Formation of dipeptidyl peptidase-IV (DPP-IV) inhibitory peptides from Jack Bean (Canavalia ensiformis (L.) DC.) sprout in simulated digestion.

Bean sprouts are potential plant proteins that produce DPP-IV inhibitory peptides. These peptides must be stable and active in the brush border membrane of the small intestine to inhibit DPP-IV. The purpose of this research is to evaluate the DPP-IV inhibitory activity of jack bean sprouts using pepsin-pancreatin during simulated digestion, as well as the absorption of these peptides through the everted gut sac method. The results showed that after 180 min of digestion simulation, the Mw < 1 kDa peptide fraction of jack bean hydrolysate, which germinated for 60 h (HG60), had the highest inhibitory activity. The duodenum absorbs most of the peptides with inhibitory activity of 61.77%, which is slightly lower than activity after digestion (62.19%). These outcomes suggest that the DPP-IV inhibitory activity of HG60 can be maintained after digestion and absorption. Two novel peptides KAVGDPI and QGVVLRP identified after absorption contain crucial amino acids confirming as DPP-IV inhibitor. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-023-01343-9.

Exogenous brassinolide treatment regulates phenolic accumulation in mung bean sprouts through the modulation of sugar and energy metabolism.

BACKGROUND: The effects of exogenous brassinolide (BR) treatment (3.0 µmol L-1 ) on phenolic biosynthesis in mung bean sprouts were investigated. This investigation included the analysis of sugar content, substrates within the phenylpropane pathway, energy substances, enzymatic activity within the phenylpropane pathway, sugar metabolism and energy metabolism. RESULTS: Results showed that BR treatment significantly increased the levels of total phenolics, p-hydroxybenzoic acid, p-coumaric acid, gallic acid, fumalic acid and caffeic acid. This enhancement was accomplished through the elevation of l-phenylalanine levels and the activation of enzymes associated with the phenylpropane pathway in mung bean sprouts, including phenylalanine ammonia-lyase, cinnamate 4-hydroxylase and 4-coumarate CoA ligase. Furthermore, BR treatment induced alterations in sugar metabolism in mung bean sprouts as evidenced by the increased levels of glucose, fructose, sucrose and phosphoenolpyruvate. Moreover, increased activity was observed for enzymes linked to sucrose metabolism and glycolysis in the BR-treated group. Concurrently, BR treatment bolstered the levels of adenosine triphosphate and energy charge in mung bean sprouts, which was attributed to the activation of H+ -adenosine triphosphatase, Ca2+ -adenosine triphosphatase and succinic dehydrogenase. CONCLUSION: These results suggest that BR treatment can accelerate the accumulation of phenolic compounds in mung bean sprouts. This effect is achieved not only through the activation of the phenylpropane pathway, but also through the modulation of sugar and energy metabolism. The modulation provides ample energy and a substrate for the biosynthesis of phenolics. © 2023 Society of Chemical Industry.

A fluorescent Salamo-Salen-Salamo-Zn(II) sensor for bioimaging and biosensing H2PO4- in Zebrafish and plants.

A newly designed and synthesized Salamo-Salen-Salamo-Zn(II) complex sensor (sensor ZT) was extensively explored for anion sensing studies. The selectivity and sensitivity of the sensor ZT towards H2PO4- ions were based on ICT and CHEF effects, and via displacement pathways in DMSO/H2O (9:1, v/v) medium in the presence of other anions like, PO43-, HPO42- and P2O74- in a short time, separately. The prepared ZT sensor has excellent association constant and low detection lines. The sensing mechanism and binding mode of the sensor were studied by UV-Vis spectroscopy, HR-MS, 1H NMR titration and theory calculations (DFT & TD-DFT) for analytes. The time response and stability of the sensor are also given. Meanwhile, the sensor ZT can be widely used as a simple and effective solid-state optical sensor to detect H2PO4- by intuitive fluorescence changes. In addition, besides the environment can be used as a powerful instrument for detecting H2PO4-, based on the good biocompatibility and tissue permeability of ZT, effectively monitoring H2PO4- in cellular distribution by confocal microscopy using Zebrafish and bean sprout.

