Γ-oryzanol Research Articles

Identification and quantitation of γ‐oryzanol components and simultaneous assessment of tocols in rice bran oil

A reverse‐phase high‐performance liquid chromatography method was developed for the simultaneous separation and quantitation of tocopherols, tocotrienols and oryzanols present in rice bran oil. Tocopherols and tocotrienols were quantitated by fluorescence detection and oryzanols (ferulic acid esters of sterols and triterpene alcohols) by photodiode array detection. Chemical ionization mass spectrometry was used to identify cycloartenyl ferulate, 24‐methylene cycloartanyl ferulate, campesteryl ferulate, β‐sitosteryl ferulate and cycloartanyl ferulate as the major oryzanols separated by this procedure. The levels of these nutritionally significant components were found to vary in fully processed, edible rice bran oils from different manufacturers.

Commercially marketed supplements for bodybuilding athletes.

We conducted a survey of 624 commercially available supplements targeted towards bodybuilding athletes. Over 800 performance claims were made for these supplements. Supplements include amino acids, boron, carnitine, choline, chromium, dibencozide, ferulic acid, gamma oryzanol, medium chain triglycerides, weight gain powders, Smilax compounds and yohimbine. Many performance claims advertised were not supported by published research studies. In some instances, we found no research to validate the claims; in other cases, research findings were extrapolated to inappropriate applications. For example, biological functions of some non-essential compounds were interpreted as performance claims for the supplements. Claims for others were based on their ability to enhance hormonal release or activity. We suggest that more research be conducted on this group of athletes and their nutritional needs. Furthermore, the effectiveness and safety of supplements merit further investigation.

Gamma Oryzanol–Plant Sterol Supplementation: Metabolic, Endocrine, and Physiologic Effects

The use of gamma-oryzanol and phytosterols is gaining popularity among various athletic populations. These compounds are being consumed in the belief that they elicit anabolic effects ranging from increased testosterone production and release to stimulating human growth hormone release. However, published scientific studies suggest that these compounds are poorly absorbed. Furthermore, animal studies indicate that when these compounds are injected subcutaneously or intravenously, they induce antianabolic or catabolic activity. Normally, less than 5% of orally consumed phytosterols are absorbed from the intestinal tract, with the majority being excreted in the feces. Intravenous or subcutaneous injections of gamma-oryzanol in rats have been shown to suppress luteinizing hormone release, reduce growth hormone synthesis and release, and increase release of the catecholamines, dopamine and norepinephrine, in the brain. Although it hasn't been directly measured, this metabolic milieu, if accurate, may actually reduce testosterone production.

Effect of cycloartenyl ferulate on gastric lesion produced by intraspecies emotional communication in mice

Effect of cycloartenyl ferulate on gastric lesion produced by intraspecies emotional communication in mice

Thermal Properties of Several Ferulates

The thermogravimetric analyses, changes of ultraviolet spectra by heating, and thermal transitions of several ferulates were investigated.The results of thermogravimetric analyses of cholesteryl ferulate, sitosteryl ferulate, and trimethylysteryl ferulate showed that the thermal stabilities of sitosteryl ferulate and trimethylsteryl ferulate were little inferior to that of cholesteryl ferulate. Although, the thermogravimetric analysis curves of sitosteryl ferulate and trimethylsteryl ferulate were similar to that of cholesteryl ferulate.Under various conditions of heating, the stabilities of ferulates were examined by determining the intensity of absorption at 315nm. Sitosteryl ferulate was more unstable than campesteryl ferulate, stigmasteryl ferulate, and trimethylsteryl ferulate, and cholesteryl ferulate was most stable among the five kinds of ferulates. When the ferulates were heated at 200°C for 4 h in the air atmosphere, the decrease of their absorption by heating was as follows : Cholesteryl ferulate, 35%; sitosteryl ferulate, 65%; campesteryl ferulate, 55%; stigmasteryl ferulate, 50%; and trimethylsteryl ferulate, 55%. The thermal decomposition products of cholesteryl ferulate that was heated at 200°C for 4 h in the air atmosphere were investigated. Cholesterol, vanillin and ferulic acid from the decomposition products were confirmed by TLC, GLC, UV, and mass spectrometry. When a crude rice bran oil containing the ferulates was heated at 180°C for 2 h in the air atmosphere, the absorption maximum of the oil at 291nm was disappeared, and shown newly at 270nm.The heats of transition of four steryl ferulates, trimethylsteryl ferulate and their acetyl derivatives, and oryzanol which is a mixture of ferulates have been evaluated. The order of increase to heats of fusion for steryl ferulates were sitosteryl ferulate, stigmasteryl ferulate, cholesteryl ferulate and campesteryl ferulate, and the result indicates that is in proportion to melting point of each ferulates. The heats of fusion of acetyl derivatives of ferulates were higher than those of corresponding ferulates. There are presence of shoulders in the peak of the melting curves of acetyl derivatives of cholesteryl ferulate and stigmasteryl ferulate, and the melting curves differ from those of corresponding ferulates.

