Alpha-ketoamides and alpha-ketocarbonyls: conformational analysis and development of all-atom OPLS force field

The molecular structures and barriers for the internal rotation around the OC-CO single bond in four alpha-ketoamides and eight alpha-ketocarbonyls have been determined from the MP3/aug-cc-pVDZ and MP2/aug-cc-pVDZ calculations. Alpha-ketocarbonyls with non-bulky substituents adopt planar conformations with two carbonyl oxygens in s-trans arrangement. The s-cis conformation is significantly less stable due to the electrostatic repulsion between the two carbonyl groups. Primary and secondary alpha-ketoamides are planar when the substituent at the carbonyl carbon is hydrogen or methyl group but tertiary alpha-ketoamides adopt a conformation where the OC-CO unit is significantly bent. Based on current ab initio structural data, a set of OPLS-AA force field parameters has been derived. These parameters can be used for the modeling of a variety of alpha-ketoamide or alpha-ketocarbonyl containing drugs such as novel protease inhibitors or neuroregenerative polyketides.     

Synthesis and biological activity of macrocyclic inhibitors of hepatitis C virus (HCV) NS3 protease

The 17-membered phenylalanine-based macrocycle 6 was prepared starting from 3-iodo-phenylalanine. Macrocyclization of alkene phenyl iodide 5 was effected through a palladium-catalyzed Heck reaction. The macrocyclic alpha-ketoamides were active inhibitors of the HCV NS3 protease, with the C-terminal acids and amides being more potent than tert-butyl esters.     

Investigation of glycine alpha-ketoamide HCV NS3 protease inhibitors: effect of carboxylic acid isosteres

The design and synthesis of tetrapeptide-based alpha-ketoamides containing prime side acid isosteres HCV NS3 protease inhibitors are described. Tetrazole, sulfonic acid, and N-sulfonylcarboxamids were demonstrated to be efficient carboxylic acid replacements. Further optimization yielded a series of potent HCV NS3 protease inhibitors with IC(50) of 0.020-0.060 microM.     

Alpha-ketoamides, alpha-ketoesters and alpha-diketones as HCV NS3 protease inhibitors

Peptide-based alpha-ketoamides, alpha-ketoesters and alpha-diketones were designed, synthesized and evaluated against HCV NS3 protease. Alpha-ketoamides have the highest affinity among the three classes, with 8 being the most potent inhibitor with an IC50 of 340 nM.     

Novel P4 truncated tripeptidyl alpha-ketoamides as HCV protease inhibitors

We describe herein the synthesis and evaluation of two series of P-4 truncated tripeptidyl alpha-ketoamides as HCV serine protease inhibitors. The most promising compound disclosed in this communication 7b demonstrated enzyme binding affinity (K(i)) at 0.27 uM.     

Synthesis and activity studies of conformationally restricted alpha-ketoamide factor Xa inhibitors

Conformationally restricted borolysine compounds containing a 2-(2-cyanophenylthio) benzoyl in the P3 position unexpectedly led to enhanced factor Xa inhibition. In an effort to improve both the potency and selectivity of this series by extending into the S' domain, we have replaced the boronic acid with alpha-ketoamides, utilizing a novel process that was developed in our labs.     

Polymer-assisted solution-phase (PASP) library synthesis of alpha-ketoamides

A parallel solution-phase library synthesis of alpha-ketoamides is described. The two-step library synthesis is accomplished using polymer-assisted solution-phase (PASP) synthesis techniques. This high-yielding, multi-step sequence utilizes sequestering resins for the removal of reactants, reactant by-products, and tagged reagents. The first step of the library synthesis utilizes PASP resins to mediate the amide coupling of an alpha-hydroxy acid with an amine. The second step uses PASP resins for the periodinane oxidation of the alpha-hydroxy acid to an alpha-ketoamide leaving highly pure products after simple filtration and evaporation.     

Exploration of orally available calpain inhibitors. Part 3: Dipeptidyl alpha-ketoamide derivatives containing pyridine moiety

Calpain-mediated proteolysis has been implicated as a major process in neuronal cell death including retinal neurological degeneration. The previously reported calpain inhibitor SJA6017 (1) showed oral efficacy in a retinal pharmacological model, but its oral bioavailability was low due to the metabolic lability and low water-solubility. The purpose of present study was to identify good orally bioavailable calpain inhibitors. A series of water-soluble dipeptidyl alpha-ketoamides containing a pyridine moiety at P3 were designed, synthesized, and evaluated for their oral bioavailability and retinal penetration. Introduction of a pyridineethanol moiety provided the potent alpha-ketoamide inhibitor 8 with good oral bioavailability. Compound 8 showed about 12-fold higher retinal AUC than 1.     

