NEURAMIDE STIMULATES ADRENOCORTICOTROPIN BUT NOT PROLACTIN RELEASE FROM RAT PITUITARY

Neuramide (NMD), a substance found in crude preparations of porcine stomach extract, is a viral inhibitor that also has putative immunostimulatory effects. The effects of NMD on stress-hormone (ACTH and prolactin—PRL) release were assessed inin vivoandin vitrostudies. In the former, blood levels of corticosterone and PRL were measured in NMD-treated male rats.In vitroexperiments were performed to evaluate the effects of NMD and three of its fractions (obtained with high performance liquid chromatography) on ACTH and PRL release from perfused rat pituitary slices. NMD increased plasma corticosterone levelsin vivoand produced dose-dependent increases inin vitropituitary release of ACTH. No effects on PRL secretion were observedin vivoorin vitro. The stimulatory effects on ACTH release were caused by the NMD fraction with a molecular weight of >5000<10000Da.     

薄层层离法在研究天然化合物中的应用 Ⅳ.番麻(Agave americana L.)总甾体皂甙元的鉴定

本文报告了无粘合剂的氧化鋁薄层层离法在甾体皂甙元分离鉴定工作中的实际应用。通过一系列实驗确定:(1)作为吸附剂的氧化鋁应为中性,細度小于140篩孔,活度为Ⅲ或Ⅳ級;(2)不同比例的甲醇-苯作为推进剂,其中(0.5∶99.5)适于分离单經基无酮的甾体皂甙元,(2.5∶97.5)适于分离单羥基无酮及有酮的甾体皂甙元,(5∶95)适于分离双羥基无酮及有酮的甾体皂甙元;(3)适宜的显色剂为25%的磷錮酸醇溶液。应用上述条件对番麻总甾体皂甙元进行薄层层离,得到八个斑点,經用标准品对照,初步鉴定了其中的七个成分。     

Cytotoxicities of ginseng saponins and their degradation products against some cancer cell lines

In order to elucidate the cytotoxicity-structure correlation of ginseng-derived components, several prosapogenins and sapogenins were prepared from Korean red ginseng (Panax ginseng) saponins by acid hydrolysis or alkaline cleveage, and their chemical structures were identified by a combination of spectral and physical methods. Some of these degradation products showed the cytotoxic activities against various cancer cell lines, A549, SK-OV-3, SK-Mel-2, P388, L 1210 and K562. The significant difference in cytotoxicity between stereoisomers was not found and the activity was inversely proportional to the number of sugars linked to sapogenins. Diol-type prosapogenins and sapogenins showed higher cytotoxicity than triol-type ones.     

Allele and genotype frequency of CYP2C9 in Tamilnadu population

Objectives To identify the frequency of CYP2C9*1, *2 and *3 alleles and the genotype of CYP2C9 gene in the Tamilian population.Methods The study was conducted on 135 unrelated healthy human volunteers. DNA was extracted from the peripheral leukocytes samples and was analyzed using the polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) protocol. The PCR products were digested with AvaII, KpnI or NsiI restriction enzymes. The digested products were separated using 8% polyacrylamide gel and stained by ethidium bromide. Genotyping of the subjects was done based on DNA fragment size.Results The frequencies of CYP2C9*1, *2 and *3 alleles in the Tamilian population were 0.907, 0.026 and 0.067, respectively. The distribution of CYP2C9*1/*1, *1/*2, *1/*3 and *2/*3 genotypes were 0.823, 0.044, 0.126 and 0.007, respectively.Conclusion CYP2C9*3 is the most frequent mutant allele found in the Tamilian population. The distribution of this mutant allele in the Tamilian population was found to be lesser than in Caucasians but higher than in Chinese.     

