Insight into TLR4 receptor inhibitory activity via QSAR for the treatment of Mycoplasma pneumonia disease.

Mycoplasma pneumoniae (MP) is one of the most common pathogenic organisms causing upper and lower respiratory tract infections, lung injury, and even death in young children. Toll-like receptors (TLRs) play an important role in innate immunity by allowing the host to recognize pathogens invading the body. Previous studies demonstrated that TLR4 is a potential therapeutic target for the treatment of MP pneumonia. Therefore, the present study aimed to screen biologically active ingredients that target the TLR4 receptor pathway. We first used molecular docking to screen out the active compounds inhibiting the TLR4 pathway, and then used regression and classification machine learning algorithms to establish a quantitative structure-activity relationship (QSAR) model to predict the biological activity of the screened compounds. A total of 78 molecules were used in QSAR modelling, which were retrieved from the ChEMBL database. The QSAR models had acceptable correlation coefficients of R 2 on the training and testing dataset in the range of 0.96 to 0.91 and 0.93 to 0.76, respectively. The multiclass classification models showed accuracy on training and testing data within ranges of 1.0 to 0.70, 0.96 to 0.63, and log loss ranges from 0.27 to 8.63, respectively. In addition, molecular descriptors and fingerprints have been studied as structural elements involved in increased and decreased inhibitory activities. These results provide a quantitative analysis of QSAR and classification models applicable for high-throughput screening, as well as insights into the mechanisms of inhibition of TLR4 antagonists.

Lactitol and ß-cyclodextrin alleviate the intensity of goaty flavor.

BACKGROUND: Goat milk has balanced nutritional composition, is conducive to digestion and absorption, and does not easily lead to allergic reactions. However, the special goaty flavor in milk has seriously affected consumer acceptance. It is imperative to alleviate the goaty flavor in a safe and efficient way. RESULTS: This study indicated that the supplementation of 6 g kg-1 ß-cyclodextrin or 8 g kg-1 lactitol in goat milk significantly alleviated goaty flavor and improved sensory characteristics. Furthermore, the supplementation of ß-cyclodextrin and lactitol had a synergistic effect in reducing the content of free fatty acids that cause goaty flavor. The content of caproic acid (C6 H12 O2 ), octanoic acid (C8 H6 O2 ), and decanoic acid (C10 H20 O2 ) decreased by 42.46%, 39.45%, and 46.41%, respectively, after a combined group was supplemented with 6 g kg-1 ß-cyclodextrin and 7 g kg-1 lactitol, which was significantly lower than in groups given ß-cyclodextrin or lactitol individually. CONCLUSION: This study provides a novel and effective approach to alleviate goaty flavor and promote the competitiveness of goat milk products. © 2022 Society of Chemical Industry.

Synergism of selective thermal denaturation and glycosylation improves quality characteristics of green soybean tofu.

BACKGROUND: Tofu is rich in nutrients and contains high-quality protein. However, commercial tofu products usually have weak gel strength and low water holding capacity (WHC). In the present study, the effects of selective thermal denaturation (STD) time (0-20 min, 5-min interval; 85 °C) and glycosylation (100 °C; 0, 10 and 20 g kg-1 glucose) on the quality characteristics of green soybean tofu were studied through by the evaluation method of the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) model for the best synergism condition of STD and glycosylation. RESULTS: Compared to STD or glycosylation, combination treatment of STD and glycosylation improved hardness, WHC, yield, protein and fat contents of green soybean tofu. Furthermore, the gel strength, WHC, yield, protein and fat contents of tofu was increased by 135.21%, 20.18%, 12.21%, 24.91%, 44.15% compared to untreated tofu. Meanwhile, synergistic treatment of STD and glycosylation significantly improved microstructure network structure of green soybean tofu and made it more homogeneous and denser. However, the green soybean tofu was faded and turned yellow under the combination of the STD and glycosylation. CONCLUSION: The results obtained through TOPSIS showed that the combination of thermal treatment (85 °C for 15 min) and glycosylation (20 g kg-1 glucose at 100 °C) had the greatest improvement in the characteristics of green soybean tofu. Hence, the combination treatment of STD and glycosylation should be useful for improving the quality characteristics of green soybean tofu and providing the technical references for industrial processing of tofu. © 2022 Society of Chemical Industry.

Comparison of Oxidative and Physical Stabilities of Conjugated Linoleic Acid Emulsions Stabilized by Glycosylated Whey Protein Hydrolysates via Two Pathways.

The objective of the research was to analyze and compare the oxidative and physical stabilities of conjugated linoleic acid (CLA) emulsions stabilized by two glycosylated hydrolysates (GPP-A and GPP-B) that were formed via two different pathways. This study showed that GPP-A exhibited higher browning intensity and DPPH radical scavenging ability in comparison with GPP-B. Moreover, the CLA emulsion formed by GPP-A exhibited a lower creaming index, average particle size, primary and secondary oxidative products, in comparison with GPP-B-loaded emulsion. However, the GPP-A-loaded emulsion showed a higher absolute potential and fraction of interfacial adsorption than that of the CLA emulsion formed by GPP-B. Therefore, the CLA emulsion formed by GPP-A exhibited stronger stabilities in comparison with the GPP-B-loaded emulsion. These results suggested that GPP-A showed an emulsification-based delivery system for embedding CLA to avoid the loss of biological activities. Additionally, the development of CLA emulsions could exert its physiological functions and prevent its oxidation.

