Estigmasterol: alterações estruturais nos anéis A e B e estudo de atividade biológica

Abstract

This study aimed to the synthesis of Stigmasterol derivatives of stigmasterol to study biological activity against the enzyme acetylcholinesterase and bactericidal and fungicidal activities. Stigmasterol was oxidized with Jones reagent producing the ketones in a single step: stigmasta-5,22-dien-3-one, stigmasta-4,22-dien-3-one, stigmasta-4,22-dien-3,6-dione. Subsequently the oximes were synthesized stigmasta-4, 22-dien-3-one, oxime and stigmasta-4,22-dien-3,6-dione, oxime. The stigmasterol and derivatives were characterized by 1H and 13C NMR, mass spectrometry and infrared. The derivatives obtained are not frequentily reported in the literature on SciFinder search site with only one citation to the oxime and to dioxime are also scarce NMR data for ketone stigmasta-5,22-dien-3-one. The substances were subjected to the screening study by the ELISA method for biological assessment of activity against Gram-positive bacteria: Bacillus cereus (BC, ATCC 11778), Listeria monocytogenes (LM, ATCC 15313), Staphylococcus aureus (SA, ATCC 29212) and Streptococcus sanguinis (SS, ATCC 49456); Gram-negative bacteria: Citrobacter freundii (CF, ATCC 8090), Escherichia coli (EC, ATCC 25922), Pseudomonas aeruginosa (PA, ATCC 27853) and Salmonella typhimurium (ST, ATCC 14028); addition to the species of Candida: Candida albicans (CA, ATCC 18804), Candida tropicalis (CT, ATCC 750), Candida glabrata (CG, ATCC 90030), Candida parapsilosis (CP, ATCC 22019), Candida lusitaniae (CL, CBS 6936) and Candida dubliniensis (CD, clinical Isolated 28) and inhibitory activity of the enzyme acetylcholinesterase (Alzheimer's) by ELISA. The oxidized derivatives stigmasta-4,22-dien-3-one and stigmasta-5,22-dien-3-one respectively showed specificity for bacteria and Candida classes. The stigmasta-4,22-dien-3,6-dione, oxime showed broad activity against the screened microorganisms. The substance stigmasta-5,22-dien-3-one showed activity greater than 90% inhibition of acetylcholinesterase.