Determination of E,E-farnesol in Makgeolli (rice wine) using dynamic headspace sampling and stir bar sorptive extraction coupled with gas chromatography-mass spectrometry

SAFE and SBSE combined with GC-MS and GC-O for characterization of flavor compounds in Zhizhonghe Wujiapi medicinal liquor

Volatile compounds in Chinese Zhizhonghe Wujiapi (WJP) medicinal liquor were extracted by solvent-assisted flavor evaporation extraction (SAFE) and stir bar sorptive extraction (SBSE), respectively, and identified by gas chromatography-mass spectrometry. Results showed that a total of 123 volatile compounds (i.e., 108 by SAFE, 50 by SBSE, and 34 by both) including esters, alcohols, acids, aldehydes, ketones, heterocycles, terpenes and terpenoids, alkenes, phenols, and other compounds were identified, and 67 of them were confirmed as aroma-active compounds by the application of the aroma extract dilution analysis coupled with gas chromatography-olfactometry. After making a simulated reconstitute by mixing 41 characterized aroma-active compounds (odor activity values ≥1) based on their concentrations, the aroma profile of the reconstitute showed good similarity to that of the original WJP liquor. Omission test further corroborated 34 key aroma-active compounds in the WJP liquor. The study of WJP liquor is expected to provide some insights into the characterization of special volatile components in traditional Chinese medicine liquors for the purpose of quality improvement and aroma optimization.

UHPLC-DAD Method Development and Validation: Degradation Kinetic, Stress Studies of Farnesol and Characterization of Degradation Products Using LC-QTOF-ESI-MS with in silico Pharmacokinetics and Toxicity Predictions

Farnesol (FAR) is a sesquiterpene molecule with high lipophilicity that has antibacterial and other pharmacological properties along with broad nutritional values with high commercial values. Although having potential, FAR stability behavior and degradation kinetics are not available in the literature. Hence, it is very essential to develop a simple, rapid, accurate, precise, robust, cheap UHPLC-DAD method for FAR. It was also proposed to study mechanistic insights into FAR under different degradation conditions. Therefore, we hypothesized to do systematic stability studies along with degradation kinetic and accelerated stability studies. The developed method was validated. FAR was studied for stress studies, degradation kinetics and ADMET prediction of degradants. Degradation products were characterized using LC-QTOF-ESI-MS. Developed method consists of an isocratic mobile phase with a wavelength of 215 nm. The percent recoveries for FAR were observed within the acceptance limit of 98-102%. The eight major degradation products were formed during stress studies. FAR follows first-order degradation kinetics. FAR and all degradants were found to have more than 75% good human oral absorption, and are non-toxic. FAR UHPLC-DAD method was developed, validated and performed stability studies to know the possible degradation pattern along with degradation kinetic studies.

Unambiguous determination of farnesol and tyrosol in vaginal fluid using fast and sensitive UHPLC-MS/MS method

The new ultra-high performance liquid chromatography method with tandem mass spectrometry detection (UHPLC-MS/MS) has been optimized to allow fast, selective, and high-throughput analysis of two Candida albicans quorum sensing molecules (QSM), farnesol and tyrosol. The problem of the presence of the interference in the samples and system was successfully solved by careful optimization of chromatographic conditions. Charged hybrid stationary phase modified with pentafluorophenyl group and optimized gradient elution provided adequate separation selectivity and peak shapes. The impurity was identified as dibutyl phthalate and had the same m/z ions as farnesol leading to an important interference on selected reaction monitoring channel. Two different types of biological matrices originating from vaginal fluid, supernatant and sediment, were analysed. Micro-solid phase extraction in pipette tips was optimized for the selective isolation of QSM from the supernatant. The insufficient retention of farnesol on the extraction sorbent was improved when 1% of organic solvent was added prior to extraction, while the retention of tyrosol was only possible when using combined C8 and polymer sorbent type. Strong retention of farnesol had to be solved by increasing elution solvent strength and volume up to 600 μL. However, this approach did not allow the pretreatment of sediment samples due to the sorbent clogging. Therefore, our previously developed protein precipitation method was modified and validated to analyse the sediments. New developed UHPLC-MS/MS method provided suitable accuracy and precision for the determination of QSM in vaginal fluid while using only 50 μL sample volume and two different sample preparation methods.

Impact of Microbial Composition of Cambodian Traditional Dried Starters (Dombea) on Flavor Compounds of Rice Wine: Combining Amplicon Sequencing With HP-SPME-GCMS

Dombae is a traditional ferment starter which has been used for starchy based wine production in Cambodia. However, the production technology of rice wine in Cambodia is not optimized. The current study aimed to investigate the microbiota associated in five ferment starters and the effect of a traditional fermentation process using a metagenomics sequencing analysis and HS-SPME-GCMS for the characterization of the aromatic profiles at the end of fermentation. Most of bacteria identified in this study were lactic acid bacteria including Weissella cibaria, Pediococcus sp. MMZ60A, Lactobacillus fermentum, and Lactobacillus plantarum. Saccharomyces cerevisiae and Saccharomycopsis fibuligera were found to be abundant yeasts while the only amylolytic filamentous fungus was Rhizopus oryzae. A total of 25 aromatic compounds were detected and identified as esters, alcohols, acids, ketones and aldehydes. The alcohol group was dominant in each rice wine. Significant changes were observed at the level of microbial communities during fermentation, suggesting microbial succession for the assimilation of starch and subsequently assimilation of fermentation by-products leading to the production of flavor compounds. At this level, the presence of Weissella, Pediococcus, and Lactobacillus genus was strongly correlated with most of the flavor compounds detected.

Stir bar sorptive extraction: recent applications, limitations and future trends

Stir bar sorptive extraction (SBSE) has generated growing interest due to its high effectiveness for the extraction of non-polar and medium-polarity compounds from liquid samples or liquid extracts. In particular, in recent years, a large amount of new analytical applications of SBSE has been proposed for the extraction of natural compounds, pollutants and other organic compounds in foods, biological samples, environmental matrices and pharmaceutical products. The present review summarizes and discusses the theory behind SBSE and the most recent developments concerning its effectiveness. In addition, the main results of recent analytical approaches and their applications, published in the last three years, are described. The advantages, limitations and disadvantages of SBSE are described and an overview of future trends and novel extraction sorbents and supports is given.

Immunostimulatory effects of polysaccharides isolated from Makgeolli (traditional Korean rice wine)

Makgeolli is a traditional Korean rice wine, reported to have various biological functions. In this study, the immunostimulatory activity of a polysaccharide from makgeolli (PSM) was investigated. The polysaccharide fraction was isolated from makgeolli by hot water extraction, ethanol precipitation, dialysis, and lyophilization. The major constituents in PSM were neutral sugars (87.3%). PSM was composed of five different sugars, glucose, mannose, galactose, xylose, and arabinose. In normal mice, PSM treatment increased the spleen index (p < 0.05) as well as splenocyte proliferation (p < 0.05) in combination with concanavalin A or lipopolysaccharide. The immunostimulatory activities of PSM were also examined in cyclophosphamide (CY)-induced immunosuppressed mice. Mice treated with PSM exhibited increased splenocyte proliferation (p < 0.05), natural killer cell activity, and white blood cell counts (p < 0.01) compared with immunosuppressed mice. These results indicate that PSM can enhance immune function in normal mice and CY-induced immunosuppressed mice.