Some works directly mention the alpha and beta designated substances – that were (incl. gamma) rather fractions obtained during first historic isolations:[1]
(…) Oryzanol occurs in the unsaponifiable fraction of rice bran oil and is so named because it was first discovered in rice bran oil (Orysae Sativa L.) (Kaneko and Tsuchiya, 1954)[2] and contained a hydroxyl group. Oryzanol was originally considered a single compound but later was determined to be a mixture of ferulic acids esterified with normal sterols or triterpene alcohols, called α-, β- and γ-oryzanol, of which γ-oryzanol has been the most commonly mentioned. The sterol components of γ-oryzanol are primarily campesterol and sitosterol, and the triterpene alcohol components are cycloartenol and 24-methylene cycloartanol (…)
Other text sound like alpha a beta fractions were not oryzanol at all:[3]
(…) During their studies, a number of lipid fractions were isolated from rice bran oil; the third (gamma) fraction isolated was oryzanol[2]. Its chemical composition was later identified as a mixture of ferulic acid esters of various plant sterols (…)
(Hard to tell, the article[2] is in Japanese.)
As airhuff already said in his answer, γ-oryzanol (or just oryzanol) is a mixture of various sterol ferulates, which now usually are listed by their chemical names, however a couple of notable compendia[4,5] list the two major[6] formerly isolated constituents under names oryzanol A and C (since B turned out to be a mixture of A and C[7]).
(I) oryzanol A, CAS 21238-33-5, cycloartenyl ferulate,
9,19-cyclo-5α-lanost-24-en-3β-yl (2E)-3-(4-hydroxy-3-methoxyphenyl)prop-2-enoate(II) oryzanol C, CAS 469-36-3, 24-methylenecycloartanyl ferulate,
24-methylidene-9,19-cyclo-5α-lanostan-3β-yl (2E)-3-(4-hydroxy-3-methoxyphenyl)prop-2-enoate
Your structure happens to be oryzanol A.
References:
- Huang, C. J. Potential Functionality and Digestibility of Oryzanol as Determined Using in Vitro Cell Culture Models, Dissertation thesis, Louisiana State University and Agricultural and Mechanical College, 2003.
- Kaneko, R.; Tsuchiya, T. New Compound in Rice Bran and Germ Oils. J. Chem. Soc. Jpn. 1954, 57, 526–529.
- Wheeler, K. B.; Garleb, K. A. Gamma Oryzanol—Plant Sterol Supplementation: Metabolic, Endocrine, and Physiologic Effects. International Journal of Sport Nutrition 1991, 1 (2), 170–177.
- O’Neil, M. J.; Heckelman, P.; Koch, C.; Roman, K. The Merck Index, 14th ed.; 2006.
- Hill, R. A.; Makin, H.; Kirk, D.; Murphy, G. Dictionary of Steroids; CRC Press, 1991.
- Xu, Z.; Godber, J. S. Purification and Identification of Components of γ-Oryzanol in Rice Bran Oil. J. Agric. Food Chem. 1999, 47 (7), 2724–2728.
- Shimizu, M.; Ohta, G. Studies on the Constituents of Rice Bran Oil. V. Reexamination of Oryzanol-B. Chem. Pharm. Bull. 1960, 8 (2), 108–111.