7α和7β-甲基-10β,17β-二乙酰氧基-4-雌甾烯-3-酮的合成

由于7α-甲基或10β-乙酰氧基4(5)烯-3-酮雌(雄)甾化合物具有显著的抗着床或抗蜕膜活性,我们合成了既具有7α-甲基或7β-甲基又具有10β-乙酰氧基的两个新甾族化合物(1_a)和(1_b)。经药理试验表明(1_a)和(1_b)对孕鼠均有抗早孕作用。     

药食同源植物-葱（Allium fistulosum）种植物的研究进展

药食同源植物葱（Allium fistulosum）的化学成分复杂,主要的化学成分主要集中在黄酮类、甾体皂苷类、含硫类化合物等几部分。有较好的消除亚硝酸盐、抑制肿瘤细胞增殖、降血脂、防治非酒精性脂肪肝等作用。本文综述近年关于葱的化学成分及药理活性,为其进一步开发利用提供依据。     

薯蓣属植物化学成分的研究——Ⅱ.叉蕊薯蓣中甾体皂甙的分离和鉴定

从叉蕊薯蓣(D.collettii HooK.f.)根茎的乙醇提取物分离到四个甾体皂甙,根据理化性质、光谱数据,推定化学结构为3-O-(β-D-葡萄吡喃糖)-约莫皂甙元(3-O-(β-D-glucopyranosyl)-yamogenin)[Ⅰ];3-O-[α-L-鼠李吡喃糖(1→4)-β-D-葡萄吡喃糖]-约莫皂甙元(3-O-[α-L-rahmnopyranosyl(1→4)-β-D-glucopyranosyl]-yamogenin)[Ⅱ];3-O-{α-L-鼠李吡喃糖(1→4)-[α-L-鼠李吡喃糖(1→2)]-β-D-葡萄吡喃糖}-约莫皂甙元(3-O-{α-L-rhamnopyranosyl(1→4)-[α-L-rhamnopyranosyl(1→2)]-β-D-glucopranosyl}-yamogenin)[Ⅲ];3-O-{β-D-葡萄吡喃糖(1→3)-[α-L-鼠李吡喃糖(1→2)3-β-D-葡萄吡喃糖}-约莫皂甙元(3-O-{β-D-glucopyranosyl(1→3)-[α-L-rhamnopyranosyl(1→2)]-β-D-glucopyranosyl}-yamogenin)[Ⅳ]。其中Ⅰ为已知物,Ⅱ、Ⅲ、Ⅳ为首次从植物界得到的新甾体皂甙。     

Re-investigation of the concordance of human NAT2 phenotypes and genotypes

A comparative study of N-acetyltransferase 2 (NAT2) genotyping and phenotyping (caffeine test method) was performed on 211 persons to elucidate apparent discrepancies in the assignment of NAT2*12 and NAT2*13 alleles which occur in the literature. The study used the standard procedures of genotyping (two PCR runs and application of seven restriction enzymes) and phenotyping (determination of the two caffeine metabolites 5-acetylamino-6-formylamino-3-methyluracil (AFMU) and 1-methylxanthine (1X)), as documented in detail and validated by the Deutsche Forschungsgemeinschaft. The data were consistent with an AFMU/1X molar ratio of 0.85 as cut-off point (antimode) between phenotypically slow and rapid acetylators. Under this provision, several R/S allele combinations did not comply, either fully or partly, with their associated phenotypes. In particular, there was a wide phenotypic overlap of the alleged rapid allele combination groups (i) NAT2*12A/*5A; NAT2*12C/*5D; NAT2*4/*5B, (ii) NAT2*13/*6B; NAT2*4/*6A, and (iii) NAT2*13/*7A; NAT2*4/*7B. These groups obviously contained both phenotypically rapid and slow acetylators. If one assumes that the presence of one wild type allele NAT2*4 defines a rapid acetylator the assignment of the alleles NAT2*12A, NAT2*12C, and NAT*13 as determinants of a rapid acetylator phenotype must be questioned. This refers in particular to the nucleotide changes A⁸⁰³G (NAT2*12A, NAT2*12C) and C²⁸²T (NAT2*13). Based on discussions in the literature and the data presented here, there is accumulating evidence that current assignments of the NAT2*12 and NAT2*13 alleles as determinants of a rapid acetylator state should be reconsidered.     

