Venom samples were corrected from several poisonous snakes, such as Bungarus multicinctus, Trimeresurus mucrosquamatus, T. gramineus, T. flavoviridis, and Agkistrodon acutus, and stored in a desiccator at room temperature for 25 to 31 years. Then they were compared with fresh venoms as to their biological activities. The characteristic local symptoms produced by the bite of venomous snakes of Crotalidae and Viperidae are hemorrhage, necrosis and muscular degeneration. Hemorrhagic toxins were purified from Trimeresurus mucrosquamatus, Crotalus ruber ruber, Vipera aspis aspis, and Agkistrodon acutus venoms and their biological, biochemical, and pathological properties were investigated. Arginine ester hydrolases are present in the venoms of Crotalidae and Viperidae, but are not found in the venoms of Elapidae and Hydrophiidae. In this paper we describe the enzymatic and biological activities of arginine ester hydrolases from a Trimeresurus mucrosquamatus venom.
This paper describes 1) the drug delivery through the skin to produce systemic effects, 2) the enhancement of percutaneous absorption by absorption enhancers, heating and complex formation, 3) the mechanism for the enhancement effect by enhancers, 4) the percutaneous absorption of peptides, and 5) the pharmacokinetic analysis for percutaneous absorption. 1, 3-Dinitroglycerin, indomethacin (IND) and many drugs were efficiently absorbed via rat and rabbit skins in the presence of some enhancers, and using a microporous membrane therapeutic plasma concentrations were maintained for a long time. Enhancement of percutaneous absorption by the complex formation with fatty acid was observed for propranolol (PL) in vitro and in vivo. Heating at 42-45°C also enhanced the percutaneous absorption dramatically, with decreased activation energies. The following mechanisms for the enhancement effect by enhancers were found : a) an increase in the fluidity of the stratum corneum lipids and reduction in the diffusional resistance to permeants, b) the removal of intercellular lipids and dilation between adherent cornified cells, c) an increase in the thermodynamic activity of drugs in vehicles, d) the exfoliation of stratum corneum cell membranes, the dissociation of adherent cornified cells and elimination of the barrier function. Peptides such as enkephalin, elcatonin and insulin were effectively absorbed through the skin in the presence of some enhancers and specific inhibitors, with no proteolytic degradation. The pharmacokinetic model with two parallel absorption processes, lipidic and aqueous pore transport pathways, in skin could adequately describe the percutaneous absorption of IND, PL and valproic acid. With peptides, a kinetic model including zero-order input rate, first-order permeation rate and first-order degradation rate was able to describe well the steady-state flux of peptides.
This review summarizes several effective synthetic methods of fluorinated organic compounds developed by our group. Two topics have been described in this review. The first topic describes novel fluorinations using diethylaminosulfur trifluoride (DAST). The treatment of tertiary cyclopropyl silyl ethers with DAST caused ring opening and produced allylic fluorides. The reaction of DAST with a tertiary cyclobutanol provided a fluorocyclobutane, a (fluoromethyl) cyclopropane or a homoallylic fluoride. DAST reacted with cyclic ketoximes bearing substituent(s) that can stabilize a carbocation to cause the fluorinative fragmentation which produces fluorinated carbonitrile. The second topic describes the novel syntheses of organic compounds containing the difluoromethylene moiety using fluorinated building blocks. The indium-mediated coupling of aldehydes with 3-bromo-3, 3-difluoropropene gives α, α-difluorohomoallylic alcohols in high yields. α, α-Difluorohomopropargylic alcohols were also obtained from the indium-mediated coupling of aldehydes with α-bromo-α, α-difluoropropargyl compounds. In the presence of a palladium(0) catalyst, several nucleophiles regioselectively reacted with 3-bromo-3, 3-difluoropropene at its γ-position, and reacted with 1-substituted-3-bromo-3, 3-difluoropropenes at their α-position. (+)-(R)-1-Amino-2, 2-difluorocyclopropane-1-carboxylic acid was synthesized via the lipase-catalyzed asymmetric acetylation of a pro-chiral diol as a key step.
