Sucrose Hydrolysis Research Articles

Enhanced Extracellular Production and Characterization of Sucrose Isomerase in Bacillus subtilis with Optimized Signal Peptides

Sucrose isomerase (SIase) catalyzes the hydrolysis and isomerization of sucrose into isomaltulose, which is an important functional sugar widely used in the food industry. However, the lack of safe and efficient expression systems for recombinant SIase has impeded its production and application. In this study, enhanced expression of a SIase from Klebsiella sp. LX3 (referred to as KsLX3-SIase) was achieved in Bacillus subtilis WB800N, by optimizing the signal peptides. First, 13 candidate signal peptides were selected using a semi-rational approach, and their effects on KsLX3-SIase secretion were compared. The signal peptide WapA was most efficient in directing the secretion of KsLX3-SIase into the culture medium, producing a specific activity of 23.0 U/mL, as demonstrated by shake flask culture. Using a fed-batch strategy, the activity of KsLX3-SIase in the culture medium was increased to 125.0 U/mL in a 5-L fermentor. Finally, the expressed KsLX3-SIase was purified and was found to have maximum activity at 45 °C and pH 5.5. Its Km for sucrose was 267.6 ± 18.6 mmol/L, and its kcat/Km was 10.1 ± 0.2 s−1mM−1. These findings demonstrated an efficient expression of SIase in B. subtilis, and this is thought to be the highest level of SIase produced in a food-grade bacteria to date.

Comparing the effects of isoleucine and leucine supplementation at different dosage on the growth and metabolism of Torulaspora delbrueckii Biodiva during soy whey fermentation

Soy whey is a liquid by-product generated from tofu production and it is often discarded as wastewater after it is generated. Previous studies have shown that out of the three branched-chain amino acids, isoleucine was found to have an inhibitory effect on Torulaspora delbrueckii Biodiva during soy whey fermentation. In this study, a comparison between isoleucine and leucine was carried out to ascertain how these two structural isomers could affect the growth and metabolism of T. delbrueckii Biodiva at various concentrations (40, 80 and 160 mg nitrogen/L). In general, amino acid supplementation sped up the fermentation process relative to unsupplemented samples. Even though glycerol and ethanol production were enhanced in all isoleucine supplemented samples in comparison to unsupplemented samples, isoleucine supplementation resulted in slower yeast growth at day 1 and slower sucrose hydrolysis regardless of the concentration supplemented. As for leucine supplementation, there was no impact on yeast growth, glycerol and ethanol production but sucrose hydrolysis was enhanced in comparison to the unsupplemented samples. Increasing isoleucine and leucine supplementation resulted in corresponding increase in active amyl alcohol and isoamyl alcohol production respectively, but isoleucine had a stimulating effect on increasing the production of other higher alcohols while leucine had an inhibitory effect on the production of other higher alcohols. Therefore, even though isoleucine and leucine are structural isomers with the positional difference of only one methyl group, the impact on the yeast metabolism and growth is visibly different.

High-quality reference genome sequences of two Cannaceae species provide insights into the evolution of Cannaceae.

Canna edulis Ker-Gawl and Canna indica L. are species belonging to the Cannaceae family and both have a very high economic value. Here, we aimed to assemble genomes of C. edulis and C. indica at the chromosome level to generate a reference genome for the Cannaceae family. We also comparatively analyzed the genomes of C. edulis and C. indica and examined the molecular mechanisms responsible for the remarkable differences in plant characteristics in C. edulis varieties. Our results indicated that genome-wide duplication events had recently occurred in C. edulis and C. indica. The comparative analysis of the genomes of C. edulis and C. indica revealed that C. edulis exhibited a remarkable level of replication of genes in the starch and sucrose metabolic pathways, especially during sucrose hydrolysis. This finding is consistent with the fact that the starch content of the C. edulis tuber is higher than that of C. indica. Simplified genome re-sequencing revealed the population structure of 241 C. edulis genes, and a genome-wide association study of leaf traits revealed the location of key genes related to leaf color and morphology. These findings extend our understanding of Cannaceade at the molecular level, and provide an effective theoretical basis for further study and utilization of Cannaceae plants.

