DISCOVERY OF β-LACTAM ANTIBIOTICS WITH NOVEL NUCLEI

The discovery of penicillin in1929,and cephalosporin in 1956 leadto the development of new semisynthetic β-lactam antibiotics by the acylation of 6-aminopenicillanic acid and 7aminocephalosporanic acid. Success withthese antibiotics, which were of greatclinical value, stimulated the pharmaceutical industry to search for new β-lactam antibiotics,and a variety of newmethodologies were established andapplied to their detection.As a result,many β-lactam antibiotics with novelnuclei were discovered from microbialsources, mainly from actinomycetes and     

Effects of tanshinone on neuropathological changes induced by amyloid β-peptide(1-40)injection in rat hippocampus

INTRODUCTION Alzheimer’s disease (AD) is characterized by neu-ronal loss and extracellular senile plaque, whose majorconstituentis amyloid β-peptide(Aβ), a 39-43 amino acidspeptide derived from amyloid precursor protein (APP).It is widely believed that the cellular actions of Aβ areresponsible for the neuronal cell loss observed in ADand play a causal role in the pathogenesis of AD[1,2].Aggregated Aβ and its activefragmentshave beenshownto have clear neurotoxic effect[3]. …     

Glutamate transporters in brain ischemia： to modulate or not？

In this review, we briefly describe glutamate （Glu） metabolism and its specific transports and receptors in the central nervous system （CNS）. Thereafter, we focus on excitatory amino acid transporters, cystine/glutamate antiporters （system xc-） and vesicular glutamate transporters, specifically addressing their location and roles in CNS and the molecular mechanisms underlying the regulation of Glu transporters. We provide evidence from in vitro or in vivo studies concerning alterations in Glu transporter expression in response to hypoxia or ischemia, including limited human data that supports the role of Glu transporters in stroke patients. Moreover, the potential to induce brain tolerance to ischemia through modulation of the expression and/or activities of Glu transporters is also discussed. Finally we present strategies involving the application of ischemic preconditioning and pharmacological agents, eg β-lactam antibiotics, amitriptyline, riluzole and N-acetylcysteine, which result in the significant protection of nervous tissues against ischemia.     

Nicotine and inflammatory neurological disorders

Cigarette smoke is a major health risk factor which significantly increases the incidence of diseases including lung cancer and respiratory infections. However, there is increasing evidence that smokers have a lower incidence of some inflammatory and neurodegenerative diseases. Nicotine is the main irnrnunosuppressive constituent of cigarette smoke, which inhibits both the innate and adaptive immune responses. Unlike cigarette smoke, nicotine is not yet considered to be a carcinogen and may, in fact, have therapeutic potential as a neuroprotective and anti-inflammatory agent. This review provides a synopsis summarizing the effects of nicotine on the immune system and its （nicotine） influences on various neurological diseases.     

Tetrandrine and related bis—benzylisoquinoline alkaloids from medicinal herbs：cardiovascular effects and mechanisms of action

Tetrandrine(TET),a bis-benzylisoquinoline alkaloid purified and identified an active ingredient in a Chinese medicinal herb,Radix Stephanae tetrandrae,has been used traditionally for the treatment of congestive circulatory disorder and inflammatory diseases.TET,together with a few of its structural analogues,has long been demonstrated to have antihypertensive action in clinical as well as animal studies.Presumably,the primary anti-hypertensive action of TET is due to its vasodilatory properties.TET prevents or inhibits vascular contraction induced by membrane depolarization with KCl or α-adrenoceptor activation with phenylephrine (PE).TET(30μmol/L) also inhibits the release of endothelium-derived nitric oxide(NO) as well as NO production by inducible NO synthase.TET apparently inhibits multiple Ca^2 entry pathways as demonstrated in cell types lacking the L-type Ca^2 channels.In cardiac muscle cells,TET inhibits both L-and T-type Ca^2 channels.In addition to its actions on cardiovascular tissues,TET may also exert its anti-hypertensive action via a Ca^2 -dependent manner on other tissues intimately involved in the modulation of blood pressure control,such as adrenal grands.In adrenal glomerulosa cells,KCl-or angiotensin II-induced aldosterone synthesis is highly dependent on extracellular Ca^2 .Steroidogenesis and Ca^2 -influx in bovine adrenal glomerulosa cells have been shown to be potently inhibited by TET.In bovine adrenal chromaffin cells,TET inhibits Ca^2 currents via L-and N-type channels as well as other unidentified channels with IC50 of 10μmol/L.Other than the Ca^2 antagonistic effects.TET also interacts with the α-adrenergic receptors and muscarinic receptors based on functional as well as radioligand binding studies.Apart from its functional effects,TET and related compounds also exert effects on tissue structures,such as remodelling of hypertrophied heart and inhibition of angiogenesis,probably by causing apoptotic responses.TET is also known for its anti-inflammatory and anti-fibrogenic actions,which make TET and related compound potentially useful in the treatment of lung silicosis,liver cirrhosis,and rheumatoid arthritis.     

