Identification of metabolites in coriander seeds (Coriandrum Sativum L.) aided by ultrahigh resolution total correlation NMR spectroscopy

NMR is a fast method for obtaining a holistic snapshot of the metabolome and also offers quantitative information without separating the compounds present in a complex mixture. Identification of the metabolites present in a plant extract sample is a crucial step for all plant metabolomics studies. In the present work, we used various two dimensional (2D) NMR methods such as J-resolved NMR, total correlation spectroscopy (TOCSY), and heteronuclear single quantum coherence sensitivity enhanced NMR spectroscopy for the identification of 36 common metabolites present in Coriandrum sativum L. seed extract. The identified metabolites belong to the following classes: organic acids, amino acids, and carbohydrates. ¹H NMR spectra of such complex mixtures in general display tremendous signal overlap due to the presence of a large number of metabolites with closely resonating multiplet signals. This signal overlapping leads to ambiguity in an assignment, and hence, identification of metabolites becomes tedious or impossible in many cases. Therefore, the utility of pure-shift proton spectrum along the indirect (F₁) dimension of the F₁-PSYCHE-TOCSY spectrum is demonstrated for overcoming ambiguity in assignment of metabolites in crowded spectral regions from Coriandrum sativum L. seed extract sample. Because pure-shift NMR methods yield ultrahigh resolution spectrum (i.e., a singlet peak per chemical site) along one or more dimensions, such spectra provide better identification of metabolites compared with regular 2D TOCSY where signal overlap and peak distortions lead to ambiguity in the assignment. Nine metabolites were unambiguously assigned by pure-shift F₁-PSYCHE-TOCSY spectrum, which was unresolved in regular TOCSY spectrum.     

Comparison of sample preparation methods combined with gas chromatography with electron‐capture detection for the analysis of multipesticide residues in lotus seeds

Sample preparation is always the major bottleneck in analytical chemistry for the determination of pesticide residues. Different sample preparation methods have been proposed due to the wide variety of pesticides used and the inherent complexity of the matrices. In this study, different sample preparation methods including SPE, matrix solid‐phase dispersion, the quick, easy, cheap, efficient, rugged, and safe method, and a one‐step completion method were compared and evaluated for extracting pesticides from lotus seeds. Analysis was carried out using GC with electron‐capture detection. The results showed that good recoveries for tested pesticides were obtained by using Florisil in the four methods, and the extraction efficiency of the one‐step completion method was superior to the other three methods. The one‐step completion method was confirmed to have good linearity, reproducibility, stability, and recovery for the detection of 36 pesticides in lotus seed samples. The data collected from this study are expected to prove useful in regulating the concentration of the residues in lotus seeds, as well as in protecting human health from the hazards posed by these residues.     

Hydrophilic interaction LC–MS/MS method to avoid endogenous interference in the analysis of 4-hydroxy isoleucine from dietary supplementation of fenugreek

4-Hydroxy isoleucine is one of the potent hypoglycemic active constituents of fenugreek seeds. A method capable of reducing biological interferences is required for bioavailability studies. An isocratic separation of 4-hydroxy isoleucine from endogenous interferences was achieved in ZIC-cHILIC column using 0.1% formic acid in water and acetonitrile (20:80, % v/v) pumped at 0.5 ml/min. Quantification was performed in multiple reaction monitoring mode using the transitions of m/z 148.1→102.1 and m/z 276.1→142.2 for 4-hydroxy isoleucine and homatropine (as internal standard), respectively. After full method validation, 4-hydroxy isoleucine levels in human plasma and commercial fenugreek formulations were determined. This method showed good linearity in the range of 50–2000 ng/mL. Intra- and interday accuracies were in the range of 90.64–109.0% and precision was <4.82% CV. The mean (SD) plasma concentration of 4-hydroxy isoleucine in healthy individuals at 2 h after oral administration of fenugreek tablet was found to be 1590 (260) ng/mL. Half of marketed formulations were found to contain <0.05% of 4-hydroxy isoleucine content. We developed a rapid hydrophilic interaction liquid chromatography–tandem mass spectrometry method for analysis of 4-hydroxy isoleucine in human plasma. This method can be applied directly to conduct the clinical pharmacokinetics studies of 4-hydroxy isoleucine in human population.     

Interspecific Variation between the American Quercus virginiana and Mediterranean Quercus Species in Terms of Seed Nutritional Composition,Phytochemical Content,and Antioxidant Activity

This study aimed to evaluate a complete nutritional composition in the seeds Quercus virginiana to compare this nutritional composition with three Mediterranean Quercus species. We analyzed the seed morphometry, proximate composition, phytochemicals, and antioxidant capacity. The seed of Q. virginiana presented the smaller seed size and weight, while Q. suber presented the highest values. Moreover, Q. virginiana seeds showed the highest amounts of sugar and total lipids, digestibility, energy, palmitic acid, and stearic acid. On the other hand, Q. virginiana seeds showed the lowest values of linoleic acid. Moreover, Q. coccifera seeds presented the highest total phenolics and flavonoids contents and antioxidant activity. The clustering analysis revealed a significant similarity in seed morphometry and nutritional composition between the Mediterranean Q. ilex and Q. suber, grouping with the American Q. virginiana, but to a considerable distance; by contrast, the Mediterranean Q. coccifera was the most distant in the clustering analysis. The content of phenolics and flavonoids and digestibility value were the variables that contributed to the separation to a greater extent in the clustering of the four species. The nutritional and biological activity assessment of plant seed may be considered as an essential mission to find new sustainable sources and novel chemical agents. In this sense, Quercus seeds may be an alternative and a competitive food source for the agri-food industry.     