Isatin (indole-2, 3-dione)has been found in mammalian tissues as one of major components of tribulin, a postulated endogenous marker of stress and anxiety. I previously identified isatin as an endogenous inhibitor of monoamine oxidase (MAO) in the human urine and the brain of stroke-prone spontaneously hypertensive rats (SHRSP) using GC-MS. A single dose of isatin significantly increased norepinephrine (NE) and 5-hydroxytryptamine (5-HT) concentrations measured 2 h later in the various brain regions of normotensive Wistar Kyoto rats (WKY). Striatal acetylcholine (ACh) and dopamine (DA) levels significantly increased 2 h after the administration of isatin. Perfused through a microdialysis probe, isatin also produced a significant and concentration-dependent increase in the ACh and DA concentration in the perfusate from the rat striatum. In the patients with Parkinson's disease, urinary isatin concentrations tended to increase according to the severity of disease, as classified by the Hoehn and Yahr criteria. Isatin significantly increased striatal DA levels in a rat model of Parkinson's disease. Isatin may play a role in the regulation of the brain levels of ACh and DA. Furthermore, isatin has a wide spectrum of biological properties : (a) a marker of stress and anxiety, (b) an inhibitor of a number of enzymes, (c) an anti-seizure agent, (d) an inhibitor of benzodiazepin receptors and ANP binding to its receptors.
In our continuing work on synthesizing 4-substituted indole alkaloids as simple as possible by creating suitable reactions, we developed synthetic methods for 4-substituted indoles having a nitrogen or oxygen functional group at the 4-position starting from indole-3-carbaldehyde and one step conversion method of indole-3-carbaldehydes into indole-3-acetonitriles. Utilizing them, we could establish a practical synthetic route to 1, 3, 4, 5-tetrahydropyrrolo[4, 3, 2-de]-quinoline in three steps from indole-3-carbaldehyde. On the basis of these results, short step total syntheses of marine indole alkaloids, such as isobatzelline C, batzelline C, makaluvamine A, and damirones A and B, were achieved. Furthermore, a novel preparative method of psilocin was established in only five steps from indole-3-carbaldehyde. The syntheses of psilocin analogs having a formyl group or bromine in the benzene part were also achieved.
Macrolide antibiotics (Mac) consist of a 12- to 16-membered lactone ring combined with a sugar moiety, and they inhibit protein synthesis via binding to 23S ribosomal RNA in bacteria. The 14- and 16-membered Mac are used for treating infectious diseases caused by Gram-positive and other bacteria; e.g., Haemophilus influenzae, Bordetella pertussis, Legionella pneumophila, Campylobacter, Treponema pallidum and Mycoplasma. Resistance to macrolide, lincosamide, and streptogramin-B(MLS) antibiotics in staphylococci is known to have the following mechanisms : 1) alteration of the target on ribosome due to dimethylation of a specific adenine residue in the 23S ribosomal RNA by the product of the erm gene, and consequently a decrease in binding of MLS antibiotics; 2) inactivation of streptogramin-B (STG-B) and lincosamide by the products of the sbh (encoding streptogramin B hydrolase) and linA'(encoding 3-lincomycin 4-clindamycin O-nucleotidyltransferase) genes, respectively; and 3) active efflux of Mac and STG-B antibiotics determined by the msrA and msrB genes in Staphylococcus epidermidis and Staphylococcus xylosus, respectively, both of which appear to act as an ATP-dependent efflux pump. I have shown that Staphylococcus aureus 8325(pEP2104) exhibits inducible resistance to PMS (partial macrolide and streptogramin B)-antibiotics [the 14-membered macrolides, erythromycin (EM), and oleandomycin (OL), and the 16-membered macrolide mycinamicin (MCM)and STG-B]. The sequence of the N-terminal amino acid residues of a 63 kDa protein (MsrSA) that appeared in the membrane of PMS-resistant strains was identical to that of an MsrA polypeptide related to enhanced efflux of[ 14C]EM. Ribosomes from PMS-resistant strains showed a similar affinity for EM to those from the PMS-sensitive host strain NCTC8325, and no inactivation of EM by 8325(pEP2104) was observed. In the present study, I showed the DNA sequence of the msrSA region on the constitutive PMS-resistant plasmid pMC38, PMS-inducible resistant plasmid pEP2104 and PMS-sensitive mutant plasmid pSP6, and the region that is essential for inducible expression in PMS resistance. In addition, I investigated the relationship between PMS resistance and intracellular accumulation of EM.
