The correlation between skin-care effects and phytochemical contents in Lamiaceae plants

In this study, well-known skin-care functional parameters were used, including UV absorption, DPPH-scavenging, NO-production-inhibition, tyrosinase-inhibition activity and anti-Staphylococcus aureus activity to measure the effects of the 70% acetone-extracts form 28 species of Lamiaceae plants. Further, the phytochemical contents were explored by total phenol (TP), total flavone (TF) and total coumarin (TC). The correlation between the skin-care effects and the phytochemical contents was analysed by non-parametric correlation analysis. Amongst the 70% acetone-extracts, Origanum majorana displayed the strongest DPPH-scavenging and tyrosinase-inhibitory effects and the richest phenol content. Based on the statistics results, the phytochemical contents were related with those parameters, such as: DPPH-scavenging effects vs. TP (R = 0.542), TF vs. TP (R = 0.613), and NO-inhibitory vs. anti-bacterial activities (R = 0.767). Moreover, each genus of Lamiaceae had different properties of skin-care effects. Form our research works, the Lamiaceae is good resources to develop skin-care cosmetics.     

Inhibitory effects of 4-chlorosalicylic acid on mushroom tyrosinase and its antimicrobial activities

The inhibitory effects of 4-chlorosalicylic acid on the activity of mushroom tyrosinase have been investigated. The results showed that 4-chlorosalicylic acid could strongly inhibit both monophenolase activity and diphenolase activity. The IC₅₀ values were estimated as 1.89 mM and 1.10 mM for monophenolase and diphenolase activities, respectively. For the monophenolase activity, 4-chlorosalicylic acid could not only lengthen the lag time, but also decrease the steady-state rate. For the diphenolase activity, kinetic analyses showed that the inhibition by 4-chlorosalicylic acid was reversible and its mechanism was mixed-II type, which is different from salicylic acid. The inhibition constants (K_I and K_IS) were determined to be 1.51 mM and 0.82 mM, respectively. Furthermore, the antibacterial activity against Escherichia coli, Bacillus subtilis and Staphyloccocus aureus and antifungal activity against Aspergillus niger and Candida boidinii were investigated. The results showed that 4-chlorosalicylic acid was the most effective against E. coli with the MIC of 250 μg/ml and with the MBC of 500 μg/ml.     

乌鸦果根甲醇提取物的抑真菌作用研究

乌鸦果根经甲醇回流提取、石油醚脱脂得到鸟鸦果根甲醇提取物。采用双层培养基法测定其抑真菌活性、琼脂梯度稀释法测定最小抑菌浓度和最小杀菌浓度。结果表明,乌鸦果根甲醇提取物（1000mg·mL^-1）对供试的21种真菌均有不同程度的抑菌活性。最小抑菌浓度和最小杀菌浓度均为31．2-250mg·mL^-1;且提取物抑菌能力与其浓度呈正相关关系。表明乌鸦果根甲醇提取物具有广谱抑制真菌作用,可以作为植物源农药进一步深入研究,具有潜在的开发利用价值。     

Biodegradable synthetic polymers: Preparation, functionalization and biomedical application

Biodegradable polymers have been widely used and have greatly promoted the development of biomedical fields because of their biocompatibility and biodegradability. The development of biotechnology and medical technology has set higher requirements for biomedical materials. Novel biodegradable polymers with specific properties are in great demand. Biodegradable polymers can be classified as natural or synthetic polymers according to the source. Synthetic biodegradable polymers have found more versatile and diverse biomedical applications owing to their tailorable designs or modifications. This review presents a comprehensive introduction to various types of synthetic biodegradable polymers with reactive groups and bioactive groups, and further describes their structure, preparation procedures and properties. The focus is on advances in the past decade in functionalization and responsive strategies of biodegradable polymers and their biomedical applications. The possible future developments of the materials are also discussed.     

Antibacterial activity of some Lamiaceae essential oils using resazurin as an indicator of cell growth

