Padina boergesenii is one of the most abundant brown algae distributed in the north of Persian Gulf and
Oman Sea. In this study after sampling and preparation of Padina boergesenii by Chroform-Etanol (3-1)
solvent and by Methanol has been extract. Separation and purification of the compounds was carried
out using thin layer, general and inverse column chromatography, Cephadex and high-performance
liquid chromatography (HPLC). Structural elucidation of the constituents was based on the data obtained
from H-NMR, 13C-NMR, HSQC, HMBC, DEPT and Cephadex LH-20. The steroids compounds
separated from above alga were identified as 22-dehydrocholesterol (1), cholesterol (2), fucosterol (3), β-
sitosterol (4), stigmasterol (5), ostreasterol (6) and two epimer of hyroxyestrol(7), based on their spectral
data and from comparison with those previously reported in the literature.