In this study, we aimed to investigate the effects of stabilizers and processing parameters on the size reduction of alpha-mangostin (AMG) using high-pressure homogenization (HPH). The solubility of AMG in various stabilizers was studied. Selected stabilizers were used to prepare AMG suspensions by HPH under different conditions. After HPH, the particle size of AMG suspensions with stabilizers significantly decreased to microns. Percent size reduction efficiency of all AMG suspensions with each stabilizer increased with the increase in the number of homogenization cycles. Sodium lauryl sulfate and poloxamer188 provided a greater extent of particle size reduction than polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer. AMG suspensions with binary stabilizers at higher pressure were also prepared. The use of high pressure increased percent size reduction efficiency.
Yiqi Tongluo Granule (YQTL) is a kind of proprietary Chinese medicine, manufactured by China Shineway Pharmaceutical Group Ltd, under the authority of China Food and Drug Administration (CFDA) treating cardiovascular and cerebrovascular diseases such as ischemic stroke in China, however the underlying mechanism of YQTL on treating ischemic stroke has not been revealed. This study is aimed to evaluate the protective effect of YQTL on cerebral ischemia reperfusion (I/R) injury and inquire into its underlying mechanisms. Cerebral I/R injury was induced by occluding the middle cerebral artery for 2 h followed by 24 h reperfusion. And regional cerebral flow was monitored by Laser Doppler flow during ischemia phase. The infarct volume was evaluated by Triphenyte-trazolium chloride staining. The protective effects of YQTL were assessed by a number of parameters, including neurological scores, regional cerebral blood flow, pathological changes of neuron in hippocampuses and hippocampus calcium level. The proteins of ERK, GluN2B and p-CaMKII response were assayed by western blotting. I/R caused significant change in neurological deficit scores, regional cerebral flow and infarct volume. However results in YQTL groups and Nimodipine Tablets (NMDP) group were reversed. Subsequently YQTL reduced I/R-induced calcium influx. Results of hematoxylin-eosin staining manifested that YQTL significantly improved neuronal injury after I/R in rats. Meanwhile, microdialysis data demonstrated that extracellular glutamate was increased in the striatum during ischemia reperfusion, which was reduced by YQTL. YQTL and MEK inhibitor suppressed the I/R-mediated over-expression of GluN2B, p-ERK, ERK and p-CaMKII proteins expression. Putting these together, our results suggest that YQTL played a neuroprotective role in cerebral I/R injury, which might be exerted by inhibiting the excitotoxicity and expression of GluN2B, p-CaMKII and MEK/ERK signal pathway.
Rhodiola is widely consumed in traditional folk medicine and nutraceuticals. To establish a procedure for the hydrogen nuclear magnetic resonance (1H-NMR) spectroscopic fingerprinting of secondary metabolites from three different Rhodiola species, the variation among three Rhodiola species were studied using 1H-NMR metabolomics combined with multivariate data analysis. Gene expression programming (GEP) was used to generate a formula to distinguish Rhodiola crenulata from two other Rhodiola species. Finally, high-performance liquid chromatography (HPLC) was used to demonstrate the results. Same metabolites were compared by quantitative 1H-NMR (qNMR). Three Rhodiola species were clearly discriminated by 1H-NMR fingerprinting involved 22 nuclear magnetic signals of chemical constituents. y=d166×2+C1+d56+d236−d128×C2 can be used to distinguish R. crenulata from two other Rhodiola species by GEP. The gallic acid concentration in R. crenulata was significantly higher than in the other. Rhodiola species as was the level of salidroside. R. crenulata also exhibited substantially higher levels of α-glucose. The fatty acid level in Rhodiola kirilowii was lower than the other species. These findings demonstrated that 1H-NMR fingerprinting combined with principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), hierarchical cluster analysis (HCA) and GEP can be used to distinguish different Rhodiola species and these methods were applicable and effective approaches for metabolic analysis, species differentiation, and quality assessment. In addition, gallic acid, salidroside, α-D-glucose, glycine, alanine, caffeic acid and tyrosol and are the discriminators.
