Enhanced bioactivity of Zanthoxylum schinifolium fermented extract: Anti-inflammatory,anti-bacterial,and anti-melanogenic activity

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Synthesis and characterization of coumarin thiazole derivative 2-(2-amino-1,3-thiazol-4-yl)-3H-benzo[f]chromen-3-one with anti-microbial activity and its potential application in antimicrobial polyurethane coating

Coumarin, thiazole and their respective derivative products are some of the oldest and most commonly known class of nitrogen and sulphur containing compounds. In recent years there has been considerable interest in this coumarin–thiazole derivatives, which have been reported to exhibit significant biological activity and are widely used as pharmaceuticals. They are capable of imparting anti-microbial activity properties when incorporated into polymers and polymer composites. In this research, coumarin–thiazole derivative 2-(2-amino-1,3-thiazol-4-yl)-3H benzo[f]chromen-3-one (compound III), was prepared and its structure was confirmed by means of its spectra data. It was also screened for its anti-microbial activity against eight different micro-organisms when physically incorporated into a polyurethane varnish formula. Experimental coatings were manufactured on a laboratory scale and applied by means of a brush on both glass and steel panels. The results of the biological activity indicated that the polyurethane varnishes containing the 2-(2-amino-1,3-thiazol-4-yl)-3H-benzo[f]chromen-3-one (compound III) derivative, exhibit a very good antimicrobial effect. The molecular modeling study revealed that it is biologically safe, it is active and it fulfills Lipinski's rule of five. The physical and mechanical resistances of the polyurethane varnish formulations were also studied to evaluate any drawbacks associated with the addition of the derivative. The studies indicate that the physical incorporation of compound III actually enhances slightly both the physical and mechanical properties.     

Impact of edible coating with or without anti-microbial agent on microbial growth during osmotic dehydration and refrigerated storage of a model plant material

The use of edible coating has proved a valuable tool in improving the efficiency of osmotic dehydration (OD) of plant material. In this study the impact of edible coating with or without an anti-microbial agent (A–M) on microbial growth was investigated. Potato cylinders (15 × 57 mm — D × L) were used as a model plant material. Calcium alginate (CA) coating was applied with or without incorporation of potassium sorbate (PS), at 0.3% of sample weight (before coating). OD took place for 3 h in stirred jars using sucrose solution at 50 °Brix and 40 °C. Microbial growth (Aerobic Plate Count — APC) was monitored both during OD (3 h) and during refrigerated storage at 5 °C (14 days). During OD, a significant reduction of the initial microbial load (ML) in the control (non-coated) treatment was observed, possibly due to a microbial “wash-out” effect. Both coating treatments resulted in a marginal decrease of initial ML in the OD product, suggesting some kind of protection against this effect. During refrigerated storage, the use of coating resulted in reaching the growth plateau several days earlier, which lead to significant reduction of maximum ML, compared to the control treatment. Besides this benefit, coating with A–M helped extend the lag phase and postpone time to reach maximum load by almost 4 days, compared to the simple coating treatment. These results can support further work on the use of more effective types and concentrations of preferably natural anti-microbials to achieve satisfactory stabilization of osmo-dehydrated/refrigerated products, without a negative impact on their minimal processing profile.

Industrial relevance

Osmotic dehydration is a very potent processing tool that has been studied extensively in terms of mass transfer phenomena. Yet, microbial studies in this area are rather scarce; thus industrial applications are very difficult to proceed, due to lack of microbial stabilization data. This is especially crucial in the case of combined, minimal processing methods, such as osmotic dehydration and refrigeration. This work is using edible coating (which is known to promote dehydration efficiency) to incorporate a common anti-microbial agent, in an effort to establish an effective series of hurdles leading to microbial stabilization of osmo-dehydrated, refrigerated products.     

纺织品的防螨整理(一)

纺织品的防螨虫可采用化学处理方法，以减少室内螨虫的滋生，以改善室内生活环境的清洁卫生和提高人们的生活质量。作者从室内尘埃中微生物的共生关系、室内螨虫的种类及其危害、防螨虫的制剂、防螨虫效果的试验方法和羧酸酯类的防螨效果等方面作详细介绍，认为采用化学法防螨整理可获得理想的效果。     

生物表面活性剂的应用

介绍了生物表面活性剂在石油、环境、食品、生物、医药等行业的应用。展望了未来生物表面活性剂的发展。     

Assessment of the Anti-Microbial Activity of Dried Garlic Powders Produced by Different Methods of Drying

