Facile synthesis of a new chiral polyimine macrocycle and its application for enantioseparation in high-performance liquid chromatography.

Macrocyclic compounds such as crown ethers and cyclodextrins play an important role in the field of chromatography and show excellent separation performance. The design of simple and convenient methods for the efficient synthesis of novel chiral macrocycles for chromatographic separation is of great significance. In this work, a novel chiral polyimine macrocycle (PIMC) was designed and synthesized by the simply one-step reaction of 2,6-diformyl-4-tert-butylphenol with (S)-(-)-1,2-propanediamine. Then, it was bonded onto silica by the thiol-ene click reaction to construct a new chiral stationary phase (CSP) for high-performance liquid chromatography (HPLC). The chiral separation performance of the proposed CSP was examined by separating various racemates in the normal-phase (NP) and reversed-phase (RP) HPLC. In total, twelve and nine racemates, including ethers, esters, amines, alcohols, organic acids, ketones, and epoxides, were separated to varying degrees via NP-HPLC and RP-HPLC, respectively, Moreover, the CSP offered good chiral separation complementarity to Chiralcel OD-H and Chiralpak AD-H columns for resolution of these test racemates, and it can separate several racemic compounds that either cannot be separated or cannot be separated well be separated by the two commercially available columns. After the column was used for hundreds of injections, the relative standard deviations of the retention time and resolution were below 0.56 % and 0.45 %, respectively, showing the good reproducibility and stability of the CSP. This study provides a simple and convenient approach to synthesize a novel chiral macrocycle and CSP and also indicates the broad application prospects of such chiral PIMCs in HPLC chiral separation.

Preparation and evaluation of a 1,1'-bi-2-naphthol-based chiral macrocycle bonded silica chiral stationary phase for high performance liquid chromatography.

Macrocycles play vital roles in supramolecular chemistry and chromatography. 1,1'-Bi-2-naphthol (BINOL)-based chiral polyimine macrocycles are an emerging class of chiral macrocycles that can be constructed by one-step aldehyde-amine condensation of BINOL derivatives with other building blocks. These macrocycles exhibit good characteristics, such as facile preparation, rigid cyclic structures, multiple chiral centers, and defined molecular cavities, that make them good candidates as new chiral recognition materials for chromatographic enantioseparations. In this study, a BINOL-based [2+2] chiral polyimine macrocycle was synthesized by one-step condensation of enantiopure (S)-2,2'-dihydroxy-[1,1'-binaphthalene]-3,3'-dicarboxaldehyde with (1R,2R)-1,2-diaminocyclohexane. The product was modified with 5-bromo-1-pentene and then attached to thiolated silica using click chemistry to construct a new chiral stationary phase (CSP). The enantioselectivity of the new CSP was explored by separating various racemates under normal phase (NP) and reversed phase (RP) high performance liquid chromatography (HPLC). Thirteen racemates and eight racemates were enantioseparated under the two separation modes, respectively, including chiral alcohols, phenols, esters, ketones, amines, and organic acids. Among them, nine racemates achieved baseline separation under NP-HPLC and seven racemates achieved baseline separation under RP-HPLC. High resolution separation was observed with benzoin (Rs = 5.10), epinephrine (Rs = 4.98), 3-benzyloxy-1,2-propanediol (Rs = 4.42), and 4,4'-dimethylbenzoin (Rs = 4.52) in NP-HPLC, and with 4-methylbenzhydrol (Rs = 4.72), benzoin ethyl ether (Rs = 3.79), 1-phenyl-1-pentanol (Rs = 3.68), and 1-(3-bromophenyl)ethanol (Rs = 3.60) in RP-HPLC. Interestingly, the CSP complemented Chiralcel OD-H, Chiralpak AD-H, and CYCLOBOND I 2000 RSP columns for resolution of these test racemates, separating several racemic compounds that could not be well separated by the three commercially available columns. The influences of injected sample amount on separation were also evaluated. It was found that the column exhibited excellent stability and reproducibility after hundreds of injections, and the relative standard deviations (n = 5) of the retention time and resolution were less than 0.49% and 0.69%, respectively. This study indicates that the BINOL-based chiral macrocycle has great potential for HPLC enantioseparation.

