Examination of crude rice bran oil and their foots obtained from different local manufacturers revealed the absence of cyclobranol, which is one of triterpene alcohols and occurres in some of commercial oryzanols.
On the other hand, cyclobranol was proved to be formed from 24-methylenecycloartanol, originally found in rice brans, by the translocation of a double bond in the side carbon chain in the presence of a catalystic amount of hydrogen ions.
The isomerization of 24-methylenecycloartanol to cyclobranol was observed to proceed most efficciently in the presence of sulfuric acid as a catalyst along with isopropyl alcohol as a solvent.
The determination of isolated cyclobranol was carried out by the IR, NMR and mass spectra as well as elementary analysis, and showed the following properties ; mp, 165°C and [α] ²⁶_D, +46.6°