Structure-activity relationship of natural and synthetic coumarin derivatives against Mycobacterium tuberculosis.

Aim: Eight coumarin derivatives (1a-h) obtained from natural (-)-mammea A/BB (1) and 13 synthetic coumarins (2-14) had their cytotoxicity and biological activity evaluated against Mycobacterium tuberculosis H37Rv reference strain and multidrug-resistant clinical isolates. Materials & methods: Anti-M. tuberculosis activity was evaluated by resazurin microtiter assay plate, and the cytotoxicity of natural and synthetic products using J774A.1 macrophages by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide. Results: Compounds 1g, 5, 6, 12 and 14 were more active against M. tuberculosis H37Rv and multidrug-resistant clinical isolates with MIC values ranging from 15.6 to 62.5 µg/ml. Conclusion: These results demonstrate that the coumarin derivatives were active against multidrug-resistant clinical isolates, becoming potential candidates to be used in the treatment of resistant tuberculosis.

Angelica Lactones: From Biomass-Derived Platform Chemicals to Value-Added Products.

The upgrading of biomass-derived compounds has arisen in recent years as a very promising research field in both academia and industry. In this sense, a lot of new processes and products have been developed, often involving levulinic acid as a starting material or intermediate. In the last few years, though, other scaffolds have been receiving growing attention, especially, angelica lactones. Considering these facts and the emergent applications of said molecules, in this review we will discuss their preparation and applications; the use of these frameworks as starting materials in organic synthesis to produce potential bioactive compounds will be covered, as will their use as a foundation to highly regarded compounds such as liquid alkanes with prospective use as fuels and polymers.

Antileishmanial activity of amides from Piper amalago and synthetic analogs

Two natural amides isolated from the chloroform extract of Piper amalago L., Piperaceae, leaves, a hydrogenated derivative and seven synthetic analogs were tested against the promastigote and intracellular amastigote forms of Leishmania amazonensis. The antileishmanial activity was evaluated in terms of growth inhibitory concentration for 50% of protozoa (IC50). The cytotoxicity toward the J774A1 macrophages was evaluated in terms of the cytotoxic concentrations for 50% of macrophages (CC50). The ability to induce nitric oxide production was also investigated for all compounds. The saturated amide 7-(1,3-benzodioxol-5-yl)-1-(1-pyrrolidinyl)-1-heptanone was obtained by hydrogenation of the natural compound N-[7-(3',4'-methylenedioxyphenyl)-2(Z),4(Z)-heptadienoyl]pyrrolidine. Synthetic amides were prepared by addition of the appropriate amine to the corresponding acyl chloride. The natural compound, N-[7-(3',4'-methylenedioxyphenyl)-2(E),4(E)-heptadienoyl]pyrrolidine, was the most active of all tested compounds against the promastigote and intracellular amastigote forms with IC50 values of 15 µM and 14.5 µM, respectively. None of the compounds modulated the production of nitric oxide.

Synthesis of a combinatorial library of amides and its evaluation against the fall armyworm, Spodoptera frugiperda.

The fall armyworm Spodoptera frugiperda is a polyphagous pest that causes important damage in different regions of America and mainly affects corn crops in both tropical and subtropical areas. Currently, control relies on both transgenic plants and/or chemical pesticides. In this work we describe the preparation of an indexed combinatorial library of amides and its toxic effect by contact against S. frugiperda . (E)-1-(1-Piperidinyl)-3-[4-(trifluoromethoxy)phenyl]-2-propen-1-one was the most active compound with an LD(50) = 0.793 µg mg(-1) of larva. This amide was also evaluated by ingestion and at the lowest concentration (1 mg kg(-1)) achieved 83.3% mortality.