在线二维液相色谱技术在中药研究中的应用进展

中药的组成复杂,其化学成分的表征和识别一直是中药研究的基础和关键。在线二维液相色谱是基于两种分离模式构建的色谱分析技术,主要包括中心切割二维液相色谱和全二维液相色谱两种模式,因二者具有更高的峰容量而在中药研究中备受青睐。该文对在线二维液相色谱技术的概念和特点进行了讨论,并对二维液相色谱在中药研究中的应用进行了综述,以期为该技术在中药质量控制、物质基础表征、活性成分筛选等研究方面提供一定参考。     

Identification of novel anti cancer agents by applying insilico methods for inhibition of TSPO protein

Cancer is a genomic disease characterised as impaired cellular energy metabolism. Cancer cells derive most of their energy from oxidative phosphorylation unlike normal ones during cell progression TSPO protein present in external mitochondrial membrane, is involved in various cellular functions like Cell proliferation, mitochondrial respiration, synthesis of steroids and also participates in import of cholesterol into the inner mitochondrial membrane from outside of the membrane of mitochondria.The 3D model of TSPO protein is built using comparative homology modelling techniques and validated by proSA, Ramachandran plot and ERRAT in the present work. Active site prediction is carried out using SiteMap and literature, which allows the prediction of the important binding pockets for the identification of putative active site. New molecular entities as TSPO inhibitors were obtained from Virtual screening using MS Spectrum databank in Schrodinger suite and were prioritised based on Glide Score. Docking was performed using Autodock to identify molecules with different scaffolds and were prioritised based on binding energy and RMSD values. Qikprop is used to calculate pharmacokinetic properties of the screened molecules which are found to be in permissible range as possible novel inhibitors of TSPO protein to supress cell proliferation.     

Accelerated Combinatorial High Throughput Star Polymer Synthesis via a Rapid One‐Pot Sequential Aqueous RAFT (rosa‐RAFT) Polymerization Scheme

Advanced polymerization methodologies, such as reversible addition‐fragmentation transfer (RAFT), allow unprecedented control over star polymer composition, topology, and functionality. However, using RAFT to produce high throughput (HTP) combinatorial star polymer libraries remains, to date, impracticable due to several technical limitations. Herein, the methodology “rapid one‐pot sequential aqueous RAFT” or “rosa‐RAFT,” in which well‐defined homo‐, copolymer, and mikto‐arm star polymers can be prepared in very low to medium reaction volumes (50 µL to 2 mL) via an “arm‐first” approach in air within minutes, is reported. Due to the high conversion of a variety of acrylamide/acrylate monomers achieved during each successive short reaction step (each taking 3 min), the requirement for intermediary purification is avoided, drastically facilitating and accelerating the star synthesis process. The presented methodology enables RAFT to be applied to HTP polymeric bio/nanomaterials discovery pipelines, in which hundreds of complex polymeric formulations can be rapidly produced, screened, and scaled up for assessment in a wide range of applications.

     

Osteoblast cell membrane chromatography coupled with liquid chromatography and time‐of‐flight mass spectrometry for screening specific active components from traditional Chinese medicines

A method using osteoblast membrane chromatography coupled with liquid chromatography and time‐of‐flight mass spectrometry was developed to recognize and identify the specific active components from traditional Chinese medicines. Primary rat osteoblasts were used for the preparation of the stationary phase in the cell chromatography method. Retention components from the cell chromatography were collected and analyzed by liquid chromatography with time‐of‐flight mass spectrometry. This method was applied in screening active components from extracts of four traditional Chinese medicines. In total, 24 potentially active components with different structures were retained by osteoblast cell chromatography. There were five phenolic glucosides and one triterpenoid saponin from Curculigo orchioides Gaertn, two organic acids and ten flavonoids from Epimedium sagittatum Maxim, one phthalide compound and one organic acid from Angelica sinensis Diels, and two flavonoids and two saponins from Anemarrhena asphodeloides Bunge. Among those, four components (icariin, curculigoside, ferulaic acid, and timosaponin BII) were used for in vitro pharmacodynamics validation. They significantly increased the osteoblast proliferation, alkaline phosphatase activity, levels of bone gla protein and collagen type 1, and promoted mineralized nodule formation. The developed method was an effective screening method for finding active components from complex medicines that act on bone diseases.     

