Antinociceptive Activity of Thymoquinone and its Structural Analogues: A Structure-Activity Relationship Study

Purpose: To investigate the structural features that influence the antinociceptive activity of thymoquinone and their structural analogues.Methods: The quinones were prepared by an oxidation procedure using molecular oxygen and catalysis with [CoII(salen)] from the respective phenols. The antinociceptive activity of para-benzoquinones (10 mg/kg, ip) was evaluated using formalin test in mice. Vehicle (5 % Tween 80) or morphine (10 mg/kg) were used as control group and standard drug, respectively. The amount of time spent licking the injected paw was considered as the nociceptive response.Results: Among the compounds tested, five para-benzoquinones showed antinociceptive activity. The 2-isopropyl-para-benzoquinone presented the highest potency in first and second phases and produced a near-maximal inhibition (p < 0.001) in the formalin test, similar to morphine (p < 0.001).Conclusion: Our experimental results show that by appropriate structural modification of parabenzoquinones it may be possible to develop novel analgesic drugs.Keywords: Quinones, Antinociceptive activity, Analgesic, Central nervous system, Structure-activity relationship, Medicinal plant

Harvestman Phenols and Benzoquinones: Characterisation and Biosynthetic Pathway

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Benzoquinones are usually present in arthropod defence exudates. Here, we describe the chemical profiles of 12 harvestman species belonging to the neotropical family Gonyleptidae. Nine of the studied species produced benzoquinones, while three produced alkyl phenols. Two benzoquinones and one phenol exhibited biological activity against bacteria and fungi. We also studied the biosynthesis of 2-ethyl-1,4-benzoquinone by feeding Magnispina neptunus individuals with C-13-labelled precursors; the benzoquinones were biosynthesised through a polyketide pathway using acetate and propionate building blocks.1891142911451Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)PetrobrasFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [FAPESP-GM 08/06604-7]FAPESP [AJM 10/51278-0

Solvent-free Diels-Alder reactions catalyzed by FeCl3 on Aerosil((R)) silica

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)A mild solvent-free protocol for the promotion of the Diels-Alder reactions of simple dienes and p-benzoquinones, catalyzed by a mixture of iron(III) chloride on Aerosil((R)) silica is reported. (C) 2014 Elsevier Ltd. All rights reserved.702032313238Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)University of Sao Paulo through the NAP-CatSinQ (Research Core in Catalysis and Chemical Synthesis)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)FAPESP [2005/59572-7, 2008/55401-1, 2011/03244-2, 2012/17093-9, 2011/13993-2, 2013/06532-4, 2011/11613-8