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No âmbito de um programa de estudo de reações de macrociclização intramolecular de radicais arila de o-iodobenzamidas mediadas por hidreto de tri-n-butilestanho foi obtida a benzomacrolactama 2, proveniente de ciclização regiosseletiva 11-endo a partir de 4-O-alil-2,3-di-O-benzil-6-desoxi-6-(2-iodobenzoilamino)-α-D-galactopiranosídeo de metila (1). A benzamida 1 foi sintetizada a partir do α-D-galactopiranosídeo de metila em oito etapas. Da reação de 1 com hidreto de tri-n-butilestanho, além da macrolactama 2, foi isolado o produto de hidrogenólise 3. As estruturas das substâncias 1, 2 e 3 foram identificadas pelos seus espectros de RMN 1 H, RMN 13 C e DEPT e por experimentos de RMN bidimensional (COSY e HMQC).Encouraged by our previous studies of tri-n-butyltin-mediated radical cyclization reaction of oiodobenzamides, we applied this methodology to the synthesis of benzomacrolactam 2 from methyl 4-O-allyl-2,3-di-O-benzyl-6-deoxy-6-(2-iodobenzoylamino)-α-D-galactopyranoside 1. Apart from the macrolactam 2, resulting from regioselective 11-endo aryl radical cyclization, the hydrogenolysis produt 3 was obtained. The o-iodobenzamide 1 was prepared in eight conventional synthetic steps from methyl α-D-galactopyranoside. The unequivocal structures of 1, 2 and 3 were supported by 1 H, 13C and DEPT NMR spectroscopy and by COSY and HMQC experiments.

This article reports the structural elucidation by IR, UV and MS spectroscopic data along with 1H and 13C NMR chemical shift assignments of two benzophenones isolated from the fruit pericarp of Garcinia brasiliensis Mart. (Clusiaceae): garciniaphenone, (1R,5S,7S)-3-benzoyl-4-hydroxy-6,6-dimethyl-5,7-di(3-methyl-2-butenyl)bicyclo[3.3.1]non-3-ene-2,9-dione, a novel triprenylated benzophenone; and 7-epi-clusianone, a tetraprenylated benzophenone that has already been extracted from another species of the same family. Furthermore, the keto-enol tautomeric equilibrium at solution-state was described for these compounds by 1D and 2D NMR spectral methods and one attempt to rationalize the different ratios between the noted tautomers was based on stereochemical features.

Solanum species are traditionally employed as antiherpes and anticancer agents in different countries. S. paniculatum has widespread ethnomedical uses in Brazil, including the treatment of viral infections. This paper reports on the isolation of neotigogenin (1) and the new compound Δ25(27)-tigogenin-3-O-β-D-glucopyranoside (2), obtained as a mixture of R and S diastereoisomers at C22 from an ethanol extract of S. paniculatum leaves, along with the determination of their cytotoxicity against Vero cells and antiviral effect against human herpes virus type 1 (HHV-1), murine encephalomyocarditis virus (EMCv), and vaccinia virus strain Western Reserve (VACV-WR). The extract of S. paniculatum inhibited HHV-1 replication [EC50 = (298.0 ± 11.2) μg/ml] and showed no effect on EMCv and VACV-WR. On its turn, 1 was inactive against the assayed strains but presented high cytotoxicity [CC50 = (2.03 ± 0.03) μg/ml], whereas 2 exhibited signifi cant antiherpes [EC50 = (170.8 ± 1.7) μg/ml] and antivaccinia virus effects [EC50 = (177.0 ± 3.3) μg/ml], with low cytotoxicity (CC50 > 400 μg/ml). The results corroborate Solanum paniculatum as a source of cytotoxic and antiviral compounds.