Latest ArticlesAsiatic acid (AA) is a ursane pentacyclic triterpenoids, which possesses a wide range of pharmacological activities, such as anti-tumor, hypoglycemic, anti-inflammatory, anti-bacterial. Due to poor solubility and low bioavailability, clinical application of asiatic acid is limited. To address these defects, the structural modifications of AA have been carried out, and large numbers of AA-based derivatives with novel structure and eximious biological activity have been developed. In this paper, the research progress of structural modifications, biological activity, structure-activity relationship and mechanism studies in recent twenty years are reviewed, which provides reference for development of AA-related drugs.
We intend to study the structural characteristics of Lycopus europaeus Linn. chloroplast genome and compare the evolutionary relationship of species from Lamiaceae with similar medicinal effects. The total DNA of Lycopus europaeus was sequenced using the Illumina Hiseq 4000 Sequencing platform and was assembled using NOVOplasty software. And then we annotated and analyzed the genome using the CPGAVAS2 online tool. We constructed the phylogenetic tree using the Stellera chamaejasme and Potentilla chinensis as the outgroup. The whole length of Lycopus europaeus chloroplast genome was 152 085 bp. A total of 132 genes were annotated including 88 protein-coding genes, 8 rRNA genes and 36 tRNA genes. Among them, 8 protein-coding genes (ndhB, rps7, rps12, rps19, rpl2, rpl23, ycf2, ycf15), 7 tRNA coding genes (trnM-CAU, trnL CAA, trnN-GUU, trnE-UUC, trnV-GAC, trnA-UGC, trnR-ACG) and 4 rRNA coding genes (rrn16s, rrn23s, rrn4.5s, rrn5s) are located in the IR region. There are 13 protein coding genes [rps16, rps19 (×2), atpF, rpoC1, rpl2 (×2), petB, petD, rpl16, ndhB (×2), ndhA] each contains one intron, two protein-coding genes (ycf3, clpP) each contain two introns, and 8 tRNA coding genes each contain one intron. A total of 34 SSRs were detected in the chloroplast genome of Lycopus europaeus. Phylogenetic analysis revealed that two species in the Lycopus genus, four species in the Dracocephalum genus, Glechoma longituba, two species in the Mentha genus and Prunella vulgari, in total 10 species are most related. The complete genome sequence of Lycopus europaeus was obtained and analyzed, which clarified the evolutional relationship between the species of Lycopus europaeus and in the Lamiaceae family.
The secondary metabolites from the dandelion-derived Epicoccum sorghinum 1-2 were isolated by silica gel and Sephadex gel column chromatography, and semi-preparative high performance liquid chromatography (HPLC). Their structures were identified by comprehensive NMR and MS methods. Their antibacterial activities were determined by filter paper method. Finally, seven compounds were isolated and identified from the fermentation product of E. sorghinum 1-2, including (4R*, 5R*, 6S*)-4, 5-dihydroxy-6-(6'-methylsalicyloxy)-2-methoxymethyl-2-cyclohexen-l-one (1), (4R*, 5R*, 6S*)-4, 5-dihydroxy-6-(6'-methylsalicyloxy)-2-methyl-2-cyclohexen-1-one (2), (4R, 5R, 6S)-4, 5-dihydroxy-6-(6'-methylsalicyloxy)-2-hydroxymethyl-2-cyclohexen-1-one (3), (-)-gabosine E (4), theobroxide (5), 3-chlorogentisyl alcohol (6), and 3-hydroxybenzyl alcohol (7), of which 1-5 are epoxydons, and 6 and 7 are phenolics. Compounds 1 and 2 are new structures reported for the first time. Compound 6 showed significant antibacterial activity against Staphylococcus aureus.
Based on the idea of multi-target drug design, taking p-aminosalicylic acid (PAS) as the parent nucleus, the unreported target molecules TM1 and TM2 were designed with PAS, isonicotinic acid and fluoroquinolone as three structural units conjugated by different linkers. Sixteen target molecules were synthesized by multi-step reaction, and their activities against Mycobacterium tuberculosis and human pathogenic bacteria were evaluated. The results showed that the anti-tuberculosis activity of TM2a was stronger than those of the assayed fluoroquinolones, while TM1a was comparable to that of clinafloxacin, the most active compound of the positive control fluoroquinolones; TM1a showed the strongest inhibitory activity to all almost tested strains, TM1b and TM2a showed very strong inhibitory activity to most strains, and TM1h/2h had strong inhibitory activity to some strains; The inhibitory activities of TM1a/1h on Staphylococcus aureus ATCC14125 are much stronger than those of fluoroquinolones, which eminently deserves further study. The hemolysis test results showed that the highly active molecules TM1a and TM2a exhibited relative safety below the concentrations of 8 and 32 μg·mL-1, respectively. In this study, a new hybrid molecule of three molecular pharmacophores with PAS as the parent nucleus was synthesized for the first time, and some of which have highly strong antibacterial activity, which provides a new idea for the research and development of antibiotics.
