兔血中叶枯灵的代谢产物的分离和鉴定

本文用 RP-HPLC 法从染毒兔血中分离出叶枯灵的两个代谢产物。用标准品核对色谱行为,再经质谱鉴定,证实保留时间 tr=8.07±0.15min,为苯甲酸 S-氧-N-1,3-二噻茂烷酰肼(Benzoicacid s-oxo-N-1,3-dithiolan-2-ylidene hydrazide)。保留时间 tr=16.69±0.10min,为苯甲酸(benzoic acid)。     

Stimulation of capsaicin-sensitive sensory peripheral nerves with topically applied resiniferatoxin decreases salicylate-induced gastric H+ back-diffusion in the rat

Capsaicin-sensitive sensory nerves (CSSN) exert local protective functions in the stomach and have been proposed to regulate gastric H⁺ back-diffusion. The present study aimed to evaluate the possible influence of stimulation of CSSN with the intragastrically (ig) applied capsaicin analogue, resiniferatoxin (RTX), on gastric H⁺ back-diffusion and mucosal injury caused by ig application of HCl (2 ml 0.15 mol/L) or acidified salicylate (200 mg/kg in 2 ml 0.15 mol/L HCl) after 1 or 2 h in the pylorus-ligated rat. Stimulation of CSSN with a low concentration (0.04 μg/ml) of RTX markedly decreased H⁺ back-diffusion caused by acidified salicylate. After acute bilateral truncal vagotomy or treatment with atropine sulphate, RTX did not inhibit gastric acid back-diffusion. Surgical vagotomy alone increased, while RTX or atropine markedly diminished, the development of gastric mucosal injury in these models. In saline-treated rats, RTX significantly reduced gastric secretory volume and acid output. The inhibitory effect lasted for 1 h. These data suggest an essential role for CSSN in regulation of gastric acid secretion and in maintaining the integrity of the gastric mucosa that appear to depend on intact vagal nerves.     

3,4-二氯-N-甲基-N-[反式-2-(1-△3-吡咯啉基)环己基]-苯乙酰胺盐酸盐的合成及其镇痛活性的研究

3, 4-Dichloro-N-methyl-N-[trans-2- (1-△³-pyrrolinyl)-cyclohexyl]-benzenacetamide hydrochloride (K-Ⅱ) was synthesized from N-methyl-7-azabicyclo [4.1.0] heptane by treatment with 2,5-dihydropyrrole to give N-[trans-2(1-△³-pyrrolinyl)-cyclohexyl]-N-methylamine which was amidated with 3,4-dichlorophenyl-acetic acid. K-Ⅱ is an analogue of U-50488 H(K-Ⅰ), a known kappa receptor agonist.The results of animal tests showed that K-Ⅱ is 3 times as potent as K-Ⅰ as an analgesic in the mouse hot plate test and 5 times in the mouse writhing test and that the affinity of K-Ⅱ for kappa receptor may be higher than that of K-Ⅰ. The general behavioural effects of these two agents are similar in mice.     

Differential desensitization of ionotropic non-NMDA receptors having distinct neuronal location and function