Characterization of major volatile compounds in whey spirits produced by different distillation stages of fermented lactose-supplemented whey.

This research aimed to advance the understanding of acceptable sensory qualities of potable whey-based spirit from nonsupplemented, mid-supplemented, and high-supplemented whey samples by analyzing major volatile compounds during different stages of distillation (head, heart, and tail). The results demonstrated that commercial Saccharomyces cerevisiae strain in lactase-hydrolyzed whey showed rapid and complete sugar hydrolysis and efficient ethanol production in 24, 30, and 36 h on average, producing up to 29.5, 42.1, and 56.4 g/L of ethanol, respectively. The variations in titratable acidity, specific gravity, pH value, residual protein, sugar content, and alcohol yield were investigated during the fermentation. The total amount of volatile compound concentrations significantly decreased from the head (2,087-2,549 mg/L) to the tail whey spirits (890-1,407 mg/L). In the whey spirit, 2-methyl-1-butanol, 3-methyl-1-butanol, 2-methyl-1-propanol, 1-propanol, acetaldehyde, and ethyl acetate were the most prevalent dominant compounds, accounting for the largest proportion of total volatile compounds. The volatile compounds detected were far below the acceptable legal limit. The results suggest that high sensory qualities of potable whey-based spirits can be produced by fermentation of lactose-supplemented whey with S. cerevisiae cells.

Laccase cross-linking of sonicated α-Lactalbumin improves physical and oxidative stability of CLA oil in water emulsion.

α-lactalbumin was modified by ultrasound (US, 20 kHz, 43 ± 3.4 W/cm-2) pre-treatments (0, 15, 30 and 60 min) and laccase cross-linking of sonicated α-lactalbumin was used to evaluate the physical and oxidative stability of conjugated linoleic acid (CLA) emulsions. The emulsions prepared with laccase cross-linking US-α-lactalbumin (α-lactalbumin treated with US pre-treatment) and US-α-lactalbumin were scrutinized for oxidative and physical stability at room temperature for two weeks of storage. Laccase cross-linking US-α-lactalbumin (Lac-US-α-lactalbumin) revealed improved physical stability in comparison with US-α-lactalbumin, specified by droplet size, structural morphology, adsorbed protein, emulsifying properties and creaming index. SDS-PAGE analysis showed that there was formation of polymers in Lac-US-α-lactalbumin emulsion. Surface hydrophobicity of Lac-US-α-lactalbumin was higher than that of US-α-lactalbumin, and gradually enhanced with the increase of ultrasound time. More importantly, the measurements of peroxide values and conjugated dienes were used to study the oxidative stability of the CLA emulsions. The Lac-US-α-lactalbumin emulsion proved to be reducing the synthesis of fatty acid hydroperoxides and less conjugated dienes compared to the native and US-α-lactalbumin emulsions. This study revealed that the combination of US pre-treatment and laccase cross-linking might be an effective technique for the modification of CLA emulsions.

Citric acid promotes disulfide bond formation of whey protein isolate in non-acidic aqueous system.

Impacts of citric acid (CA) treatment under non-acidic conditions (pH 7.0, 8.0 and 9.0) on whey protein isolate (WPI) were examined in this study. Size exclusion chromatography and SDS-PAGE indicated that molecular size and weight of WPI-CA became larger at pH 7.0, 8.0 and 9.0 with CA ranged from 0 to 15 mg/mL, but the protein aggregates disappeared after ß-mercaptoethanol was added. The free SH groups of WPI-CA gradually decreased. This could be deduced that CA could promote disulfide bond formation of WPI at the non-acidic pH values. Furthermore, fourier transform infra-red (FTIR) spectroscopy and fluorescence spectroscopy data confirmed the conformational changes of secondary and tertiary structures of CA-modified WPI, respectively. Therefore, these results suggested that disulfide bond formation of WPI occurred at citric acid treatment under non-acidic conditions, being contributed to production of its larger molecular size substances and alteration of its structural characteristics.

Comparison in bioactivity and characteristics of Ginkgo biloba seed polysaccharides from four extract pathways.

The effects of hot-water extraction (HWE), ultrasound-treated extraction (UTE), enzyme-treated extraction (ETE) and ultrasound-enzyme treated extraction (UETE) on the α-glucosidase inhibitory activity, antioxidant activities and characteristics of Ginkgo biloba seed polysaccharides were investigated and compared in this study. Among the four extracted polysaccharides, the UETE-polysaccharide initially exhibited the highest α-glucosidase inhibitory activity and antioxidant activities. The HWE-polysaccharide showed a large number of small compact spherical structures, and the UTE-polysaccharide exhibited an irregular pleated porous shape; meanwhile, the ETE-polysaccharide and UETE-polysaccharide were spongy with smooth surface topography, as observed by scanning electron microscopy (SEM). The four polysaccharides varied in monosaccharide composition. The HWE-polysaccharide mainly consisted of homogeneous mannose; the UETE-polysaccharide was primarily composed of mannose, rhamnose, and glucose in a molar ratio of 8.25:1.00:1.53. The HWE-polysaccharide had the largest molecular weight (4.2 × 105 Da), reduced by the order of the UETE-polysaccharide (2.02 × 104 Da), ETE-polysaccharide (1.72 × 104 Da), and UTE-polysaccharide (1.34 × 104 Da). Thus, the four extract methods exerted significant effects on the bioactivity and characteristics of the polysaccharides. The UETE-polysaccharide from G. biloba seeds showed the highest bioactive activities and distinctive structural characteristics.