inhibitor of ligand-operated ion channels in the central nervous system, has been prepared in three steps from 10-benzylginkgolide C, an intermediate generated during the isolation and separation of ginkgolides from Ginkgo biloba leaf extract. The described synthetic sequence can be applied to access GM derivatives for biological studies.


Assuntos
Diterpenos/síntese química , Ginkgo biloba/química , Lactonas/síntese química , Plantas Medicinais/química , Ginkgolídeos , Estrutura Molecular , Raízes de Plantas/química
15.
J Am Chem Soc ; 125(16): 4870-3, 2003 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-12696906

RESUMO

This study delineates general methods to create a new class of folded oligomers by covalently attaching overcrowded aromatics to each other. Crucial to observing the secondary structure in these oligomers was the employment of C-shaped linkers. These linkers preorganize the strands to form intramolecular hydrogen bonds. In solution, one- and two-dimensional (1)H NMR data show well-defined columnar conformations. The side chains in these oligomers are critical for the secondary structure to emerge in solution. Using tris(dodecyloxy)phenethyl side chains in combination with tert-butyl side chains in the terminal subunit provides a soluble trimer and prevents intermolecular association above millimolar concentrations. This new folding motif, formed through a synergy between hydrogen bonds and pi-stacking, is so robust that even dimers have secondary structure in solution.

16.
J Am Chem Soc ; 124(25): 7294-302, 2002 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-12071738

RESUMO

To gain information on the conformation of the 11-cis-retinylidene chromophore bound to bovine opsin, the enantiomeric pair (2a and 2b) of 11-cis-locked bicyclo[5.1.0]octyl retinal (retCPr) 2 was prepared and its conformation was investigated by NMR, geometry optimization, and CD calculations. This compound is also of interest since it contains a unique moiety in which a chiral cyclopropyl group is flanked by triene and enal chromophores, and hence would clarify the little-known chiroptical contribution of a cyclopropyl ring linked to polyene systems. NMR revealed that the seven-membered ring of retCPr adopts a twist chair conformation. The NMR-derived structure constraints were then used for optimizing the geometry of 2 with molecular mechanics and ab initio methods. This revealed that enantiomer 2a with a 11 beta,12 beta-cyclopropyl group exists as two populations of diastereomers depending on the twist around the 6-s bond; however, the sense of twist around the 12-s is positive in both rotamers. The theoretical Boltzmann-weighted CD obtained with the pi-SCF-CI-DV MO method and experimental spectra were consistent, thus suggesting that the conjugative effect of the cyclopropyl moiety is minimal. It was found that only the beta-cyclopropyl enantiomer 2a, but not the alpha-enantiomer 2b, binds to opsin. This observation, together with earlier retinal analogues incorporation results, led to the conclusion that the chromophore sinks into the N-terminal of the opsin receptor from the side of the 4-methylene and 15-aldehyde, and that the binding cleft accommodates 11-cis-retinal with a slightly positive twist around C12/C13. A reinterpretation of the previously published negative CD couplet of 11,12-dihydrorhodopsin also leads to a chromophoric C12/C13 twist conformation with the 13-Me in front as in 1b. Such a conformation for the chromophore accounts for both the observed biostereoselectivity of retCPr 2a and the observed negative couplet of 11,12-dihydro-Rh7.


Assuntos
Ciclopropanos/química , Retinaldeído/análogos & derivados , Animais , Compostos Bicíclicos com Pontes/química , Bovinos , Dicroísmo Circular , Modelos Moleculares , Conformação Molecular , Ressonância Magnética Nuclear Biomolecular , Retinaldeído/química , Rodopsina/química , Soluções , Estereoisomerismo
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