Engineering Saccharomyces cerevisiae for the one-step production of a functional sweetening mixture towards food applications

Fructooligosaccharides (FOS) are recognized prebiotics with proven beneficial effects, usually produced by two-step processes. In this work, an in vivo bioprocess was developed for the one-step production of a functional sweetening mixture containing FOS. Sucrose was directly fermented by yeast towards process simplification and cost reduction. Saccharomyces cerevisiae YIL162W lacking the gene responsible for sucrose hydrolysis (SUC2) was transformed to express β-fructofuranosidase FTase inv gene from Schwanniomyces occidentalis (clone GAL1_S196), and its mutated version (clone GAL1_L196), under the inducible galactokinase (GAL1) promotor. The FTase inv mutated gene was also expressed under the glyceraldehyde-3-phosphate dehydrogenase (GPD) constitutive promoter (clone GPD_L196). GPD_L196 clone showed the highest potential for FOS production, achieving a maximum productivity of 8.9 ± 0.4 mg.g−1.h−1 after 60 h, with sucrose supplementation by two pulses, 150 g.L−1 at 0 and 24 h. When co-cultured with S. cerevisiae wild type (WT), GPD_L196 clone achieved the maximum productivity of 10.9 ± 0.5 mg.g−1.h−1 (48 h) with an 1:200 inoculum ratio (WT:GPD_L196) and 150 g.L−1 of sucrose added at 0 and 24 h. After partial purification, a sweetening mixture composed by 75 ± 2 % of FOS and 24 ± 2 % of sucrose was obtained. This bioprocess approach presents high potential for industrial production of functional sweetening mixtures towards food applications.

Two AT-Hook proteins regulate A/NINV7 expression to modulate sucrose catabolism for cold tolerance in Poncirus trifoliata.

Invertase (INV)-mediated sucrose (Suc) hydrolysis, leading to the irreversible production of glucose (Glc) and fructose (Frc), plays an essential role in abiotic stress tolerance of plants. However, the regulatory network associated with the Suc catabolism in response to cold environment remains largely elusive. Herein, the cold-induced alkaline/neutral INV gene PtrA/NINV7 of trifoliate orange (Poncirus trifoliata (L.) Raf.) was shown to function in cold tolerance via mediating the Suc hydrolysis. Meanwhile, a nuclear matrix-associated region containing A/T-rich sequences within its promoter was indispensable for the cold induction of PtrA/NINV7. Two AT-Hook Motif Containing Nuclear Localized (AHL) proteins, PtrAHL14 and PtrAHL17, were identified as upstream transcriptional activators of PtrA/NINV7 by interacting with the A/T-rich motifs. PtrAHL14 and PtrAHL17 function positively in the cold tolerance by modulating PtrA/NINV7-mediated Suc catabolism. Furthermore, both PtrAHL14 and PtrAHL17 could form homo- and heterodimers between each other, and interacted with two histone acetyltransferases (HATs), GCN5 and TAF1, leading to elevated histone3 acetylation level under the cold stress. Taken together, our findings unraveled a new cold-responsive signaling module (AHL14/17-HATs-A/NINV7) for orchestration of Suc catabolism and cold tolerance, which shed light on the molecular mechanisms underlying Suc catabolism catalyzed by A/NINVs under cold stress.

Invertase enzyme

The enzyme known as invertase catalysis the conversion of sucrose into glucose and fructose (EC 3.2.1.26). The best source of invertase is yeast. Internal and exterior in vertases are the two varieties found in S. cerevisiae. Invertase catalyses the hydrolysis of sucrose into fructose and glucose. Pharmaceuticals, analytical measuring probes, and yeast species detection ELISA kits all include this invertase. Immobilization of the invertase naturally is what is meant by this. Different levels of glycoprotein polymerization, glycosylation, and phosphorylation make bacteria invertase unique. A range of gram-positive and gram-negative organisms, including Zymomonas mobilis, and Bacillus strains, produce invertase. Comparing fungal growth to the time course of invertase synthesis by fungi, which ranged from 24 to 192 hours, was analysed. Twenty-four-hour intervals were used to measure the invertase activity. The biological characteristics that were looked at in this study included the amount of invertase-producing bacteria and soil invertase activity. Invertase is used to replace traditional acid hydrolysis.

