Synthesis and evaluation of 2-amino-8-alkoxy quinolines as MCHr1 antagonists. Part 2

The continued SAR investigation of 2-amino-8-alkoxy quinolines as melanin concentrating hormone receptor-1 (MCHr1) antagonists is reported. Prior hit-to-lead efforts resulted in the identification of 1 as a robust MCHr1 antagonist. Further delineation of the structural parameters essential for MCHr1-binding affinity of this class of nontraditional GPCR ligands resulted in the identification of compounds such as 33, 34 and 37, which demonstrate single digit nanomolar antagonism of MCHr1-mediated Ca(2+) release. The synthesis and biological evaluation of these compounds are reported.     

Synthesis and evaluation of urea-based indazoles as melanin-concentrating hormone receptor 1 antagonists for the treatment of obesity

A series of urea-based N-1-(2-aminoethyl)-indazoles was synthesized and evaluated for melanin-concentrating hormone receptor 1 (MCHr1) antagonism in both binding and functional assays. Several compounds that acted as MCHr1 antagonists were identified, and optimization afforded a compound with excellent binding affinity, good functional potency, and oral efficacy in a chronic model for weight loss in diet-induced obese mice.     

Importance of melanin-concentrating hormone receptor for the acute effects of ghrelin

The hypothalamic peptide melanin-concentrating hormone (MCH) and the gastric hormone ghrelin take part in the regulation of energy homeostasis and stimulate food intake. In the present study, ghrelin was administered centrally to MCH-receptor knockout (MCHr KO) mice. MCHr KO mice and wild type (WT) controls both consumed more food when treated with ghrelin. After ghrelin administration, the serum levels of insulin increased only in WT mice whereas the serum levels of corticosterone increased both in WT and MCHr KO mice. The level of growth hormone (GH) mRNA in the pituitary gland was markedly increased in response to ghrelin injection in the WT mice but was unaffected in the MCHr KO mice. The different ghrelin responses could not be explained by a difference in growth hormone secretagogue receptor expression between MCHr KO and WT mice in the pituitary or hypothalamus. In summary, the MCHr is not required for ghrelin induced feeding. However, the MCHr does play a role for the effect of ghrelin on GH expression in the pituitary and serum insulin levels.     

Identification of ortho-amino benzamides and nicotinamides as MCHr1 antagonists

Several potent and efficacious MCHr1 antagonists containing an ortho-amino benzamide or nicotinamide chemotype have been identified, exemplified by 28 and 50.     

Synthesis and evaluation of 2-amino-8-alkoxy quinolines as MCHr1 antagonists. Part 3

Prior SAR studies on 2-amino-8-alkoxyquinoline MCHr1 antagonists demonstrated that compounds with acyclic amide-containing sidechains displayed exceptional binding and functional potency, but negligible CNS penetration. Related analogs with acyclic benzylamine-containing sidechains showed greatly improved CNS exposure, but suffered in functional potency. In this report, we demonstrate that cyclization of these benzylic amine sidechains affords compounds that combine the best elements of potency and CNS penetration among this class of antagonists. This is exemplified by compound 21, which has sub-nanomolar MCHr1 binding affinity, good functional potency, and excellent CNS exposure over 24h.     

Constrained 7-fluorocarboxychromone-4-aminopiperidine based Melanin-concentrating hormone receptor 1 antagonists: the effects of chirality on substituted indan-1-ylamines

The incorporation of constrained tertiary amines into an existing class of N-benzyl-4-aminopiperidinyl chromone-based MCHr1 antagonists led to the identification of a series of chiral racemic compounds that displayed good to excellent functional potency, binding affinity, and selectivity over the hERG channel. Further separation of two distinct chiral racemic compounds into their corresponding pairs of enantiomers revealed a considerable selectivity for MCHr1 for one configuration, in addition to a striking difference in oral exposure between one pair of enantiomers in diet-induced obese mice. Oral administration of the most potent compound in this class in the same animal model led to significant reduction of fat mass in a semi-chronic model for weight loss.     

Identification of aminopiperidine benzamides as MCHr1 antagonists

The identification of a novel series of benzamide-containing MCHr1 antagonists is described. Compound 22 displayed moderate efficacy in a diet induced obesity mice model.     

Identification and characterization of amino-piperidinequinolones and quinazolinones as MCHr1 antagonists

Several potent, functionally active MCHr1 antagonists derived from quinolin-2(1H)-ones and quinazoline-2(1H)-ones have been synthesized and evaluated. Pyridylmethyl substitution at the quinolone 1-position results in derivatives with low-nM binding potency and good selectivity with respect to hERG binding.     