Production of Dipeptidyl Peptidase-IV Inhibitory Peptides from Germinated Jack Bean [Canavalia ensiformis (L.) DC.] Flour.

An alternate plant-based protein, jack bean sprout, was explored as a source of bioactive peptides. Germination to increase dipeptidyl peptidase-IV (DPP-IV) inhibitory peptide in jack bean sprout flour has yet to be reported. Therefore, this study aimed to investigate the optimal condition to maximize the content of bioactive peptides with maximum DPP-IV inhibitory activity. The relationship between germination and DPP-IV inhibitory activity was determined by analyzing the proteolytic activity, percentage of degree of hydrolysis (%DH), and peptide content. Peptide samples with the most potent DPP-IV inhibitory activity were subsequently fractionated, identified, and characterized. The 60-h germinated jack bean had the best DPP-IV inhibitory activity (41.57%; half maximal inhibitory concentration=2.24 mg/mL). Proteolytic activity (15.24 unit/g), %DH (11.43%), and peptide content (59.71 mg/g) supported this result. Furthermore, the <1.0 kDa peptide fraction of this sprouted flour had the highest molecular weight (MW) distribution (32.60%) and DPP-IV inhibitory activity (71.99%). Peptide sequences identified from MW <1.0 and 1.0∼3.5 kDa peptide fractions had valine, leucine, isoleucine, glycine, and tryptophan at the N-terminal and also had alanine at the penultimate N-terminal, verifying their presence as DPP-IV inhibitors. Furthermore, peptide sequences generated exhibited other biological activities, including angiotensin-converting enzyme, renin, and α-glucosidase inhibitors.

Authenticating Emergent Adulterant 6-Benzylaminopurine in Bean Sprouts: Virtual Hapten Similarity Enhanced Immunoassay.

6-Benzylaminopurine (6-BA), a plant growth regulator with cytokinin-like properties, was recently reported to be illegally used in bean sprouts to increase their commercial appearance. It is still nevertheless challenging to quickly detect this adulteration. In this work, four novel haptens (haptens 1-4) of 6-BA were rationally designed with computer-assisted modeling analysis and then synthesized for use as immunizing haptens to produce antibodies. One of two obtained antibodies showed high sensitivity and specificity toward 6-BA. Based on the most sensitive anti-6-BA antibody, an indirect competitive enzyme-linked immunosorbent assay (icELISA) was performed, which demonstrated a 50% inhibition concentration (IC50) of 1.18 µg/L and a limit of detection of 0.075 µg/L. The average recoveries of this icELISA for 6-BA of spiked samples ranged from 87.2 to 95.0% with a coefficient of variation of less than 8.7%. Furthermore, the blind samples were detected simultaneously by the method and HPLC-MS/MS, and the results showed good agreement with each other. Therefore, the proposed icELISA can facilitate the rapid surveillance screening of adulterated 6-BA in sprout vegetables.

Polymer brush grafted immobilized metal ion affinity adsorbent based on polydopamine/polyethyleneimine-coated magnetic graphene oxide for selective enrichment of cytokinins in plants.

An immobilized metal affinity (IMAC) adsorbent was prepared for selective enrichment of adenine type CKs, via grafting polymer chain pendant with iminodiacetic acid (IDA) from polydopamine (PDA)/polyethyleneimine (PEI)-coated magnetic graphene oxide (magGO) via surface-initiated-atom transfer radical polymerization (SI-ATRP). The prepared IMAC sorbent exhibited remarkable adsorption performances and good selectivity for adenine-type CKs and was utilized as a sorbent of magnetic solid-phase extraction (MSPE) for effective enrichment of four adenine-type CKs in bean sprouts. Under the optimized extraction conditions, an analytical method for four adenine type CKs in bean sprouts was established by combining the MSPE combined with ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The recoveries of the analytes were between 80.4 ± 1.9% and 114.6 ± 1.5% (n = 3). The limits of detection (LODs) range from 0.63 to 2.30 pg⋅mL-1. The relative standard deviations of intra-day and inter-day were less than 12.6%. The established method was successfully applied to the selective extraction and sensitive detection of trace adenine-type CKs in plant samples.

Sucrose-induced abiotic stress improves the phytochemical profiles and bioactivities of mung bean sprouts.