Triterpenoids from the roots ofRubus parvifolius

From the roots ofRubus parvifolius L., four triterpenoidal sapogenins, ursolic acid1, 2α-hydroxyursolic acid2, euscapic acid3, 2α, 3β, 19α-trihydroxyurs-12-en-23,28-dioic acid4 and one triterpenoidal glycoside, suavissimoside R₁ 5, were isolated. The structures were elucidated by spectroscopic methods and chemical transformations. Compound4 was first isolated as free form.     

Simplified methods for the evaluation of the parameters of the time course of plasma concentration in the one-compartment body model with first-order invasion and first-order drug elimination including methods for ascertaining when such rate constants are equal

The many limitations in determining the pharmacokinetic parameters of firstorder invasion of, and elimination from, the onecompartment body model by the method of residuals or by feathering Ct data can be minimized by applying the simplified methods outlined herein. Comparisons of the apparent volumes of distribution, V, calculated on the premises that the Bateman Function represents k_a>k_e or its converse, k_e>k_a,i.e., flip-flop, can permit a proper choice of the correct version. Estimation of k_e can be obtained by regression of (A₀/V)/C(oncentration) on AUC₁/ Cwhere A₀/Vis estimable from knowledge of C_max and t_max since .The ratio of the magnitude of the rate constant of invasion to that of elimination, m=k_a/k_e,is related to k_et_max by the expression k_et_max=ln m/ (m–1)for all possible values of m.A table for the determination of m from values of k_et_max is given. When bioavailability, =A₀/Dose,is known or complete, k_e and Vcan be determined from the respective ordinate and abscissa of the intersection of and Cl(clearance)/k_e,both plotted against arbitrary k_e values. The two functions may not intersect at low values of mdue to errored C-t values but the k_e value when the two curves are closest (k_min)may approximate k_e.The intersections of and k_eAUCT (AUC_trap)plotted against variable k_e values (Method A) provide estimates of k_e from their abscissa values and A/Vfrom their ordinate values when is unknown. Method B appears to give more reliable estimates of k_e at the k_min of the difference plotted against k_e.Since k_min of this plot is 1/t_max when m=1,the identity of the mas unity underlying the C-t data is indicated when either k_mint_max is approximately unity or k_min ispractically synonymous with 1/t_max.This was clearly shown when 12 constructed m=1,C-t cases with 10% random error were evaluated by Method B. Better estimates were effected by all procedures when the raw C-t data were smoothed.We regretfully announce that Dr. Edward Garrett passed away on October 25, 1993, after an extended illness.     

Cesdiurins I–III,steroidal saponins from <Emphasis Type="Italic">Cestrum diurnum</Emphasis> L.

Phytochemical investigation of a methanolic extract of leaves of Cestrum diurnum L (Solanaceae) resulted in isolation of several furostanol steroidal saponins, named cesdiurins I–III (1–3). Their structures of the isolated compounds were determined by spectroscopic analyses, including by use of 1D and 2D NMR spectroscopic techniques as well as by mass spectral analyses.     

Distinction of water-soluble constituents between some Paecilomyces (= Isaria) and Cordyceps fungi by capillary electrophoresis

In order to reveal the differences between Cordyceps, Paecilomyces (= Isaria) and Nomuraea, we collected seven entomogenous fungi grown in natural field and analyzed the profiles of water-soluble constituents derived from some different sources of Cordyceps, Paecilomyces and Nomuraea by determination using capillary electrophoresis. C. sinensis and C. kyushuensis showed similar peak clusters of protein migrated at 5–7, 8–9, and 12–20 min. The peak clusters obtained from N. atypicola was similar to those of C. sinensis and C. kyushuensis. The water-soluble constituent clusters of C. militaris migrated at 5–9 and 10–15 min were partly different from those of other Cordyceps. It was also revealed that the P. tenuipes and P. cicadae showed lesser peak clusters rather than Cordyceps. These results indicated that the profiles of protein of these entomogenous fungi by capillary electrophoretic analysis could serve as fingerprints for classification and medicinal quality control of Cordyceps.     

