Synthesis, characterisation, crystal structure and antimicrobial evaluation of novel 6-alkoxyergosta-4,6,8(14),22-tetraen-3-one derived from natural ergosta-5,7,22-trien-3β-ol
Bacho, Mitchell
Universidad de Chile
Artigas, Vania
Pontificia Universidad Catolica de Valparaiso
Araya-Contreras, Tiare
Universidad Andres Bello
Bittner, Mauricio
Universidad Andres Bello
Escobar, Carlos A.
Universidad Autonoma de Chile
Fuentealba, Mauricio
Pontificia Universidad Catolica de Valparaiso
Becerra, Jose
Universidad de Concepcion
Journal
Natural Product Research
ISSN
1478-6419
1478-6427
Open Access
closed
Volume
37
Start page
16
End page
23
In this study, we report a facile transformation starting from 5 alpha-hydroxyergosta-7,22-dien-3,6-dione (1) to afford two novel compounds: 6-methoxyergosta-4,6,8(14),22-tetraen-3-one (2) and 6-ethoxyergosta-4,6,8(14),22-tetraen-3-one (3) using alcoholic acid catalysis. Their structures were elucidated using NMR experiments, FT-IR, MS and X-ray analysis. These compounds were evaluated for antibacterial activity using the disk and broth diffusion test. In those tests, compound 3 was found to be the most significant antibacterial agent. In general, compounds 1-3 showed inhibition zone in the range of 7.00-12.3 mm for S. aureus and S. mutans, meanwhile for Gram-negative bacteria E. coli and Pseudomonas sp. was found to be in the range of 7.00-8.00 mm. For the most active, compound 3, MIC was significantly lower than that reported for ergosterol, in a value of 160 mu g/mL. Overall, these compounds were more active than their natural precursor.