Latest ArticlesGold nanoclusters (AuNCs) are gold atom aggregates less than 2 nm (excluding the ligand shell) or 150 atoms. It has been widely studied due to its small size effect, fluorescence property, and catalytic activity. In this review, research progress in the preparation of gold nanoclusters containing accurate atom numbers using biomolecules and chemically synthesized molecules as ligands have been summarized. The factors that affect the preparation of gold nanoclusters have been discussed. The applications of AuNCs having accurate atomic numbers in the fields of analyte assay, catalysis, bioimaging, and drug delivery have been introduced. This review provides references to the further researches on the preparation technology and biomedical applications of AuNCs.
Dendrobium officinale is a member of the family Orchidaceae. The dried stem of D. officinale is used as a valuable traditional Chinese medicine, known as Dendrobii Officamlis Caulis (called TiepiShihu in Chinese). According to Chinese Pharmacopoeia, Dendrobii Officamlis Caulis has effects of tonifying stomach, promoting fluid, nourishing Yin and clearing heat. At present, the planting area of D. officinale is over 100 000 Mu (over 6 670 hm2) and the annual output of its fresh stem is in excess of 10 000 tons. Good variety is the guarantee of herbal medicine's quality, while germplasm resource is the base for breeding excellent variety. In this paper, we summed the characteristics of present main varieties of D. officinale and reviewed the progress on germplasm resources and genetics and breeding of the plant, in order to provide a scientific basis for the further research.
This study was designed to investigate the therapeutic effect of novel compound Z-9-octadecenyl-2-propanesulfonamide (N15) on diabetes-associated cognitive decline (DACD). Type 2 diabetes (T2DM) mice models were established with multiple injection of low doses of streptozotocin (STZ) in mice on high fat diet (HFD). Vehicle and different concentrations of N15 (50 and 100 mg·kg-1·d-1) were administrated orally for 6 weeks. The step-down test, dark avoidance task and Morris water maze were conducted at the 6th week. The level of glucose and lactic acid in hippocampus were determined and mRNA of growth associated protein-43 (GAP-43), synaptophysin (SYN), brain derived neurotrophic factor (BDNF) and neurotrophins-3 (NT-3) in hippocampus were analyzed by real time PCR. The beneficial effects of N15 on learning and memory were found in the test of step-down, dark avoidance and Morris water maze. N15 reduced the level of glucose and lactic acid in hippocampus of HFD+STZ-induced diabetic encephalopathy model mice. Additionally, the mRNA expression of GAP-43, SYN, BDNF and NT-3 in hippocampus of HFD+STZ-induced diabetic encephalopathy mice were significantly increased by N15 (P < 0.01). These results suggest that the novel compound N15 can ameliorate diabetes-associated cognitive decline and the potential mechanism may be associated with the expressions of increased synaptic-related factors and neurotrophic factor in the hippocampus of diabetesassociated cognitive decline in mice.
The purpose of this research is to investigate the effects and mechanisms of paeonol (PL), a phenolic compound found in many traditional Chinese formulations, on reversing drug resistance in the ovarian cancer resistant SKOV3/DDP cells. The results showed that PL had significant drug-resistant reversal effect on SKOV3/DDP cells. Flow cytometry showed that PL could inhibit P-glycoprotein (P-gp) function in a concentration-dependent manner. Fluorescent quantitative PCR and cell immunofluorescence techniques were used to detect mechanisms of action. Results revealed that both the inhibitory effect on MDR1/P-gp and metadherin (MTDH) expression and the induction effect on phosphatase and tensin homolog (PTEN), by 15, 30, and 60 μmol·L-1 PL, were increased with increased concentrations of PL (P < 0.01, P < 0.05). The inhibitory effect on MTDH mRNA and the induction effect on PTEN mRNA, by PI3K inhibitor LY294002, were stronger or equivalent to that of the 60 μmol·L-1 PL treated group; however, the inhibition or induction effect on MTDH or PTEN protein were only comparable to the 15 μmol·L-1 PL treated group. The present study shows that the effect of PL on SKOV3/DDP cells may be related to the inhibition of P-gp function and expression, the inhibition of MDR1, MTDH expression, and the induction of PTEN expression, all which can provide a theoretical foundation for PL as a drug resistance reversal agent on the treatment of ovarian cancer chemotherapy resistance.
Thiochromanones and 1, 3, 4-thiadazoles as heterocyclic compounds have broad biological activities. In order to find novel compounds with antifungal activity, we synthesized a novel series of (E)-3-(((1, 3, 4-thiadiazol-2-yl) amino)methylene)-thiochroman-4-ones. Structures of these compounds were established by HR-MS, 1H NMR, 13C NMR and 1D-noesy. All of the synthesized compounds were screened for antifungal activity by using an established agar double dilution method (plate method) against ten fungi species in vitro. Compound 5j showed significant inhibitory activity to Colletotrichum capsici, Rhizoctonia cerealis and Aspergillus niger compared with that of the positive control carbendazim. Compounds 5h exhibited better antifungal activity to Canidia albicans and Aspergillus funigatus than the positive control fluconazole, in which the minimum inhibition concentration can reach 8 μg·mL-1 and 16 μg·mL-1. Moreover, the molecular docking method was used to study the interaction mode of compound 5h and CYP51, and the results will be helpful for designing of CYP51 inhibitors in the future.