Differential protein acetylation induced by novel histone deacetylase inhibitors

Histone deacetylase (HDAC) inhibitors induce the hyperacetylation of nucleosomal histones in carcinoma cells resulting in the expression of repressed genes that cause growth arrest, terminal differentiation, and/or apoptosis. In vitro selectivity of several novel hydroxamate HDAC inhibitors including succinimide macrocyclic hydroxamates and the non-hydroxamate alpha-ketoamide inhibitors was investigated using isolated enzyme preparations and cellular assays. In vitro selectivity for the HDAC isozymes (HDAC1/2, 3, 4/3, and 6) was not observed for these HDAC inhibitors or the reference HDAC inhibitors, MS-275 and SAHA. In T24 and HCT116 cells these compounds caused the accumulation of acetylated histones H3 and H4; however, the succinimide macrocyclic hydroxamates and the alpha-ketoamides did not cause the accumulation of acetylated alpha-tubulin. These data suggest "selectivity" can be observed at the cellular level with HDAC inhibitors and that the nature of the zinc-chelating moiety is an important determinant of activity against tubulin deacetylase.     

Plasmodium subtilisin-like protease 1 (SUB1): insights into the active-site structure, specificity and function of a pan-malaria drug target

Release of the malaria merozoite from its host erythrocyte (egress) and invasion of a fresh cell are crucial steps in the life cycle of the malaria pathogen. Subtilisin-like protease 1 (SUB1) is a parasite serine protease implicated in both processes. In the most dangerous human malarial species, Plasmodium falciparum, SUB1 has previously been shown to have several parasite-derived substrates, proteolytic cleavage of which is important both for egress and maturation of the merozoite surface to enable invasion. Here we have used molecular modelling, existing knowledge of SUB1 substrates, and recombinant expression and characterisation of additional Plasmodium SUB1 orthologues, to examine the active site architecture and substrate specificity of P. falciparum SUB1 and its orthologues from the two other major human malaria pathogens Plasmodium vivax and Plasmodium knowlesi, as well as from the rodent malaria species, Plasmodium berghei. Our results reveal a number of unusual features of the SUB1 substrate binding cleft, including a requirement to interact with both prime and non-prime side residues of the substrate recognition motif. Cleavage of conserved parasite substrates is mediated by SUB1 in all parasite species examined, and the importance of this is supported by evidence for species-specific co-evolution of protease and substrates. Two peptidyl alpha-ketoamides based on an authentic PfSUB1 substrate inhibit all SUB1 orthologues examined, with inhibitory potency enhanced by the presence of a carboxyl moiety designed to introduce prime side interactions with the protease. Our findings demonstrate that it should be possible to develop 'pan-reactive' drug-like compounds that inhibit SUB1 in all three major human malaria pathogens, enabling production of broad-spectrum antimalarial drugs targeting SUB1.     

海南文昌汉族体质特征

在海南文昌市调查了城市汉族315例(男为150例, 女为165例)和乡村汉族407例(男为216例, 女为191例)成人的73项体质指标, 计算了25项体质指数, 统计了指数分型情况, 与我国族群资料进行了比较, 对海南文昌汉族体质特征进行了初步分析。结果显示: 1)文昌汉族有上眼睑皱褶, 蒙古褶欠发达,眼裂窄且多呈眼外角高, 鼻根高度中等, 直鼻梁, 鼻基部上翘, 鼻翼高度中等, 鼻孔最大径斜位, 鼻翼宽, 耳垂多为圆形、三角形, 上唇皮肤部高度中等, 红唇较厚, 发色黑, 肤色、眼色较深。2)文昌汉族男女性均为特圆头型、高头型、中头型、中鼻型。男性还为中面型, 女性还为狭面型。3)文昌汉族男女性均为长躯干型、中胸型、中肩型、中骨盆型, 男性还为中腿型, 女性还为亚短腿型。文昌汉族城市、乡村的男性与女性身高均属于中等身材。4)文昌汉族头面部特征更接近于我国蒙古人种北亚类型族群。从体部指标来看。文昌汉族介于北亚类型族群与南亚类型族群之间, 更接近于北亚类型族群。     

猪苓营养菌丝与栽培菌核蛋白质成分的分析

对猪苓(Polyporus umbellate)营养菌丝与栽培菌核中蛋白质的氨基酸种类及含量进行了测定。结果表明,猪苓营养菌丝中各物质质量分数是:粗蛋白325.9g·kg-1,必需氨基酸总量34.924 g·kg-1,氨基酸总量91.956 g·kg-1;栽培菌核中各物质质量分数是:粗蛋白49.1 g·kg-1,必需氨基酸总量8.465 g·kg-1,氨基酸总量35.847 g·kg-1。营养菌丝中所含粗蛋白、氨基酸的量显著高于栽培菌核中粗蛋白、氨基酸的量。     

星状雪兔子植物叶的解剖结构对高山环境的适应性

对青藏高原东缘两个不同居群的星状雪兔子植物叶的结构进行了显微观察,观察结果表明:两种不同居群植物的叶片类型均为等面叶,表皮细胞单层,角质层厚,表皮细胞形状为多边形,垂周壁平直或弓形。生于海拔2850m处的星状雪兔子植物,叶片厚度为330.66μm,上表皮气孔密度为106.75,下表皮气孔密度为144.79;海拔2890m处的星状雪兔子植物,叶片厚度为537.07μm,上表皮气孔密度为53.6,下表皮气孔密度为77.30。两种植物叶片类型虽然均为等面叶,但明显表现为两种不同的生态类型,这表明了星状雪兔子植物的叶在无表皮毛保护的情况下对高山环境的适应性并不是单一的。     