Regulation of thenorphine on the CKK and CKK- BR gene expression in the different brain domains of rats

Thenorphine is a new partial agonist of opioid receptors synthesized by our department. Our previous studies have found that thenorphine can antagonize the effects of morphine with a long time, suggesting a promising effect for the detoxification treatment. It is known that cholecystokinin （CKK） is one of the important antiopioid peptides that counter opioid effects. Furtherly, CCK appears to exert its anti-opioid actions mainly through the activation of CCK - B receptors.     

氢溴酸2，4—二氯—6—苯基苯氧乙基二乙基胺（Lilly 18947）抗克氏锥虫的作用

AIM: To study the effect of the inhibitor of cytochrome P450 known as Lilly 18947 (2,4 dichloro-6 phenyl-phenoxy ethyl diethylamine) on Trypanosoma cruzi. METHODS: Trypanosoma cruzi epimastigotes wen grown in culture, in absence or in presence of drug. The inhibition of its growth was followed by daily counting using a Neubauer chamber. The effect of Lilly 18947 on the parasite ultrastructure was examined by electron microscopy. To test the effect of different concentrations of drug on the parasite cycle, Vero cells were inoculated with trypomastigotes ( RA strain ) and after 72 h the percentage of infected cells and the number of intracellular parasites were estimated and expressed as the endocytic index. RESULTS: Growth of epimastigotes was inhibited by Lilly 18947. Concentrations as low as 50 μmol/L resulted in a complete disappearance of the parasites in culture by the fourth day. With lower concentrations, little growth was observed and total (25 μmol/L) or partial lysis (10μmol/L) were register     

Recent insights for the emerging COVID-19:Drug discovery,therapeutic options and vaccine development

SARS-CoV-2 has been marked as a highly pathogenic coronavirus of COVID-19 disease into the human population,causing over 5.5 million confirmed cases worldwide.As COVID-19 has posed a global threat with significant human casualties and severe economic losses,there is a pressing demand to further understand the current situation and develop rational strategies to contain the drastic spread of the virus.Although there are no specific antiviral therapies that have proven effective in randomized clinical trials,currently,the rapid detection technology along with several promising therapeutics for COVID-19 have mitigated its drastic transmission.Besides,global institutions and corporations have commenced to parse out effective vaccines for the prevention of COVID-19.Herein,the present review will give exhaustive details of extensive researches concerning the drug discovery and therapeutic options for COVID-19 as well as some insightful discussions of the status of COVID-19.     

2-〔4(s)-4-酚胺基-3-氧代-2-异噁唑烷基〕-5-氧代-2-四氢呋喃甲酸钠类化合物的合成

以L-丝氨酸和α-酮戊二酸为原料,采用三条合成路线,经6～8步反应,合成8个目标化合物。其部份中间体的结构经IR,PMR,MS及元素分析证实。产物的结构也经IR及PMR证实。体外抑菌试验表明,TM7和TM8显示较强的广谱抑菌活性,TM6则具有中等强度。TM2和TM3对金葡菌也有一定活性。     

选择性保护合成2-〔4(S)-4-酰氨基-3-氧代-2-异噁唑烷基〕-5-氧代-2-四氢呋喃甲酸类化合物及其体外抑菌活性

采用两种新选择性保护方法由L-丝氨酸和α-酮戊二酸为原料经几步合成了8个目标化合物。体外抑菌该验表明除TMV外,对金葡球菌209P和大肠杆菌44822具有中等到强的活性。     

α-甲基-4-(3-氧-2H-1,2-苯并异硒唑-2-基)苯乙酸的体外抗氧活性

A synthetic seleno-organic compound, α-methyl-4-(3-oxo-2H-1,2-benzoisoselenazol-2-yl) benzeneacetic acid (MBBA) inhibited the lipid peroxidation of rat liver microsome induced by cysteine/Fe²⁺ and NADPH/Fe²⁺, the IC₅₀ (95% confidence limits) values were 12.2(3.8-39.6) and 7.1(2.5-20.3) μmol·L^-１ respectively. Furthermore, it showed a glutathione peroxidase like activity in vitro. However MBBA (2-100 μmol·L^-１) had no direct inhibition on the production of superoxide anions (O^-₂) and hydroxy radical. Our data suggest that MBBA is a novel inhibitor of lipid peroxidation. Its antioxidant effect may be attributed to glutathione peroxidase like activity. The direct free radical quenching activity of MBBA is ruled out.     