The aim of this work was to investigate the antibacterial activity of six Lamiaceae essential oils, against pathogenic and food spoilage bacteria. The chemical profiles of essential oils were evaluated by the means of GC and GC-MS. The major constituents of the oils were 1,8-cineol (29.2%), camphor (17.2%), α-pinene (11.5%) in Rosmarinus officinalis, citronellal (20.5%), β- geraniol (17.0%), β-citronellol (11.5%) in Melissa officinalis, 1,8-cineol (27.4%), α-thujone (16.3%), β-thujone (11.2%), borneol (10.4%), camphor (7.98%) in Salvia officinalis, linalool (25.1%), linalyl acetate (22.5%) in Lavandula angustifolia, thymol (52.4%), p-cymene (17.9%) in Thymus vulgaris and Patcholene alcohol (22.7%), α-bulnesene (17.1%), α-guaine (13.8%) in Pogostemon cablin. On quantitative basis, the amounts of 1,8-cineol, citronellal, 1,8-cineol, linalool, thymol and patchouli alcohol, calculated using calibrated curve with pure standard compounds, in the respective essential oils were found to be 28.4, 19.0, 26.7, 23.3, 51.1 and 21.1 g/100 g of oil, respectively. The modified resazurin microtitre-plate assay was used to evaluate the antibacterial activity of the essential oils and their principal components. All the essential oils analyzed presented inhibitory effects on most of the strains tested. Thymus vulgaris essential oil showed the highest inhibition. It was concluded that modified resazurin assay could be effectively used for reliable assessment of antibacterial activity of the tested essential oils against several Gram positive and negative bacterial taxa. The present results also demonstrated that Lamiaceae essential oils exhibiting higher antibacterial activity were generally rich in oxygenated monoterpens.     

Simple robust control structures based on the model‐following concept–A theoretical analysis

The paper deals with three robust control systems that may be regarded as a part of the model‐following control (MFC) family. The systems are easy‐to‐synthesize control structures, thus offering an alternative to the low‐robust single‐loop PID system, to the relatively difficult‐to‐synthesize internal‐model control structures, or to complex adaptive systems. A basic comparative theoretical and computational analysis of properties exhibited by the presented control structures is given. Also, recommendations as to practical implementation are provided. The solutions presented in the paper have found some application, e.g. in force/position control for an industrial robotic manipulator, temperature control of electro‐heated furnaces with highly varying parameters, and oxide content control in a steam boiler. Owing to the interesting robustness properties displayed by MFC strict requirements on quality of controlled processes that are both strongly nonlinear and time variant have been met. Copyright © 2010 John Wiley & Sons, Ltd.     

Chemical Composition and in Vitro Antifungal Activity Screening of the Allium ursinum L. (Liliaceae)

The objective of the study was to summarize the methods for isolating and identifying natural sulfur compounds from Allium ursinum (ramson) and to discuss the active constituents with regard to antifungal action. Using chromatographic techniques, the active constituents were isolated and subsequently identified. Analyses by high-performance liquid chromatography (HPLC) suggested that these compounds were sulfur constituents, with a characteristic absorbance at 250 nm. Gas chromatography-mass spectrometry (GC-MS) analyses allowed the chemical structures of the isolated constituents to be postulated. We adopted the same methods to identify the health-giving profiling of ramsons and the effects are thought to be primarily derived from the presence and breakdown of the alk(en)ylcysteine sulphoxide, alliin and its subsequent breakdown to allicin (sulfur-compounds of ramson) in connection with antifungal action. The aim of the study was the characterization of the chemical composition of ramsons and the testing of the action of the in vitro extracts, on different strains of Candida albicans. The main goal was to highlight the most efficient extracts of Allium ursinum that can provide long-term antifungal activity without remissions. The extracts from Allium ursinum plants, inhibited growth of Candida spp. cells at concentrations ranging from 0.5 to 4.0 mg/mL, while that of adherent cells at concentrations ranging from 1.0 to > 4.0 mg/mL, depending on the yeast and plant species.     

流星余迹通信最佳传输帧长设计

在分析流星余迹通信原理及其传输信道物理特性基础上,根据流星余迹电子线密度的分布特性,构建出流星余迹信号初始接收功率的概率密度函数.针对以信号帧为单位的自适应变速率传输机制,推导出欠密类余迹平均信息通过量与传输帧长的关系,提出最佳帧长设计原则,得到自适应传输帧长的理论最佳值.仿真结果表明,在满足通信可靠性及实时性的要求下,所得最佳帧长能使系统平均信息通过量达到最大,有效提高流星余迹信道利用率.     

啶菌恶唑体外抑真菌研究

应用二倍试管稀释法测定了啶菌恶唑对石膏样毛癣菌的体外最小抑菌浓度(MIC)和最小杀菌浓度(MBC)及其最小杀菌曲线，并对培养基的pH值和菌液浓度对啶菌恶唑抑菌效果的影响进行了研究。结果表明啶菌恶唑的MIC及MBC分别为0．63mg／ml、5mg／ml。随着培养时间的延长，时间-杀菌曲线显示了从抑菌到杀菌的趋势。MIC及MBC值随着菌液浓度的增加及培养基pH值的降低而增加。