[Monolithic column-gold composite substrate preparation and application to SERS detection of pigment].

In the present study, we developed a novel SERS substrate with the porous monolith material combined with classic gold nanoparticles, and erythrosine as the research object, by adjusting the different experimental conditions for optimal SERS enhancements, including system pH and mixing time, and ultimately selected the optimum pH value 5.06 and mixing time 25 min. Compared with the traditional gold plastic substrate enhancement effect, the experimental conditions were applied to the monolith substrate SERS detection of dye erythrosine, different concentrations of samples were used for erythrosine SERS detection, and the detection limit reached 0.1 g x mL(-1). The method uses the payload of gold nanoparticles in mesoporous materials to effectively enhance the SERS signal. And this method has the advantages of simpleness and good stability, which provides a favorable theoretical basis for the rapid prohibited colorings screening.

[Structural characterization and spectroscopic analysis of the aloin].

Aloe is widely used in various fields for its rich polysaccharides, proteins, amino acids, vitamins, active enzymes and trace beneficial elements to human body. However, the main active ingredient aloin is also an allergenic ingredient, which even may cause a severe allergic reaction In this study, infrared spectroscopy, Raman spectroscopy applied to the structural characterization of the aloin Density functional theory (DFT) is applied to the theoretical calculations using the B3LYP/6-31G (d) basis set vibration, which was helpful to understand the aloin molecular vibrational frequency. By comparing we choose the optimal experimental condition for water as solvent under alkaline conditions, the detection limit of the Aloin can reach a level of 5 ppm, which can be considered the theoretical basis for rapid detection of aloin content.

Core-shell Au@MIL-100 (Fe) as an enhanced substrate for flunixin meglumine ultra-sensitive detection.

This study aimed to develop and validate a simple and efficient surface-enhanced Raman spectroscopy (SERS) method to determine flunixin meglumine (FM) residues in animal tissues through using core-shell Au@MIL-100 (Fe) as enhanced substrate. Au@MIL-100 (Fe) composite material was synthesized by coating metal-organic framework materials (MOFs) on the surface of gold nanoparticles using the solvothermal method. Transmission electron microscopy (TEM), UV-vis spectrum, SERS spectrum, X-ray diffraction (XRD), Infrared spectrum (FT-IR), and EDX elemental mapping results revealed that the structural composition of the compound has good properties with localized surface plasmon resonance (LSPR) properties, high adsorption capacity, excellent SERS sensitivity and stability. When it was used as SERS substrate, the results of quantitative analysis of FM in pork showed a linear range of 0.10-50 mg·L-1 with a correlation coefficient (R2) of 0.9819, the limit of detection (LOD) of 0.15 mg·g-1, the recovery rate of 88.94%∼104.77%, the intra- and inter- batch relative standard deviation (RSD) of 3.57%∼14.22% and 0.18%∼3.44% respectively. Further verification results of the existing standard methods showed no significant difference between the SERS and UV methods (P < 0.05), as well as demonstrating that the SERS method has optimal precision, accuracy, and practicality. These results exposed that Au@MIL-100 (Fe) as a SERS substrate has great potential in rapid and on-site detection analysis.

Development of UPLC-MS/MS method for determining hainanmycin in foods of animal origin.

Hainanmycin is a polyether antibiotic. Toxicological studies have shown the adverse effects of hainanmycin on animals and humans. At present, no study is available on the detection of hainanmycin in edible tissues of animals. Hence, a fast and accurate detection method for hainanmycin is essential. This study aimed to develop a new analytical method based on ultra-high-performance liquid chromatography-tandem mass spectrometry to detect hainanmycin in 10 matrices, including milk, eggs, fat, kidney, muscles and livers of chicken, beef and sheep. The limit of detection and the limit of quantitation of the 10 matrices were 0.1-0.4 µg/kg and 0.25-1 µg/kg, respectively, and were far below the maximum residue limits of other polyether anticoccidial drugs (1-150 µg/kg). The recoveries of hainanmycin ranged from 79% to 105%, and the relative standard deviation ranged from 2.8% to 12.0%. The research results prove that the proposed method is operational and simple in detecting hainanmycin, and has high precision and accuracy in a variety of matrices.

