A series of 34 3-benzyl-5-(arylmethylene)furan-2(5H)-ones, designed using the naturally occurring toxins nostoclides as a lead structure, was synthesized as potential inhibitors of the photosynthetic electron transport. All compounds were fully characterized by IR, NMR (1H and 13C), and MS spectrometry. HMBC and HSQC bidimensional experiments allowed 13C and 1H assignments. Their biological activities were evaluated in vitro as the ability to interfere with light-driven reduction of ferricyanide by isolated spinach chloroplasts. About two-thirds of the compounds exhibited inhibitory properties in the micromolar range against the basal electron flow from water to K3[Fe(CN)6]. The inhibitory potential of these 3-benzyl-5-(arylmethylene)furan-2(5H)-one lactones is higher than that of other nostoclide analogues previously synthesized in the same laboratories.

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Six nostoclide analogues were synthesised from 3-benzyl-2(5H)-furanone in one step, with yields ranging from 10 to 71%, and subjected to several biological assays. The two most active of these, 5d and 5e, were shown to be phytogrowth inhibitors of the radicle of Lolium multiflorum Lam, while enhancing the root growth of Physalis ixocarpa Brot. Both compounds inhibited electron flow (basal, phosphorylating and uncoupled) from water to methylviologen (MV); both acted as Hill reaction inhibitors, since the synthesis of ATP was prevented. The uncoupled electron transport from photosystem II (PSII) (water to 2,6-dichlorophenol-indophenol (DPIP)) and photosystem I (PSI) (2,6-dichlorophenol-indophenol reduced (DPIPred) to MV) was inhibited with 500 microM of 5d by 22 and 14% respectively. In addition, 400 microM of 5d inhibited PSI (from tetramethyl-p-benzohydroquinone (TMQH(2)) to MV) by 40%. Thus 5d inhibited electron transport at the b(6)f complex. Finally, 500 microM of 5e inhibited electron flow (basal and phosphorylating) by 25%, and 300 microM of 5e enhanced light-activated membrane-bound Mg(2+)-ATPase by 66%. Thus 5e behaved as a weak Hill reaction inhibitor and an uncoupler. In general, the phytotoxicity of the synthetic lactones was only weakly related to inhibition of photosynthesis.

Many natural products have been used as a model for the development of new drugs and agrochemicals. Following this strategy 11 rubrolide analogues, bearing electron-withdrawing and -donating groups at both benzene rings, were prepared starting from commercially available mucobromic acid. The ability of all compounds to inhibit the photosynthetic electron transport chain in the chloroplast was investigated. The rubrolide analogues were effective in interfering with the light-driven ferricyanide reduction by isolated chloroplasts. The IC(50) values of the most active derivatives are in fact only 1 order of magnitude higher than those of commercial herbicides sharing the same mode of action, such as Diuron (0.27 μM). QSAR studies indicate that the most efficient compounds are those having higher ability to accept electrons, either by a reduction process or by an electrophilic reaction mechanism. The results obtained suggest that the rubrolide analogues represent promising candidates for the development of new active principles targeting photosynthesis to be used as herbicides.

The composition of the volatile oil obtained by hydrodistillation from the fruit peel of Garcinia brasiliensis (Mart.) Planch. et Triana was determined by GC/MS. A total of 38 components were identified, including gamma-muurolene (10.3%), spathulenol (8.7%), delta-cadinene (8.3%), torreyol (8.0%), alpha-cadinol (7.0%), cadalene (6.3%), and gamma-cadinene (5.3%). Oxygenated sesquiterpenes (43%) were the main group of compounds. The anti-inflammatory activity of the volatile oil was evaluated through the rat-paw edema model induced by carrageenan. Inhibition of the inflammatory process was noticed 3 h after carrageenan administration. In addition, the volatile oil showed poor antioxidant activity.

Support: This study was supported by CAPES, CNPq and Fapemig. AMM received a CAPES scholarship during her Master course. Conflict of interest:There is no conflict of interest to declare.Received 28 January 2013; Received in final form 10 July 2013; Accepted 17 July 2013. ABSTRACTObjective: To translate and to perform the cross-cultural adaptation of the "Questionnaire of Life Quality Specific for Myasthenia Gravis -15 items" (MG-QOL15). Method: The original English version of the questionnaire was translated into Portuguese. This version was revised and translated back into English. Later, both English versions were compared and the divergences were corrected in the Portuguese text. At a second stage, ten patients with MG followed at the Neuromuscular Diseases Clinic from the University Hospital, Universidade Federal de Minas Gerais answered the questionnaire. The authors analyzed the difficulties and misunderstandings in the application of the questionnaire. Results: The questions 8, 13 and 15 were considered difficult to understand and were modified in the final Portuguese version. Most patients (70%) had a total score above 25, and the statements 3, 8 and 9 showed the highest scores. Conclusion: The Brazilian version of the questionnaire MG-QOL15 seems to be a promising tool for the assessment of Brazilian patients with MG.Keywords: myasthenia gravis, quality of life, questionnaire. RESuMoObjetivo: Realizar a tradução e a adaptação transcultural do "Questionário de Qualidade de Vida Específico para Miastenia Gravis -15 itens" (MG-QOL15). Método: Inicialmente, foi realizada a tradução do instrumento original em inglês para o português. Esta versão foi revisada e retrotraduzida para o inglês. A versão retrotraduzida foi comparada à versão original em inglês, sendo corrigidas as divergências no texto em português. Em um segundo momento, dez pacientes com MG acompanhados na Clínica de Doenças Neuromusculares do Hospital das Clíni-cas da Universidade Federal de Minas Gerais responderam ao questionário. Na aplicação do questionário, os itens mal compreendidos foram analisados pelos autores. Resultados: Os itens 8, 13 e 15 foram considerados de difícil compreensão e modificados na versão final em português. A maioria dos pacientes (70%) apresentou uma pontuação total superior a 25, sendo que os itens 3, 8 e 9 apresentaram os escores mais elevados. Conclusão: A versão brasileira do MG-QOL15 é um instrumento promissor para a avaliação de pacientes brasileiros com MG.Palavras-chave: miastenia gravis, qualidade de vida, questionário.

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