Characterization of triterpene alcohol and sterol ferulates in rice bran using LC-MS/MS.
25 Apr 2003-Journal of Agricultural and Food Chemistry (American Chemical Society)-Vol. 51, Iss: 11, pp 3260-3267
TL;DR: Nine new relatively polar triterpene alcohol and sterol esters were characterized by their retention behaviors in LC and ESI-MS data from both negative- and positive-ion mode, providing the first evidence for the presence of hydroxylated ferulate esters and caffeate esters as part of gamma-oryzanol in rice bran.
Abstract: Ferulic acid esters of triterpene alcohols and sterols in rice bran oil have been extensively studied and reported to possess important pharmacological actions. Inconsistent results on the numbers and structures of ferulates have been reported, primarily because of the analytical procedures employed. Conventional methods for analysis of phytosterol content in oil are carried out by characterization of trimethylsilylated derivatives (TMS) using GC-EI-MS after saponification of oils or individual compound isolated from oils. This study developed an LC-MS/MS method for the direct analysis of triterpene alcohol and sterol esters in rice bran oil. In addition to verifying the results of previous research, nine new relatively polar triterpene alcohol and sterol esters were characterized by their retention behaviors in LC and ESI-MS data from both negative- and positive-ion mode. This is the first evidence for the presence of hydroxylated ferulate esters and caffeate esters as part of gamma-oryzanol in rice bran. The method enables rapid and direct on-line characterization of triterpene alcohol and sterol esters in oils. LC-MS/MS equipped with reverse-phase LC and ESI-MS should be well-suited for identification and quantification of the polar metabolites of phytosterols in biological fluids after consumption of rice bran oil or other oils.
Citations
More filters
TL;DR: Sorghum is a rich source of various phytochemicals including tannins, phenolic acids, anthocyanins, phytosterols and policosanols as discussed by the authors.
753 citations
Cites background from "Characterization of triterpene alco..."
...Cereal brans reported to have high levels of these compounds include rice (Rogers et al., 1993; Dunford and King, 2000; Fang et al., 2003) and corn (Moreau et al., 1996; Singh et al., 2003)....
[...]
TL;DR: It is clear that to maximize the intake of antioxidant compounds, rice should be preferentially consumed in the form of bran or as whole grain, and on a whole grain basis and with the exception of γ-oryzanol and anthocyanins, the contents of antioxidants in other cereals appear to be higher than those in rice.
Abstract: Epidemiological studies suggested that the low incidence of certain chronic diseases in rice-consuming regions of the world might be associated with the antioxidant compound contents of rice. The molecules with antioxidant activity contained in rice include phenolic acids, flavonoids, anthocyanins, proanthocyanidins, tocopherols, tocotrienols, γ-oryzanol, and phytic acid. This review provides information on the contents of these compounds in rice using a food composition database built from compiling data from 316 papers. The database provides access to information that would have otherwise remained hidden in the literature. For example, among the four types of rice ranked by color, black rice varieties emerged as those exhibiting the highest antioxidant activities, followed by purple, red, and brown rice varieties. Furthermore, insoluble compounds appear to constitute the major fraction of phenolic acids and proanthocyanidins in rice, but not of flavonoids and anthocyanins. It is clear that to maximize the intake of antioxidant compounds, rice should be preferentially consumed in the form of bran or as whole grain. With respect to breeding, japonica rice varieties were found to be richer in antioxidant compounds compared with indica rice varieties. Overall, rice grain fractions appear to be rich sources of antioxidant compounds. However, on a whole grain basis and with the exception of γ-oryzanol and anthocyanins, the contents of antioxidants in other cereals appear to be higher than those in rice.
468 citations
Cites background from "Characterization of triterpene alco..."
...Other components of c-oryzanol include 24-methylenecylcoartanyl cis-ferulate, cycloartenyl cis-ferulate, b-sitosteryl cis-ferulate, 24-methylenecholesterol cis-ferulate, stigmastanyl cis-ferulate, b-sitostanyl trans-ferulate, D(7)-sitostenyl transferulate, campestanyl trans-ferulate, stigmastanyl trans-ferulate, D(7)-stigmastenyl trans-ferulate, D(7)-campestenyl trans-ferulate, 24-hydroxy-24-methylcycloartanol transferulate, 25-hydroxy-24-methylcycloartanol trans-ferulate, (24S)-cycloart-25-ene-3b, 24-diol-3b-trans-ferulate, (24R)-cycloart-25-ene-3b,24-diol-3b-trans-ferulate, cycloart-23Z-ene-3b,25-diol-3b-trans-ferulate, hydroxylated cycloartenol trans-ferulate, 24-methylcholesterol trans-ferulate, cycloeucalenol trans-ferulate, and 24-methylenecholesterol trans-ferulate (Diack and Sask 1994; Akihisa et al. 2000; Xu et al. 2001; Fang et al. 2003)....
[...]
...…cycloart-23Z-ene-3b,25-diol-3b-trans-ferulate, hydroxylated cycloartenol trans-ferulate, 24-methylcholesterol trans-ferulate, cycloeucalenol trans-ferulate, and 24-methylenecholesterol trans-ferulate (Diack and Sask 1994; Akihisa et al. 2000; Xu et al. 2001; Fang et al. 2003)....
[...]
...One caffeate ester (cycloartenyl trans-caffeate) has also been reported as part of c-oryzanol in rice (Fang et al. 2003), but this remains to be confirmed....
[...]
