乙醇对小白鼠胚胎的毒性和维生素的解毒作用

乙醇对小白鼠有致畸效应,尤其是对中枢神经系统(CNS)和骨骼系统.适量的维生素B_1和烟酰胺能解除由乙醇引起的小白鼠胎鼠毒害作用.     

醚类汽油添加剂与L-02正常人肝细胞、人血红蛋白的体外作用研究

研究了新型无铅汽油添加剂甲基叔丁基醚（MTBE）、甲基叔戊基醚（TMAE）对正常人肝细胞系L－02的毒性作用，在较高浓度下，MTBE、TAME均对L－02正常人肝细胞的生长有影响，且TAME的毒性作用稍强，另外，用FT－IR法和^1H-NMR法研究了MTBE、TAME与人血红蛋白的体外作用，结果显示，MTBE、TAME与人血红蛋白无明显的直接作用。     

Aspirin-like drugs may block pain independently of prostaglandin synthesis inhibition

Summary Using flurbiprofen, a chiral anti-inflammatory and analgesic 2-arylpropionic acid derivative, the enantiomers of which are not converted to each other (less than 5%) in rats or man, we obtained evidence that prostaglandin synthesis inhibition is primarily mediating the anti-inflammatory activity but prostaglandin synthesis independent mechanisms contribute to the analgesic effects. Thus, the S-form inhibited prostaglandin synthesis, inflammation and nociception in rats. The R-form had much less effect on prostaglandin synthesis and did not affect inflammation. It did, however, block nociception in rats almost as potently as the S-form. S-flurbiprofen, in contrast to the R-form, was clearly ulcerogenic in the gastrointestinal mucosa. These results indicate additional molecular mechanisms of analgesia and suggest the use of R-arylpropionic acids as analgesics.     

改性磺化木质素LSA阻垢分散性能及机理研究

以工业木质素磺酸盐LS为原料，采用自由基共聚反应对LS进行接枝羧基改性，制备得到改性磺化木质素LSA，用红外光谱对其结构进行表征。对LSA与目前常用几种阻垢剂进行阻垢分散性能的比较，结果表明，改性产物LSA为一种阻垢分散性能较为理想的绿色阻垢剂，并从螯合使用、分散作用及晶格畸变作用三方面对LSA阻垢机理进行了探讨。     

铝胁迫下龙眼幼苗对通气的响应及其铝毒的矫治

在营养液中添加AlCl3.6H2O培养龙眼,研究铝胁迫下通气对龙眼生长及生理生化的影响,探讨铝毒矫治措施。结果表明:通气处理可以矫治龙眼铝毒且促进铝胁迫下龙眼幼苗的生长,其根、茎、叶的生物量和根系活力分别比不通气处理增加20.1%~41.0%,23.9%~59.2%,26.5%~126.9%,62.9%~322.3%;通气有助于解除或减轻铝对龙眼幼苗光合作用的限制,Chla,Chlb,Car分别比不通气处理提高129.2%~492.8%,120.2%~463.0%,111.9%~328.0%,Pn,CE也明显高于不通气处理;NR活性提高了18.1%~53.6%,促进铝胁迫下龙眼幼苗对N的吸收和利用;通气可以减轻或减缓铝对细胞膜系统的伤害,龙眼叶片大分子渗漏值OD254下降了34.4%~48.6%。另外,CaCl2,KH2PO4,MgSO4及柠檬酸处理可明显抑制铝胁迫下龙眼幼苗对铝的吸收,根、茎、叶中铝的含量均比对照下降。     

A new indolic antiauxin, α-(5,7-dichloroindole-3-)isobutyric acid: its chemical synthesis and biological activity

Summary A new potent antiauxin, -(5,7-dichloroindole-3-)isobutyric acid has been synthesized and shown to inhibit auxin-mediated elongation ofAvena coleoptiles and to stimulate root growth of rice seedlings. Its activity is stronger than -(p-chlorophenoxy)isobutyric acid and is comparable to that of 2,3,5-triiodobenzoic acid, which are typical antiauxins.     

The discovery of antidepressants: A winding path

Summary Modern treatment of mental depression started with the availability of monoamine oxidase (MAO) inhibitors and tricyclic antidepressants. These drugs also contributed to the early development of psychopharmacology. Attempts to improve the anti-tuberculous action of the hydrazine derivative isoniazid by developing derivatives thereof led to the synthesis of iproniazid. Its introduction as the first modern antidepressant was based on three unexpected actions of the drug: MAO-inhibition, reversal of reserpine-induced sedation, and the presence of psychostimulation as a clinical side effect in man. However, the initial success of iproniazid and other MAO inhibitors, hydrazides and non-hydrazides, was curtailed by the occurrence of undesirable side effects such as potentiation of the blood-pressure elevating action of food amines. The tricyclic antidepressants were a development of the class of antihistamines, one of which, chlorpromazine, showed neuroleptic activity. A congener of this compound, imipramine, was discovered by clinical observation to have unexpected antidepressant effects. The clinical success of this drug (which is still in use) led to the development of a successful series of other tricyclic and non-tricyclic antidepressants. Progress in the elucidation of possible mechanisms of the action of the tricyclic compounds has helped this development. Recent advances in basic research have also induced a revival of MAO-inhibitors since, due to the discovery of MAO-subtypes, inhibitors with higher specificity and fewer undesirable side effects are now available.     

Increase in the survival time of mice exposed to ionizing radiation by a new class of free radical scavengers

Summary N-acyl dehydroalanines react with and scavenge mainly superoxide radical and hydroxyl radical (HO^.). The ortho-methoxyphenylacetyl dehydroalanine derivative, indexed as AD-20, protects mice against damage resulting from total body X-irradiation, as measured by the increase in their survival time. AD-20 increases the LD₅₀ at 30 days from 6.1 to 7.3 Gy in animals exposed to a wide range of X-rays (6 to 10 Gy). The dose reduction factor (D R F) of AD-20 is 1.20. We postulate that such radioprotective effect may result from its free radical scavenging activity.     

Inhibition of the growth of cariogenic bacteria in vitro by plant falvanones

Phytoalexins, defensive compounds produced by plants against microbial infections, were purified fromSophora exigua (Leguminosae) and their growth inhibitory effects on oral cariogenic bacteria were determined in vitro. Among three isolated compounds, 5,7,2,4-tetrahydroxy-8-lavandulylflavanone completely inhibited the growth of oral bacteria including primary cariogenic mutans streptococci, other oral streptococci, actinomycetes, and lactobacilli, at concentrations of 1.56 to 6.25 g/ml.     

Cl-、NO3-和SO42-离子对漆酶催化活性的抑制作用

以５,６－二溴－２,３－二氰基氢醌为底物,在ｐＨ值４．５０条件下,用分光光度法考察了Ｃｌ－、ＮＯ－３和ＳＯ２－４离子对漆酶催化活性的影响。发现Ｃｌ－、ＮＯ－３和ＳＯ２－４离子对漆酶的催化活性均有不同程度的抑制作用,其最大抑制率分别可达７５％、３１．４％和１７．１％。动力学研究表明,Ｃｌ－、ＮＯ－３和ＳＯ２－４离子的抑制作用是瞬时完成的,属于竞争性抑制过程,是通过与底物分子竞争漆酶分子中的Ⅱ型铜（Ⅱ）部位实现的。经测定,Ｃｌ－和ＮＯ－３离子与漆酶所形成的复合物其解离常数分别为１．１２×１０－４ｍｏｌ·ｄｍ－３和１．７８×１０－３ｍｏｌ·ｄｍ－３。