Effects of gamma-oryzanol on the hypothalamo-pituitary axis in the rat

The effects of gamma oryzanol (gamma-OZ), a ferulic acid of triterpene alcohol, on the synthesis and release of the growth hormone (GH) and prolactin (PRL) in vitro and turnover rates of hypothalamic catecholamines were investigated. A single subcutaneous injection of 20 mg/kg of gamma-OZ suppressed GH synthesis and PRL release 1 hour after the injection. gamma-OZ increased medial basal hypothalamic (MBH) dopamine (DA) content, and the DA content was decreased by a treatment of alpha-methyl-p-tyrosine (alpha MpT), a tyrosine hydroxylase inhibitor, indicating increased synthesis and release of DA in MBH by gamma-OZ. gamma-OZ did not alter norepinephrine (NE) content in MBH, while the NE content was significantly decreased, indicating unchanged synthesis and increased release of NE in MBH by gamma-OZ. These results may explain the previous data concerning the changes in serum levels of GH and PRL by gamma-OZ and also suggest that gamma-OZ can affect the synthesis and/or release of at least two hypothalamic neurotransmitters, DA and NE, resulting in the alterations of anterior pituitary hormone synthesis and/or release.

家兎におけるγ-Oryzanolの代謝

家兎におけるγ-Oryzanolの代謝

Mass Spectra of Several Ferulates

The mass spectra of cholesteryl ferulate, campesteryl ferulate, β-sitosteryl ferulate and stigmasteryl ferulate, and of their acetyl derivatives and trimethylsilyl ether derivatives, and of a mixture of campesteryl farulate, β-sitosteryl ferulate and stigmasteryl ferulate, and of oryzanol that is a mixture of some ferulates from rice bran oil were measured. In these spectra, the molecular ion peaks of steryl ferulates and their acetyl derivatives were not observed. The base peaks were observed at m/e 368 in the spectra of free cholesteryl ferulate and its acetate, at m/e 382 in the spectra of free campesteryl ferulate and its acetate, at m/e 394 in the spectra of free stigmasteryl ferulate and its acetate, and at m/e 396 in the spectra of free β-sitosteryl ferulate and its acetate. These base peaks are corresponding to M-194 in spectra of ferulates and M- (194+42) in spectra of acetyl derivatives of ferulates. These peaks serve to distinguish a steryl ferulate from other steryl ferulates. Moreover, the characteristic ion of these steryl ferulates due to the formation of ferulic acid ion occured at m/e 194. The fragmentation patterns of the mass spectra of acetyl derivatives of steryl ferulates were similar to those of corresponding steryl ferulates, and the characteristic ions of these acetyl derivatives of the steryl ferulates were not found. In the mass spectra of trimethylsilyl ether derivatives of the steryl ferulates, the molecular ion peaks were observed for each derivative, but they were very small. Furthermore, the mass spectra of the mixture of campesteryl ferulate, β-sitosteryl ferulate and stigmasteryl ferulate, and of the oryzanol were investigated. It was found that the mass spectrum of oryzanol can be used for the qualitative analysis of the components in the mixture of ferulates from rice bran oil.