Synergistic combination of Sapindoside A and B: A novel antibiofilm agent against Cutibacterium acnes.

Sapindus saponins extracted from Sapindus mukorossi Gaertn. have been reported to exert antibacterial activity against Cutibacterium acnes (C. acnes). However, there are no reports about their potentials against its biofilm, which is a major contributor to the antibiotic resistance of C. acnes. This study aimed to investigate the synergistic antibiofilm activity and action of the combination of Sapindoside A and B (SAB) against C. acnes. SAB with sub-MICs significantly inhibited the early-formed and mature biofilm of C. acnes and decreased the adhesion and cell surface hydrophobicity (p < 0.05). Also, SAB greatly reduced the production of exopolysaccharide and lipase (p < 0.05), and the binding mode of SAB and lipase was predicted by molecular docking, via hydrogen bonds and hydrophobic interactions. Biofilm observed with electron microscopies further confirmed the high antibiofilm activity of SAB against C. acnes. Furthermore, a significant down-regulation of biofilm biosynthesis-associated genes was observed. The combination index explained the synergistic effects of SAB leading to the above results, and the contribution of SA was greater than that of SB. The current results showed that SAB had synergistic antibiofilm activity against C. acnes, and the Sapindoside A played a major role, indicating that SAB could be a natural antiacne additive against C. acnes biofilm-associated infections.

[DFT and surface-enhanced Raman scattering studies of BPA].

On the base of the vibration theory, the spectrum of bisphenol A(BPA) molecule was calculated by the density functional theory(DFT) using B3LYP/6-311G(d), and the normal Raman spectrum (NRS) of BPA was assigned in detail. The surface enhanced Raman scattering (SERS) of the BPA molecule was obtained by gold sol enhancement. The adsorption of BPA to gold surface was analyzed: in acidic pH, the molecule was adsorbed on the gold surface by =CO-, the vibration of the band O-H disappeared, and the benzene ring was perpendicular on the surface of gold sol.

Potent in vitro synergistic antibacterial activity of natural amphiphilic Sapindoside A and B against Cutibacterium acnes with destructive effect on bacterial membrane.

Sapindus saponins are obtained from the outer bark of Sapindus mukorossi Gaertn. (S. mukorossi), and they have become an interesting subject in the search for new anti-acne agents without resistance. This study aimed to screen the synergistic antibacterial combination from Sapindus saponins and investigated the synergistic antibacterial action via targeting the cell membrane of Cutibacterium acnes (C. acnes) to reduce the effective dose. The combination of Sapindoside A and B (SAB) was obtained with synergistic activity against C. acnes. SAB led to the leakage of ions and disturbed the membrane morphology of C. acnes. The spectral features of cell membrane composition showed obvious changes based on Raman spectroscopy, and changes in membrane protein microenvironment were also observed by fluorescence spectroscopy. Among the above results, the contribution of Sapindoside A was greater than that of Sapindoside B to the synergistic combination of SAB. Furthermore, molecular docking demonstrated that Sapindoside A interacted with penicillin-binding protein 2, playing an important role in peptidoglycan synthesis for the cross wall, and showed a higher binding score than Sapindoside B, further indicating that the greater contribution in the synergistic action of SAB on membrane proteins. Collectively, these results showed that the synergistic antibacterial action of SAB against C. acnes could be achieved by attacking cell membrane, and Sapindoside A played a major role, suggesting that SAB has the potential to be the natural anti-acne agent additive in the cosmetic industry.

Synergistic antibacterial combination of Sapindoside A and B changes the fatty acid compositions and membrane properties of Cutibacterium acnes.

