Simultaneous determination of four sesame lignans and conversion in Monascus aged vinegar using HPLC method.
A simple, accurate and specific high-performance liquid chromatography (HPLC) method has been developed and validated for simultaneous determination of sesamol, sesamin, asarinin and sesamolin in Monascus aged vinegar. The effects of acid hydrolysis and four heating treatments on the components content in Monascus aged vinegar were discussed. The results showed that the isomerisation of sesamin to asarinin, and decomposition of sesamolin to sesamol significantly increased, regardless of heating or acid hydrolysis. Thermal processes and acid hydrolysis increased the content of sesamol and asarinin, respectively, but severe thermal processes resulted in the loss of total sesame lignans. Sesamol and asarinin reached the highest (2.720 ± 0.202 μg/mL and 2.064 ± 0.075 μg/mL) for autoclaving (125 °C, 15 min) and acid hydrolysis (25 °C, 15 min, nature pH), respectively. Therefore, autoclaving and acid hydrolysis were considered as the optimal way to obtain higher content of sesamol and asarinin.
Analysis of Sesamin, Asarinin, and Sesamolin by HPLC with Photodiode and Fluorescent Detection and by GC/MS: Application to Sesame Oil and Serum Samples
New sensitive and specific analytical methods are needed for the analysis of sesamin, asarinin, and sesamolin in sesame seed oils, sesame dietary supplements, as well as in serum samples from clinical studies involving sesamin, asarinin, and sesamolin. The objective of this study was to develop a high performance liquid chromatographic (HPLC) method with photodiode array and fluorescent detectors and a gas chromatography mass-spectrometry (GC/MS) method for the analysis of sesamin, asarinin (episesamin), and sesamolin in sesame oil and in serum samples. Sesame oil samples were extracted with methanol whereas the serum samples were extracted with ethyl acetate or n-hexane. The individual lignans were analyzed by HPLC using reversed phase C18 columns. Analytical recoveries of sesamin, asarinin, and sesamolin from sesame oil were 92–94 % with two extractions. Recoveries from serum ranged from 87 to 97 %. The limit of quantitation with the fluorometric detector was 0.1 ng compared to 0.1 μg with the PDA detector. The concentrations of sesamin, asarinin, and sesamolin in Orchids and Sigma sesame oil were 0.4, 0, and 0.15 % and 0.19, 0.09, and 0 %, respectively. The identities of the individual lignans obtained by HPLC were confirmed by GC/MS and the concentrations of sesamin, asarinin, and sesamolin obtained with the fluorometric detector correlated with those obtained by GC/MS (r2 = 0.94, P < 0.001). The HPLC and GC/MS methods permit simple and efficient procedures for the analysis of sesamin, asarinin, and sesamolin in sesame oil samples as well as in serum samples.
Bioavailability and tissue distribution of sesamol in rat.
Sesamol, generally regarded as the main antioxidative component in sesame oil, can be generated from sesamolin by roasting sesame seed or bleaching sesame oil. This paper reports the bioavailability of sesamol in Sprague-Dawley (SD) rats. Biological fluid was sampled following a dose of sesamol of 50 mg/kg by gastric gavage (p.o.) or by intravenous injection. The pharmacokinetic data of sesamol were calculated by noncompartmental model. The tissue distribution of sesamol (p.o., 100 mg/kg) in SD rats was also investigated. The concentration changes of sesamol were determined in various tissues and plasma within a 24 h period after oral administration of sesamol. The results showed that the oral bioavailability of sesamol was 35.5 +/- 8.5%. Sesamol was found to be able to penetrate the blood-brain barrier and go through hepatobiliary excretion. Sesamol conjugated metabolites were widely distributed in SD rat tissues, with the highest concentrations in the liver and kidneys and the lowest in the brain. It is postulated that sesamol is incorporated into the liver first and then transported to the other tissues (lung, kidneys, and brain). The major metabolites of sesamol distributed in the lung and kidney were glucuronide and sulfate.