Lipid peroxidation in biomembranes is mediated by free radical reactions. It leads to membrane damage and has been proposed to be associated with the pathogenesis to tissue injuries. Iron is known as a catalyst of lipid peroxidation.Microsomal lipid peroxidation by both NADPH and iron-chelate, such as Fe3+-ADP or Fe3+-PPi, is believed to be enzymatically associated with iron reduction. On the other hand, the addition of free Fe2+ to microsomes or liposomes produces a lag phase before the maximal rates of lipid peroxidation. We examined the interaction of iron with membrane in iron-supported lipid peroxidation and microsomal membrane components associated with iron reduction in NADPH-supported lipid peroxidation. Iron-supproted lipid peroxidation was affected by the surface charges of liposomal membrane. Liposomes containing phosphatidylserine (PS) were most sensitive to iron-supported lipid peroxidation. The effect of PS on iron-supported lipid peroxidation indicates that iron participates in binding to membrane surface charges and also indicates that Fe2+ at high level bound to membranes plays a role in producing a lag phase. The mechanism producing a lag phase in Fe2+-PPi-supported lipid peroxidation is discussed. In NADPH-supported lipid peroxidation in microsomes, it seemed unlikely that superoxide may be involved in iron reduction. Alternatively, under anaerobic conditions, NADPH-supported iron reduction in microsomes was not dependent on cytochrome P450 content and not inhibited by CO. A cholate-solubilized fraction of microsomes was applied to a laurate-Sepharose column and an active fraction for lipid peroxidation was obtained. Involvement of a heat-labile component, distinct from cytochrome P450, responsible for iron reduction in microsomal lipid peroxidation was demonstrated.
Objectives : The purpose of this study was to develop, implement, and assess an estimation procedure for preventing adverse drug reaction by subjective symptoms (complaints) of patients. This time, we carried out this study focusing on drug-induced leucopenia. Methods : We have built a database for CARPIS(Case Reports of Adverse Drug Reaction and Poisoning Information System) since 1987, and the total number of case reports of adverse drug reaction accumulated in the CARPIS database amounts to about 16000. Using the date obtained from 139 cases of drug-induced leucopenia accumulated in the CARPIS database, we investigated a relationship between leucopenia and patients. The evaluation scores were created based on the subjective symptoms and backgrounds of the patients. Results : We could estimate 91 case (65.5%) in 139 cases to be drug-induced leucopenia by the use of these evaluation scores. The validity of this evaluation scores was estimated to be as follows; sensitivity=65.5%, specificity=80.0% and predictive value of positive test(PVP)=82.0%. The positive likelihood(LR) ratio was 3.3 and negative likelihood ratio 0.43. Conclusions : In this study, PVP and LR values were not good, because among the symptoms of leucopenia a very few specific symptoms could be detected. But we reported previous by the evaluation scores about drug-induced liver disorders. Therefore, in order to apply these evaluation scores to the clinical practice, we prepared an evaluation form for subjective symptoms and backgrounds of the patients with adverse drug reactions. In the future, we plan to examine other adverse reactions which adds the data to this form.
Psidium genus Myrtaceae(Psidium) is known to be a chinese medicine with an anti-allergy effect. In the present study, to identify active components in Psidium and investigate mechanisms of its anti-allergy effect, effects of several components isolated from Psidium on cytokine production in helper T cell subtypes, Th1 and Th2 cells, were studied. All components, except methyl gallate, suppressed cytokine production in both Th1 and Th2 cells. Then, effects of methyl gallate on IgE production in a model mouse with type I allergy were studied. Methyl gallate suppressed IgE production in the mouse. Only methyl gallate selectively suppressed Th2-cytokine production.