Sapindus saponins extracted from S. mukorossi have been reported to exert antibacterial activities against skin pathogenic bacteria, but their antibacterial mechanism is still at an exploratory stage. The objective of this study was to explore the synergistic antibacterial mechanism of the combination of two Sapindus saponins, namely Sapindoside A and B (SAB) against Cutibacterium acnes (C. acnes) 6919 via targeting the fatty acid compositions and membrane properties. After exposure to SAB, C. acnes cells increased the cell surface hydrophobicity and reduced the cell membrane fluidity by changing the composition of membrane fatty acids. In the fatty acid compositions, the content of two main fatty acids 12-methyl-tetradecanoic acid (isoC15:0) and octadecanoic acid (C18:0) reduced and improved respectively with the addition of SAB, and fatty acid biosynthesis-related genes were significantly down-regulated (p < 0.05). Further, molecular docking demonstrated that SAB interacted with FabD, which is an essential enzyme for bacterial type II fatty acid synthesis, via hydrogen bonds and hydrophobic interactions. In the above results, the contribution of SA to SAB was greater than that of SB. In summary, the results revealed that SAB changed the fatty acid compositions of C. acnes, further disrupting the cell membrane properties, and SA played a major role, suggesting that SAB could be a natural antiacne additive against C. acnes-associated infections.

Isolation of two sesquiterpene glycosides from Sapindus mukorossi Gaertn. with cytotoxic properties and analysis of their mechanism based on network pharmacology.

The anti-tumor effects of two compounds purified from Sapindus mukorossi Gaertn. (S. mukorossi.) on breast cancer in vitro were observed. Their chemical structures were identified as sesquiterpene glycosides, namely, Mukurozioside IIa and Mukurozioside IIb. The results of XTT assay indicated that their inhibition rates against three cancer cell lines (MCF-7, MDA-MB-231 and MDA-MB-435s) reached approximately 80% at a concentration of 200 µg/mL, which were higher than that of cyclophosphamide (below 40% at 200 µg/mL), and their 50% inhibiting concentrations were ranged from 120.73 to 154.01 µg/mL, indicating their inhibition were weaker than their parent fraction. Furthermore, the mechanism on breast cancer was predicted, and 22 targets including PTPN1, IL2 and VEGFA were relatively important. These results illustrated the anti-breast cancer activity of S. mukorossi was related to the two compounds with the structure of sesquiterpene glycosides, but they did not represent the full activity of their parent fraction.

Saponin fraction from Sapindus mukorossi Gaertn as a novel cosmetic additive: Extraction, biological evaluation, analysis of anti-acne mechanism and toxicity prediction.

ETHNOPHARMACOLOGICAL RELEVANCE: Sapindus mukorossi Gaertn. (S. mukorossi), known as 'mu huan zi' in Chinese folklore, belongs to the family Sapindaceae and it has been traditionally used for treating coughing and excessive salivation, removing freckle, whitening skin, etc. Evidence-based medicine also verified the antimicrobial, anti-tyrosinase and anti-acne activity of S. mukorossi extract, suggesting that it has the potential to be a pharmaceutical and cosmetic additive. AIM OF THE STUDY: The present study was intended to evaluate the freckle-removing and skin-whitening activities of S. mukorossi extracts, and further analyzing the potential anti-acne mechanism. METHODS: Saponin fractions were purified by using the semi-preparative high-performance liquid chromatography, and their antibacterial activity was detected against Propionibacterium acnes (P. acnes), which was the leading cause of inflamed lesions in acne vulgaris. The anti-lipase and anti-tyrosinase activities were assayed using a commercial kit, while the potential anti-acne mechanism was predicted on the basis of the network pharmacology. Active components of saponin fraction were identified by HPLC-MS analysis. Furthermore, the different toxicity level of compounds was predicted according to the quantitative structure-activity relationship, and the first application of crude extract and saponin fraction to facial masks was analyzed based on the comprehensive evaluation method. RESULTS: The saponin fraction (F4) purified from the fermentation liquid-based water extract (SWF) showed the best antibacterial activity against P. acnes ATCC 6919 with the MIC of 0.06 mg/mL, which was 33-fold of its parent SWF (with the MIC of 2.0 mg/mL). Compared with SWF, the application of F4 caused greater inhibition rates on lipase and tyrosinase. Chemical constituents of F4 were evaluated, from which four oleanane-type triterpenoid saponins were detected to contribute to the above biological activities of F4. The mechanism of the four compounds on anti-acne was predicted, and seven targets such as PTGS2 and F2RL1 were obtained to be important for the treatment of acne. The four compounds were also predicted to have different levels of toxicity to various species, and they were not harmful to rats. Besides, F4 and SWF were applied to facial masks and there was no significant influence on the physicochemical properties including pH, stability, and sensory characteristics. CONCLUSION: This work demonstrated that oleanane-type triterpenoid saponins were speculated to contribute to the skin-whitening, freckle-removing, and anti-acne activities of F4. These findings will facilitate the development of the S. mukorossi extract and the allied products as the new and natural anti-acne agent and cosmetic additives.