This study aimed to examine the impact of sucrose treatment on the growth conditions, dietary nutritional quality, and biological activities of mung bean sprouts. Mung bean seeds were sprouted with solutions containing different sucrose concentrations (10, 20, and 30 g/L). The application of exogenous sucrose significantly decreased the height and fresh weight of mung bean sprouts. However, the sucrose-treated sprouts contained more polyphenols, flavonoids, γ-aminobutyric acid, phytosterols, and vitamins. The antioxidant capacities were also significantly higher in the sucrose-treated sprouts than in the control sprouts. The sprouts treated with 2-3 % sucrose showed markedly improved FFA-induced insulin resistance and alcohol-induced oxidative injury in HepG2 cells. Taken together, the elicitor application of sucrose at 3 % during mung bean sprouting could be an effective strategy to improve the dietary phytochemical composition and provide potential health benefits.

[Simultaneous determination of 40 plant growth regulators, fungicides, insecticides, and antibiotics in bean sprouts by QuEChERS-high performance liquid chromatography-tandem mass spectrometry].

Chromatography combined with mass spectrometry is the most commonly used detection technology, and it offers the advantages of high sensitivity and high selectivity. The quick, easy, inexpensive, effective, rugged, and safe (QuEChERS) method is low-cost, effective, and time efficient. The application of the QuEChERS has now been extended to the analysis of contaminants in food samples. The aim of the study was to identify different concentration levels of multiple harmful drug residues in bean sprouts. In this study, QuEChERS coupled with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was established for the simultaneous determination of 40 plant growth regulators, fungicides, insecticides, and antibiotics in bean sprouts. In the HPLC-MS/MS experiment, gibberellic acid, 4-fluorophenoxyacetic acid, chloramphenicol, N6-(δ2-isopentenyl)-adenine, 6-benzylaminopurine, 4-chlorophenoxyacetic acid, and 2,4-dichlorophenoxyacetic acid (2,4-D) were analyzed by MS/MS with negative electrospray ionization (ESI-). The other 33 target analytes (chlormequat, ronidazole, metronidazole, pymetrozine, dimetridazole, methomyl, carbendazim, enoxacin, levofloxacin, pefloxacin mesylate, norfloxacin, ciprofloxacin, enrofloxacin, thiabendazole, lomefloxacin, chlorpyrifos, sarafloxacin, imidacloprid, etc.) were analyzed by MS/MS with positive electrospray ionization (ESI+). Sensitive MS conditions were realized by optimizing the instrumental parameters such as the desolvent temperature, collision energy, spraying needle position, precursor ions, and product ions. Then, the optimal pretreatment method was determined by comparing the recovery rates of the 40 drugs obtained with different extraction solvents (methanol, acetonitrile, acetonitrile containing 0.1% ammonia, acetonitrile with 1% acetic acid), different extraction methods (ultrasonic extraction, shaking extraction), and purification with primary secondary amine (PSA) and C18. In this study, the bean sprouts samples were extracted twice by 10 mL acetonitrile with 1% acetic acid, and extracted under ultrasonic conditions. Then, the extracting solution was only cleaned with 100 mg C18. The chromatographic separation of the 40 compounds was accomplished on a Waters ACQUITY UPLC BEH C18 column (100 mm×2.1 mm, 1.7 µm) with gradient elution. Methanol and 0.01% formic acid aqueous solution were used as the mobile phases. The 40 compounds were analyzed in the multiple reaction monitoring (MRM) mode. The matrix matching external standard method was used for quantitative determination. The results showed that the 40 compounds could be analyzed within 15 min. Under the optimized conditions, the calibration curves showed good linearities for the 40 compounds, and the coefficients of determination (r2) were greater than 0.99 in the range of 2-200 µg/L. The limits of detection (LODs) and limits of quantification (LOQs) were in the range of 0.1-3 µg/kg and 0.3-9 µg/kg, respectively. Using negative bean sprouts as the substrates, the recovery tests were carried out at three spiked levels of 5, 10, and 50 µg/kg. The average recoveries of the 40 drugs were 78.5% to 115.3%, and the corresponding relative standard deviations (RSDs) were 1.3% to 9.7% (n=6). This method was successfully applied to the analysis of the 40 drug residues in 21 batches of local bean sprouts in Handan city. The results revealed the presence of extensive drug residues in the bean sprouts. The 26 batches were detected to varying degrees, among which 4-chlorophenoxyacetic acid, carbendazim, 6-benzyladenine, 2,4-D, enrofloxacin, and metronidazole were detected at high rates. The detection rates of 4-chlorophenoxyacetic acid, 6-benzyladenine, carbendazim, 2,4-D, gibberellic acid, and enrofloxacin were 28.6%, 19.0%, 9.5%, 9.5%, 4.8%, and 4.8%, respectively. The contents ranged from 37.5-352.4, 32.4-273.1, 28.8-38.7, 316.1-20.2, 19.9 and 13.6 µg/kg, respectively. Given its advantages of simplicity, rapidness, and high sensitivity, the developed method can be used for the rapid and accurate determination of trace levels of the 40 drug residues in large quantities of bean sprouts.