Separation and Quantitative Analysis of Ferulates in Rice Bran Oil by Thin-Layer Chromatography

The methods of separation of ferulates by TLC and reversed-phase TLC and quantitative estimation of ferulates using both TLC and ultraviolet spectroscopy were investigated.The separation of ferulates from the mixture of ferulates and rice bran oil were investigated by TLC. The ferulates from the samples gave a single spot that was not found to each of the ferulates by the TLC method. However, a separation of β-sitosteryl ferulate, stigmasteryl ferulate and 24-methylenecycloartanyl ferulate was accomplished by reversed-phase TLC in the system, liquid paraffin/methanol-acetonitrile (2 : 1), thus enabling the analysis of mixtures of ferulates in rice bran oils. Also, in this way β-sitosterol, stigmasterol and 24-methylenecycloartanol were clearly separated.The double-development procedure, employing hexane-diethyl ether (9 : 1) firstly and then benzene-diethyl ether (4 : 1), was most suitable for the separation of ferulates from other components in rice bran oil. The separated ferulates in the chromatogram were extracted with ethanol. The optical density of the ethanol solution at 327 mμ was determined and the ferulate content was calculated. Since materials interfering with the ultraviolet spectroscopic analysis were eliminated by TLC, the results obtained by the method mentioned above are more accurate as compared with those determined directly by ultraviolet spectroscopic method.

Studies on the Ferulates in Rice Bran Oil. V.

The ferulates from rice bran oil consist of esters of a few kind of alcohols and ferulic acid and these ferulates were saponified in alkali solution, but there recognized a relation between saponification rates and the structures of the alcohols. The saponification rates increase in the following serial order : campesteryl ferulate > β-sitosteryl ferulate > cycloaltenyl ferulate > 24-methylenecycloartanyl ferulate>cyclobranyl f erulate. Furthermore, it was confirmed that digitonides of cycloartenol, 24-methylenecycloartanol and cyclobranol were formed. The formation rates of digitonides of these triterpenoides were lower than those of sterols.

Studies on the Ferulates Contained in Rice Bran Oil. III.

Melting points of mixed samples of steryl (campesteryl and β-sitosteryl ferulates, 46 : 54 (wt%)), cycloartenyl, 24-methylene cycloartanyl ferulates were studied. A mixture of cycloartenyl and steryl ferulates, 52 : 48 (wt%) showed a minimum of melting point as the eutective type. Also, a minimum melting point as the eutective type was observed at a mixture of 24-methylene-cycloartanyl and steryl ferulates, 25 : 75 (wt%). The isothermals were made from the melting points of the mixtures of steryl, cycloartenyl and 24-methylene-cycloartanyl ferulates. The heat stability of the mixture of four kinds of ferulate was investigated. Four samples of the mixture were heated for 8 hours at 120, 195 and 240°C and for five minutes at 350°C, respectively. The heated samples were analysed by thin-layer chromatography and ultraviolet absorption spectra. Unchanged ferulates in heated samples were separated and saponified. The unsaponifiable matters of unchanged ferulates were analysed by gas chromatography to estimate the compositions of the unchanged ferulates. The order of heat stabilities of the ferulates was considered as follows : campesteryl ferulate > β-sitosteryl ferulate > cycloartenyl ferulate > 24-methylene-cycloartenyl f erulate.

Studies on the Constituents of Rice Bran Oil. V. Reexamination of Oryzanol-B

Oryzanol-B was shown to be largely a mixture of cycloart-24-enyl ferulate (oryzanol-A) and 24-methylenecycloartanyl ferulate (oryzanol-C) by comparison of melting points of their derivatives and by degradation. Alcohol-B, obtained by saponification of oryzanol-B, was acetylated and ozonolysis of acetate afforded 24-oxocycloartanyl acetate and 3β-acetoxy-25, 26, 27-trisnorcycloartan-24-oic acid. Comparison of alcohol-B with reported triterpenes of rice-bran oil is described.

Studies on the constituents of rice bran oil. II. Structure of oryzanol-A.

The methyl ether obtained from oryzanol-A and dimethyl sulfate is saponified with ethanolic potassium hydroxide to form 3, 4-dimethoxycinnamic acid and a neutral substance. Under a more drastic conditions, oryzanol-A itself is saponified to form the same neutral substance and ferulic acid. The neutral substance is a kind of triterpenoid alcohol and was determined as cycloartenol by the comparison of the constants of various derivatives and a mixed fusion of its acetate and benzoate. Therefore, oryzanol-A is cycloartenyl ferulate and the absorption in the ultraviolet range is due to the ferulic acid moiety. Oryzanol-B was also found to be the ferulate of a triterpenoid alcohol but the nature of this alcohol was not established. Its properties were similar to cycloartenol but its infrared spectrum revealed the presence of a vinylidene group, while cyclo-artenol possesses anisopropy lidene group. As shown in Table II, the constants of various derivatives were clearly different from those of cyclolaudenol, which possesses a vinylidene group.