Identification of diamino chromone-2-carboxamides as MCHr1 antagonists with minimal hERG channel activity

A series of potent 2-carboxychromone-based melanin-concentrating hormone receptor 1 (MCHr1) antagonists were synthesized and evaluated for hERG (human Ether-a-go-go Related Gene) channel affinity and functional blockade. Basic dialkylamine-terminated analogs were found to weakly bind the hERG channel and provided marked improvement in a functional patch-clamp assay versus previously reported antagonists of the series.     

Synthesis and evaluation of 2-amino-8-alkoxy quinolines as MCHr1 antagonists. Part 1

A high-throughput screen was performed in order to identify chemotypes that are bound by the melanin concentrating hormone receptor-1 (MCHr1). A novel 2-amino-8-alkoxyquinoline compound (1) was identified and subsequently optimized using a parallel and automated procedure for the rapid production of multiple analogs. The structure-activity relationships that emerged from this effort are described, along with selected pharmacokinetic parameters of compound (d)-61 when dosed orally in diet-induced obese mice.     

Effects of pH profiles on nisin production in biofilm reactor

Apart from its widely accepted commercial applications as a food preservative, nisin emerges as a promising alternative in medical applications for bacterial infection in both humans and livestock. Improving nisin production through optimization of fermentation parameters would make nisin more cost-effective for various applications. Since nisin production by Lactococcus lactis NIZO 22186 was highly influenced by the pH profile employed during fermentation, three different pH profiles were evaluated in this study: (1) a constant pH profile at 6.8 (profile 1), (2) a constant pH profile with autoacidification at 4 h (profile 2), and (3) a stepwise pH profile with pH adjustment every 2 h (profile 3). The results demonstrated that the low-pH stress exerted during the first 4 h of fermentation in profile 3 detrimentally affected nisin production, resulting in a very low maximum nisin concentration (593 IU ml⁻¹). On the other hand, growth and lactic acid production were only slightly delayed, indicating that the loss in nisin production was not a result of lower growth or shifting of metabolic activity toward lactic acid production. Profile 2, in which pH was allowed to drop freely via autoacidification after 4 h of fermentation, was found to yield almost 1.9 times higher nisin (3,553 IU ml⁻¹) than profile 1 (1,898 IU ml⁻¹), possibly as a result of less adsorption of nisin onto producer cells. Therefore, a combination of constant pH and autoacidification period (profile 2) was recommended as the pH profile during nisin production in a biofilm reactor.     

Structural analysis of the capsid polypeptides of herpes simplex virus types 1 and 2

Capsids of herpes simplex virus (HSV) types 1 and 2 contain seven polypeptides ranging in molecular weight from 154,000 to 12,000 (termed NC-1 through NC-7 in order of descending molecular weight). Antibodies prepared to HSV-1 capsid polypeptides isolated from sodium dodecyl sulfate-polyacrylamide gels reacted in an immunofluorescence assay against HSV-1-infected KB cells. Three of the antibodies (anti-NC-1, anti-NC-2, and anti-NC-3,4) also reacted with HSV-2-infected cells. Tryptic peptide analysis showed that each of the HSV-1 capsid polypeptides had a unique methionine peptide profile, and none appeared to be derived from the major capsid polypeptide. Comparative peptide analysis of HSV-1 and HSV-2 showed that one polypeptide (NC-7, 12,000 molecular weight) had an identical methionine peptide profile and a very similar arginine peptide profile in both virus types. The arginine peptide profile of NC-7 of HSV-1 was very different from the arginine profile of KB histone H4. Although there were certain intertypic similarities in the methionine peptide profiles of the other capsid components especially in NC-1 (the major capsid protein), there was no case where the tryptic peptides were identical in the two virus types.     