The tumor microenvironment is considered as one of the important targets for anticancer drug discovery. In particular, nutrient deficiency may be observed in tumor microenvironment; biakamides A-D (1-4) isolated from marine sponge Petrosaspongia sp. as growth inhibitors against cancer cells adapted to glucose-deprived conditions have potential as new drugs and tools for elucidating adaptation mechanisms to these conditions. In this paper, we investigated structure-activity relationship (SAR) of biakamide to create easily accessible analog and gain insights about participation of the substructures to growth-inhibitory activity toward development of anticancer drug. This work revealed that 14,15-dinor-biakamide C (5), which is easily accessible, has similar activity to natural biakamide C (3). In addition, detailed SAR study showed the terminal acyl chain is important for interacting with target molecule and amide part including thiazole ring has acceptability to convert structures without losing activity.
Targeted protein degradation by small molecules is an emerging modality with significant potential for drug discovery. We previously developed chimeric molecules, termed specific and non-genetic inhibitor of apoptosis protein (IAP)-dependent protein erasers (SNIPERs), which induce the ubiquitylation and proteasomal degradation of target proteins. This degradation is mediated by the IAPs; the target proteins include bromodomain-containing protein 4 (BRD4), an epigenetic regulator protein. The SNIPER that degrades this particular protein, SNIPER(BRD)-1, consists of an IAP antagonist LCL-161 derivative and a bromodomain and extra-terminal (BET) inhibitor, (+)-JQ-1. SNIPER(BRD)-1 also degrades a cellular inhibitor of apoptosis protein 1 (cIAP1) and an X-linked inhibitor of apoptosis protein (XIAP), the mechanisms of which are not well understood. Here, we show that the degradation of cIAP1 and XIAP by SNIPER(BRD)-1 is induced via different mechanisms. Using a chemical biology-based approach, we developed two inactive SNIPERs, SNIPER(BRD)-3 and SNIPER(BRD)-4, incapable of degrading BRD4. SNIPER(BRD)-3 contained an N-methylated LCL-161 derivative as the IAP ligand, which prevented it from binding IAPs, and resulted in the abrogated degradation of cIAP1, XIAP, and BRD4. SNIPER(BRD)-4, however, incorporated the enantiomer (−)-JQ-1 which was incapable of binding BRD4; this SNIPER degraded cIAP1 but lost the ability to degrade XIAP and BRD4. Furthermore, a mixture of the ligands, (+)-JQ-1 and LCL-161, induced the degradation of cIAP1, but not XIAP and BRD4. These results indicate that cIAP1 degradation is triggered by the binding of the IAP antagonist module to induce autoubiquitylation of cIAP1, whereas a ternary complex formation is required for the SNIPER-induced degradation of XIAP and BRD4.
Prodrug approaches are useful for enhancing the efficacies and reducing the side effects of anticancer drugs. Previously, we proposed a prodrug strategy for targeting cancers overexpressing lysine-specific demethylase 1 (LSD1), namely, conjugates of trans-2-phenylcyclopropylamine (PCPA, an LSD1 inhibitor) and anticancer drugs. In this study, we applied this prodrug strategy to the anticancer agent 5-fluorouracil (5-FU). In vitro assays showed that the PCPA-5-FU conjugate (1) released 5-FU upon the inhibition of LSD1. Furthermore, the conjugate (1) exerted an antiproliferative effect on colon cancer HCT116 cells. Thus, the PCPA-5-FU conjugate (1) was able to function as a prodrug of 5-FU, activated by LSD1 inhibition, and provided a useful new lead structure for further development.
Reversibly glycosylated conjugates were developed by adding complex-type N-linked oligosaccharides to peptides through self-cleavable linkers with the aim of increasing the solubility and stability of the peptides in plasma. The amino or carboxyl group of the peptide was connected to a glycosylated Ascendis or ester/thioester-type linker, respectively. Use of the linkers enabled extended release of the peptides depending on the pH and temperature of the buffer according to a first order reaction, and their cleavage rate was also affected by the structure of the peptide-linker coupling. This tunability will allow optimization towards the intended use of the peptides to be released. Furthermore, because glycosylation is a reliable method of greatly increasing the solubility of a peptide, the presented glycosylated linkers are expected to permit the preparation of antibodies in aqueous buffers even in the case of sparingly soluble antigen peptides.
We developed a palladium-catalyzed C–H N-heteroarylation of N-protected-2,5-disubstituted imidazoles at the C4-position using N-heteroaryl halides as a coupling partner. Intensive reaction condition screening led us to identify fluorinated bathophenanthroline 7 as the optimum ligand for the palladium catalyst. This reaction will enhance lead optimization of drug candidates by facilitating the synthesis of heterobiaryl compounds containing an imidazole ring.