Anticancer efficiency of cycloartane triterpenoid derivatives isolated from Cimicifuga yunnanensis Hsiao on triple-negative breast cancer cells.

BACKGROUND: The roots and rhizomes of Cimicifuga yunnanensis Hsiao are commonly used as anti-inflammatory, antipyretic, and analgesic remedies and detoxification agents in traditional Chinese medicine (TCM). Although C. yunnanensis has been considered as supplementary medicine for several disorders, the antitumor effect of this herb and its key components has not been explored. MATERIALS AND METHODS: The rhizomes of C. yunnanensis were isolated by chromatographic techniques. Structures of isolated compounds were identified based on spectroscopic methods and comparison with published data. The in vitro anticancer activities of purified components were also performed by MTT experiments. The in vivo anticancer activities were examined by subcutaneous tumor model or a breast cancer liver metastasis model. RESULTS: In this study, we aimed to identify and characterize the effective antitumor components from the rhizomes of C. yunnanensis. By bioassay-guided fractionation techniques and chemical characterization, 12 cycloartane triterpenes and four chromones were isolated, among them, 11 compounds were identified in this genus at first. The identified two compounds showed dramatic inhibitory activities against breast cancer cells: compound 4 (23-epi-26-deoxyactein) and compound 13 (cimigenol). Then, we examined the antitumor effect of these two selective candidate chemicals on triple-negative breast cancer (TNBC) cells in vivo and found that they could reduce tumor growth in subcutaneous tumor model or breast cancer liver metastasis model. CONCLUSION: These results suggested that the selective compounds isolated from C. yunnanensis Hsiao could be the promising new agents for TNBC treatment.

Association of vitamin D receptor gene polymorphisms with the susceptibility to ulcerative colitis in patients from Southeast China.

The association studies from different ethnic groups showed that vitamin D receptor (VDR) gene polymorphisms might be connected with the susceptibility to ulcerative colitis (UC); however, the conclusions were less consistent. Our study aimed to analyze the associations of UC with common mutations of VDR in Chinese patients. A total of 382 UC patients and 489 healthy controls were recruited. The genotypes of VDR FokI (rs2228570), BsmI (rs1544410), ApaI (rs7975232) and TaqI (rs731236) were examined by SNaPshot assays. Haplotype analysis was performed in all study subjects. After Bonferroni correction, the mutant alleles and genotypes of VDR FokI, BsmI, ApaI and TaqI did not statistically differ between UC patients and the controls (all p > 0.0125). However, the mutant allele C and genotype TC + CC of FokI gene were significantly increased in patients with mild and moderate UC compared to those with severe UC (C allele: 54.1% versus 39.3%, OR = 1.83, 95% CI: 1.21-2.75, p = 0.004; TC + CC genotype: 81.6% versus 57.1%, OR = 3.32, 95% CI: 1.83-6.06, p < 0.001, respectively). Haplotype analysis showed that the VDR BsmI, ApaI and TaqI polymorphic loci were in a strong linkage disequilibrium. Furthermore, the frequency of AAC haplotype was statistically lower in UC patients than that in the controls (3.8 versus 5.9%, OR = 0.63, 95% CI: 0.39-1.01, p = 0.039). In conclusion, the mutation of FokI gene influenced severity of the disease in UC patients. Moreover, the AAC haplotype formed by the VDR BsmI, ApaI and TaqI gene might engender a reduced risk of UC attack.

Associations of FUT2 and FUT3 gene polymorphisms with Crohn's disease in Chinese patients.

