During the routine impurity profile of lisinopril bulk drug by HPLC (high-performance liquid chromatography), a potential impurity was detected. Using multidimensional NMR (nuclear magnetic resonance) technique, the trace-level impurity was unambiguously identified to be 2-(-2-oxo-azocan-3-ylamino)-4-phenyl-butyric acid after isolation from lisinopril bulk drug by semi-preparative HPLC. Formation of the impurity was also discussed. To our knowledge, this is a novel impurity and not reported elsewhere.
Butyrates ; analysis ; isolation & purification ; Drug Contamination ; Lisinopril ; analysis ; Magnetic Resonance Spectroscopy ; Models, Molecular

OBJECTIVETo investigate the protective effect of neferine against damages of endothelial cells induced by lysophos-phatidylcholine (LPC) and the relationship with asymmetric dimethylarginine (ADMA).

METHODThe human umbilical vein endothelial cells (HUVEC-12) were treated with LPC (10 mg x L(-1)) for 24 h to establish the model of endothelial cells damages; HUVECs were prior exposed to neferine (0.1, 1.0 or 10.0 micromol x L(-1) ) for 1 h, and then exposed to LPC in the presence of the neferine for 24 h. At the end of the experiment, the cultured medium was collected for measuring the concentration of nitric oxide (NO), aleic dialdehyde (MDA) as well as ADMA and the cells were collected for measuring the level of intracellular reactive oxygen species (ROS).

RESULTCompared with control group, exposure of endothelial cells to LPC (10 mg x L(-1)) for 24 h significantly increased the concentration of MDA and ADMA in the medium and the level of intracellular ROS and coinstantaneously significantly decreased the concentration of NO in the medium. Neferine (0.1, 1.0 or 10.0 micromol x L(-1)) significantly inhibited the elevated concentration of MDA, ADMA as well as the level of intracellular ROS and coinstantaneously significantly attenuated the decreased level of NO induced by LPC.

CONCLUSIONNeferine can protect the endothelial cells against damages induced by LPC and the protective effect is related to the decrease of the concentration of ADMA.

Arginine ; analogs & derivatives ; metabolism ; Benzylisoquinolines ; pharmacology ; Cell Line ; Endothelial Cells ; drug effects ; metabolism ; Humans ; Lysophosphatidylcholines ; pharmacology ; Malondialdehyde ; metabolism ; Nitric Oxide ; metabolism ; Reactive Oxygen Species ; metabolism

The discovery of induced pluripotent stem cells(iPSCs) is a promising advancement in the field of regenerative medicine. Previous studies have indicated that the teratoma-forming propensity of iPSCs is variable; however, the relationship between tumorigenic potential and genomic instability in human iPSCs (HiPSCs) remains to be fully elucidated. Here, we evaluated the malignant potential of HiPSCs by using both colony formation assays and tumorigenicity tests. We demonstrated that HiPSCs formed tumorigenic colonies when grown in cancer cell culture medium and produced malignancies in immunodeficient mice. Furthermore, we analyzed genomic instability in HiPSCs using whole-genome copy number variation analysis and determined that the extent of genomic instability was related with both the cells' propensity to form colonies and their potential for tumorigenesis. These findings indicate a risk for potential malignancy of HiPSCs derived from genomic instability and suggest that quality control tests, including comprehensive tumorigenicity assays and genomic integrity validation, should be rigorously executed before the clinical application of HiPSCs. In addition, HiPSCs should be generated through the use of combined factors or other approaches that decrease the likelihood of genomic instability.
Animals ; Carcinogenesis ; Cells, Cultured ; DNA Copy Number Variations ; Genomic Instability ; Humans ; Induced Pluripotent Stem Cells ; cytology ; metabolism ; transplantation ; Mice ; Mice, SCID ; NIH 3T3 Cells ; Octamer Transcription Factor-3 ; metabolism ; Teratocarcinoma ; etiology ; Teratoma ; etiology ; Tumor Stem Cell Assay

In the present study, four new sesquiterpenoids, chimonols A-D (compounds 1-4), together with four known compounds (5-8) were isolated from the EtOAc extract of Chimonanthus praecox Link. The structures of these new compounds were elucidated on the basis of spectroscopic techniques (UV, IR, MS, and 1D and 2D NMR), and their absolute configurations were established by comparing experimental and calculated electronic circular dichroism (ECD) spectra. Compounds 1-8 were evaluated for antimicrobial activities and the minimum inhibitory concentrations (MICs) were determined by the broth microdilution method in 96-well culture plates. Compounds 1, 2, and 7 exhibited weak antibacterial effects for S. aureus (ATCC 6538), E. coli (ATCC 11775), and P. aeruginosa (ATCC 10145) with MIC values being 158-249 µg·mL. Compounds 3-7 showed activities against C. glabrata (ATCC 2001) and S. aureus (ATCC 43300) with MIC values being 128-197 µg·mL. Compounds 1-4 showed activity against S. aureus (ATCC 25923) with MIC values being 162-254 µg·mL. The present study provided a basis for future evaluation of these compounds as antibacterial agents.
Anti-Bacterial Agents ; chemistry ; isolation & purification ; pharmacology ; Calycanthaceae ; chemistry ; Escherichia coli ; drug effects ; Microbial Sensitivity Tests ; Molecular Structure ; Plant Extracts ; chemistry ; isolation & purification ; pharmacology ; Sesquiterpenes ; chemistry ; isolation & purification ; pharmacology ; Staphylococcus aureus ; drug effects