Chemical Reduction of Zoanthamine and Evaluation of Antibacterial Activity

Abstract

Zoanthamine 1 when treated with H 2 /Pd-C in EtOH yielded dihydrozoanthamine 2 and on treatment with NaBH 4 in dry dichloromethane yielded deoxyzoanthamine 3 and deoxytetrahydrozoanthamine 4 The structures of 2,3 and 4 were determined on the basis of spectral studies. Compounds !, 2, 3 and 4 were tested for their antimicrobial activity.Unusual biosynthetic alkaloids of the class zoanthamine (1,2) have been increasingly becoming important because of their biological activities (3,4,5). In continuation of our search for biologically active molecules from marine organisms (6,7), we isolated zoanthamine I as major constituent from unidentified colonial zoanthid of the genus Zoanthus We report herein the preparation of zoanthamine reduced analogues and evaluation of their antimicrobial activity.

The Biology and Chemistry of the Zoanthamine Alkaloids

“…Its structure and relative configuration were established by extensive NMR studies. Zooxanthellamine (29) has the same absolute configuration as the zoanthamine alkaloids, as demonstrated by comparison of the NMR data of its MTPA ester. [4] The remarkable similarity between zooxanthellamine (29) and zoanthamine (1) has called into question the role of the zoanthids in producing the zoanthamine natural products.…”

“…Zooxanthellamine (29) has the same absolute configuration as the zoanthamine alkaloids, as demonstrated by comparison of the NMR data of its MTPA ester. [4] The remarkable similarity between zooxanthellamine (29) and zoanthamine (1) has called into question the role of the zoanthids in producing the zoanthamine natural products. [20] It may be that the zoanthids play only a small role in the biosynthesis, such as adjusting the oxidation state of the completed zoanthamine skeleton.…”

“…[19] Although such symbiotic strains are difficult to culture axenically, [ * ] Nakamura et al have been able to produce quantities of Symbiodinium species free of zoanthids. [4] While the algae produced different distributions of metabolites depending on the media used, significant experimentation with culture conditions allowed the Nakamura research group to isolate the new C 30 alkaloid zooxanthellamine (29). Zooxanthellamine exists as an equilibrium between a hemiaminal lactone and an iminium carboxylate (Scheme 8).…”

Avaliação da atividade antiinflamatória e analgésica do extrato bruto hidroalcoólico do zoantídeo Palythoa caribaeorum (Duchassaing & Michelotti, 1860)

“…Rinehart et al (1981) estudaram a atividade antiviral, antimicrobiana e antineoplásica dos produtos naturais extraídos de 1300 amostras de 142 espécies de cnidários; e encontraram que aproximadamente 32% dos extratos revelavam atividade antimicrobiana. Venkateswarlu et al (1998) encontrou atividade antibacteriana de metabólitos secundários em espécies de zoantídeos; Kuramoto et al (1998) isolaram um alcalóide com atividade inibidora da osteoporose de uma espécie do gênero Zoanthus e Grace e Jacobs (1998) descobriram atividade antiinfl amatoria e analgésica num alcalóide extraído de Zoanthus sp.…”

In vitro Evaluation of the Effects of Fluconazole and Nano-Fluconazole on A. flavus and Aspergillus fumigatus Isolates

“…Therefore, they have a wide range of biomedical applications (12). The small size of lipid nanoparticles increases their access to the tissue, thereby enhances the influence of encapsulated drugs (13).…”