Preparation of body-temperature-triggered shape-memory polyurethane with biocompatibility using isosorbide and castor oil

Shape memory polyurethanes (SMPUs) have attracted much attention in the biomedical field because they can easily control the transition temperature (T_trans) to shape memory and are biocompatible. In this study, a shape memory polyurethane with both biocompatibility and a T_trans close to the body temperature was synthesized by using natural derivatives of isosorbide and castor oil in place of petroleum-based materials. Isosorbide and castor oil were used to form net points, and polycaprolactone diol (PCL diol) acted as the switching segment. The synthesized four polyurethane (PCL diol/isosorbide/castor oil, PICU-1, 2, 3, 4) with different isosorbide contents exhibited desired thermal and mechanical properties. In the thermo-cyclic shape memory testing experiment, the PICU series demonstrated good shape memory property, with more than 95% shape recovery ratio (R_r) and more than 90% shape fixity ratio (R_f), and PICU-3 recovered its shape within 20 s in a 37 °C water bath. In addition, the PICU series proved to be safe materials with excellent biocompatibility, as indicated by the observed C2C12 cells viability and proliferation. The stent made with the PICU-3 film showed near complete magnetization at 37 °C within 18 s and proved to be a suitable self-expanding stent.     

Antimicrobial Activities of Plant Extracts against Solanum tuberosum L. Phytopathogens

The purpose of the study was to select an environmentally friendly plant biopesticide to protect seed potatoes against phytopathogens. The scope included the evaluation of the antimicrobial activities of 22 plant water extracts, 22 water-glycol extracts, and 3 subcritical carbon dioxide extracts using the agar diffusion method against 10 potato phytopathogens. For the most effective extracts, minimal inhibitory concentration (MIC), chemical composition analysis by gas chromatography–mass spectrometry and in situ assays on seed potatoes were performed. Garlic water extract was finally selected as the most effective in phytopathogen growth inhibition, both in vitro and in situ, with MIC values ranging between 6.3–25 mg/mL. 5-Hydroxymethylfurfural was determined to be the main component of this extract (33.24%). Garlic water extract was proposed as a potential biopesticide against potato phytopathogens.     

The Current State of Knowledge on Salvia hispanica and Salviae hispanicae semen (Chia Seeds)

Chia seeds (Salviae hispanicae semen) are obtained from Salvia hispanica L. This raw material is distinguished by its rich chemical composition and valuable nutritional properties. It is currently referred to as “health food”. The purpose of the present work was to perform a literature review on S. hispanica and chia seeds, focusing on their chemical composition, biological properties, dietary importance, and medicinal uses. The valuable biological properties of chia seeds are related to their rich chemical composition, with particularly high content of polyunsaturated fatty acids, essential amino acids, polyphenols, as well as vitamins and bioelements. The available scientific literature indicates the cardioprotective, hypotensive, antidiabetic, and antiatherosclerotic effects of this raw material. In addition, studies based on in vitro assays and animal and human models have proven that chia seeds are characterized by neuroprotective, hepatoprotective, anti-inflammatory, and antioxidant properties. These properties indicate a valuable role of chia in the prevention of civilization diseases. Chia seeds are increasingly popular in functional food and cosmetic and pharmaceutical industries. That is attributed not only to their desirable chemical composition and biological activity but also to their high availability. Nevertheless, S. hispanica is also the object of specific biotechnological studies aimed at elaboration of micropropagation protocols of this plant species.     

太赫兹成像技术对玉米种子的鉴定和识别

利用太赫兹时域光谱(THz_TDS)测试技术及透射式太赫兹逐点扫描成像技术分别对几种玉米种子DNA和胚的样品进行了光谱和成像测量;利用空间图样成份分析(component spatial pattern analysis)方法对得到的THz像进行识别运算。实验结果表明,几种样品在THz波段都有不同的吸收特性,但都没有明显的吸收峰,不能利用“特征指纹谱”进行识别。用基于THz扫描成像的空间图样成份分析方法能很好地实现不同玉米种子DNA样品的鉴定和识别。与现有的THz图像识别方法相比,这个方法只需要THz像的实验数据和样品的吸收谱信息,不需要样品的其它特征。这项研究为进一步利用THz成像技术实现无损检测、安全检查、质量监测等提供了依据,具有实际应用价值。     

Optimization of a New Extraction Technique for Analysis of Verbenone and cis-Verbenol in Pine Seeds

Results from a systematic study of the factors affecting extraction of cis-verbenol and verbenone from pine seeds are presented. Five extraction conditions were investigated: extraction solvent, method of extraction, extraction temperature, volume of solvent, and the ratio of the mass of sample to the amount of extraction solvent. The resulting optimized method uses magnetic-stirring-assisted extraction of pine seeds (5 g) with ethyl acetate (75 mL) for 20 min, at room temperature. RSDs were less than 5% for both compounds. GC–FID was used for quantification of cis-verbenol and verbenone in the extracts.