The release of tritium from rat hippocampal synaptosomes prelabeled with [³H]noradrenaline ([³H]NA) or [³H]5-hydroxytryptamine ([³H]5-HT) and from rat neocortex synaptosomes prelabeled with [³H]choline and the release of endogenous GABA and glutamate from rat neocortex synaptosomes were monitored during superfusion with media containing varying concentrations of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) or kainic acid. Concentration-dependent release potentiations were elicited by both excitatory amino acids (EAAs) in all the transmitter systems investigated. The releases evoked by 100 μM AMPA were, in all cases, almost totally dependent on external Ca²⁺ and sensitive to 6,7-dinitroquinoxaline-2,3-dione (DNQX), indicating involvement of non-NMDA receptors. When cyclothiazide, a drug able to prevent desensitization of AMPA-preferring receptors, was added to the superfusion medium (at 1 or 10 μM) concomitantly with 100 μM AMPA or kainate, the EAA-evoked release of [³H]NA was significantly enhanced. Concanavalin A, a lectin thought to prevent desensitization of kainate-preferring receptors, had no effect (up to 10 μM) on the release of [³H]NA evoked by AMPA or kainate. The effect of cyclothiazide was lost if, after an 8-min pretreatment, the drug was removed just before the AMPA stimulus. When added concomitantly with the EAAs, cyclothiazide potentiated the release of [³H]5-HT elicited by AMPA and, less so, that evoked by kainate. Concanavalin A was ineffective. Neither cyclothiazide (1 or 10 μM) nor concanavalin A (3 or 10 μM) could affect the release of [³H]ACh or endogenous GABA provoked by 100 μM AMPA or kainate, suggesting that the receptors involved do not desensitize. Exposure of neocortex synaptosomes to AMPA or kainate concomitantly with cyclothiazide caused endogenous glutamate release that did not differ from that evoked by the EAAs alone. In contrast, the effects of AMPA and kainate were potentiated by concanavalin A. The activity of the lectin (3 μM) persisted when it was applied for 8 min and then removed before the AMPA or kainate (100 μM) pulse. When hippocampal synaptosomes prelabeled with [³H]NA were subjected to three subsequent AMPA (100 μM) stimuli (S₁, S₂ and S₃), the release of [³H]NA decreased dramatically from S₁ to S₃ (S₃/S₁ = 0.14 ± 0.04); a significant ‘protection’ of the AMPA effect was offered by 1 μM cyclothiazide (S₃/S₁ = 0.36 ± 0.06). This value did not differ from the S₃/S₁ ratio (0.38 ± 0.04) obtained in parallel experiments with 12 mM K⁺. The release evoked by high-K⁺ was insensitive to cyclothiazide. Finally, the effect of AMPA on the release of [³H]ACh did not respond to cyclothiazide also during three subsequent stimuli with 100 μM AMPA. To conclude: a) ionotropic non-NMDA receptors mediating enhancement of NA, 5-HT, ACh, GABA and glutamate release exist on the corresponding nerve terminals; b) the receptors present on noradrenergic and serotonergic neurons are AMPA-preferring receptors, whereas the glutamate autoreceptors resemble most the kainate-preferring subtype; the receptors mediating ACh and GABA release can not be subclassified at present; c) desensitization may not be a property of all non-NMDA ionotropic receptors. The receptors here characterized represent five models of native non-NMDA receptors suitable for pharmacological and molecular studies. Received: 28 January 1997 / Accepted: 14 April 1997     

Ontogeny of adenosine receptors in the longitudinal muscle and muscularis mucosae of the rat distal colon

The development of adenosine A₁ and A_2B receptors on the longitudinal muscle and muscularis mucosae of the neonatal rat distal colon has been investigated using homogenate binding, quantitative autoradiography and functional studies. In homogenate binding studies 1,3-[³H]-dipropyl-8-cyclopentylxanthine ([³H]DPCPX) bound with high affinity to A₁ receptors in the muscularis mucosae and intact colon from rats aged 10, 15, 20, 25 and 30 days. The affinity of [³H]DPCPX was similar to that in the adult at all ages, but the density of binding sites was higher in the neonatal tissues. Quantitative autoradiography showed a higher density of [³H]DPCPX binding sites in the longitudinal muscle than in the muscularis mucosae at all ages studied (day 10 to adult), and this binding was concentration-dependently displaced by N ⁶-cyclopentyladenosine (CPA). In functional studies the longitudinal muscle relaxed in response to 5’-N-ethylcarboxamidoadenosine (NECA) and CPA at all ages studied (15–30 days), NECA being more potent than CPA. The potency of NECA remained constant and it was antagonised by 1 μM DPCPX at all ages with pA ₂-values consistent with activation of A₂ receptors. The inactivity of 2-[p-(carboxyethyl)-phenylethylamino]-5’-N-ethylcarbox-amidoadenosine (CGS 21680) indicated that the A₂ receptors were of the A_2B subtype. The muscularis mucosae contracted in response to CPA at all ages studied (day 15 to adult) and the antagonism by DPCPX (10 nM) were consistent with activation of A₁ receptors. In conclusion, binding, autoradiographic and functional studies identified A₁ receptors on the rat colon muscularis mucosae at all ages studied. However, while binding and autoradiographic localisation showed the presence of A₁ receptors in the longitudinal muscle at all ages studied, functional data only revealed the presence of A_2B receptors. Received: 3 July 1998 / Accepted: 25 November 1998     

A novel Na+/Ca2+ channel blocker, NS-7, suppresses hypoxic injury in rat cerebrocortical slices