In the process of evolution, pathogenic Streptococcus pyogenes secretes an immunoglobulin G-degrading enzyme IdeS which can specifically cleave the hinge region of immunoglobulin G in order to escape the immune response against the host. On the one hand, IdeS can be used for IgG fingerprinting as a tool enzyme combined with mass spectrometry technology. On the other hand, IdeS can be used to treat the antibody-responsive diseases produced by autoimmunity as a therapeutic protein. In this study, the backbone of plasmid pCold was used to construct two expression vectors of recombinant protein IdeS, which were heterologously expressed in Escherichia coli Shuffle T7. After purification by affinity chromatography, the recombinant IdeS activity was detected and their activity differences between the two were compared. Among them, the yield of the recombinant IdeS containing the His6-tag at the N-terminus was 4 mg·L-1, and the cleavage reaction with antibody IgG1 at 1∶200 (m/m) at 37 ℃ for 30 min could complete. However, the yield of the recombinant IdeS containing both the N-terminal His6 tag and the C-terminal silica affinity tag (silica bing peptide, SiBP) is 1.5 mg·L-1, and the degradation reaction with antibody IgG1 at 1∶20 (m/m) at 37 ℃ for 30 min could reach the end. The C-terminal fusion peptide has a great influence on the yield and activity of IdeS, which is not conducive to subsequent application in drug development. Above all, the recombinant IdeS containing the His6-tag at the N-terminus expressed by this system has high activity and can fully meet the needs of antibody drug development and mapping analysis of IgG.
The method of homogeneity evaluation for active pharmaceutical ingredient (API) spatial distribution in lyophilized product was investigated for the first time with confocal micro-Raman spectroscopy mapping, using pemetrexed disodium for injection as a model drug. Certain areas of the lyophilized product were scanned to obtain Raman spectra. The classical method ("peak clipping" method) was employed for mapping with characteristic Raman peaks of the API and the excipient. Due to the API being finely dispersed in the excipient in lyophilized products, the classical method cannot discriminate between the two ingredients making the distribution homogeneity difficult to evaluate. The "ratio of characteristic peak intensities" method was then utilized. Using this method, the relative intensity of the characteristic Raman peaks of the API to the excipient was applied for mapping and the relative content of API to excipient was calculated for a homogeneity evaluation of the drug distribution. The validation of this method showed a good linear relationship between the relative intensity and the relative content of API to excipient (r2 > 0.99), and the precision and recovery were adequate for homogeneity evaluation of API by Raman spectroscopy mapping. Five products of pemetrexed disodium for injection from different manufacturers were tested through Raman maps applying this method and the histograms of relative Raman intensity were also plotted by frequency to help the homogeneity evaluation of drug distribution. The results showed that there were obvious differences in the drug distribution homogeneity from different products, where a more homogeneous API distribution was found in the brand product. This research provides a reliable method for the homogeneity evaluation of API distribution, which facilitates quality evaluation and process optimization of lyophilized products.
The quality control and evaluation methods of Schizonepeta tenuifolia were established by HPLC fingerprint, multi index component content determination and chemical pattern recognition to provide basis for the quality control of medicinal materials. The chemical components of 25 batches of Schizonepeta tenuifolia panicle medicinal materials and decoction pieces collected were analyzed by high performance liquid chromatography, and the common pattern of fingerprint was established. A total of 22 common chromatographic peaks were calibrated, and their similarity was more than 0.9. The samples were divided into three categories according to different producing areas by cluster analysis. The results of principal component analysis and cluster analysis were consistent. Finally, five differential markers of different batches of Schizonepeta tenuifolia were selected by orthogonal partial least squares discriminant analysis. Through the identification of the reference substance, it was determined that peak 9 was hesperidin, peak 10 was rosmarinic acid, peak 13 was tilianin, peak 14 was quercetin, and peak 20 was pulegone. The quality evaluation method established in this study is stable and reliable, and is suitable for the quality control of Schizonepeta tenuifolia.