Determination of the serine palmitoyl transferase inhibitor myriocin by electrospray and Q‐trap mass spectrometry

Myriocin is a potent inhibitor of serine‐palmitoyl‐transferase, the first and rate‐determining enzyme in the sphingolipids biosynthetic pathway. This study developed, validated and applied a LC–MS/MS method to measure myriocin in minute specimens of animal tissue. The chemical analog 14‐OH–myriocin was used as the internal standard. The two molecules were extracted from the tissue homogenate by solid‐phase extraction, separated by gradient reversed‐phase liquid chromatography and measured by negative ion electrospray mass spectrometry in the triple quadrupole. Detection was accomplished by multiple reaction monitoring, employing the most representative transitions, 400@104 and 402@104 for myriocin and 14‐OH‐myriocin, respectively. The typical limit of detection and lower limit of quantitation of the optimized method were 0.9 pmol/mL (~0.016 pmol injected) and 2.3 pmol/mL, respectively, and the method was linear up to 250 pmol/mL range (r ² = 0.9996). The intra‐ and between‐day repeatability afforded a coefficient of variation ≤7.0%. Applications included quantification of myriocin in mouse lungs after 24 h from administration of ~4 nmol by intra‐tracheal delivery. Measured levels ranged from 4.11 (median; 2.3–7.4 IQR, n = 4) to 11.7 (median; 7.6–22.7 interquartile range (IQR), n = 6) pmol/lung depending on the different formulations used. Myriocin was also measured in retinas of mice treated by intravitreal injection and ranged from 0.045 (less than the limit of detection) to 0.35 pmol/retina.     

在校大学生足部真菌带菌情况及菌种分布的调查

目的:了解大学生足部真菌的带菌状况,对培养出来的真菌进行病原学研究及为临床预防和治疗提供依据。方法:对262名自愿受检大学生用棉签对其足部进行涂擦,然后将标本直接镜检,同进进行真菌培养,对培养出来的真菌进行菌种鉴定。结果:262份标本中,共分离出397株真菌,阳性率为74.04%,其中男生为71.8%,女生为77.4%,男、女生真菌携带率差异无统计学意义(P>0.05)。所分到的菌株中,皮肤癣菌113株,占28.4%(113/397);酵母属114株,占28.7%(114/397);其他未能分类多细胞真菌23株,占5.8%(23/397)。多细胞真菌在男、女生中的携带率差异无统计学意义(P>0.05);酵母菌在男、女生中的携带率分别为35.2%、55.7%,差异有统计学意义(χ2=10.6 904,P<0.01)。大学生群体中,足部真菌病的发病率为11.1%。结论:大学生足部真菌的携带率较高,男、女生差异不明显,但总体发病率相对较低。多细胞真菌、酵母菌的携带率在人群中的整体分布无明显差异,但酵母菌在女生中的携带率明显高于男生。     

壳聚糖酶产生菌筛选及产酶培养优化

以胶体壳聚糖为唯一碳源和DNS酶活鉴定法从烟台近海土壤中分离得到一株高产壳聚糖酶菌株,初步鉴定为白色链霉菌.经发酵培养组分与条件优化,获得最佳培养组分(g.L-1):葡萄糖55,壳聚糖0.5,胰蛋白胨1,尿素8,(NH4)2SO42,NH4Cl 1,KH2PO43,FeSO4·7H2O 1,ZnSO4·7H2O 2,CaCl2·6H2O2,MnSO4·H2O2,NaCl2.最适产酶pH 7.0,温度28℃,装液量50 mL,接种量2%.优化后菌株培养48 h时产酶量为51.65 U.mL-1.     

Optical joint density of states in InGaN/GaN-based multiple-quantum-well light-emitting diodes

The optical joint densities of states of three InGaN/GaN-based light-emitting diodes with different emission wavelengths (violet, blue and green) operated at various currents were investigated. The results indicate that the blueshift of the emission with increasing current is related to the variation in optical joint density of states. Thus, the blueshift is ascribed to the screening of the piezoelectric field by carriers. A tail at the low-energy end of the density of states, corresponding to localized states, was found, and the presence of these tails broadens the spectra of the devices.     

Frozen water phase method for logD measurement using a 96-well plate

In this study, a frozen water phase method for log D measurement using a 96-well plate was developed. In the case of log D measurement of compounds, the problem of octanol contamination often occurs; in lipophilic compounds, the concentration of the octanol phase is much higher than that of the water phase. When the water phase is separated from the octanol phase, a small amount of octanol phase contamination could strongly influence the concentration of the water phase. To avoid this problem, the frozen water phase method was developed. The water phase was frozen in liquid nitrogen and then the unfrozen octanol phase was removed. To remove the portion of the octanol remaining on the frozen water phase, the surface of the frozen water phase was washed with octanol and water/ethanol (50/50, v/v). The validity of the method was confirmed by results of commercially available drugs at the log D range from 0 to 4. Further, it was found that this method had the ability to evaluate the pH-log D profile of compounds in the range from pH 2 to pH 12. As a result, we developed the convenient and accurate method that is effective in preventing contamination with a wide dynamic range.