The simultaneous saccharification and fermentation of pretreated woody crops to ethanol

Four promising woody crops (Populusmaximowiczii x nigra (NE388), P.trichocarpa x deltoides (Nll), P.tremuloides, and SweetgumLiquidambar styraciflua) were pretreated by dilute sulfuric acid and evaluated in the simultaneous saccharification and fermentation (SSF) process for ethanol production. The yeastSaccharomyces cerevisiae was used in the fermentations alone, and in mixed cultures with β -glucosidase producingBrettanomyces dausenii. Commercial Genencor 150L cellulase enyme was either employed alone or supplemented with β- glucosidase. All SSFs were run at 37 …C for 8 d and compared to saccharifications at 45…C under the same enzyme loadings.S. cerevisiae alone achieved the highest ethanol yields and rates of hydrolysis at the higher enzyme loadings, whereas the mixed culture performed better at the lower enzyme loadings without β -glucosidase supplementation. The best overall rates of fermentation (3 d) and final theoretical ethanol yields (86–90%) were achieved with P.maximowiczii x nigra (NE388) and SweetgumLiquidambar styraciflua, followed by P.tremuloides and P.trichocarpa xdeltoides (N1l) with slightly slower rates and lower yields. Although there were some differences in SSF performance, all these pretreated woody crops show promise as substrates for ethanol production.     

Acid Pullulanase from Bacillus polymyxa MIR-23

Within the frame of a screening program aimed at the isolation of amylolytic sporeformers, one strain with high amylolytic activity designated MIR-23 was selected. The microbial characterization was carried out by morphological and biochemical tests and, by means of statistical treatment, was identified asBacillus polymyxa. The organism could grow in acidic conditions (pH 5.0) on a starch medium and produce α-amylase, pullulanase, and α-glucosidase. Batch cultures showed the highest enzyme activities in the stationary phase. Pullulanase activity exhibited an optimal temperature of 52–57°C at pH 4.5–5.5. These properties would allow its use in the saccharification processes in the starch industries.     

Purification and Characterization of an Intracellular β-Glucosidase from Lactobacillus casei ATCC 393

The lactic acid bacterium,Lactobacillus casei, produces an intracellular β-glucosidase when grown on Man-Rogosa-Sharpe (MRS) medium with cellobiose as carbon source. The β-glucosidase activity is produced intracellulary, and no extracellulary activity was detected. The enzyme was purified by ion-exchange chromatography and gel filtration. The molecular mass of the purified intracellular β-glucosidase as estimated by gel filtration was 480 kDa, consisting of six probably identical subunits. The enzyme exhibited optimum activity at 35°C and pH 6.3 with citrate-phosphate buffer. The enzyme was active against soluble glycosides with (1→4)-β configuration and from Lineweaver Burk plots, K_m value of 16 mmol/L was found for β-pNPG. The β-glucosidase was competitively inhibited by glucose, and no glycosyl transferase activity was observed in the presence of ethanol.     

Hydrolysis of cellobiose by immobilized β-glucosidase entrapped in maintenance-free gel spheres

A crude preparation of Aspergillus niger β-glucosidase (27.5 cello-biase U/mg protein at 40°C, pH 5.0) was immobilized on concanavalin A-Sepharose (CAS). The cellobiase activity of the immobilized enzyme was 1334 U/mg dried CAS or 108 U/mL CAS gel. The β-glucosidase-CAS complex was entrapped within crosslinked propylene glycol alginate/bone-geletin gel spheres that possessed between 0.67 and 2.35 cellobiase U/mL spheres, depending on their size. The effect of cellobiose concentration (10–300 mM) on the activity of native, immobilized, and gel-entrapped enzyme was determined. It was shown that concentrations of cellobiose between 10 and 180 mM were not inhibitory to the entrapped enzyme, although inhibition was found to occur with the native and immobilized enzyme. Exogenous ion addition was not necessary to maintain the structural integrity of the spheres, which were stable for 4 d at 40°C.     

Anti-Inflammatory,Antidiabetic Properties and In Silico Modeling of Cucurbitane-Type Triterpene Glycosides from Fruits of an Indian Cultivar of Momordica charantia L.

Diabetes mellitus is a chronic disease and one of the fastest-growing health challenges of the last decades. Studies have shown that chronic low-grade inflammation and activation of the innate immune system are intimately involved in type 2 diabetes pathogenesis. Momordica charantia L. fruits are used in traditional medicine to manage diabetes. Herein, we report the purification of a new 23-O-β-d-allopyranosyl-5β,19-epoxycucurbitane-6,24-diene triterpene (charantoside XV, 6) along with 25ξ-isopropenylchole-5(6)-ene-3-O-β-d-glucopyranoside (1), karaviloside VI (2), karaviloside VIII (3), momordicoside L (4), momordicoside A (5) and kuguaglycoside C (7) from an Indian cultivar of Momordica charantia. At 50 µM compounds, 2–6 differentially affected the expression of pro-inflammatory markers IL-6, TNF-α, and iNOS, and mitochondrial marker COX-2. Compounds tested for the inhibition of α-amylase and α-glucosidase enzymes at 0.87 mM and 1.33 mM, respectively. Compounds showed similar α-amylase inhibitory activity than acarbose (0.13 mM) of control (68.0–76.6%). Karaviloside VIII (56.5%) was the most active compound in the α-glucosidase assay, followed by karaviloside VI (40.3%), while momordicoside L (23.7%), A (33.5%), and charantoside XV (23.9%) were the least active compounds. To better understand the mode of binding of cucurbitane-triterpenes to these enzymes, in silico docking of the isolated compounds was evaluated with α-amylase and α-glucosidase.     