This study is to explore the mechanism of Xueshuantong improving cerebral microcirculation disorder through the combination of network pharmacology and experimental validation in vivo. Structural formulas of main Panax notoginseng saponins, including notoginsenoside R1, and ginsenoside Rg1, Re, Rb1 and Rd were obtained from Pubchem website and their potential targets were predicted by Swiss Target Prediction database. Potential molecular targets of brain microcirculation disorder were acquired from OMIM and GeneCards database. The overlapped molecular targets between the drug and disease were analyzed. Protein interaction analysis and topology maps were constructed through the STRING online analysis platform and Cytoscape software. Core action targets were selected. GO function and KEGG pathway were analyzed by DAVID database. Immunohistochemical method was used to examine the expression of platelet endothelial cell adhesion molecule-1 (CD31) in the ischemic cortex of middle cerebral artery occlusion and reperfusion (MCAO/R) rats. The levels of mRNA and protein expressions of core action targets in MCAO/R model rats′ brain microvessels were verified by RT-qPCR and Western blot. Based on network pharmacology, 242 targets of Xueshuantong, 425 targets of brain microcirculation disorder, and 35 overlapped targets were obtained. The potential key targets of Xueshuantong, protein kinase B (AKT1), vascular endothelial growth factor A (VEGFA), caspase 3 (CASP3), matrix metallopeptidase 9 (MMP-9), phosphatidylinositol-4, 5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), signal transducer and activator of transcription 3 (STAT3) involved in the alleviation of cerebral microcirculation disorder were obtained by setting degree and betweenness centrality as screening parameters. Xueshuantong at the dose of 48 mg·kg-1 was shown to significantly improve the injury of neurological behaviors, as well as the density and morphology of microvessels of MCAO/R model rats. Xueshuantong could down-regulate the mRNA levels of AKT1, MMP-9, and STAT3, increase the protein expression levels of CD31, phosphorylated AKT and phosphatidylinositol-4, 5-bisphosphate 3-kinase (PI3K), and the ratio of B-cell lymphoma 2/Bcl-2-associated X (Bcl-2/Bax), but decrease the protein expression levels of MMP-9, cleaved caspase-3 and phosphorylated STAT3. In summary, Xueshuantong could improve ischemic cerebral microcirculation disorder and thereby reduce nerve damage in ischemia-reperfusion rats by regulating signaling pathways related with PI3K, AKT, MMP-9, STAT3 and caspase-3 in microvessels. The study strictly adhered to all ethical protocols that experimental animals should follow in the course of medical research.
Increasingly researches suggested that intermittent fasting (IF) can be part of a healthy lifestyle, which can improve risk factors associated with obesity and diabetes. Based on LC-MS metabolomics technology, this study preliminarily discussed the effect of IF on the metabolism of mice under normal physiological conditions by detecting the fecal metabolites. All experiments were approved by the Animal Research Committee of Shanghai University of Traditional Chinese Medicine. Animal welfare and the animal experimental protocols were strictly consistent with related ethics regulations of Shanghai University of Traditional Chinese Medicine. The mice were subjected to intermittent fasting for 10 weeks by fasting for 24 hours on alternate days, and their feces at 5 and 10 weeks were collected. The results show that the weight, food and water intake was not significant altered in mice with IF, but fasting blood glucose level was decreased. We found that fecal metabolites change was present at 5-week, being more prominent in 10-week. Relative to the control mice, we detected 17 and 108 metabolites in two time points, respectively. These metabolites were mainly enriched in the pathways of linoleic acid metabolism and bile acid biosynthesis. We further found that 10 metabolites may be a close correlation with IF, which had the same change trend at two time points. In conclusion, the present study provides a new approach to study the metabolism mechanism in IF treatment of related diseases.
A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed to determine the plasma concentration of progesterone in Beagle dogs, and apply it to the study of the pharmacokinetics of progesterone sustained-release formulation in Beagle dogs. The plasma samples were processed by protein precipitation method and megestrol acetate was used as an internal standard (IS). The quantitation analysis was performed using multiple-reaction monitoring (MRM) mode at the specific ion transitions of m/z 315.2→97.0 for progesterone and m/z 385.2→267.1 for megestrol acetate (IS) under the positive ion condition. Male Beagle dogs were injected intramuscularly with progesterone sustained-release microspheres and the plasma samples were collected at different time points after administration. The relevant pharmacokinetic parameters were calculated by WinNonlin 8.1 software. A good linearity over the range of 0.1-500.0 ng·mL-1 was yielded by this method. The intra- and inter-day precision (RSD) were all less than 13.25% and the accuracy (RE) was within 8.92%. Stability test showed that progesterone in dog plasma was stable at room temperature for 12 h, up to 60 days at -20 ℃ and after three cycles of freeze-thaw. The recovery of it ranged from 71.43%-77.97%. After intramuscular injection of progesterone sustained-release microspheres in Beagle dogs, tmax was 19.00 ± 25.36 h, Cmax was 137.72 ± 11.59 ng·mL-1, t1/2 was 83.83 ± 26.43 h. The drug was released continuously in vivo and in a continuous absorption process for many times with good sustained-release effect. The method developed in this study is sensitive, rapid and stable. It is suitable for the determination of progesterone plasma concentration in Beagle dogs, and can be applied to the preclinical pharmacokinetic study of progesterone-related formulations. The animal experiment scheme of this study was approved by the Animal Ethics Committee of the Academy of Military Medical Sciences.