Integrated microsphere-packed bed enzymatic membrane reactor for enhanced bioconversion efficiency and stability: A proof-of-concept study

Fabricating high-performance enzyme reactors is requested for achieving efficient and stable bioconversions, but remains challenging, because few of them can possess high enzyme loading, sufficient mixing, and efficient mass transfer at the same time. Herein, we propose to develop a novel enzymatic packed bed membrane reactor (EPBMR) by integrating the advantages of both packed bed reactor (PBR) and enzymatic membrane reactor (EMR). A prototype study is conducted with the simplified enzyme-loaded microsphere-ultrafiltration EMR model (Mic-UF EMR). Invertase and dextranase are used in this work to produce glucose and oligodextran by hydrolysis of sucrose and dextran, respectively. Specifically, the use of microspheres can enlarge the contact area between enzymes and substrates and mitigate membrane fouling induced by free enzymes. Thus, Free&Mic-UF EMR (with both free and immobilized enzymes) exhibits a higher sucrose conversion rate (84%) than the EMR with free invertase (34%) and a negligible decline in sucrose conversion for 36 h continuous operation. Membrane fouling is ameliorated by alkaline cleaning and implementation of covalent bonding strategy. In addition, commercial resins with larger sizes are employed to replace konjac glucomannan microspheres (KGM) which reduce the pressure drop of EMR. Finally, by selecting the UF membrane with proper molecular weight cut-off (MWCO), the dextranase-based Mic-UF EMR system successfully produces oligodextran with desired molecular weight (Mw) and narrow Mw distribution. The outcome of this work not only offers a novel enzyme reactor construction strategy but also provides guidance for regulating the performance of EMR.

A versatile CRISPR Cas12a-based point-of-care biosensor enabling convenient glucometer readout for ultrasensitive detection of pathogen nucleic acids

Pathogen nucleic acid detection is of great significance to control the spread of diseases caused by the viruses. Nevertheless, traditional methods for nucleic acid detection such as polymerase chain reaction (PCR) and oligonucleotide microarrays require bulky instruments, which restrain their point-of-care (POC) testing application. Here, we proposed a POC method enabling sensitive detection of pathogen nucleic acids by combining the clustered regularly interspaced short palindromic repeat (CRISPR) Cas12a-based assay and personal glucometer readout (PGM). The quantification of target pathogen DNA by PGM was achieved based on pathogen DNA activates Cas12a ssDNase to cleave magnetic bead-DNA-invertase reporter probe, and separated free invertase to catalyze hydrolysis of sucrose to glucose. Without using nucleic acid amplification technology, we demonstrated here dual signal amplifications based on Cas12a and invertase-mediated catalytic reactions, making it possible to sensitively detect HIV-related DNA or SARS-CoV-2 pseudovirus with the limits of detection of 11.0 fM and 50 copies/μL, respectively. This strategy also showed excellent selectivity as well as potential applicability for detection of HIV in human serum samples or of SARS-CoV-2 in saliva samples. Therefore, our CRISPR-PGM-based dual signal amplifications detection platform might offer a great promise in POC diagnosis of pathogen nucleic acids.

Real-time monitoring the hydrolysis of chiral molecules by optical weak measurement

As one of important optical properties of chiral molecules, the real-time monitoring of the optical rotation is of great significance to study the reaction characteristics of chiral molecules. In this study, we have built an optical frequency domain weak measurement system with linear common-path method for chiral sensing, in which the response between optical rotation and central wavelength shift can reach more than 1200 nm/rad. The high-precision measurement of the optical rotation of chiral molecules and the high-sensitivity real-time monitoring of the decomposition rate in the acidic hydrolysis of sucrose under different concentrations of catalysts are realized using this system. The experimental results are basically consistent with the theoretical prediction. This study shows that optical weak measurement chiral sensing can monitor the hydrolysis degree of chiral molecules in real time without separating and labeling molecules. It has great application potential in the production and research of chiral compounds, especially chiral medicine.

How is Trehalulose Formed by Australian Stingless Bees? - An Intermolecular Displacement of Nectar Sucrose.

Trehalulose, a rare sucrose isomer, is a dominant sugar in stingless bee honey, with traces of the trisaccharide erlose. Incubating sucrose solutions with macerated stingless bee parts (head, thorax, and abdomen) from Tetragonula carbonaria, we observed that sucrose isomerization occurs predominantly in the head incubations, with trehalulose constituting 76.2-80.0% of total detected sugar. By contrast, sucrose hydrolysis occurred in stingless bee abdomen incubations, with glucose and fructose observed as 48.6-51.7% and 48.3-49.7%, respectively, of total detected sugar. Incubating glucose/fructose (1:1) solutions with any bee part did not result in trehalulose formation. In addition, by tracing the 13C isotope-labeled monosaccharide moieties throughout the isomerization from sucrose to trehalulose and erlose, for the first time, the mechanism was established as an enzymatic double displacement reaction. Sucrose acts as a glucose donor giving a β-d-glucosyl enzyme intermediate with fructose release as demonstrated by mixed isotope products. Glucosylation of fructose (inter- or intramolecularly) with isomerization forms trehalulose (favorable), while glucosylation of sucrose forms erlose (less favorable).