The substance 4-(4-fluorophenyl)-2-methyl-6-(5-piperidinopentyloxy) pyrimidine hydrochloride (NS-7) has been developed recently as a cerebroprotective compound with Na⁺ and Ca²⁺ channel blocking action. In the present study, the effect of NS-7 in an in vitro model of hypoxic injury was examined and the possible involvement of Na⁺ and Ca²⁺ channels in the hypoxic injury subsequently determined. When slices of rat cerebral cortex were exposed to hypoxia/glucose deprivation followed by reoxygenation and restoration of the glucose supply, marked leakage of lactate dehydrogenase (LDH) occurred 3–6 h after reoxygenation. This hypoxia/reoxygenation-induced injury was blocked almost completely by the removal of extracellular Ca²⁺ or by chelating intracellular Ca²⁺ with 1,2-bis(o-aminophenoxy)ethane-N,N,N’,N’-tetraacetic acid tetra(acetoxymethyl)ester (BAPTA/AM). In addition, combined treatment with the N-type Ca²⁺ channel blocker ω-conotoxin GVIA and the P/Q-type Ca²⁺ channel blocker ω-agatoxin IVA significantly reduced LDH leakage, although neither of these Ca²⁺ channel blockers alone, nor nimodipine, an L-type Ca²⁺ channel blocker, was effective. On the other hand, several Na⁺ channel blockers, including tetrodotoxin, local anaesthetics and antiepileptics, significantly reduced the hypoxic injury. NS-7 (3–30 μM) concentration-dependently inhibited LDH leakage caused by hypoxia/reoxygenation, but had no influence on the reduction of tissue ATP content and energy charge during hypoxia and glucose deprivation. It is suggested that blockade of Na⁺ and Ca²⁺ channels is implicated in the cerebroprotective action of NS-7. Received: 10 March 1998 / Accepted: 19 April 1998     

中药秦艽中总生物碱的含量测定

A method for determining the total alkaloids of the Chinese drug Tsingjiu (秦艽) (Gentiana macrophylla) based on titration with silicotungstic acid was found. Weigh out accurately 2 g of pulverized (80 mesh) sample. Macerate it in a glass-stoppered flask with 50 ml of a mixture of chloroform-methanol-concentrated ammonia water (75: 25: 5) for 48 hours with occasional shaking. Take exactly 25 ml of the filtrate, evaporate and dissolve the residue in 0.6 N acetic acid, Impurities in the acetic acid solution are removed with lead acetate and the excess of Pb⁺² is removed by sodium sulphate. The clear filtrate is adjusted to about 50 ml with an acidity at about 0.5 N. The solution is titrated with 0.01 M silicotungstic acid, using malachite green as an outside indicator. Results are calculated on gentianine (C₁0H₉O₂N).     

Involvement of different Ca2+ pools during the canine bronchial sustained contraction in Ca2+-free medium: lack of effect of PKC inhibition

We evaluated the role of protein kinase C (PKC) in the sustained bronchial contraction (SBC) induced by carbachol (Cch) or histamine in a Ca²⁺-free medium and the possibility that each agonist uses a different Ca²⁺ store for this response. We studied third-order bronchi and airway smooth muscle (ASM) from first-order bronchi dissected free of cartilage and epithelium. Bronchial and ASM responsiveness to Cch or histamine were evaluated in Krebs solution (2.5 mM Ca²⁺) and in Ca²⁺-free medium. Cch and histamine induced an SBC in bronchial tissues in Ca²⁺-free medium. In ASM each agonist produced a transient contraction, but the response to histamine was much smaller. Cch induced a concentration-dependent accumulation of inositol phosphates (IPs) in both bronchi and ASM; however, histamine did not induce significant accumulation of IPs. Repeated exposure to histamine in bronchial rings abolished contractile responses in Ca²⁺-free media, but Cch added afterwards still produced a sustained contraction. This response was blocked when bronchial tissues were preincubated with 10 μM cyclopiazonic acid (CPA). Brief incubation of these preparations with a high EGTA concentration (1 mM) abolished the histamine-induced SBC. The SBC induced by Cch or histamine in Ca²⁺-free medium was not affected by the preincubation of the tissues with calphostin C, chelerythrine or staurosporine. We concluded that Cch mobilizes Ca²⁺ from two different sources during the SBC in Ca²⁺-free medium: from a CPA-sensitive one from sarcoplasmic reticulum (SR) and from a putative extracellular membrane Ca²⁺ pool sensitive to 1 mM EGTA, and neither process involved PKC activation. Histamine appeared to utilize the extracellular membrane pool only. Received: 12 March 1998 / Accepted: 2 September 1998     