Analysis of potential phenylacetone precursors (ethyl 3-oxo-2-phenylbutyrate,methyl 3-oxo-4-phenylbutyrate,and ethyl 3-oxo-4-phenylbutyrate) by gas chromatography/mass spectrometry and their conversion to phenylacetone

Methyl 3-oxo-2-phenylbutyrate (MAPA) is a recently circulating precursor of phenylacetone (P2P), a precursor of amphetamine and methamphetamine. MAPA has a hybrid chemical structure of acetoacetic acid ester and P2P. Acetoacetic acid ester is de-esterified and decarboxylated to give the ketone by heating under acidic conditions; therefore, MAPA is presumed to be converted to P2P by such treatment. Considering that ethyl 3-oxo-2-phenylbutyrate (EAPA), methyl 3-oxo-4-phenylbutyrate (MGPA), and ethyl 3-oxo-4-phenylbutyrate (EGPA) have the same chemical features as MAPA, these three compounds are potential P2P precursors. The authors examined the analysis of these compounds by gas chromatography–mass spectrometry (GC-MS) and their conversion to P2P by heating under acidic and basic conditions. These compounds were remarkably decomposed into P2P during GC-MS analysis regardless of the injection method and injector temperature. EAPA and EGPA also caused ester exchange to methyl ester by injection of methanol solution. P2P production and transesterification were almost prevented by methoxime derivatization. These compounds were converted to P2P by heating under acidic conditions. The reaction of MGPA and EGPA proceeded quicker than that of EAPA. The important by-product associated with the reaction was phenylacetylcarbinol (formed from EAPA and MGPA), which will be converted to (pseudo)ephedrine, important methamphetamine impurities. By heating under basic conditions, MGPA and EGPA were converted to P2P but EAPA was mainly converted to phenylacetic acid. In the future, when these compounds are in circulation, our study will be useful for identifying and elucidating the synthetic method of P2P.     

4-氯-2-氧代-1,2-二氢喹啉-3-甲醛的合成工艺研究

目的 对4-氯-2-氧代-1,2-二氢喹啉-3-甲醛的合成工艺进行研究。方法 以苯胺为原料通过酯的氨解、环合、胺亚甲基化、水解反应得到目标化合物。结果 合成了目标化合物,并利用MS和¹H-NMR确证了结构,此路线所得产品收率为62.1%。结论 此路线操作简单,成本低廉,设计合理,收率高,适合该化合物的工业化生产。     

2''''-乙酰基-3-酮基-10,11-脱水-6-O-甲氧基红霉素的合成

目的:合成泰利霉素中间体2'-乙酰基-3-酮基-10,11-脱水-6-O-甲氧基红霉素.方法:以6-O-甲氧基红霉素为起始原料,经脱水、酸水解、乙酰化和氧化得到目标产物.结果:以6-O-甲氧基红霉素计,总收率79.9%.目标产物的光谱数据与文献报道一致.结论:该方法合成操作简单,反应条件温和.     

Inhibitory effects of α-methyl-4-(3-oxo-2H-1,2-benzoisoselenazol-2-yl)benzeneacetic acid on Cu~(2+) and Fe~(2+) induced oxidative modification of human low density lipoprotein