The transcription factor StTINY3 enhances cold-induced sweetening resistance by coordinating starch resynthesis and sucrose hydrolysis in potato.

The accumulation of reducing sugars in cold-stored tubers, known as cold-induced sweetening (CIS), negatively affects potato processing quality. The starch to sugar interconversion pathways that are altered in cold-stored CIS tubers have been elucidated, but the mechanism that regulates them remains largely unknown. This study identified a CBF/DREB transcription factor (StTINY3) that enhances CIS resistance by both activating starch biosynthesis and repressing the hydrolysis of sucrose to reducing sugars in detached cold-stored tubers. Silencing StTINY3 in a CIS-resistant genotype decreased CIS resistance, while overexpressing StTINY3 in a CIS-sensitive genotype increased CIS resistance, and altering StTINY3 expression was associated with expression changes in starch resynthesis-related genes. We showed first that overexpressing StTINY3 inhibited sucrose hydrolysis by enhancing expression of the invertase inhibitor gene StInvInh2, and second that StTINY3 promoted starch resynthesis by up-regulating a large subunit of the ADP-glucose pyrophosphorylase gene StAGPaseL3, and the glucose-6-phosphate transporter gene StG6PT2. Using electrophoretic mobility shift assays, we revealed that StTINY3 is a nuclear-localized transcriptional activator that directly binds to the dehydration-responsive element/CRT cis-element in the promoters of StInvInh2 and StAGPaseL3. Taken together, these findings established that StTINY3 influences CIS resistance in cold-stored tubers by coordinately modulating the starch to sugar interconversion pathways and is a good target for improving potato processing quality.

Contrasting Strategies for Sucrose Utilization in a Floral Yeast Clade.

ABSTRACTYeast species in the Wickerhamiella and Starmerella genera (W/S clade) thrive in the sugar-rich floral niche. We have previously shown that species belonging to this clade harbor an unparalleled number of genes of bacterial origin, among which is the SUC2 gene, encoding a sucrose-hydrolyzing enzyme. In this study, we used complementary in silico and experimental approaches to examine sucrose utilization in a broader cohort of species representing extant diversity in the W/S clade. Distinct strategies and modes of sucrose assimilation were unveiled, involving either extracellular sucrose hydrolysis through secreted bacterial Suc2 or intracellular assimilation using broad-substrate-range α-glucoside/H+ symporters and α-glucosidases. The intracellular pathway is encoded in two types of gene clusters reminiscent of the MAL clusters in Saccharomyces cerevisiae, where they are involved in maltose utilization. The genes composing each of the two types of MAL clusters found in the W/S clade have disparate evolutionary histories, suggesting that they formed de novo. Both transporters and glucosidases were shown to be functional and additionally involved in the metabolization of other disaccharides, such as maltose and melezitose. In one Wickerhamiella species lacking the α-glucoside transporter, maltose assimilation is accomplished extracellularly, an attribute which has been rarely observed in fungi. Sucrose assimilation in Wickerhamiella generally escaped both glucose repression and the need for an activator and is thus essentially constitutive, which is consistent with the abundance of both glucose and sucrose in the floral niche. The notable plasticity associated with disaccharide utilization in the W/S clade is discussed in the context of ecological implications and energy metabolism.IMPORTANCE Microbes usually have flexible metabolic capabilities and are able to use different compounds to meet their needs. The yeasts belonging to the Wickerhamiella and Starmerella genera (forming the so-called W/S clade) are usually found in flowers or insects that visit flowers and are known for having acquired many genes from bacteria by a process called horizontal gene transfer. One such gene, dubbed SUC2, is used to assimilate sucrose, which is one of the most abundant sugars in floral nectar. Here, we show that different lineages within the W/S clade used different solutions for sucrose utilization that dispensed SUC2 and differed in their energy requirements, in their capacity to scavenge small amounts of sucrose from the environment, and in the potential for sharing this resource with other microbial species. We posit that this plasticity is possibly dictated by adaptation to the specific requirements of each species.