没食子酸丙酯对大鼠肝线粒体肿胀和脂质过氧化物形成的作用

The extract of Radix Paeonia rubra, a common traditional Chinese drug was shown to inhibit platelet aggragation and oxidative phosphorylation while increasing fluidity of rat liver mitochondria. This paper reports the effects of propyl gallic acid, one component isolated from Radix Paeonia, on rat liver mitochondrial swelling and malondialdehyde (MDA) formation.Experiments on the formation MD and swelling of rat liver mitochondria induced by Fe²⁺ (5 μM)and vit C (0.1 mM) with or without the drug was carried out in vitro. In order to study the protectiye effects of drug against the damage of the mitochondria. The results show-that propyl gallic acid inhibited the swelling of mitochondrta andMDA formation. Fe²⁺ and vit C were also shown to reduce ANS fluorescence in mitochondrial suspension. It is inferred that the cross reaction of MDA with biological macromolecules and the decrease of surface potential of mitochondrial membrane are factors that induced damage to the function of mitochondria. This compound was shown to be unable to inhibit MDA damage to the mitochondria. However, the anti-oxidative and antiswelling action of the drug on mitochondria may be associated with the Pharmacological effects of Radix Paeonia rubra.     

豹皮菌中2-Amino-3-(1,2-dicarboxyethylthio)propanoic acid非对映异构体的绝对构型

Four stereoisomers of 2-amino-3-(1,2-dicarboxyethylthio) propanoic acid were prepared by reaction of L- and D-cysteine with fumaric acid. The absolute configuration of the diastereoisomer of 2-amino-3-(1,2-dicarboxyethylthio) propanoic acid from Amanita pantherina were assigned as (2R, 1'R) and (2R, 1'S) by analysis of the optical properties. Pharmacological tests showed that all of the four stereoisomers inhibited the depolarization of NMDA on spinal motorneurones in newborn rats, The inhibition intensity of L-A,D-A and D-B were higher than that of L-B.     

大鼠尿中2-苯甲酰肼叉-1,3-二噻茂烷及其代谢产物定量研究

本文建立了线性梯度洗脱,两波长切换检测和两内标法测定染毒大鼠尿中2苯甲酰肼叉-1.3二噻茂烷(BADYH)及其代谢产物的反相高效液相色谱方法.研究了大鼠ig不同剂量BADYH后,经尿排泄的DADYH及其代谢产物累积量-时间过程.结果表明,BADYH及其代谢产物累积排泄量占染毒总量的39.7％。其中主要代谢产物丙酮缩肝叉1.3二噻茂烷,占23.6％;肼叉1.2二噻茂炼占14.0％     

2-苯甲酰肼叉-1,3-二噻茂烷在大鼠原位灌流肝中的代谢动力学

采用反相高压液相色谱的三内标三波长切换技术对不同剂量的农药2-苯甲酰肼叉-1.3二噻茂烷在大鼠原位灌流肝中的代谢动力学进行了研究.结果表明,该农药经门静脉进入大鼠原位灌流肝后,很快分布于肝脏中,而在灌流肝中的消除过程较缓慢。随着给药剂量的增加,大鼠肝灌流液中各种代谢产物的生成量也逐渐增加,尤以肼叉1.3-二噻茂烷和苯甲酸生成量的增加更为显著.可见,该农药在大鼠原位灌流肝中的主要代谢途径为水解作用。     

农药叶枯灵在大鼠原位灌流肝中的代谢研究

采用反相HPLC、TLC、UV、IR和MS对农药叶枯灵经大鼠原位灌流肝代谢后所形成的代谢产物进行分离和鉴定。结果表明,叶枯灵在大鼠肝脏中进行了广泛的代谢,包括S-氧化作用、水解作用、丙酮酸缩合作用和乙酰化作用,共分离鉴定出5种代谢产物。     

叶枯灵在大鼠尿内的代谢产物分析

大鼠ig叶枯灵后,用HPLC和TLC分离纯化尿提取液中的叶枯灵及其代谢产物,得到六个组分,经MS和UV初步鉴定为叶枯灵,苯甲酸,马尿酸和三个新化合物:肼叉-1.3-二噻茂烷,乙酰肼叉-1.3-二噻茂烷和丙酮酸缩肼叉-1.3-二噻茂烷,通过对代谢物的化学合成,进一步确证了它们的化学结构。     