The chemical profile and biological activity of different extracts of Sapindus mukorossi Gaertn. against Cutibacterium acnes.

This study evaluated the antibacterial activities of different extracts of Sapindus mukorossi Gaertn. (S. mukorossi) on Cutibacterium acnes (C. acnes). The extract solvent and procedure were screened, based on the yield of saponins and minimum inhibitory concentration (MIC). The results showed that the optimized product, fermentation and ethyl acetate extract by adding isoamyl alcohol from water extract of S. mukorossi (SWFEAI), had the highest yield of saponins (7.83 ± 0.26%) and the best antibacterial activity (MIC = 0.125 mg/mL) on C. acnes. The destroyed bacterial cell membrane and wall were observed by transmission electron microscopy, which then resulted in cell lysis and death. Furthermore, 20 compounds of SWFEAI were detected, among which oleanane-type triterpenoid saponins with molecular weights of 734, 750, 882, 924 and 966 were speculated to contribute to the antibacterial activities of SWFEAI. The results showed that SWFEAI could be a natural anti-acne agent.

Mitochondrial Dynamics Mediated by DRP1 and MFN2 Contributes to Cisplatin Chemoresistance in Human Ovarian Cancer SKOV3 cells.

Cisplatin (DDP) is the first-line chemotherapeutic agent for ovarian cancer. However, the development of DDP resistance seriously influences the chemotherapeutic effect and prognosis of ovarian cancer. It was reported that DDP can directly impinge on the mitochondria and activate the intrinsic apoptotic pathway. Herein, the role of mitochondrial dynamics in DDP chemoresistance in human ovarian cancer SKOV3 cells was investigated. In DDP-resistant SKOV3/DDP cells, mitochondrial fission protein DRP1 was down-regulated, while mitochondrial fusion protein MFN2 was up-regulated. In accordance with the expression of DRP1 and MFN2, the average mitochondrial length was significantly increased in SKOV3/DDP cells. In DDP-sensitive parental SKOV3 cells, downregulation of DRP1 and upregulation of mitochondrial fusion proteins including MFN1,2 and OPA1 occurred at day 2~6 under cisplatin stress. Knockdown of DRP1 or overexpression of MFN2 promoted the resistance of SKOV3 cells to cisplatin. Intriguingly, weaker migration capability and lower ATP level were detected in SKOV3/DDP cells. Respective knockdown of DRP1 in parental SKOV3 cells or MFN2 in SKOV3/DDP cells using siRNA efficiently reversed mitochondrial dynamics, migration capability and ATP level. Moreover, MFN2 siRNA significantly aggravated the DDP-induced ROS production, mitochondrial membrane potential disruption, expression of pro-apoptotic protein BAX and Cleaved Caspase-3/9 in SKOV3/DDP cells. In contrast, DRP1 siRNA alleviated DDP-induced ROS production, mitochondrial membrane potential disruption, expression of pro-apoptotic protein BAX and Cleaved Caspase-3/9 in SKOV3 cells. Thus, these results indicate that mitochondrial dynamics mediated by DRP1 and MFN2 contributes to the development of DDP resistance in ovarian cancer cells, and will also provide a new strategy to prevent chemoresistance in ovarian cancer by targeting mitochondrial dynamics.