发霉叉蕊薯蓣中的甾体皂甙元

前报报道了从国产野生叉蕊薯蓣(Dioscorea collettii Hook.f.)根茎的水解物中分得了10个甾体化合物,其中约莫皂甙元(yamogenin)和薯蓣皂甙元(diosgenin)为主要成分。从根茎中还分得4个约莫皂甙元的甾体皂甙。在研究国产野生薯蓣属植物化学成分的工作中,我们曾观察到一些薯蓣属植物的根茎长时间发霉后可生成表丝兰皂甙元(epi-smilagenin)和丝兰皂甙元酮(smilagenone)。这些皂甙元的存在造成薯蓣皂甙元产品的熔点降低,质     

Physiological functions of solanaceous and tomato steroidal glycosides

Solanaceous plants are widely distributed. They are used as food and in folk medicine. Our studies focused on these plants, starting with Solanum lyratum and S. nigrum, which are used as anti-cancer and anti-herpes agents. Extensive investigations in 45 Solanum plant species revealed that a considerable amount of glycosides such as spirosolane, solanidane, spirostane and furostane is in these plants, and some of the isolated glycosides showed strong anti-proliferative activity against various cancer cell lines and anti-herpes activity. Furthermore, we have discovered a few new hypothetical biosynthetic routes in which the pathways for the biosynthesis of 16-acyl-pregnane and pregnane glycosides were the most interesting. The occurrence of these pregnane compounds indicates that they might be internally biosynthesized in the plant from furostanol glycosides by a reaction that is similar to Marker degradation. Furthermore, this may imply that the administration of steroidal glycosides may result in their metabolization into pregnane derivatives possessing various activities. In order to perform metabolic experiments using the steroidal glycosides, we recently isolated tomato glycosides from ripe tomato fruits for the first time. For this experiment, we examined the metabolites in urine obtained from persons that consumed tomatoes. We obtained androstane derivatives that were probably metabolized via pregnane derivatives from tomato glycoside. Hence, when a steroidal glycoside is administered, it may be metabolized into a type of steroidal hormone with various physiological activities.     

Effect ofLentinus edodes on the growth of intestinal lactic acid bacteria

As the growth factor of lactic acid bacteria, LD (trehalose) was isolated fromLentinus edodes by using silica gel column chromatography. LD induced the growth ofBifidobacteria breve andLactobacillus brevis, which were isolated from human feces. LD selectively induced the growth of lactic acid bacteria among total microflora. When total intestinal microflora were cultured in the medium containing LD, it stimulated the growth of lactic acid bacteria and inhibited harmful enzymes, β-glucosidase, β-glucuronidase, and tryptophanase, of intestinal bacteria. LM, which was a monosaccharide fromL. edodes, induced the growth of lactic acid bacteria but it seems to be invaluablein vivo. LH isolated fromL. edodes by Sephadex G-100 column chromatography was not effective for the growth of lactic acid bacteria.     

In vitro andin vivo evaluations of LB10517, a novel parenteral broad-spectrum cephalosporin

Thein vitro activity of LB10517, a new catechol-substituted cephalosporin, was compared with those of E-1077, cefpirome and ceftazidime against 1034 clinical isolates collected in Japan. LB10517 showed a broad-spectrum antibacterial activity against a wide range of gram-positive and gram-negative bacteria including non-glucose fermenting rods,Pseudomonas aeruginosa. Against the methicillin-susceptible strains ofStaphylococcus aureus (MSSA) andStreptococcus pyogenes, the MIC₉₀ values of LB10517 which required to inhibit 90% of the strains were 3.13 μg/ml and 0.1 μ/ml, respectively. It was as active as E-1077 but more active than cefpirome and ceftazidime. Methicillin-resistant strains ofS. aureus (MRSA) andEnterococcus spp. were highly resistant to all the test compounds. LB10517 was highly active against most members of the familyEnterobacteriaceae, 90% of which were inhibited at a concentration of less than 0.78 μg/ml, except forEnterobacter cloacae (1.56 μg/ml) andSerratia marcescens (3.13 μg/ml). Its activity was comparable to those of E-1077 and cefpirome but it was greater than that of ceftazidime. AgainstPseudomonas aeruginosa, LB10517 showed the most potent antibacterial activity among the compounds tested. Ninety percent ofP. aeruginosa isolates were susceptible at the concentration of 0.39 μg/ml. Its activity was 32- to 128-fold higher than those of E-1077, cefpirome and ceftazidime. Against imipenem- or ofloxacinresistantP. aeruginosa, LB10517 with MIC₉₀s of 6.25 μg/ml and 3.13 μg/ml, respectively, showed 16-fold more potent activity than the other test compounds. LB10517 showed a relatively high plasma level and long plasma elimination half-life in rats (t_1/2(β), 52 min) and dogs (t_1/2(β), 103 min).     