...On the basis of their absorbance maxima at 330 nm, at least 25 components of c-oryzanol have been identified so far, with five of them comprising about 95% of the total c-oryzanol content (Akihisa et al. 2000; Xu et al. 2001; Fang et al. 2003; Miller and Engel 2006)....
[...]
TL;DR: Phytosterol-enriched functional foods first appeared about twenty years ago and many clinical studies have confirmed the low density lipoprotein (LDL) cholesterol-lowering properties of various types of phytosterols, which have provided insights to better understand the cholesterol- Lowering and other biological effects of plant sterols.
258 citations
TL;DR: A review focusing on the 2003-2008 period, where an average of 13-14 references per year were published as mentioned in this paper, however, some relevant work reported during the 1998-2002 period is also briefly commented upon.
231 citations
TL;DR: In this paper, the effects of each individual step of the chemical refining process on major and minor components of rice bran oil were examined, and the results showed that rice brain oil contains a significantly higher level of several bioactive minor components such as γ-oryzanol, tocotrienols, and phytosterols.
Abstract: The effects of each individual step of the chemical refining process on major and minor components of rice bran oil were examined. In comparison with common vegetable oils, rice brain oil contains a significantly higher level of several bioactive minor components such as γ-oryzanol, tocotrienols, and phytosterols. Alkali treatment or neutralization results in a significant loss of oryzanol. In addition, it gives rise to a change in the individual phytosterol composition. After bleaching, some isomers of 24-methylenecycloartanol were detected. Because of their relatively high volatility, phytosterols and tocotrienols are stripped from the rice brain oil during deodorization and concentrated in the deodorizer distillate. At the same time, oryzanol is not volatile enough to be stripped during deodorization; hence, the oryzanol concentration does not change after deodorization. Complete refining removed 99.5% of the FFA content. Depending on the applied deodorization conditions, trans FA can be formed, but the total trans content generally remains below 1%.
175 citations
References
More filters
TL;DR: The authors find that OS deserve much more attention than cholesterol itself in terms of research activity but that unfortunately the reverse is true with regard to funding.
291 citations
TL;DR: Six novel feruloyl esters of triterpene alcohols and sterols, besides five known trans-ferulates, showed marked inhibitory activity against 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation in mice, and eight free sterols examined showed weaker activity than their corresponding ferulates.
Abstract: Six novel feruloyl esters of triterpene alcohols and sterols, viz., two trans-ferulates, cycloeucalenol and 24-methylenecholesterol trans-ferulates, and four cis-ferulates, cycloartenol, 24-methyelenecycloartanol, 24-methylcholesterol, and sitosterol cis-ferulates, besides five known trans-ferulates, cycloartenol (CAR), 24-methylenecycloartanol (24-MCA), 24-methylcholesterol, sitosterol, and stigmastanol trans-ferulates, and one known cis-ferulate, stigmastanol cis-ferulate, were isolated from the methanol extract of edible rice bran. These and eight other synthetic trans- and cis-ferulates of triterpene alcohols and sterols, along with the corresponding free alcohols, were evaluated with respect to their anti-inflammatory activity against 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation (1 microg per ear) in mice. All of the ferulates showed marked inhibitory activity, and their 50% inhibitory dose (ID(50)) was 0. 1-0.8 mg per ear. On the other hand, whereas two free triterpene alcohols, CAR and 24-MCA, showed strong inhibition (ID(50) 0.2-0.3 mg/ear), eight free sterols examined showed weaker activity (ID(50) 0.7-2.7 mg/ear) than their corresponding ferulates.
289 citations
TL;DR: In this paper, a reverse-phase high-performance liquid chromatography method was developed for the simultaneous separation and quantification of tocopherols, tocotrienols and oryzanols present in rice bran oil.
Abstract: 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.
264 citations
TL;DR: The observation that blending RBO with safflower oil at a definite proportion magnifies the hypocholesterolemic efficacy, compared with the effect of each oil alone, may have a practical significance.
Abstract: A range of human and animal studies have shown that rice bran oil (RBO) is an edible oil of preference for improving serum cholesterol levels and lipoprotein profiles with similarity to the more commonly used vegetable oils such as corn oil and safflower oil. Of particular interest is the observation that blending RBO with safflower oil at a definite proportion (7:3, wt/wt) magnifies the hypocholesterolemic efficacy, compared with the effect of each oil alone. Although the mechanism underlying this effect is not apparent at present, the blending may have a practical significance. The blending effect was reproduced in rats fed a cholesterol-enriched diet, and there was also a decrease in liver cholesterol. The occurrence of peculiar components such as gamma-oryzanol and tocotrienols could be responsible for the hypocholesterolemic effect of RBO.
190 citations
TL;DR: Inhibitory activity against 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation in mice was observed in the methanol extract of rice bran and gamma-oryzanol, and cycloartenol ferulate markedly inhibited the tumor-promoting effect of TPA in 7,12-dimethylbenz[a]anthracene-initiated mice.
Abstract: Inhibitory activity against 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation in mice was observed in the methanol extract of rice bran and gamma-oryzanol. The active components of rice bran, sitosterol ferulate, 24-methylcholesterol ferulate, cycloartenol ferulate and 24-methylenecycloartanol ferulate inhibited markedly the TPA-induced inflammation in mice. The 50% inhibitory dose of these compounds for TPA-induced inflammation was 0.2-0.3 mg/ear. Furthermore, cycloartenol ferulate markedly inhibited the tumor-promoting effect of TPA in 7,12-dimethylbenz[a]anthracene-initiated mice.
155 citations