Diffusion Mechanism of Cinnamon Essential Oils Release from Calcium Alginate Based Controlled Release Films in Contact with Food Simulating Solvent.

Calcium alginate based controlled release films with moderate mechanical properties were fabricated in this paper. The diffusion mechanism of these films contacting food simulating solvent (FSS) was explored in some detail. With the increase of glycerol content, the diffusion coefficient (D) values of cinnamon essential oils (CEOs) diffusing to ethanol first increased slowly (0.3-0.6 mL), then vigorously (0.6-0.9 mL), and then mildly (0.9-1.2 mL). The D values of the CEOs diffused to water are all in the order of magnitude of 10-10 cm2/s. The D values of CEOs diffused from films EG3 and EGC1 to aqueous ethanol altered enormously at a small moisture percentage (w = 0.3), then continuously varied vigorously, and at last altered mildly in the range of w = 0.3-1. All the results above indicate that, considering the FSS, the diffusion ability of molecules is jointly determined by the size and distribution of free volume in the system (polymer + diffusive substance + solvents), the intermolecular interaction, and the partition coefficient of the solvents. In addition, several pairs of D values, such as DEG and DGA, are very close to each other, indicating that different kinds of interactions between different groups may have the same effect on the diffusion ability of molecules. The correlation between D1 and D2 indicates that polymeric emulsifier chains also exist in the polymer-rich layer. All the findings and analysis could provide the theoretical basis and data support for further molecular dynamic simulation and could guide the design of controlled release food packaging for food protection.

A Double-Switch Temperature-Sensitive Controlled Release Antioxidant Film Embedded with Lyophilized Nanoliposomes Encapsulating Rosemary Essential Oils for Solid Food.

In order to match the solid food oxidation during logistics and storage process under severe high temperature, a double-switch temperature-sensitive controlled release antioxidant film embedded with lyophilized nanoliposomes encapsulating rosemary essential oils (REOs) was prepared. The double switch temperature at 35.26 and 56.98 °C was achieved by development of a temperature sensitive polyurethane (TSPU) film. With biaxially oriented polyethylene terephthalate (BOPET) as a barrier layer, the intelligent complex film was prepared via coating the TSPU embedded with lyophilized nanoliposomes encapsulating REOs on BOPET. The results indicate that the REO is well encapsulated in nanoliposomes with encapsulation efficiency (EE) of 67.3%, high stability and lasting antioxidant effect during 60 days. The incorporation of lyophilized nanoliposomes containing REOs into TSPU remains the double-switch temperature-sensitive characteristic of the prepared TSPU. In agreement with porosity and WVTR results, the diffusion coefficient (D) of the antioxidant complex film sharply increases respectively at two switching temperatures, indicating that the intelligent double-switch temperature-sensitive controlled release property is functioning. Furthermore, compared with films directly added with REO, the lower Ds of films added with lyophilized nanoliposomes encapsulating REOs provides a longer-lasting antioxidant activity. Thus, the acquired controlled release antioxidant film sensitive to temperature at 39.56 and 56.00 °C can be potentially applied for protection of solid food during distribution and storage process under severe high temperatures.

Replanning Criteria and Timing Definition for Parotid Protection-Based Adaptive Radiation Therapy in Nasopharyngeal Carcinoma.

