Latest ArticlesCompared with the racemate of chiral drugs, enantiopure chiral drugs have been the hot spot of drug research because of their higher selectivity and lower side-effects. Although remarkable progress of asymmetric synthesis has been achieved in the last decades, chiral resolution is regarded as an important approach to obtain chiral drugs. Recent research advancements in the field of chiral resolution of racemic drugs and intermediates are reviewed here. It is clear that combination of chiral separation and racemization to improve the resolution efficiency has become a trend of chiral resolution. In addition, we also introduce some novel resolution methods, such as chiral extraction, membrane resolution, and resolution using nanoparticles.
The key of gene therapy is to deliver the functional gene to the target tissue in the body. The safe and efficient gene carrier is particularly important in the targeted delivery. Multifunctional envelope-type nano device (MEND), based on concept "Programmed packaging", is a new type of gene carrier system, with high encapsulation efficiency, favourable stability, high transfection efficiency, easy preparation, etc. MEND is designed to control intracellular trafficking as well as the tissue distribution of encapsulated compounds such as nucleic acids/proteins/peptides, permitting them to function at the appropriate location. In this paper, research progresses in MEND are reviewed in accordance with three types of payloads:the small interfering RNA (siRNA), DNA and proteins/peptides in recent years.
As a new generation of anti-tumor drugs, taxanes has a good clinical efficacy in the treatment of ovarian cancer, breast cancer, non-small cell lung cancer, head and neck cancer. However, low bioavailability of oral administration from low water solubility and low permeability significantly limited the development of their oral applications. Currently, the marketed preparations were non-oral drug preparations, and the injection contained a large number of surfactants (cremophor EL or Tween 80) and organic solvents (ethanol), which could result in fluid retention, hypersensitivity and other side effects, as well as poor compliance. Oral preparation will be an ideal form for development of taxanes medicines. According to the research by our and other groups in recent years, we investigate the technical strategies enhancing the water solubility and absorptive permeability to improve their oral bioavailability. Among them, we emphasize the application prospects of crystallography technology, and provide a theoretical basis to guide future research in the development of oral preparations for taxanes.
This study was to investigate the effect of RORα activator SR1078 on ovarian cancer cells and its molecular mechanism in vitro. The survival rate of HeyA8 and Hey cells was detected by MTS assay; the apoptosis and cells cycle distribution after SR1078 treatment and the effect of p53 siRNA or PFT-α and PFT-β of p53 inhibitors on SR1078-induced apoptosis of HeyA8 or Hey cells were analyzed by flow cytometry. Western blot was used to detect the effect of SR1078 and p53 siRNA on the expression of p53 protein and the effect of p53 inhibitors alone or in combination with SR1078 on the expression of p53, p-p53 and its downstream pro-apoptotic protein Noxa. The results showed that SR1078 significantly reduced the cell viability and induced apoptosis in HeyA8 and Hey cells. In addition, SR1078 up-regulated the protein expression of p53 and Noxa, and p53 suppression led to significant inhibition of SR1078-induced apoptosis and the expression of Noxa in ovarian cancer cells. In summary, SR1078 induced apoptosis of ovarian cancer cells by activation of p53 signaling pathway.
The study was designed to test the estrogen-like effects about allantoin. The activity of the allantoin was investigated by mouse uterine weight gain test and MCF-7 cell proliferation assay. The levels of E2, FSH and LH were also measured. ICI182, 780, MPP, THC and G15 antagonnist assay and Western blot were adopted to explore the mechanism of allantoin. Allantoin increased the uterus index of premature female mice, the levels of E2 and FSH, and the expression of ERα and GPR30, compared with the control group. Allantoin also promoted the proliferation of MCF-7 cells. Co-incubation of MCF-7 cells with estrogen receptor blockers, ICI182, 780, MPP and G15 abolished the inductive effect of the proliferation. These results suggest that allantoin has estrogenic activities, which are mainly mediated by ERα, GPR30.