Ultrasonic Waves Regulate Antioxidant Defense and Gluconeogenesis to Improve Germination From Naturally Aged Soybean Seeds.

Soybean seeds contain substantial triacylglycerols and fatty acids that are prone to oxidation during storage, contributing to the dramatic deterioration of seed vigor. This study reports an ultrasonic waves treatment (UWT), which is a physical method capable of promoting the germination ability of the aged soybean seeds by regulating the antioxidant defense and gluconeogenesis. Germination test revealed that UWT significantly increased the germination rate and seedlings’ establishment of the soybean seeds stored for 12 months, although insignificantly impacting the vigor of fresh (stored for 1 month) and short-term stored (for 6 months) seeds. Further biochemical analysis revealed that UWT decreased the hydrogen peroxide (H2O2), O2⋅–, and malondialdehyde contents in the aged soybean seeds during early germination. Consistently, UWT prominently elevated the activities of superoxide dismutase, catalase, and acetaldehyde dehydrogenase, and also the corresponding gene expressions. Besides, the soluble sugar content of UWT was significantly higher than that of the untreated aged seeds. Analysis of enzyme activity showed UWT significantly upregulated the activities of several key enzymes in gluconeogenesis and the transcription levels of corresponding genes. Moreover, UWT enhanced the invertase activity within aged seeds, which was responsible for catalyzing sucrose hydrolysis for forming glucose and fructose. In summary, UWT improved germination and seedlings establishment of aged soybean seeds by regulating antioxidant defense and gluconeogenesis. This study expands the application of ultrasonication in agricultural production and further clarifies the physiological and molecular mechanisms of the aged seed germination, aiming to provide theoretical and practical guidance for seed quality and safety.

Understanding of exogenous auxin in regulating sucrose metabolism during postharvest tomato fruit ripening

Auxin is involved in regulating the ripening process of tomato fruit, and sucrose metabolism is a vital part of the quality formation during tomato ripening. In comparison, the comprehensive effect of auxin on regulating sucrose metabolism during postharvest tomato fruit ripening remains to be clarified. In this research, tomato fruit at the mature green stage were treated with 2,4-dichlorophenoxyacetic acid (0.45 mM) or deionized water under vacuum respectively. The ethylene production, a* value, firmness, and the contents of sucrose, fructose and glucose, enzymatic activities, also the expressions of major genes related to sucrose metabolism, were measured every 3 d after treatment during the 22 d of storage. Results showed exogenous auxin inhibited tomato fruit ripening, along with the lower a* value and the higher firmness. Meanwhile, exogenous auxin inhibited ethylene production, activities of sucrose phosphate synthase (SPS) and sucrose synthase (SUS), whereas enhanced sucrose hydrolysis and acid invertase (AI) activity. These activities above caused the lower sucrose content during tomato fruit ripening. Furthermore, exogenous auxin changed the expressions of major genes in response to sucrose metabolism, including the induction of sucrose-phosphate synthase3 (SPS3), vacuolar invertase1 (VIN1; TIV1), and cell wall invertase1-3 (CWIN1–3; Lin5-7) (log2 fold change ranged from 1.10 to 7.98), the inhibition of SPS1, SPS4 and sucrosesynthase3 (SUS3) (−3.60 ≤ log2 fold change ≤ −1.67), and the fluctuation of transcript levels of cytoplasmic invertase6 (CIN6), SUS6, SUS2 and vacuolar invertase2 (VIN2; Lin9) (−8.94 ≤ log2 fold change ≤ 3.45). Results indicated auxin might affect sucrose metabolism in the ripening process of postharvest tomato fruit by means of controlling the corresponding enzymatic activities and transcription profiles of key genes to a certain extent, suggesting auxin is probably not the main key regulator of sucrose accumulation during tomato fruit ripening. This study provides an illuminating insight into the regulatory mechanism of auxin in tomato fruit sucrose metabolism.

Enzymatic and structural characterization of β-fructofuranosidase from the honeybee gut bacterium Frischella perrara.