The goal of this study was to evaluate real-time volumetric and dosimetric changes of the parotid gland so as to determine replanning criteria and timing for parotid protection-based adaptive radiation therapy in nasopharyngeal carcinoma. Fifty NPC patients were treated with helical tomotherapy; volumetric and dosimetric (D mean, V 1, and D 50) changes of the parotid gland at the 1st, 6th, 11th, 16th, 21st, 26th, 31st, and 33rd fractions were evaluated. The clinical parameters affecting these changes were studied by analyses of variance methods for repeated measures. Factors influencing the actual parotid dose were analyzed by a multivariate logistic regression model. The cut-off values predicting parotid overdose were developed from receiver operating characteristic curves and judged by combining them with a diagnostic test consistency check. The median absolute value and percentage of parotid volume reduction were 19.51 cm(3) and 35%, respectively. The interweekly parotid volume varied significantly (p < 0.05). The parotid D mean, V 1, and D 50 increased by 22.13%, 39.42%, and 48.45%, respectively. The actual parotid dose increased by an average of 11.38% at the end of radiation therapy. Initial parotid volume, initial parotid D mean, and weight loss rate are valuable indicators for parotid protection-based replanning.

Comparison of physicochemical and functional properties of flour and starch extract in different methods from Africa locust bean (Parkia biglobosa) seeds.

BACKGROUND: African locust bean tree is an important food tree for both human and livestock such as husks and pods. It plays a very vital role in the rural areas. The aim of this study was to evaluate some physicochemical, mineral characteristics and functional properties of flour and starch extract produced from Parkia biglobosa seeds, using different methods. MATERIALS AND METHODS: Three different methods were used for starch extraction in other to get the Starch yield (%),composition analysis for; moisture, protein, fat, ash and fiber contents of flour and starch extracts from Parkia biglobosa were determined on dry basis (db), by AACC method, color and PH value measurements was carried out using color flex spectrocolorimeter, and the official method of AOAC respectively. Pasting properties was determined and X-ray powder starch diffraction was used to examine the crystalline property of flour and starch extract. Gelatinization characteristics and in vitro starch digestibility were also determined, test results were processed using one-way analysis of variance (ANOVA). RESULTS: Flour showed higher (P < 0.05), moisture content, fat, carbohydrate, amylopectine, and protein content than starch, while amylose content of this starch was higher (P<0.05). Phosphorus, sodium, magnesium, and potassium minerals content were higher in flour than starch. Pasting properties, gelatinisation, color, pH values, water and oil absorption capacity content of the flour were found to be higher than that of starch. The pasting characteristics showed a decrease of viscosity, final viscosity, set back value, breakdown, and pasting temperature of flour when compared to that of starch. CONCLUSION: From our results, we speculate that flour from native Parkia biglobosa grown in Guinea under controlled environmental conditions could be considered as an ideal RS material, whereas the extract Parkia starch could be an ideal SDS material. Therefore, these may offer an interesting alternative for food developers, depending on their characteristics and functional properties.

Assessment of the antibacterial activity and the antidiarrheal function of flavonoids from bayberry fruit.

Chinese bayberry fruits are used as a folk medicine to cure diarrhea. However, the active compounds have not yet been reported. We found that bayberry fruit extract showed significant antibacterial activity against Salmonella, Listeria, and Shigella, and the minimal inhibitory concentration (MIC) ranged from 2.07 to 8.28 mg/mL. Positive relationships were found between the antibacterial activity and the total polyphenol (r = 0.88) and flavonoid contents (r = 0.92) of samples using different extraction times. The active compounds showed green or blue fluorescence under UV light using the bioautography method and were purified using a polyamide column. The fraction F1 with the most activity was comprised of flavonoids, which included cyanidin-3-O-glucoside, myricetin deoxyhexoside, quercetin-3-O-glucoside, and quercetin deoxyhexoside, and it also possessed an antidiarrheal activity (p < 0.10) at 80 mg/kg in mice. These findings provide scientific evidence for the antidiarrheal function of bayberry.