A series of linear and macrocyclic peptides 3-12 were synthesized using 3,5-pyridinedicarboxylic acid (1) as starting material and screened for their antimicrobial, anti-inflammatory and anticancer activities. Bis-ester 3 was prepared from 1 and L-leucine methyl ester. Hydrazinolysis and hydrolysis of dipeptide methyl ester 3 with hydrazine hydrate or 1 N sodium hydroxide afforded compounds 4 a...

Herein, we report the crystal structure of 2,7-dichlorofluorescein methyl ester (DCF-ME) and its fluorescence response to hydroxyapatite binding. The reported fluorophore is very selective for staining bone matrix and...

A method to determine the absolute configuration of 2,3-epoxy-2-methylbutanoate ester residues in natural products is presented, based on (i) the reduction of the ester function to yield a 2-methyl-1,2-butanediol, (ii) esterification of the obtained primary alcohol with either (R)-(+)- or (S)-(-)-Mosher's acid to afford the corresponding Mosher's ester, and (iii) 1H-NMR spectral comparison of t...

The essential oils of the aerial parts of Ocimum basilicum Linn.var. pilosum (Willd.) Benth., an endemic medicinal plant growing in China, was obtained by hydrodistillation and analysed by GC-MS. Fifteen compounds, representing 74.19% of the total oil were identified. The main components were as follows: linalool (29.68%), (Z)-cinnamic acid methyl ester (21.49%), cyclohexene (4.41%), alpha- cad...

This study analyzed the fatty acids composition and their profile qualitatively quantitatively of nine abundant macroalgal specimens collecting from Egyptian coasts. GC mass analysis identified 23 types, including 13 saturated (SFA) 10 monounsaturated (MUSFA). SFA dominated with 78%, while MUFAs had 22%, UFAs were negligible at 0.01%. MUSFA oleic acid (omega-9) was present in all species except...

We have performed a series of first-principles electronic structure calculations to examine the reaction pathways and the corresponding free energy barriers for the ester hydrolysis of protonated cocaine in its chair and boat conformations. The calculated free energy barriers for the benzoyl ester hydrolysis of protonated chair cocaine are close to the corresponding barriers calculated for the ...

We show the second order relative accuracy, on bounded sets, of the studentized bootstrap, exponentially tilted bootstrap and nonparametric likelihood tilted bootstrap, for means and smooth functions of means. We also consider the relative errors for larger deviations. Our method exploits certain connections between Edgeworth and saddlepoint approximations to simplify the computations. R esum e...