用核磁共振新技术测定川续断皂甙F和H1两个新皂甙的结构及光谱规律研究

从川续断(Dipsacus asperoides c．Y．cheng et T．M．Ai)根部的乙醇提取物中得到二个新三萜皂甙，命名为川续断皂甙(asperosaponins)F和H₁。川续断皂甙F(I)是含六个糖的皂甙，川续断皂甙H₁(II)是含八个糖的皂甙。运用化学方法及光谱(¹HNMR，¹³CNMR，¹H-¹H COSY，——维多重接力COSY，选择性远程DEPT和三重共振NOE差谱)解析，鉴定其结构分别为3-O-[β-D-吡喃木糖(1→4)-β-D-吡哺葡萄糖(1→4)][α-L-吡喃鼠李糖(1→3)]-β-D-吡喃半乳糖(1→3)-α-L-吡喃鼠李糖(1→2)-α-L-吡喃阿拉伯糖-常春藤皂甙元(I)和3-0-[β-D-吡喃木糖(1→4)-β-D-吡喃葡萄糖(1→4)][α-L-吡喃鼠李糖(1→3)]-β-D-吡喃半乳糖(1→3)-α-L-吡喃鼠李糖(1→2)-α-L一吡喃阿拉伯糖-常春藤皂甙元-28-O-β-D-吡喃葡萄糖(1→6)-β-D-吡喃葡萄糖酯甙(II)。并总结出一些光谱方面的变化规律，可用于糖的鉴定，以及构型、糖链的连接顺序和糖与甙元之间的连接位置的说明。     

有机锡化合物抗肿瘤生物活性研究

有机锡(IV)化合物能明显地抑制大鼠脑组织中PKC活性和肿瘤细胞增殖，且两者之间存在着相关性。抗肿瘤活性的构效关系是：(1)有机基团R决定整个化合物的生物活性，Ph>Et>n-Bu；(2)卤素的电负性影响化合物活性的大小。抗肿瘤活性可能通过[snR₂]²⁺实现。并能部分地阻断HL-60细胞周期中的G_I期向S期的移行。[SnPh₂F₂]，[SnPh₂(CysOS)]H₂O和[SnPh₂Cl2·phen(CH₃)₂]对PKC的IC₅₀值分别为25，15和20 umol·L^-1，对HL-60细胞的IC₅₀值分别为0．5，4．0和0．3umol·L^-1。但它们无诱导分化HL-60和K562细胞的作用。     

栾树种子的化学成分研究

目的：分离鉴定栾树(Koelreuteria paniculata Laxm.)种子的化学成分。 方法：分别用石油醚回流提取和95% EtOH浸提, 硅胶柱色谱分离, IR,MS,UV,¹HNMR,¹³CNMR等方法确定结构。 结果：分得8个化合物,分别为3/-O-十四烷酰基-1-腈基-2-甲基-1,2-丙烯(1), 3-O-二十碳-14,15-烯酰基-1-腈基-2-甲基-1,2-丙烯(2), 3-O-二十碳-14,15-烯酰基-4-O-十八烷酰基-1-腈基-2-氧代亚甲基-1,2-丙烯(3), 3-O-(6′-亚油酰基-葡萄糖)-β-谷甾醇(4), 1-O-β-D-葡萄糖-2-O-油酸-3-O-十六烷酸甘油酯（5), 1-O-十六烷酸甘油酯（6), 14,15-二十碳烯酸（7),三油酸甘油酯（8)。 结论：1～3为新化合物, 4～8系首次从该植物中分得, 并归属其波谱信号。     

N-(4-甲氧羰基-4-邻苯二甲酰亚氨基丁酰基)-N-取代甘氨酸、脯氨酸和焦谷氨酸的合成

报道11个预期有血管紧张素转化酶抑制活性的N-(4-甲氧羰基-4-邻苯二甲酰亚氨基丁酰基)-N-取代甘氨酸(VII_1～9)、脯氨酸(VII₁₀)和焦谷氨酸(VIl₁₁)的合成和鉴定。所有上述化合物以及与VⅡ_1～9相应的叔丁酯(VI_1～9)均未见文献报道。药理初试结果显示，化合物VII₈，VII₉和VI₁₀均有明显降压活性。     

五灵脂活性成分的研究

自五灵脂中分离得到13种化合物。根据化学方法及光谱(UV,IR,MS,¹H-NMR,¹³C-NMR)分析,其中晶V为一新的异海松酸的衍生物,命名为五灵脂酸。并鉴定其它9种化合物为邻苯二酚(Ⅰ)、苯甲酸(Ⅱ),3-蒈烯-9,10-二羧酸(Ⅲ)尿嘧啶(Ⅳ),间羟基苯甲酸(Ⅵ),原儿茶酸(Ⅶ),次黄嘌呤(Ⅺ),尿囊素(Ⅻ),L-酪氨酸(ⅩⅢ)。化合物Ⅰ～Ⅶ在体外有明显的抑制血小板聚集活性;Ⅰ,Ⅲ,Ⅴ,Ⅶ显示了不同程度的抗菌活性。