High prevalence of cytochrome P 450 2A6*1A alleles in a black African population of Ghana

Objective We investigated the frequencies of the functionally important variants of the CYP2A6 gene in black African populations.Methods Using genomic DNA sequencing, polymerase chain reaction (PCR)–restriction fragment length polymorphism and allele-specific PCR, the allele frequencies of CYP2A6 *1A, *1B, *2, *4A, *5, *6, *7, *8, *9, *10 and * 11 among 120 black Africans— including 105 Ghanaians, 12 Nigerians, 2 Ivorians and 1 Ugandan—were determined.Results The allele frequencies were 80.5% for CYP2A6*1A, 11.9% for CYP2A6*1B, 1.9% for CYP2A6*4A and 5.7% for CYP2A6*9 in the Ghanaian subjects. No subject homozygous for the CYP2A6*4A allele, a whole gene deletion type of polymorphism prevalent among Orientals, was found. Furthermore, CYP2A6 variants such as *2, *5, *6, *7, *8, *10 and *11 were absent in these black African populations.Conclusions This study provides, for the first time, the results of the analysis of CYP2A6 allele frequency in black African populations and confirms large ethnic differences in the polymorphic CYP2A6 gene.     

Antitumor and immunomodulating activities of the polysaccharide fractions fromArtemisia selengensis andArtemisia iwayomogi

Effects of the polysaccharide fractions purified fromArtemisia selengensis andArtemisia iwayomogi on the immune system was studied. The polysaccharide fractions, respectively called ASP1 and AIP1, may interact with macrophages and lymphocytes in spleen, increasing the population of those cell typesin vivo andin vitro. Both ASP1 and AIP1 fractions also suppress transplanted tumor cell growth and augment antibody production. This study suggests that ASP1 and AIP1 fractions may have immunomodulating and antitumor activities.     

Anticoagulant activity of ilexoside D,a triterpenoid saponin fromIlex pubescens

The anti-coagulant activity of ilexoside D isolated from the roots ofIlex pubescens Hook. et Arn. was investigated inin vivo andin vitro models of blood coagulation in rats. On oral administration, ilexoside D prolonged the bleeding time and the whole blood recalcified clotting time, but not the plasma recalcified clotting time.In vitro, ilexoside D did not affect the recalcified clotting times of whole blood, platelet-rich plasma (PRP), and platelet-poor plasma (PPP) while in the presence of tissue factor the compound prolonged the reduced prothrombin times of whole blood, PRP and PPP in the dose-dependent manner. These results indicate that ilexoside D has the anti-tissue factor activity as well as the antithrombotic activity.     

Correlation betweenin vitro andin vivo drug metabolism rate: Oxidation of ethoxybenzamide in rat

In vitroand in vivocorrelations of the microsomal oxidation of drugs were examined, using ethoxybenzamide as a model drug. Ethoxybenzamide disappearance time course from rat plasma in vivowas analyzed by a two-compartment model assuming a Michaelis-Menten type elimination process. Ethoxybenazmide oxidation in vitrowas measured by the appearance rate of salicylamide in rat liver microsomal suspension. Parameters obtained were V_max=3.46 and 3.77 moles/min/kg body weight and K_m=0.378 and 0.192mM, in vitroand in vivo,respectively.