BACKGROUND AND AIM: FUT2 and FUT3 genes are responsible for the formation of histo-blood group antigens, which act as binding sites for some intestinal microbes. Several studies suggested that FUT2 gene might affect the intestinal microbiota composition and modulate innate immune responses. However, the effect of FUT2 polymorphisms on Crohn's disease (CD) is uncertain. Our study aimed to analyze associations of CD with FUT2 and FUT3 polymorphisms in Chinese population. METHODS: A total of 273 CD patients and 479 controls were recruited. The genotypes of FUT2 (rs281377, rs1047781, and rs601338) and FUT3 (rs28362459, rs3745635, and rs3894326) were detected by SNaPshot analysis. RESULTS: Compared with controls, homozygote TT of FUT2 (rs1047781) was significantly increased in CD patients (TT vs others; P = 0.002, odds ratio [OR] = 1.767, 95% confidence interval [CI] = 1.235-2.528). The haplotype TT formed with FUT2 (rs281377) and (rs1047781) was more prevalent in CD patients than in controls (48.9% vs 43.5%, P = 0.046). Mutant T allele and homozygote TT of FUT2 (rs1047781) were increased in colonic CD patients compared with controls (P < 0.001, OR = 1.843, 95% CI = 1.353-2.512; P < 0.001, OR = 2.607, 95% CI = 1.622-4.191, respectively). Although allele and genotypic distributions of FUT3 were not statistically different between CD patients and controls, mutant allele and genotype of FUT3 (rs28362459) and (rs3745635) were significantly discrepant in three subgroups of CD patients according to lesion locations (all P < 0.05). CONCLUSIONS: Our study strongly implicates the polymorphic locus of FUT2 (rs1047781) in CD susceptibility in Chinese population. Mutations of FUT3 (rs28362459) and (rs3745635) might influence the lesion locations in CD patients.

Chronic exposure to pentachlorophenol alters thyroid hormones and thyroid hormone pathway mRNAs in zebrafish.

Pentachlorophenol (PCP) is frequently detected in the aquatic environment and has been implicated as an endocrine disruptor in fish. In the present study, 4-month-old zebrafish (Danio rerio) were exposed to 1 of 4 concentrations of PCP (0.1, 1, 9, and 27 µg/L) for 70 d. The effects of PCP exposure on plasma thyroid hormone levels, and the expression levels of selected genes, were measured in the brain and liver. The PCP exposure at 27 µg/L resulted in elevated plasma thyroxine concentrations in male and female zebrafish and depressed 3, 5, 3'-triiodothyronine concentrations in males only. In both sexes, PCP exposure resulted in decreased messenger RNA (mRNA) expression levels of thyroid-stimulating hormone ß-subunit (tshß) and thyroid hormone receptor ß (trß) in the brain, as well as increased liver levels of uridine diphosphoglucuronosyl transferase (ugt1ab) and decreased deiodinase 1 (dio1). The authors also identified several sex-specific effects of PCP exposure, including changes in mRNA levels for deiodinase 2 (dio2), cytosolic sulfotransferase (sult1 st5), and transthyretin (ttr) genes in the liver. Environmental PCP exposure also caused an increased malformation rate in offspring that received maternal exposure to PCP. The present study demonstrates that chronic exposure to environmental levels of PCP alters plasma thyroid hormone levels, as well as the expression of genes associated with thyroid hormone signaling and metabolism in the hypothalamic-pituitary-thyroid (HPT) axis and liver, resulting in abnormal zebrafish development.

[Distribution characteristics of PBDEs in surface sediment from the Three Gorges Reservoir of Yangtze River].