Alveolar rhabdomyosarcoma of the vulva. Report of two cases

The cytologic and histologic findings in two cases of the extremely rare alveolar rhabdomyosarcoma of the vulva are reported. The tumor cells in fine needle aspiration smears from one case and tumor imprints from both cases were isolated or were in sheets or reticular patterns. The nuclei were round to oval; only a few cells were multinucleated. The chromatinic material was increased in amount and finely granular. Many mitotic figures were observed. The cytoplasm was scanty in general, but some cells had abundant cytoplasm; cross striations were not recognized. The tumor cells were positive with immunocytochemical stains for desmin, vimentin and myoglobin. Similar findings were observed in biopsy and surgical specimens.     

北草蜥几种消化酶活力比较

应用酶学分析法测定了越冬后北草蜥胃、肠组织中蛋白酶、淀粉酶、纤维素酶的活力。结果表明 ,不同年龄、性别的北草蜥同一组织中消化酶活力有显著差异 ;不同地理种群的北草蜥同一组织中消化酶活力有显著差异 ;不同消化酶在北草蜥同一组织中的活力有显著差异 ;在北草蜥不同的组织中同一消化酶的活力有显著差异。说明北草蜥消化酶的活力与年龄、性别、部位和地理环境等因素有关 ,受食物组成、能量需求和遗传等因素的影响 ,产生了不同的酶活力和分布。这也说明生物长期适应环境 ,形成了不同的代谢水平     

Test of statistical stability of the electroencephalogram

The stability of the EEG during eyes closed and eyes open were tested by the statistical method. The EEG records of 25 s were segmented into ten 2.5 s intervals for each state. The mean and variance and power spectra (2.5 to 17.5 Hz at resolution of 2.5 Hz) were calculated for each segment of 2.5 s interval. Thus, the sequences of mean values, variances and power at each frequency component were obtained for 25 s epoch. The stationarity of these sequences were tested by the run test and the trend test. The stationarity of mean, variance and power spectra were not rejected for 25 s records by any of two tests. In the records of 50 s, about 10–20% of records tested were rejected. The nonstationarity of the EEG appeared for 50 s records. This means that the EEG during period the eyes were closed, or opened can be regarded as stationary over time period as long as at least 25 s.     

崇左金花茶花朵和叶片类黄酮UPLC-Q-TOF-MS分析

以崇左金花茶（Camellia chuangtsoensis）为材料,利用超高效液相色谱-四极杆-飞行时间质谱（UPLC-Q-TOF-MS）联用技术定性定量分析其花朵（花瓣、雄蕊）和叶片（老叶、新叶）中类黄酮成分与含量。结果表明,崇左金花茶中共检测到14种类黄酮成分,木犀草素、木犀草素-7-O-芸香糖苷、槲皮素-3,7-O-二葡萄糖苷、芸香柚皮苷、圣草素和染料木苷为山茶属金花茶组植物中首次发现,其中槲皮素-3,7-O-二葡萄糖苷、芸香柚皮苷、圣草素和染料木苷主要存在于花朵中,木犀草素和木犀草素-7-O-芸香糖苷在花朵中含量高于叶片,雄蕊中高于花瓣;槲皮素-3-O-葡萄糖苷、槲皮素-7-O-葡萄糖苷、槲皮素-3-O-芸香糖苷和山柰酚-3-O-葡萄糖苷为金花茶组植物叶片中首次发现,其叶片中含量远低于花朵,老叶中远低于新叶,雄蕊中远低于花瓣;儿茶素和表儿茶素在花朵中含量高于叶片,雄蕊中高于花瓣;槲皮素和山萘酚在花朵和叶片中含量均较低。崇左金花茶花瓣和雄蕊中含量较高的类黄酮为儿茶素类、木犀草素类和槲皮素类,主要是表儿茶素、木犀草素和槲皮素-3-O-葡萄糖苷;叶片中为儿茶素类和木犀草素类,主要是表儿茶素、木犀草素和木犀草素-7-O-芸香糖苷。崇左金花茶花瓣和雄蕊中儿茶素类、木犀草素类及类黄酮总量均高于叶片,且雄蕊高于花瓣;花瓣和雄蕊中槲皮素类远高于叶片,且花瓣中远高于雄蕊。     

槲寄生挥发性成分研究

目的：研究槲寄生挥发性成分。方法：利用水蒸汽蒸馏法提取槲寄生挥发性成分,用GC/MS进行分离测定,结合计算机检索技术对分离的化合物进行结构鉴定,应用色谱峰面积归一化法计算各成分的相对百分含量。结果：分离出119个成分,确定了66个化合物,占挥发油总量的77．31％。结论：槲寄生挥发性成分大于2％的化学成分有12种。