为观察α－甲基－４－（３－氧－２Ｈ－１，２－苯并异硒唑－２－基）苯乙酸（ＭＢＢＡ）对Ｃｕ２＋及Ｆｅ２＋氧化修饰低密度脂蛋白（ＬＤＬ）的保护作用及其作用机理，采用分光光度法测定ＬＤＬ中丙二醛（ＭＤＡ）和共轭双烯（ＣＤ）的产生量．ＭＢＢＡ（０．２－２μｍｏｌ·Ｌ－１）能以剂量依赖性抑制Ｃｕ２＋及Ｆｅ２＋诱导的ＭＤＡ和ＣＤ生成．２μｍｏｌ·Ｌ－１的ＭＢＢＡ对Ｃｕ２＋诱导ＬＤＬ产生ＭＤＡ和ＣＤ的抑制率分别为８９．７％和６０．３％．０．５ｍｍｏｌ·Ｌ－１ＧＳＨ对ＬＤＬ产生ＭＤＡ无影响，但能显著增强ＭＢＢＡ对ＭＤＡ生成的抑制作用．上述结果表明ＭＢＢＡ对ＬＤＬ氧化修饰的抑制作用可能依赖于其ＧＳＨ－Ｐｘ样活性的作用和（或）直接还原脂质氢过氧化物的作用．     

2-(3-Fluorophenyl)-6-methoxyl-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (YJC-1) induces mitotic phase arrest in A549 cells

A 2-phenyl-4-quinolone (2-PQ) derivative, 2-(3-fluorophenyl)-6-methoxyl-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (YJC-1), was synthesized in our laboratory. In this study, we delineated the growth-inhibitory effect of YJC-1 in human lung carcinoma A549 cells. YJC-1 inhibited cell growth with an IC(50) value of about 4.8 microM via microtubule polymerization, causing growth arrest in the mitotic phase. Immunoblotting analysis revealed a dramatic induction of cyclin-dependent kinase (CDK) inhibitor p21(Cip1/Waf1) and down-regulation of Cdc25C phosphatase to inhibit the protein expression of cyclin B1 and CDK1. We also found that YJC-1 induced a profound time-dependent elevation in p21(Cip1/Waf1) gene expression in comparison with the negative control. In vivo, we also found that YJC-1 significantly suppressed tumor growth in mice inoculated with A549 cells. These findings suggest that YJC-1 can suppress A549 cell growth via mitotic phase arrest.     

α-甲基-4-(3-氧-2H-1,2-苯并异硒唑-2-基)苯乙酸对Cu2+和Fe2+氧化修饰人低密度脂蛋白的抑制作用

为观察α-甲基-4-(3-氧-2H-1,2-苯并异硒唑-2-基)苯乙酸(MBBA) 对Cu²⁺及Fe²⁺氧化修饰低密度脂蛋白(LDL)的保护作用及其作用机理，采用分光光度法测定LDL中丙二醛(MDA)和共轭双烯(CD)的产生量. MBBA(0.2-2 μmol·L^-１)能以剂量依赖性抑制Cu²⁺及Fe²⁺诱导的MDA和CD生 成. 2 μmol·L^-１的MBBA对Cu²⁺诱导LDL产生MDA和CD的抑制率分别为89.7%和60.3%. 0.5 mmol·L^-1 GSH对LDL产生MDA无影响，但能显著增强MBBA对MDA 生成的抑制作用. 上述结果表明MBBA 对LDL氧化修饰的抑制作用可能依赖于其GSH-Px样活性的作用和(或)直接还原脂质氢过氧化物的作用.     

对氯苯氧异丁酸甲氧基苯丙烯酸酯对人肝癌细胞HepG2脂肪累积的干预作用

目的:研究对氯苯氧异丁酸甲氧基苯丙烯酸酯(AZ)对人肝癌细胞Hep G2脂肪累积的干预作用。方法:取对数生长期Hep G2细胞,用油酸诱导复制脂肪累积模型,分为模型组、阳性对照(辛伐他汀100μg/ml)组和15.63、31.25、62.5、125、250、500、1 000μg/ml AZ组,另设正常对照组。采用MTT法检测各组细胞的存活率;按试剂盒操作检测各组细胞中甘油三酯(TG)含量,计算TG清除率;油红O染色观察各组细胞内脂滴形态。结果:与正常对照组比较,模型组和15.63~125μg/ml AZ组细胞的存活率差异无明显变化,250~1 000μg/ml AZ组细胞存活率降低,差异具有统计学意义(P<0.05)。与正常对照组比较,模型组细胞中TG含量增加;与模型组比较,阳性对照组和62.5、125μg/ml AZ组细胞中TG含量降低,TG清除率依次为(28.58±0.15)%、(14.51±0.09)%、(29.72±0.16)%,以上差异均具有统计学意义(P<0.01或P<0.05)。与正常对照组比较,模型组细胞出现大量脂滴,AZ组随给药浓度的增加,脂滴逐渐变少、变小。结论:AZ对Hep G2细胞脂肪累积具有干预作用。