Seven cucurbitane-type triterpenoids were isolated from the ethanol extract of the tubers of Hemsleya dolichocarpa, with a combination of various chromatographic approaches, including silica gel, Sephadex LH-20, Semi-HPLC and so on. On the basis of spectroscopic data analysis, they were identified as 3β, 11α, 26, 27-tetrahydroxycucurbita-5, 24(E)-diene-3, 26-glucosides (1), scandenogenin D (2), jinfushanencin F (3), scandenoside R3 (4), scandenoside R1 (5), scandenogenin A (6), scandenoside R2 (7). Among them, compound 1 is a new triterpenoid, compound 2 showed remarkable activity against human cancer cell line HeLa with IC50 value of 6.78 μmol·L-1.
An analytical method was developed for determination of ginkgolic acids in Yinxing Tongzhi Dropping Pills by ultra high performance liquid chromatography-triple quadrupole mass spectrometry. The samples were purified by mix-mode anion exchange and reversed-phase SPE. A chromatographic column, Waters Cortecs T3 (50 mm×2.1 mm, 2.7 μm), was used with acetonitrile-methanol-1% acetic acid (44:44:12) as the mobile phase. The ginkgolic acids were detected by electrospray ionization mass spectrometry in negative mode with multiple reaction monitoring (MRM) mode. Ginkgolic acid C13:0, C15:1 and C17:1 possessed good linear correlation in the mass concentration range from 0.2 to 200 μg·L-1, 2 to 200 μg·L-1, 4 to 200 μg·L-1, respectively, with the correlation coefficients more than 0.999. The mean recoveries at spiked levels of 50, 250 and 600 μg·kg-1 were in the range of 70.8%-95.1%, and the RSDs were 0.7%-8.6%. The limits of quantification were 1, 10, 20 μg·kg-1, respectively. The method could be applied to the analysis of ginkgolic acids in complex matrix samples.
An ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF/MS) method was established to identify the metabolites in rat plasma after oral administration of Zhikebao tablets. The high-resolution mass spectrometer was operated in positive and negative ion mode, respectively. First, full-scan was applied, which was dependent on a multiple mass defect filter (MMDF) combined with dynamic background subtraction (DBS). These were utilized to trigger the information dependent acquisition (IDA) function in the experiment. For the IDA criteria, the eight most intense candidate ions of per cycle were selected to do a product ion scan. Then Metabolite Pilot 2.0 software was utilized to load data to seek possible metabolites. The analytical models employed by Metabolite pilot 2.0 were established for representative compounds of the Papaveris Pericarpium and licorice in Zhikebao tablet. Finally, metabolites were identified according to accurate mass measurement and retention time. 38 components from the rat plasma after oral administration of the drug have been found, including 5 prototype opium alkaloids, liquiritin, glycyrrhizic acid and 31 relative metabolites. The metabolic transformation of Zhikebao tablet in rats was mainly induced by glucuronidation, sulfation, methylation, amine to carboxylic acid, hydrolysis and so on. In this paper, the metabolites of the main active components of Zhikebao tablet were tentatively identified, and the metabolic pathway was compared with that of single chemical drugs. Moreover, it laid the fundamental elucidation of further metabolism study of Zhikebao tablet or other compound traditional Chinese medicine preparations which containing Papaveris Pericarpium or licorice.
The particle diameters of active pharmaceutical ingredient (API) and excipients are important factors to the quality of preparations and have great significances in the reverse engineering to brand products and the consistent evaluation of generic drugs. In this study, a novel method was established for particle size determination to identify the selected component and eliminate other interferential particles by comparing the microscopic images before and after fusion caused by controllable heating. Stearic acid (SA) particles in irregular and spherical shape were selected as a typical excipient to demonstrate the methodology, which were identified from the mixed particles based upon its melting characteristics to detect their particle sizes as well as the size distributions. In the same approach, the morphology and particle size of fenofibrate particles as API in tablets were analyzed. The results illustrated that the particle diameters and particle size distributions of the selected components in the mixture of particles can be detected via the hot-melting characteristics under the prerequisite of proper pretreatment to separate selected components from other particles in microscopic field. In conclusion, this research provides a practical approach for the reverse engineering purpose to brand products and the consistent evaluation of generic drugs.
The objective of this study is to develop an in vitro screening method for nasal absorption of insulin. First, the adaptability of in situ rat nasal perfusion test for the study of insulin was investigated. It was found that insulin was liable to be absorbed on the silicone tube and the traditional method is not suitable. However, addition of 0.001% Labrasol into the perfusate can effectively solve this problem. A modified method suitable for in situ rat nasal perfusion of insulin was established with the addition of 0.001% Labrasol into the perfusate. Using the modified method, effect of pH and drug concentration on the absorption of insulin in the nasal cavity was further investigated. The results suggest that compared with pH 4.5 and pH 7.4, the drug absorption rate was the lowest at pH 6.0. The intranasal absorption mechanism of insulin may be passive diffusion.
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