Fructooligosaccharide is a mixture of mostly the trisaccharide 1-kestose (GF2), tetrasaccharide nystose (GF3), and fructosyl nystose (GF4). Enzymes that hydrolyze GF3 may be useful for preparing GF2 from the fructooligosaccharide mixture. A β-fructofuranosidase belonging to glycoside hydrolase family 32 (GH32) from the honeybee gut bacterium Frischella perrara (FperFFase) was expressed in Escherichia coli and purified. The time course of the hydrolysis of 60mM sucrose, GF2, and GF3 by FperFFase was analyzed, showing that the hydrolytic activity of FperFFase for trisaccharide GF2 was lower than those for disaccharide sucrose and tetrasaccharide GF3. The crystal structure of FperFFase and its structure in complex with fructose were determined. FperFFase was found to be structurally homologous to bifidobacterial β-fructofuranosidases even though bifidobacterial enzymes preferably hydrolyze GF2 and the amino acid residues interacting with fructose at subsite - 1 are mostly conserved between them. A proline residue was inserted between Asp298 and Ser299 using site-directed mutagenesis, and the activity of the variant 298P299 was measured. The ratio of activities for 60mM GF2/GF3 by wild-type FperFFase was 35.5%, while that of 298P299 was 23.6%, indicating that the structure of the loop comprising Trp297-Asp298-Ser299 correlated with the substrate preference of FperFFase. The crystal structure also shows that a loop consisting of residues 117-127 is likely to contribute to the substrate binding of FperFFase. The results obtained herein suggest that FperFFase is potentially useful for the manufacture of GF2. KEY POINTS: • Frischella β-fructofuranosidase hydrolyzed nystose more efficiently than 1-kestose. • Trp297-Asp298-Ser299 was shown to be correlated with the substrate preference. • Loop consisting of residues 117-127 appears to contribute to the substrate binding.

Phytoremediation potential of Bermuda grass (Cynodon dactylon (L.) pers.) in soils co-contaminated with polycyclic aromatic hydrocarbons and cadmium

Soils co-contaminated with polycyclic aromatic hydrocarbons (PAHs) and cadmium (Cd) have serious environmental impacts and are highly toxic to humans and ecosystems. Phytoremediation is an effective biotechnology for the remediation and restoration of PAH- and Cd-polluted soils. Pot experiments were conducted to investigate the individual and combined effects of PAHs (1238.62 mg kg−1) and Cd (23.1 mg kg−1) on the phytoremediation potential of Bermuda grass grown in contaminated soils. Bermuda grass exhibited a significant decrease in plant growth rate, leaf pigment content, root activity, plant height and biomass and a remarkable increase in malondialdehyde content and electrolyte leakage when grown in PAH- and Cd-contaminated soils compared with grass grown in uncontaminated soils. The activity of soil enzymes, including urease, alkaline phosphatase, sucrose, and fluorescein diacetate hydrolysis, were reduced in soil with PAH and Cd stress. Furthermore, the toxicity of combined PAHs and Cd on Bermuda grass growth and soil enzyme activity was much higher than that of PAH or Cd stress alone, suggesting a synergistic effect of PAHs and Cd on cytotoxicity. To scavenge redundant reactive oxygen species and avoid oxidative damage, Bermuda grass increased plant catalase, superoxide dismutase, and peroxidase activity and soluble sugar and proline content. The bioconcentration factor of Cd in Bermuda grass grown under Cd alone and combined PAH and Cd exposure was greater than 1 for both, suggesting that Bermuda grass has a high Cd accumulation ability. Under PAH alone and combined PAH and Cd exposure conditions, a higher PAH removal rate (41.5–56.8%) was observed in soils planted with Bermuda grass than in unplanted soils (24.8–29.8%), indicating that Bermuda grass has a great ability to degrade PAHs. Bermuda grass showed great phytoremediation potential for the degradation of PAHs and phytoextraction of Cd in co-contaminated soils.

3D‐Printed Acidic Monolithic Catalysts for Liquid‐Phase Catalysis with Enhanced Mass Transfer Properties

AbstractThe thriving research and development in additive manufacturing and especially 3D printing in chemical engineering and heterogeneous catalysis enables novel and innovative approaches for the shaping of catalysts. In this work, tailor‐made monoliths with complex transport pore channels are designed and printed by fused deposition modelling (FDM) from polystyrene filament. Subsequently, sulfonic acid groups are introduced by sulfonation for a catalytic functionalization of the structured monoliths’ accessible inner surface. As a catalytic test reaction, the aqueous phase hydrolysis of sucrose was chosen. For this reaction the functionalized monoliths exhibited a superior catalytic performance in both batch and continuous reaction mode in comparison to a macroporous sulfonic acid‐functionalized ion exchange resin as commercial benchmark catalyst. This is due to the higher accessibility of the sulfonic acid groups on the surface of the monoliths’ pore channels and hence, enhanced effective reaction kinetics by decreased mass transfer limitations.