Effects of fed-batch fermentation and pH profiles on nisin production in suspended-cell and biofilm reactors

A biofilm reactor not only shortens the lag phase of nisin production, but also enhances nisin production when combined with an appropriate pH profile. Due to the substrate inhibition that takes place at high levels of carbon source, fed-batch fermentation was proposed as a better alternative for nisin production. In this study, the combined effects of fed-batch fermentation and various pH profiles on nisin production in a biofilm reactor were evaluated. The tested pH profiles include 1) a constant pH profile at 6.8 (profile 1), 2) a constant pH profile with an autoacidification after 4 h (profile 2), and 3) a step-wise pH profile with pH adjustment every 2 h (profile 3). When profile 1 was applied, fed-batch fermentation enhanced nisin production for both suspended-cell (4,188 IU ml⁻¹) and biofilm (4,314 IU ml⁻¹) reactors, yielded 1.8- and 2.3-fold higher nisin titer than their respective batch fermentation. On the other hand, pH profiles that include periods of autoacidification (profiles 2 and 3) resulted in a significantly lower nisin production in fed-batch fermentation (2,494 and 1,861 IU ml⁻¹ for biofilm reactor using profile 2 and 3, respectively) due to toxicity of excess lactic acid produced during the fermentation. Overall, this study suggested that fed-batch fermentation can be successfully used to enhance nisin production for both suspended-cell and biofilm reactors.     

弥漫大B细胞淋巴瘤1号染色体的基因表达分析

目的:探讨弥漫大B细胞淋巴瘤(Diffuse Large B-Cell Lymphoma,DLBCL)中1号染色体基因表达情况。方法:采用激光显微切割技术分离临床DLBCL病人淋巴结标本中的淋巴细胞,提取淋巴细胞的mRNA并与表达谱芯片杂交,通过信号扫描、处理后获得表达基因杂交信号强度。每基因设11-20对探针。杂交信号与错配探针对比,扣除背景值后,使用Wilcoxon符号秩和检验选取与错配杂交信号有显著差异的基因作为分析结果(P=0.05)。然后随机选取四个检测到的基因,使用PCR方法检验基因芯片结果的可靠性。结果:成功地从快速冷冻保存的DLBCL标本中提取RNA。使用表达谱芯片进行研究,发现了共316条1号染色体编码的基因在DLBCL细胞中表达。根据胞内定位,基因功能和基因所属的代谢通路三种分类方法对所得基因进行分类分析。基因表达密度分析显示DLBCL中1号染色体上的基因表达情况与编码基因分布情况存在统计学差异。结论:使用表达谱芯片研究了DLBCL中1号染色体上的基因表达情况。     

SAR of a series of anti-HSV-1 acridone derivatives, and a rational acridone-based design of a new anti-HSV-1 3H-benzo[b]pyrazolo[3,4-h]-1,6-naphthyridine series

Herpes Simplex Virus (HSV) infections are among the most common human diseases. In this work, we assess the structural features and electronic properties of a series of ten 1-hydroxyacridone derivatives (1a-j) recently described as a new class of non-nucleoside inhibitors of Herpes Simplex Virus-1 (HSV-1). Based on these molecules, we applied rigid analogue and isosteric replacement approaches to design and synthesize nine new 3H-benzo[b]pyrazolo[3,4-h]-1,6-naphthyridine derivatives (2a-i). The biological and computational results of these new molecules were compared with 1-hydroxyacridones. An inhibitory profile was observed in 10-Cl substituted 3H-benzo[b]pyrazolo[3,4-h]-1,6-naphthyridine derivative (2f), which presents the same substituent at the analogous position of 1-hydroxyacridone derivative (1b). The structure-activity relationship (SAR) studies pointed out the 10-position next to nitrogen atom as important for the anti-HSV-1 profile in the pyrazolo-naphthyridine derivatives tested, which reinforced the promising profile for further experimental investigation. The most potent acridone and pyrazolo-naphthridine derivatives were also submitted to an in silico ADMET screening in order to determine their overall drug-score, which confirmed their potential antiviral profile.     

哈尔滨市绿脓杆菌质粒图谱分析

本文对近年来从哈尔滨市五所临床医院分离的109株绿脓杆菌作了质粒图谱分析,结果发现在哈尔滨市流行的绿脓杆菌呈六种质粒图谱型别,其中77.1％的菌株呈两种相似的质粒图谱型别,且均含有一个共同的75Kb质粒。另外,还证实绿脓杆菌质粒图谱型别与血清型无明显相关性,而与耐药谱有一定的对应关系。     

Influence of soil depth on the decomposition of Bouteloua gracilis roots in the shortgrass steppe