Metabolic transformation in vivo is a critical approach in the study of toxicity, but real-time dynamic observation of the transformation is difficult. We proposed that zebrafish toxicity/metabolism synchronization may be used in the analysis of toxicity of Folium Epimedium (Yinyanghuo for Chinese, YYH) and the toxicity may be reduced by Radix Morindae Officinalis (Bajitian for Chinese, BJT). Healthy zebrafish embryos 1 day post fertilization (1 dpf) were exposed to different concentrations of YYH, total flavonoids of YYH (YTF), representative flavonoids (epimedin C and icariin) and their respective in combination with BJT. Death numbers of the embryos or larvals were counted during 1-5 days after dosing (2-6 dpf); embryonic micro-morphology of zebrafish (3 dpf) was observed and pictures were taken. The blank vehicle (0.4% DMSO) was used in the control group, and LC50 value of 2 to 6 dpf was calculated by SPSS16.0. A relative safe concentration was sampled every day to analyze the dynamic metabolites changes of major flavonoids of YYH. The results showed that epimedin A/B/C (EA/EB/EC) and icariin, the major flavonoids of YYH, were dynamically transformed into major metabolites of sagittatoside C (SC) and baohuoside I (BI) by zebrafish. BI was mainly derived from EA, EB and icariin. Neither original form nor their metabolite BI can cause zebrafish poisoning. SC was mainly derived from EC, and its accumulation was closely related to the toxicity of YYH, YTF and EC. After combination with BJT, the metabolism of EC was slowed down and the toxicity was alleviated. Zebrafish toxicity/metabolism synchronization revealed that the toxicity of EC of YYH was increased after metabolism into SC, which maybe the key potential poisonous factor of YYH, and BJT can reduce the toxicity by slowing down the metabolism rate of EC. The data provides new ideas and methods in the study of toxic substances in Chinese medicine and mechanism of detoxicity by combination.
This study was designed to explore the mechanism of Coix seed oil (Coix) impact on the drug resistance, bioluminescence imaging (BLI) and the efflux of D-luciferin potassium salt, the substrate of ABC transporters, in doxorubicin-resistant breast cancer cells. Multidrug resistance (MDR) gene and protein expression were analyzed in the cells by q-PCR and Western blot. First, in order to investigate the effect of the efflux function by ABC protein, a cell line with overexpressed luciferase was established in MCF-7 cell line. BLI was used to monitor the efflux kinetics of D-luciferin potassium salt before and after Coix treament. The results showed that the efflux of D-fluorescein potassium from MCF-7/DOXFluc was lessened when pretreated with Coix, which means that Coix may decrease the efflux of other chemotherapies using ABC transporters. Both of the results of q-PCR and Western blot showed that gene and protein expression of ABC transporters such as ABCG2, ABCC1 and ABCB1 were down-regulated by Coix treatment. The efficacy of Coix reversing MDR was verified with the chemotherapy medication doxorubicin (DOX). MTT assay showed that Coix increased the inhibitory effect of DOX on proliferation of MCF-7/DOX, and the optimal combination of ratio was 25 times that of DOX. The results suggest that Coix may reverse MDR of the substrate of ABC transporters from two aspects, one is to cut down the ABC protein efflux function, and the other is to decrease the quantity of ABC gene and protein expression.
This study was carried out to investigate the pharmacokinetics/bioequivalence of levornidazole disodium phosphate by using stable isotope labeled drug, evaluated the pharmacokinetic profile and confirmed the prodrug characteristics of levornidazole disodium phosphate in monkey. Levornidazole (Drug A) and stable isotope 15N labeled levornidazole disodium phosphate (Drug B) were mixed with equal mole amount (experiment Ⅰ); stable isotope 15N labeled levornidazole disodium phosphate (Drug B) and levornidazole disodium phosphate (Drug C) were mixed with equal mole amount, respectively. After giving the mixed drugs to the monkey, the concentration of 15N-levornidazole disodium phosphate, levornidazole disodium phosphate, 15N-levornidazole and levornidazole in plasma samples of pre-dosing and 24 h after administration were analyzed by a liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) method. Pharmacokinetic calculations were performed through non-compartmental analysis using WinNonlin software. Two-sided 90% confidence intervals (CI) were used to evaluate the bioequivalence of two drugs. The results showed that levornidazole disodium phosphate was metabolized to levornidazole rapidly after administration, the body exposure were increased with the dosage. The method of bioequivalence used in this study was different from the traditional two periods, crossover design. By using the method of this study, the effects of administration period, intra-individual variability, and sequence of administration on bioequivalence were avoided. The results of this study had successfully supported the pharmacokinetic and bioequivalence study of this drug in human using the same approach.
A new dihydroflavone:mirabiflavone (1), together with two known compounds were isolated from the ethyl acetate extract of the roots of Mirabilis himalaica by using various chromatographic techniques, such as silica gel column, Sephadex LH-20 column, and semi-preparative HPLC. Their structures were elucidated as syringaresinol (2) and lariciresinol (3) by spectroscopic analysis. Compounds 2 and 3 were isolated from this plant for the first time.
Two new diarylheptane derivatives were isolated from Rhizoma Zingiberis by Diaion HP-20, MCI Gel CHP-20, ODS, silica gel column and reverse phase semi-prepared high performance liquid chromatography. Their structures were elucidated by spectrum technology (MS, UV, IR, NMR), which were identified as 3-keto-5R-ethoxy-1-(3-methoxy-4-hydroxyphenyl)-7-(3, 4-dihydroxyphenyl)heptane (1) and 3-keto-5R-ethoxy-1-(3-methoxy-4-hydroxyphenyl)-7-(3-methoxy-4, 5-dihydroxyphenyl)heptane (2). Compounds 1 and 2 are new compounds.