Amino-modified Scholl-coupling mesoporous polymer for online solid-phase extraction of plant growth regulators from bean sprouts.

A new amino-modified Scholl-coupling mesoporous polymer (NH2@SMPA)-online solid-phase extraction method, coupled with high-performance liquid chromatography (online SPE-HPLC) was established for the analysis of six plant growth regulators (PGRs) in bean sprouts. NH2@SMPA was synthesized by acid-catalyzed deacetylation of acetylamino-Scholl-coupling mesoporous polymer (SMPA). The diversity of functional groups, such as aromatic, acetylamino, and NH2, was conducive to multiple binding interactions between NH2@SMPA and PGRs. NH2@SMPA exhibited superior extraction capability for PGRs, compared with SMPA and commercial adsorbents. The extraction conditions, including loading solvent, pH of loading solution, eluting solvent, and flow rates of loading and elution, were optimized. Under the optimized conditions, wide linear ranges (0.01-500 µg kg-1) and low detection limits (2.34-20.2 ng kg-1) were obtained. The recoveries were satisfactory, i.e., 86.0% to 109% with relative standard deviations ≤9.8% (n = 3). Finally, the online SPE-HPLC method was successfully used for determination of PGRs in bean sprouts.

Yield and quality characteristics of Korean red bean sprouts produced with different time of seed soaking.

This study was conducted to investigate the yield and quality characteristics of red bean sprouts of three cultivars (Arari, Geomguseul, and Chungju) soaked in water for 0, 6, 12 or 24 h. The sprout yields of 'Arari' and 'Geomguseul' on day 7 were highest with the seeds soaked for 12 h. For 'Chungju', the yields from the seeds soaked for 12 and 24 h were not significantly (p > 0.05) different. Longer hypocotyls and shorter roots, which are also desirable characteristics of good sprouts, were also found in the sprouts with 12 h of seed soaking. The amounts of total minerals, thiamine, total free amino acids, and total phenols and DPPH radical scavenging potential of sprouts of all cultivars were higher than those of their seeds. This study showed that higher yield and better quality of red bean sprouts could be obtained with the seeds soaked for 12 h.

Polyhedral oligomeric silsesquioxane grafted silica-based core-shell microspheres for reversed-phase high-performance liquid chromatography.

Polyhedral oligomeric silsesquioxane (POSS) was used to modify spherical silica to fabricate core-shell POSS@SiO2 microspheres. The material was characterized by Fourier transform infrared experiments, scanning electron microscopy, thermogravimetric analysis and elemental analysis. The material was also used as a stationary phase for HPLC separation. The POSS@SiO2 column exhibits a reverse-phase liquid chromatography (RPLC) retention mechanism. The column efficiency of alkylbenzenes reaches 67,200 plates·m-1. The POSS@SiO2 column was also utilized for separation of basic anilines and polycyclic aromatic hydrocarbons. Compared with the commercial C8 column, the POSS@SiO2 column exhibits enhanced separation selectivity. The column was also used for the separation of synthetic cytokinins 6-benzylaminopurine and 6-furfurylaminopurine in bean sprout after extraction. In addition, the methacrylate groups on the surface of the POSS@SiO2 microsphere were further functionalized so as to facilitate the fabrication of versatile stationary phases with various separation mechanisms. Graphical abstract Schematic presentation of the two-step fabrication of polyhedral oligomeric silsesquioxane grafted silica-based (POSS@SiO2) core-shell microspheres for use in HPLC.