The anti-microbial activity of a range of garlic products including dried garlic powder produced by different methods, commercial garlic products, and garlic oil was determined against a range of selected bacteria. The bacteria included food borne pathogens, spoilage agents, and health-beneficial agents, namely Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, Bacillus cereus, and a mixed lactic culture consisting of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus. The dried powders were produced using air-drying at both 60 and 80°C, vacuum-drying at 50 and 60°C, and freeze-drying at ?20°C. In addition, five commercial products were tested, two of which are used as spices, and three as food supplements. Before testing, the moisture content of the dried garlic powders was raised to that of fresh garlic before drying. Garlic oil was used without any addition of water. In general, the results showed that the lactic culture was the most sensitive to the growth inhibitory active compound of garlic used in this study, followed by Staphylococcus aureus. In contrast Salmonella typhimurium and Bacillus cereus demonstrated the greatest resistance to garlic. Generally, fresh garlic produced the greatest inhibition followed by freeze-dried powder. The anti-microbial activity decreased with decreasing dried garlic powder concentration. The results showed that both drying temperature and time have major effects on retaining the active components responsible for the inhibition of microbial growth. The anti-microbial substances in the moist fresh garlic were also affected by moist-heating temperatures and time. Higher heating temperatures caused faster loss of anti-microbial activity. The decrease in growth-inhibition zones for moist-heated fresh garlic followed zero-order kinetics.     

荷叶生物碱的提取及其抑菌活性研究

本文研究了荷叶生物碱提取液的抑菌活性。结果表明荷叶生物碱提取液对细菌、酵母、霉菌都有较强的抑菌作用,在碱性环境较酸性环境显著,对大多数细菌、酵母的MIC不超过12%。高温长时间处理和中低温长时间处理对提取液抑菌活性影响较大,但高温短时处理对提取液抑菌活性影响不大。     

Green tea extract: possible mechanism and antibacterial activity on skin pathogens

Camellia sinensis (tea) is known for its therapeutic properties (anti-inflammatory, anti-microbial, anti-tumour, anti-oxidative and anti-ageing). Although, anti-microbial properties of green tea have been studied, its role against bacterial strains related to skin infections and mechanism of action is not well understood. We focussed on exploring anti-microbial activity and the basic mechanism of aqueous green tea leaf extract on selected bacterial strains. Staphylococcus epidermidis, Micrococcus luteus, Brevibacterium linens, Pseudomonas fluorescens and Bacillus subtilis were found to be sensitive to green tea extract via disc diffusion assay (zone of inhibition ≥7 mm). Minimal inhibitory concentration (MIC) was determined via nitro blue tetrazolium (NBT) assay (0.156-0.313 mg/ml). Moreover, the aqueous extract was found to be not toxic to the Vero cell-line up to a concentration of 500 μg/ml. The effect of aqueous extract on adhesion of different bacteria to Vero cells indicated that it inhibits the adhesion at its MIC value.     

Thermal, ion-exchange, catalytic and antimicrobial aspects of synthetic oligomer and its polychelates with 4f-block elements

Acetophenone based oligomer was synthesized by condensation of 2-hydroxy-4-ethoxyacetophenone with 1,3-propane diol in the presence of polyphosphoric acid as a catalyst at 145 °C for 10 h. The synthesized oligomer was used to study its ion exchange efficiency and to synthesize its polychelates with 4f-block elements. The oligomer and its polychelates were characterized on the basis of elemental analyses, electronic spectra, magnetic susceptibilities, FTIR, NMR and Thermogravimetric analyses. The Number Average Molecular Weight () was determined using Vapor Pressure Osmometry (VPO) method. Ion-exchange studies at different electrolyte concentrations, pH and rate have been carried out for 4f-block elements. Antimicrobial activity of polychelates against Escherichia coli, Bacillus subtilis, Staphylococcus aureus (bacteria) and Saccharomyces cerevisiae (yeast) were measured Catalytic activity of only selected polychelates was examined for organic synthesis. It is observed that, oligomer can be used as an ion – exchanger and polychelates act as an efficient catalysts and antimicrobial agents.     

类黄酮的最新研究进展(Ⅱ) --生理功能

综述了类黄酮的生理功能进展,包括抗癌以及抑制肿瘤活性、改善心血管疾病、抗过敏以及抗发炎效果、抗微生物活性、酶的抑制活性、雌激素活性以及其它活性。其中,它的抗癌活性包括抗突变效果、抗增殖效果、抑制癌细胞的入侵以及蛋白激酶C的抑制等。