Antihyperglycemic Effects of Salvia polystachya Cav. and Its Terpenoids: α-Glucosidase and SGLT1 Inhibitors.

The antihyperglycemic activity of ethanolic extract from Salvia polystachya (EESpS) and its products was evaluated using in vivo, ex vivo and in silico assays; additionally, an acute toxicity assay was evaluated. EESpS was classified as a nontoxic class 5 drug. EESpS, ethyl acetate fraction (EtOAcFr), secondary-6-fraction (SeFr6), ursolic acid (UA), and oleanolic acid (OA) reduced the hyperglycemia in DM2 mice. α-glucosidase inhibition was evaluated with oral sucrose and starch tolerance tests (OSuTT and OStTT), an intestinal sucrose hydrolysis (ISH) assay and molecular docking studies using acarbose as control. SGLT1 inhibition was evaluated with oral glucose and galactose tolerance tests (OGTT and OGaTT), an intestinal glucose absorption (IGA) assay and molecular docking studies using canagliflozin as the control. During the carbohydrate tolerance tests, all the treatments reduced the postprandial peak, similar to the control drugs. During the ISH, IC50 values of 739.9 and 726.3 µM for UA and OA, respectively, were calculated. During the IGA, IC50 values of 966.6 and 849.3 for UA, OA respectively, were calculated. Finally, during the molecular docking studies, UA and OA showed ∆G values of −6.41 and −5.48 kcal/mol−1, respectively, on α-glucosidase enzymes. During SGLT1, UA and OA showed ∆G values of −10.55 and −9.65, respectively.

High-Resolution Determination of Kinetic Parameters of Sucrose Hydrolysis Based on Weak Measurement

We propose a high-resolution scheme for determining the kinetic parameters of sucrose hydrolysis based on the weak measurement, and the parameters including rate constant, half-life, activation energy and pre-exponential factor are experimentally determined. In the scheme, the postselection state of weak measurement is modified by the optical rotation angle in the process of sucrose hydrolysis, and the amplified spin-Hall shift acts as a probe for determining the kinetic parameters. The rate constant and half-life are obtained based on the time variations of amplified spin-Hall shifts under different reaction conditions of temperatures and hydrochloric acid concentrations. The corresponding activation energy and pre-exponential factor are also evaluated for explaining the physical mechanism which influences the rate constant and analyzing how to adjust the reaction conditions to predict or control the rate. The high resolution for optical rotation angle is achieved in our scheme, which can reach <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${\rm {4}}{\rm {.9}} \times {\rm {10}}^{\rm {-4}}$</tex-math></inline-formula> degree with one order of magnitude improvement over the polarimeter. These results can provide a possibility for the determination of chemical kinetic parameters with high-precision, real-time, label-free and convenient effects.

Polysaccharides of nutritional interest in jicama (Pachyrhizus erosus) during root development.

Jicama root applications have focused on their nutraceutical properties without clearly specifying which compounds are related to this effect. Thus, the aim of the present study was to identify the changes in polysaccharides of nutraceutical interest in two commercial jicama roots (YS – Yellow Seed; PS – Purple Seed) during four stages of maturation, focusing on starch, fructooligosaccharides, and pectin (via galacturonic acid), and on their glycemic index, with the goal of determining, if possible, the best cost‐effectiveness between jicama growing stages and nutraceutical effect. Both materials (YS, PS) presented similar growth rates (0.069 and 0.072 cm/day) and final sizes (12.7 ± 1.25, 12.3 ± 1.63 cm). Changes in size were accompanied by changes in protein, fiber, ashes, lipids, and carbohydrates, after 106 or 127 days of growing. It was also found that fructose content was higher than glucose during the maturing stages, possibly because of the hydrolysis of fructooligosaccharides or sucrose for starch production. Concerning inulin, its levels decreased (<6.0%), after the first days (YS: 13.4% ± 0.7%; PS: 8.4% ± 0.2%, 106 days); however, during development, the presence of other fructooligosaccharides was observed (nystose‐YS 106 days 15.8% ± 0.9% and PS‐106 days 18.5% ± 0.1%), while galacturonic acid and native starch levels increased, which must be related to the jicama's low glycemic index found (<25%), and their nutraceutical properties. This work proves the presence of inulin in jicama roots by analytical methods, its dependence on root development and classifies jicama as a low glycemic index food, supporting its nutraceutical character.