Novas 2-(R-fenil)amino-3-(2-metilpropenil)-[1,4]-naftoquinonas (R = H, 4-OMe, 4-Ferrocenil, 4-Me, 3-Me, 4-I, 3-I, 4-CN, 3-CN, 4-NO2 e 3-NO2) derivadas do nor-lapachol [2-hidroxi-3-(2-metilpropenil)-1,4-naftoquinona] foram obtidas em bons rendimentos. A estrutura dos compostos foi proposta com base em estudos de difração de raios-X (R = OMe, 2b), dados de RMN de ¹H e 13C e cálculos teóricos utilizando o funcional B3LYP e a base 6-311+G(2d,p). Os potenciais de meia-onda das aminonaftoquinonas e o deslocamento químico do hidrogênio da cadeia 3-propenil dos compostos 2a-k mostraram boa correlação com as constantes de Hammett dos substituintes presentes no anel fenileno. A avaliação da citotoxicidade evidenciou atividade antitumoral promissora para o substrato metóxi-nor-lapachol 1 e o derivado 4-ferrocenil 2c.

Novel 2-(R-phenyl)amino-3-(2-methyl-propenyl)-[1,4]-naphthoquinones (R = H, 4-OMe, 4-Ferrocenyl, 4-Me, 3-Me, 4-I, 3-I, 4-CN, 3-CN, 4-NO2 and 3-NO2) derived from nor-lapachol [2-hydroxy-3-(2-methylpropenyl)-1,4-naphthoquinone] were obtained in good yields. Their structures were proposed on the basis of a single crystal X-ray diffraction study (R = OMe, 2b), ¹H and 13C NMR studies and calculations using the B3LYP functional and the 6-311+G(2d,p) basis set. The half-wave potentials of the aminonaphthoquinones and ¹H NMR chemical shifts of the 3-propenyl hydrogen in 2a-k show good correlation with the substituent Hammett constants on the phenylamino ring. The antitumor assays showed promising activity for substrate methoxy-nor-lapachol 1 and the 4-ferrocenyl derivative 2c.

Uma nova substância, denominada habenariosídeo {[(2R)-2-[(2,3,4,6-tetra-O-acetil-β-D-glicopiranosil)oxi]-2-(2-metilpropil)-1,4-dioxo-1,4-butanodiil]bis(oximetileno-4,1-fenileno) bis-β-D-glicopiranosídeo}, foi isolada das frações polares do extrato etanólico de Habenaria petalodes Lindl. (Orchidaceae), juntamente com duas substâncias conhecidas e estruturalmente relacionadas, a loroglossina e a militarina. Os flavonóides: isoquercitrina, isorramnetina 3-O-β-D-glicopiranosídeo e isorramnetina 3,7-di-O-β-D-glicopiranosídeo, também foram isolados. As estruturas do habenariosídeo e das demais substâncias foram determinadas pela análise dos dados de EM, IV, UV e RMN mono e bidimensional e comparação com os dados publicados na literatura.

Habenarioside, a new natural product identified as [(2R)-2-[(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl)oxy]-2-(2-methylpropyl)-1,4-dioxo-1,4-butanediyl]bis(oxymethylene-4,1-phenylene) bis-β-D-glucopyranoside, along with two known related metabolites, loroglossin and militarin, were isolated from the ethanol extract of the whole plant Habenaria petalodes Lindl. (Orchidaceae). The flavonoids isoquercitrin, isorhamnetin 3-O-β-D-glucopyranoside, and isorhamnetin 3,7-di-O-β-D-glucopyranoside were also isolated. The structures of all compounds were established by analysis of their MS, IR, UV, 1D and 2D NMR spectra, and comparison with published data.

Herein we describe the isolation of homarine and piridiniumbetaine B from the sponge Aaptos sp. Although homarine has a common occurrence among animals, piridiniumbetaine B was only recently isolated from the marine sponge Agelas dispar. The isolation of piridiniumbetaine B from two taxonomically distant marine sponges corroborate previous assumptions that such betaines should be regarded rather as primary metabolites. We have also isolated (9-[5'-(methylthio)-beta-D-xylofuranosyl]adenine (xylosyl-MTA) from the mantle of a nudibranch identified as Doris aff. verrucosa. The occurrence of xylosyl-MTA in the mantle of this animal strongly suggests that it is the same nudibranch species described for the Mediterranean sea. We have been unable to detect any other compound in the mantle extract of D. aff. verrucosa other than xylosil-MTA and sterols. GC-MS analysis of the sterol fraction from the nudibranch and its prey, the sponge Hymeniacidon aff. heliophila, revealed the occurrence of the ubiquitous sterols, cholesterol, brassicasterol, cholestanol, 24-methylcholesterol and 24-ethylcholesterol, as the only common metabolites, therefore precluding any assumption concerning the sequestration of secondary metabolites by the nudibranch from H. aff. heliophila.