A total of 28 surface sediment samples (at the top 0-5 cm layer) were collected from the Three Gorges Reservoir of Yangtze River. The content of polybrominated diphenyl ethers (PBDEs) in sediments was measured with Varian GC-MS (NCI). The results showed that sigma26 PBDEs and BDE209 both had a low concentration in sediments, with a mass concentration of 35.24 pg x g(-1) and 11.92 pg x g(-1), respectively. Among the 26 PBDEs, BDE28, 47, 77 and 99 were the most predominant sigma26 PBDEs congeners. The highest concentrations of sigma26 PBDEs and BDE209 were detected in the sediment samples collected from Long River, with geometric mean of 146.07 and 502.63 pg x g(-1), respectively. A significant correlation was found between sigma26 PBDEs and BDE209, indicating that they might have the same pollution source. The concentrations of sigma26 PBDEs and BDE209 in the sediment were in the same order of magnitude with those reported on background levels in sediments of remote lakes in other countries, which shows the toxic biological effects on aquatic biota and potential risk due to sigma26 PBDEs and BDE209 contamination in sediments are negligible.

[Clinical study of effect of penehyclidine hydrochloride and atropine sequential therapy in the treatment of severe acute organophosphorus pesticide poisoning].

OBJECTIVE: To investigate the clinical efficacy of penehyclidine hydrochloride sequential to atropine in severe acute organophosphorus pesticide poisoning (AOPP). METHODS: A retrospective analysis of the clinical data of 180 patients with severe AOPP admitted to the Emergency Center of Wuwei City People's Hospital from January 2007 to August 2011 was conducted. The patients were divided into penehyclidine hydrochloride sequential to atropine group, atropine group and penehyclidine hydrochloride group according to difference of anti-choline drugs using, with 60 cases in each group. The complication rate, time of recovery of cholinesterase (ChE) activity to 70％, hospital stay time and cost, the cure rate, mortality rate in three groups were analyzed. RESULTS: In penehyclidine hydrochloride sequential to atropine group, except for 1 case of cancer of gastric cardia with poisoning after operation showing intermediate syndrome of poisoning, the remaining patients did not have any complication, and the incidence of complications was 1.67％.No death occurred in all the patients, and the cure rate was 100.00％.Time of recovery from ChE activity to 70％ was (4.0 ± 1.1 ) days; hospital stay was (7.0 + 2.2) days; hospital expenses were (6268 ± 238 ) yuan. In atropine group, 3 patients were found to have atropine resistance, 3 patients showed intermediate syndrome, rebound was observed in 2 cases, atropine poisoning in 2 patients, and the incidence of complications was 16.67％.Three patients died of respiratory or circulatory failure, and the mortality rate was 5.00％.Fifty-seven patients were cured, the cure rate was 95.00％.The time of ChE activity recovery to 70％ was (8.0 ± 0.9) days. Hospital stay was (12.0 ± 2.1) days. Hospital expenses were (7160 ± 110) yuan. In penehyclidine hydrochloride group, 1 patient was found to have respiratory failure, 1 case suffered from pulmonary edema, and the complication rate was 3.33％.Two patients died, the mortality rate wan 3.33％.Fifty-eight patients were cured, the cure rate was 96.67％.The time of ChE activity recovery to 70％ was (6.0 ± 0.7) days, hospital stay was (9.0 ± 1.5) days, and hospital expenses were (7921 ± 230) yuan. Compared with atropine group, penehyclidine hydrochloride sequential to atropine group had a low death rate, high cure rate, less complications, ChE activity recover fast, short hospital days, and the hospitalization expenses were lower than that of the single use of atropine or single use of penehyclidine hydrochloride group, and the differences were statistically significant (all P＜0.01). CONCLUSIONS: In treatment of severe AOPP by penehyclidine hydrochloride sequential to atropine, curative effect was more significant, with fewer adverse reactions, short hospital stay, and lower cost.

Discovery of tetrahydro-beta-carbolines as inhibitors of the mitotic kinesin KSP.

Inhibitors of kinesin spindle protein (KSP) are a promising class of anticancer agents that cause mitotic arrest in cells from a failure to form functional bipolar mitotic spindles. Here, we report the synthesis and biological evaluation of a novel series of tetrahydro-beta-carboline analogs based on the structure of the known KSP inhibitor HR22C16. Preferred compounds 11b, 12a and 19b were identified as potent inhibitors in a KSP ATPase assay with good anti-proliferative activity in A549 cells.