The distribution and turnover of plant litter contribute to soil structure, the availability of plant nutrients, and regional budgets of greenhouse gasses. Traditionally, studies of decomposition have focused on the upper soil profile. Other work has shown that temperature, precipitation, and soil texture are important determinates of patterns of decomposition. Since these factors all vary through a soil profile, it has been suggested that decomposition rates may vary with depth in a soil profile. In this work, we examine patterns of root decomposition through a shortgrass steppe soil profile. We buried fresh root litter from Bouteloua gracilis plants in litterbags at 10, 40, 70, and 100 cm. Litterbags were retrieved six times between July 1996 and May 1999. We found that the decomposition rate for fresh root litter was approximately 50% slower at 1 m than it was at 10 cm. After 33 months, 55% of the root mass buried at 10 cm remained, while 72% of the root mass buried at 1 m was still present. This corresponds to a 19-year residence time for roots at 10 cm and a 36-year residence time for roots at 1 m. Mass loss rates decreased linearly from 10 cm to 1 m. Patterns of total carbon and cellulose loss rates followed those of mass loss rates. Roots at 1 m tended to accumulate lignin-like compounds over the course of the experiment. Differences in the stabilization of lignin may be a consequence of differences in microbial community through a shortgrass steppe soil profile.     

Maternal omega-3 fatty acids maintained positive maternal lipids and cytokines profile,and improved pregnancy outcomes of C57BL/6 mice

Omega (n)-3 polyunsaturated fatty acids (PUFA) are known to regulate lipid metabolism and inflammation; however, the regulation of maternal lipid metabolism and cytokines profile by n-3 PUFA during different gestation stages, and its impact on fetal sustainability is not known. We investigated the effects of maternal diet varying in n-3 PUFA prior to, and during gestation, on maternal metabolic profile, placental inflammatory cytokines, and fetal outcomes. Female C57BL/6 mice were fed either a high, low or very low (9, 3 or 1% w/w n-3 PUFA) diet, containing n-6:n-3 PUFA of 5:1, 20:1 and 40:1, respectively for two weeks before mating, and throughout pregnancy. Animals were sacrificed prior to mating (NP), and during pregnancy at gestation days 6.5, 12.5 and 18.5. Maternal metabolic profile, placental cytokines and fetal outcomes were determined. Our results show for the first time that a maternal diet high in n-3 PUFA prevented dyslipidemia in NP mice, and maintained the expected lipid profile during pregnancy. However, females fed the very low n-3 PUFA diet became hyperlipidemic prior to pregnancy, and carried this profile into pregnancy. Maternal diet high in n-3 PUFA maintained maternal plasma progesterone and placental pro-inflammatory cytokines profile, and sustained fetal numbers throughout pregnancy, while females fed the low and very-low n-3 PUFA diet had fewer fetuses. Our findings demonstrate the importance of maternal diet before, and during pregnancy, to maintain maternal metabolic profile and fetus sustainability. These findings are important when designing dietary strategies to optimize maternal metabolism during pregnancy for successful pregnancy outcome.     

Estimation of FPAR and FPAR profile for maize canopies using airborne LiDAR

FPAR (fraction of photosynthetically active radiation) and FPAR profile (vertical FPAR distribution) are important parameters for characterizing the vegetation growth status and studying global climate change. Few studies have been carried out to estimate FPAR and FPAR profile using waveform LiDAR data. This research explored the potential of airborne small-footprint full-waveform LiDAR in the estimation of FPAR and FPAR profile of the maize canopy in Huailai County of Hebei Province, China. First, the maize growing area was identified by a simple decision tree model. Second, raw waveform data were processed to extract LiDAR-derived energy ratio and energy ratio profile. Third, FPAR and FPAR profile were estimated from LiDAR-derived metrics. Finally, we analyzed the FPAR and FPAR profile estimation results and assessed the model validity using the leave-one-out cross-validation (LOOCV) method. The comparative analyses found that the LiDAR-derived energy ratio profile and field-measured FPAR profile had the same trend and similar change rate for all maize layers. The accuracy assessments indicated that the FPAR and FPAR profile were estimated well by the LiDAR waveform data, with the high R² (0.90 for the whole canopy, and 0.95, 0.90, 0.93, 0.92, and 0.97 for layers 1–5) and low RMSEs (0.042 for the whole canopy, and 0.033, 0.035, 0.039, 0.043, and 0.044 for layers 1–5). The spatial distribution map of FPAR was produced to describe the maize growth status of the whole study area, and the map showed that the FPAR distributed relatively uniformly. This study suggested that airborne small-footprint full-waveform LiDAR was useful in accurately measuring FPAR and FPAR profile of the maize canopy and in effectively mapping the maize FPAR spatial distribution.