Synthesis of N-Substituted Iminosugar C-Glycosides and Evaluation as Promising α-Glucosidase Inhibitors

A series of N-substituted iminosugar C-glycosides were synthesized and tested for α-glucosidase inhibition. The results suggested that 6e is a promising and potent α-glucosidase inhibitor. Enzymatic kinetic assays indicated that compound 6e may be classified as an uncompetitive inhibitor. The study of structure-activity relationships of those iminosugars provided a starting point for the discovery of new α-glucosidase inhibitors.     

Synthesis,In Vitro Anti-Microbial Analysis and Molecular Docking Study of Aliphatic Hydrazide-Based Benzene Sulphonamide Derivatives as Potent Inhibitors of α-Glucosidase and Urease

A unique series of sulphonamide derivatives was attempted to be synthesized in this study using a new and effective method. All of the synthesized compounds were verified using several spectroscopic methods, including FTIR, ¹H-NMR, ¹³C-NMR, and HREI-MS, and their binding interactions were studied using molecular docking. The enzymes urease and α-glucosidase were evaluated against each derivative (1–15). When compared to their respective standard drug such as acarbose and thiourea, almost all compounds were shown to have excellent activity. Among the screened series, analogs 5 (IC₅₀ = 3.20 ± 0.40 and 2.10 ± 0.10 µM) and 6 (IC₅₀ = 2.50 ± 0.40 and 5.30 ± 0.20 µM), emerged as potent molecules when compared to the standard drugs acarbose (IC₅₀ = 8.24 ± 0.08 µM) and urease (IC₅₀ = 7.80 ± 0.30). Moreover, an anti-microbial study also demonstrated that analogs 5 and 6 were found with minimum inhibitory concentrations (MICs) in the presence of standard drugs streptomycin and terinafine.     

Chemical Constituents from the Leaves of Ligustrum robustum and Their Bioactivities

The leaves of Ligustrum robustum have been consumed as Ku-Ding-Cha for clearing heat and removing toxins, and they have been used as a folk medicine for curing hypertension, diabetes, and obesity in China. The phytochemical research on the leaves of L. robustum led to the isolation and identification of two new hexenol glycosides, two new butenol glycosides, and five new sugar esters, named ligurobustosides X (1a), X₁ (1b), Y (2a), and Y₁ (2b) and ligurobustates A (3a), B (3b), C (4b), D (5a), and E (5b), along with seven known compounds (4a and 6–10). Compounds 1–10 were tested for their inhibitory effects on fatty acid synthase (FAS), α-glucosidase, and α-amylase, as well as their antioxidant activities. Compound 2 showed strong FAS inhibitory activity (IC₅₀ 4.10 ± 0.12 μM) close to that of the positive control orlistat (IC₅₀ 4.46 ± 0.13 μM); compounds 7 and 9 revealed moderate α-glucosidase inhibitory activities; compounds 1–10 showed moderate α-amylase inhibitory activities; and compounds 1 and 10 displayed stronger 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) ammonium salt (ABTS) radical scavenging effects (IC₅₀ 3.41 ± 0.08~5.65 ± 0.19 μM) than the positive control l-(+)-ascorbic acid (IC₅₀ 10.06 ± 0.19 μM). This study provides a theoretical foundation for the leaves of L. robustum as a functional tea to prevent diabetes and its complications.     

Development and Characterization of Novel Biopolymer Derived from Abelmoschus esculentus L. Extract and Its Antidiabetic Potential

Abelmoschus esculentus (Okra) is an important vegetable crop, widely cultivated around the world due to its high nutritional significance along with several health benefits. Different parts of okra including its mucilage have been currently studied for its role in various therapeutic applications. Therefore, we aimed to develop and characterize the okra mucilage biopolymer (OMB) for its physicochemical properties as well as to evaluate its in vitro antidiabetic activity. The characterization of OMB using Fourier-transform infrared spectroscopy (FT-IR) revealed that okra mucilage containing polysaccharides lies in the bandwidth of 3279 and 1030 cm⁻¹, which constitutes the fingerprint region of the spectrum. In addition, physicochemical parameters such as percentage yield, percentage solubility, and swelling index were found to be 2.66%, 96.9%, and 5, respectively. A mineral analysis of newly developed biopolymers showed a substantial amount of calcium (412 mg/100 g), potassium (418 mg/100 g), phosphorus (60 mg/100 g), iron (47 mg/100 g), zinc (16 mg/100 g), and sodium (9 mg/100 g). The significant antidiabetic potential of OMB was demonstrated using α-amylase and α-glucosidase enzyme inhibitory assay. Further investigations are required to explore the newly developed biopolymer for its toxicity, efficacy, and its possible utilization in food, nutraceutical, as well as pharmaceutical industries.