Karla C. Pais

Synthesis and in vitro antitubercular activity of a series of quinoline derivatives.

A series of 33 quinoline derivatives have been synthesized and evaluated for their in vitro antibacterial activity against Mycobacterium tuberculosis H(37)Rv using the Alamar Blue susceptibility test and the activity expressed as the minimum inhibitory concentration (MIC) in microg/mL. Compounds 5e and 5f exhibited a significant activity at 6.25 and 3.12 microg/mL, respectively, when compared with first line drugs such as ethambutol and could be a good starting point to develop new lead compounds in the fight against multi-drug resistant tuberculosis.

Assessing the persistence of the N–H⋯N hydrogen bonding leading to supramolecular chains in molecules related to the anti-malarial drug, chloroquine

Crystal packing patterns for a range of chloroquine derivatives have been investigated. For species where the amine-bound R substituent carries atoms not capable of forming significant hydrogen bonding interactions, i.e. R = methyl (1), n-propyl (2), n-butyl (3), 2-chloroethyl (4), 2-azidoethyl (5), N–H⋯N hydrogen bonding between the amine and pyridine groups predominate leading to supramolecular chains. In species carrying hydroxyl groups, i.e. R = 2-hydroxylethyl (6), 1-butanol (7), and (S)-1-butanol (8), the N–H⋯N interactions are subverted by O–H⋯N and N–H⋯O hydrogen bonding that results in the formation of 2-D arrays, establishing an hierarchy of hydrogen bonding interactions in these systems. Despite the differences in hydrogen bonding, globally, the crystal packing in all structures is similar in that the N–H⋯N mediated supramolecular chains of (1–5) aggregate into layers usually via C–H⋯π, C–Cl⋯π and π⋯π interactions. These layers, as with those formed in (6–8), stack into a 3-D arrangement being consolidated via C–H⋯Cl and π⋯π or C–Cl⋯π interactions.

Synthesis and antitubercular activity of 7-chloro-4-quinolinylhydrazones derivatives

A series of twenty-one 7-chloro-4-quinolinylhydrazones (3a-u) have been synthesized and evaluated for their in vitro antibacterial activity against Mycobacterium tuberculosis H(37)Rv. The compounds 3f, 3i and 3o were non-cytotoxic and exhibited an important minimum inhibitory concentration (MIC) activity (2.5 microg/mL), which can be compared with that of the first line drugs, ethambutol (3.12 microg/mL) and rifampicin (2.0 microg/mL). These results can be considered an important start point for the rational design of new leads for anti-TB compounds.

Oxidação do borneol à cânfora com água sanitária - um experimento simples, de baixo custo e limpo

Regulatory pressure is increasingly focusing on the use and disposal of substances hazardous to human health and environment. In the last years efforts have also been made to introduce green chemistry concepts in undergraduate courses. In this paper we present an experiment on the oxidation reaction of borneol to camphor with bleach in acetone. This experiment is important to show undergraduate students that a cheap and non hazardous commercial product can be a useful oxidation agent of alcohols.