[Determination of 4 kinds of plant growth regulator in bean sprout by solid phase extraction column coupled with ultra-high performance liquid chromatography].

OBJECTIVE: A method for the determination of 6-benzylaminopurine( 6-BAP), isopentennyladenine( z-IP), 4-fluorophenoxyacetic acid( 4-FPA), 4-chlorophenoxyacetic acid( 4-CPA) in bean sprout was developed using solid phase extraction column with ultra-high performance liquid chromatography. METHODS: The sample was extracted by acetonitrile,dehydrated by salt,then centrifugation,and purified by PXC/PWA solid phase extraction column. The chromatographic analysis was carried out on C18 chromatographic column( 100 mm ×2. 1 mm,1. 8 µm),acetonitrile and sodium dihydrogen phosphate for gradient elution,diode array detector for detection,and quantified with external standard method. RESULTS: The calibration curves showed good linearity in the range of 0. 25-25 µg/mL( 6-BAP and z-IP) and 0. 50-50 µg/mL( 4-FPA and 4-CPA) with correlation coefficients greater than 0. 999. Three levels spiked recoveries were carried out using blank bean sprout extraction as substrate,the recoveries ranged from70. 0% to 96. 4%,and the relative standard deviations( RSDs) ranged from 2. 84% to12. 10%( n = 6). The qualitative limits of detections were 0. 0082-0. 075 mg/kg and the quantitative limits were 0. 027-0. 25 mg/kg for the 4 PGRs. CONCLUSION: The method is simple and easy to operate using solid phase extraction column coupled,simultaneous determination of 4 PGRs by ultra-high performance liquid chromatography,can ensure the corresponding accuracy,sensitivity and precision.

The effect of pristine carbon-based nanomaterial on the growth of green gram sprouts and pH of water.

We examined the toxicity of four carbon-based nanomaterials (unmodified) by using carbon quantum dots (CQDs), graphene quantum dots (GQDs), graphene oxide (GO), and single-walled carbon nanotubes (SWCNTs) to cultivate bean sprout. Results showed that the toxicity of these four carbon nanomaterials increases with the increasing of concentration and cultivating time. In addition, pH test was applied to study the effect of carbon-based nanomaterials on water. pH of culture solution displayed unconspicuous dose-dependent, but nanomaterials indeed have a considerable impact on the pH even at low concentration.

Behavior of enteroaggregative Escherichia coli, non-O157-shiga toxin-producing E. coli, enteroinvasive E. coli, enteropathogenic E. coli and enterotoxigenic E. coli strains on mung bean seeds and sprout.

The behavior of enteroaggregative Escherichia coli (EAEC), non-O157 shiga toxin-producing E. coli (non-O157-STEC), enteroinvasive E. coli (EIEC), enterotoxigenic E. coli (ETEC) and enteropathogenic E. coli (EPEC) on mung bean seeds at 25±2 °C and during germination and sprouting of mung bean seeds at 20±2 ° and 30±2 °C and on mung bean sprouts at 3±2 °C was determined. When mung bean seeds were inoculated with EAEC, non-O157 STEC, EIEC, EPEC or ETEC strains, all these diarrheagenic E. coli pathotypes (DEPs) survived at least 90 days on mung bean seeds at 25±2 °C. All DEPs grew during germination and sprouting of seeds, reaching counts of approximately 5 Log and 7 Log CFU/g after 2 days at 20±2 ° and 30±2 °C, respectively. However, when the sprouts were inoculated after 1 day of seeds germination and stored at 20±2 ° or 30±2 °C, no growth was observed for any DEPs during sprouting at 20±2 °C per 9 d; however, a significant increase in the concentration of DEPs of approximately 0.7 log CFU/g was observed during sprouting at 30±2 °C after 1 day of sprout contamination. Refrigeration reduced the number of viable DEPs strains on sprouts after 10 days in storage; nevertheless, these decreases have no practical significance in the safety of the sprouts.