Mortality of Bemisia tabaci biotype B (sternorrhyncha: aleyrodidae) adults by aliphatic and aromatic synthetic sucrose esters

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Synthesis of potentially bioactive PABA-related N-(aminoalkyl)lactamic amino acids and esters via selective SNAr reactions

Potentially bioactive N-(aminoalkyl)lactamic amino acids and esters were synthesized in satisfactory to good yields by SNAr reactions of aromatic acids with N-(3-aminopropyl)lactams followed by esterification with tertiary amino alcohols. The addition-elimination SNAr mechanism was confirmed by NMR and MS measurements.

Inhibitory Effect of Gallic Acid and Its Esters on 2,2 '-Azobis(2-amidinopropane)hydrochloride (AAPH)-Induced Hemolysis and Depletion of Intracellular Glutathione in Erythrocytes

The protective effect of gallic acid and its esters, methyl, propyl, and lauryl gallate, against 2,2'-azobis(2-amidinopropane)hydrochloride (AAPH)-induced hemolysis and depletion of intracellular glutathione (GSH) in erythrocytes was studied. The inhibition of hemolysis was dose-dependent, and the esters were significantly more effective than gallic acid. Gallic acid and its esters were compared with regard to their reactivity to free radicals, using the DPPH and AAPH/pyranine free-cell assays, and no significant difference was obtained. Gallic acid and its esters not only failed to inhibit the depletion of intracellular GSH in erythrocytes induced by AAPH but exacerbated it. Similarly, the oxidation of GSH by AAPH or horseradish peroxidase/H(2)O(2) in cell-free systems was exacerbated by gallic acid or gallates. This property could be involved in the recent findings on proapoptotic and pro-oxidant activities of gallates in tumor cells. We provide evidence that lipophilicity and not only radical scavenger potency is an important factor regarding the efficiency of antihemolytic substances.

Protocatechuic Acid Alkyl Esters: Hydrophobicity As a Determinant Factor for Inhibition of NADPH Oxidase

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of two estradiol esters (benzoate and cypionate) on the induction of synchronized ovulations in Bos indicus cows submitted to a timed artificial insemination protocol

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ultrastructural changes in the ovary cells of engorged Rhipicephalus sanguineus female ticks treated with esters of ricinoleic acid from castor oil (Ricinus communis)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of Ricinus communis oil esters on salivary glands of Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effects of ricinoleic acid esters from castor oil of Ricinus communis on the vitellogenesis of Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae) ticks

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Chemoenzymatic Synthesis of alpha-Hydroxy-beta-methyl-gamma-hydroxy Esters: Role of the Keto-Enol Equilibrium To Control the Stereoselective Hydrogenation in a Key Step

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Further monoterpene chromane esters from Peperomia obtusifolia: VCD determination of the absolute configuration of a new diastereomeric mixture

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Structure Elucidation and Absolute Stereochemistry of Isomeric Monoterpene Chromane Esters

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Asymmetric microbial reduction of ketones: absolute configuration of trans-4-ethyl-1-(1S-hydroxyethyl)cyclohexanol

A set of five fungal species, Botrytis cinerea, Trichoderma viride and Eutypa lata, and the endophytic fungi Colletotrichum crassipes and Xylaria sp., was used in screening for microbial biocatalysts to detect monooxygenase and alcohol dehydrogenase activities (for the stereoselective reduction of carbonyl compounds). 4-Ethylcyclohexanone and acetophenone were biotransformed by the fungal set. The main reaction pathways involved reduction and hydroxylations at several positions including tertiary carbons. B. cinerea was very effective in the bioreduction of both substrates leading to the chiral alcohol (S)-1-phenylethanol in up to 90% enantiomeric excess, and the cis-trans ratio for 4-ethylcyclohexanol was 0:100. trans-4-Ethyl-1-(1S-hydroxyethyl)cyclohexanol, obtained from biotransformation by means of an acyloin-type reaction, is reported here for the first time. The absolute configurations of the compounds trans-4-ethyl-1-(1S-hydroxyethyl)cyclohexanol and 4-(1S- and 4-(1R-hydroxyethyl)cyclohexanone were determined by NMR analysis of the corresponding Mosher's esters. (C) 2009 Elsevier Ltd. All rights reserved.

Suppression of TNF- induced NFB activity by gallic acid and its semi-synthetic esters: possible role in cancer chemoprevention

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Diterpene esters of aristolochic acids from Aristolochia pubescens

From the acetone and ethanol extracts of the tubercula of Aristolochia pubescens, two diterpene esters of aristolochic acids were isolated, together with 23 known compounds. The structures of the compounds were determined on the basis of spectroscopic analysis. (C) 2003 Elsevier Ltd. All rights reserved.

Electron impact and chemical ionization mass spectral analyses of methyl esters species of free mycolic acid fraction from Rhodococcus lentifragmentus

The free mycolic acid fraction from Rhodococcus lentifragmentus was derivatized to methyl esters and further fractionated into saturated (F-0), monounsaturated (F-1) and diunsaturated (F-2) species using argentation-TLC. Methyl esters fractions F-0, F-1 and F-2, accounting for approximately 7.4%, 53.1% and 39.5%, respectively, were analyzed by electron impact (EI) and chemical ionization (CI) mass spectrometries. According to EI-MS, peaks observed for M(+)-18, that were prominent compared to those representing M(+)-32 and M(+)-(18 + 32), indicated that the carbon chain size ranged from C-36 to C-48. The pyrolytic cleavage of methyl mycolates (R(2)-CHOH-CH(R(1))-COOCH3), following the McLafferty rearrangement released fragment ions corresponding to, (a) the alpha-subunit, representing the fatty acid methyl ester (R(1)-CH2-COOCH3), methyl hexadecanoate, methyl tetradecanoate and methyl dodecanoate in decreasing order of relative intensity of peaks, and (b) the beta-subunit, representing the meroaldehyde moiety (R(2)-CHO). The saturated meroaldehyde species exhibited peaks representing meroaldehyde minus 18 mass units in which R(2) ranged from C19H39 to C31H63. The monunsaturated species exhibited peaks representing the meroaldehyde in which R(2) ranged from C19H37 to C31H61; peaks corresponding to meroaldehyde minus 18 mass units appeared only in the most abundant components, C29H57CHO, C27H53CHO, C25H49CHO and C31H61CHO, in a decreasing order of relative abundance. The diunsaturated species exhibited peaks essentially corresponding to meroaldehyde in which R(2) corresponded to C31H59 and C29H55; the latter displayed a relative intensity that was about one-half compared to that of the former. Fractions F-0, F-1 and F-2 showed a more intense pyrolytic fragmentation under CI-MS in contrast to results found under EI-MS. Therefore, peaks representing the alpha-subunit and the beta-subunit were more prominent than the ones representing the fragmentation of the hydrocarbon chain. Moreover, the beta-subunit of saturated species exhibited peaks corresponding to meroaldehyde plus hydrogen, and no dehydration of the beta-subunit occurred in this case. In turn, the beta-subunit of monounsaturated and diunsaturated species showed peaks representing both the meroaldehyde plus hydrogen and its dehydration product plus hydrogen. Thus, the presence of unsaturation in the meroaldehyde subunit of methyl mycolate facilitates appearance of dehydration fragment ions under chemical ionization procedure.