Emerson T. da Silva

Improved Solvent‐Free Dakin Oxidation Protocol

Abstract A solvent‐free Dakin reaction with mCPBA was accomplished with various aromatic aldehydes, resulting in an easy and improved methodology for the preparation of corresponding phenols. 3,4‐Methylenedioxyphenol, 3,4‐dimethoxyphenol, 4‐methoxyphenol, 4‐chlorophenol, and other functionalized phenols were obtained in high yields from the corresponding aromatic aldehydes in a few minutes. This new methodology represents an efficient alternative for this important synthetic conversion.

Reaction of 1,3-dimethyl-5-acetyl-barbituric acid (DAB) with primary amines. Access to intermediates for selectively protected spermidines

Abstract The ability of 1,3-dimethyl-5-acetyl-barbituric acid (DAB) to react with primary amines in a chemoselective fashion was applied to the synthesis of a selectively protected spermidine.

AN EFFICIENT SYNTHESIS OF PROTECTED 2-DEOXY-STREPTAMINE AND ANALOGUES

Abstract Protected 2-deoxy-streptamine 13 and a variety of analogues 9, 10, 12 , and 14 were synthesized, starting with the intermediate 2L-2,3,5/3-2,3,4-tri- O -benzyl- syn - O -oximino-2,3,4,5-cyclohexanetetrol 2 , derived from D-glucose.

First Dose Combination Studies of Anti-Tuberculosis Drugs With Piperic Acid

First Dose Combination Studies of Anti-Tuberculosis Drugs With Piperic Acid The combinatorial effect of piperic acid with various anti-tuberculosis (anti-TB) drugs was evaluated in vitro against Mycobacterium tuberculosis. The present study has demonstrated for the first time that a combination of piperic acid with rifampicin imparts a synergic effect against M. tuberculosis.

Anti-inflammatory profile of N-phenylpyrazole arylhydrazone derivatives in rats.

A series of synthetic N‐phenylpyrazole arylhydrazone compounds, rationally designed as mixed‐hybrid isosteres of two known inhibitors of prostaglandin synthase and 5‐lipoxygenase enzymes, BW‐755c and CBS‐1108, has been investigated for anti‐inflammatory activity in the carrageenan‐induced pleurisy model in rats. The compounds have different oxygenated substituent groups in the aryl group of the hydrazone framework to ensure a different range of redox properties. A new arylhydrazone derivative, 2,6‐di‐tert‐butyl‐4‐(4‐nitro‐3‐methyl‐N‐phenylpyrazol‐5‐yl‐hydrazonomethyl)phenol, was also synthesized and tested for anti‐inflammatory activity.

Synthesis of Protected EPI‐2‐Deoxystreptamine and Analogs

A protected C‐3 epi‐2‐deoxystreptamine was synthesized starting with the intermediate 2‐l‐1,3/2,4,5‐1‐acetamido‐2,3,4‐tri‐O‐benzyl‐2,3,4,5‐cyclohexanetetrol 8, derived from d‐glucose. †This paper is dedicated to Professor Gérard Descotes on the occasion of his 70th birthday.

An Efficient Protocol for Solution- and Solid-Phase End-Group Differentiation of Spermidine

The end-group differentiation of a selectively protected spermidine was achieved through a short sequence of steps. The functionalization of spermidine in solid-phase was monitored by FT-IR.

The use of Fukuyama's sulfonamide in the synthesis of selectively protected spermidines

A diferenciacao dos grupos amino terminais de poliaminas frequentemente envolve uma serie de etapas de protecao e desprotecao, resultando em rotas sinteticas longas e de baixo rendimento global. Tendo em vista o relevante papel biologico atribuido a estas substâncias, torna-se necessario o desenvolvimento de sinteses mais eficientes para poliaminas. Neste artigo descrevemos uma sintese de duas espermidinas seletivamente protegidas, empregando a sulfonamida de Fukuyama. As duas sinteses foram executadas em tres etapas a partir da 1,3-propanodiamina, com um rendimento global superior a 40%.

Eco-Friendly and Highly Efficient Synthesis, Including Multigram Synthesis, of Aldehyde Isonicotinoyl Hydrazones Using Sonochemistry

Ligia S. da Silveira Pinto 1 Universidade Federal do Rio de Janeiro (PG), Emerson T. da Silva 2 Fundação Oswaldo Cruz (PQ), Carlos R. Kaiser 1 Universidade Federal do Rio de Janeiro (PQ), Marcus V. N. de Souza * 1 Universidade Federal do Rio de Janeiro and 2 Fundação Oswaldo Cruz (PQ), Solange M. S. V. Wardell 3 CHEMSOL (PQ), James L. Wardell 2 Fundação Oswaldo Cruz and 4 University of Aberdeen (PQ)

Synthesis and Biological Activities of Camphor Hydrazone and Imine Derivatives

Both sonochemical and classical methodologies have been employed to convert camphor, 1,7,7-trimethylbicyclo[2.2.1]heptan-2-one, C9H16C=O, into a number of derivatives including hydrazones, C9H16C=N-NHAr 3, imines, C9H16C=N-R 7, and the key intermediate nitroimine, C9H16C=N-NO2 6. Reactions of nitroamine 6 with nucleophiles by classical methods provided the desired compounds in a range of yields. In evaluations of activity against Mycobacterium tuberculosis, compound 7j exhibited the best activity (minimal inhibitory concentration (MIC) = 3.12 µg/mL), comparable to that of the antitubercular drug ethambutol. The other derivatives displayed modest antimycobacterial activities at 25–50 µg/mL. In in vitro tests against cancer cell lines, none of the synthesized camphor compounds exhibited cytotoxic activities.