Variability in S-Alk(en)yl-L-Cysteine Sulfoxides in Garlic within a Seven-Month Period Determined by a Liquid Chromatography - Tandem Mass Spectrometry Method.

The composition of garlic (Allium sativum L.) may vary among cultivars and, moreover, change over time, thereby affecting both biological activity and flavour. Thus, it is important to identify the trends in the content of bioactive compounds in garlic, by reliable analytical methods. This study was focused on the key sulfur-containing compounds, S-alk(en)yl-L-cysteine sulfoxides (alliin, isoalliin, methiin, propiin), which were quantified by a fast liquid chromatography - tandem mass spectrometry (LC-MS/MS) method. Several garlic cultivars were monitored repeatedly within seven months: one month before harvest maturity; at harvest maturity; and after two and six months of storage. The results showed not only a high variability among individual cultivars, but also among samples of the same cultivar grown at different localities. During storage, a significant increase in isoalliin content (up to 54-fold after six months) occurred. Nevertheless, none of the cultivars showed significantly different properties compared to others, suggesting that many other factors affect garlic composition.

Bioprospecting of Turbinaria Macroalgae as a Potential Source of Health Protective Compounds.

The present study aims to focus on the bioprospecting of marine macroalgae of Turbinaria species, plenteous biomass of the world ocean. Three types of solvents, i.e., H2 O, MeOH/H2 O (80:20, v/v) and hexane/i-PrOH (50:50, v/v), were used for extraction. Both the biological activity and the pattern of present chemicals were characterized. For the cell proliferation assay, the human embryonic kidney 293 cells, cervix/breast/pancreatic adenocarcinoma, and osteosarcoma cells were used. For the antioxidant activity determination, both intracellular assay with human embryonic kidney and cervix adenocarcinoma cells, as well as the biochemical DPPH test, were employed. To complete the information about macroalgae composition, organic compounds were characterized by the liquid chromatography coupled with high resolution tandem mass spectrometry. Attention was concentrated mainly on the lipidomic profile characterization. In spite the fact that any significant antiproliferative effect was not observed for cancer cells, both the Turbinaria species were shown to be good protectors against the oxidative stress of the non-cancer cells. Most of the antioxidants were determined in the hexane/i-PrOH extract. As regards the lipids identified, most of them belonged to the triacylglycerols followed by sphingomyelins, diacylglycerols, and polar (lyso)phospholipids. Additionally to fatty acids with 14, 16 and 18 carbons, also those with odd carbon numbers were frequently present.

Authentication of Meat and Meat Products Using Triacylglycerols Profiling and by DNA Analysis.

Two alternative, complementary analytical strategies were successfully used to identify the most common meat species-beef, pork and chicken-in meat products. The first innovative high-throughput approach was based on triacylglycerols fingerprinting by direct analysis in real time coupled with high-resolution mass spectrometry (DART-HRMS). The second was the classic commonly used DNA analysis based on the use of nuclear or mitochondrial DNA in multiplex polymerase chain reaction (mPCR). The DART-HRMS method represents a rapid, high throughput screening method and was shown to have a good potential for the authentication of meat products. Nevertheless, it should be noted that due to a limited number of samples in this pilot study, we present here a proof of concept. More samples must be analyzed by DART-HRMS to build a robust classification model applicable for reliable authentication. To verify the DART-HRMS results, all samples were analyzed by PCRs. Good compliance in samples classification was documented. In routine practice under these conditions, screening based on DART-HRMS could be used for identification of suspect samples, which could be then examined and validated by accurate PCRs. In this way, saving of both labor and cost could be achieved. In the final phase, commercially available meat products from the Czech market were tested using this new strategy. Canned meats-typical Czech sausages and luncheon meats, all with declared content of beef, pork and chicken meat-were used. Compliance with the label declaration was confirmed and no adulteration was found.

Analysis of phosphodiesterase type 5 inhibitors as possible adulterants of botanical-based dietary supplements: extensive survey of preparations available at the Czech market.

Popularity of natural-based preparations supporting the sexual potency significantly increased in recent years, which also led to the increase of illegal use of phosphodiesterase type 5 inhibitor (PDE-5) in sexual performance enhancement products. In this study, a rapid U-HPLC‒HRMS/MS method has been developed to simultaneously determine 59 PDE-5 inhibitors and their analogues. Within the development of sensitive method for analysis of 59 PDE-5 inhibitors and their analogues, both sample preparation procedure, as well as separation / detection conditions have been optimized. Extraction efficiency of particular extraction solvents, influence of different mobile phase additives on target analytes separation, as well as impact of various settings of mass analyzer on sensitivity of detection were examined. Data were collected in the 'full MS/data dependent MS/MS' acquisition mode (full MS-dd-MS/MS). Before the U-HPLC‒HRMS/MS method was used for analysis of real samples, proper validation had been conducted. The precision of the method expressed as the relative standard deviation (RSD) was ≤4.2% and ≤5.2% at spiking concentrations 5 µg/g and 0.25 µg/g, respectively. The limits of quantification were in the range 0.25 - 0.05 µg/g and the recovery ranged between 71 and 90%. The optimized method was successfully applied for analysis of 64 real samples, and 10 of them were proved to contain both registered or unregistered synthetic PDE-5 inhibitors. Additionally, the acquired U-HPLC‒HRMS/MS fingerprints were demonstrated to serve as an efficient tool for revealing of other type of possible fraud in products labeling. Retrospective mining of markers of herbs declared on dietary supplements packaging allowed to assess the trueness / untruth in the declaration of medical herbs composition.