Lepadins D-F: antiplasmodial and antitrypanosomal decahydroquinoline derivatives from the tropical marine tunicate Didemnum sp

From a new tunicate species, belonging to the genus Didemnum, three alkaloids possessing an unusual and extremely rare decahydroquinoline skeleton and showing significant and selective antiplasmodial and antitrypanosomal activity were obtained as follows: (2R*,3S*,4aR*,5R*,8aS*)-decahydro-3-hydroxy-5-(5'-hydroxyoctyl)-2-methylquinoline (lepadin D,1), its quaternary nitrogen derivative (2), (2R*,2"E,3S*,4aR*,5R*,8aS*)-decahydro-3-hydroxy-5-(5'-hydroxyoctyl)-2-methyl-3-quinolinyl ester 2"-octenoic acid (lepadin E, 3), and (2S*,2"E,3S*,4aR*,5R*,8aS*)-decahydro-3-hydroxy-5-(5'-hydroxyoctyl)-2-methyl-3-quinolinyl ester 2"-octenoic acid (lepadin F, 4). These isolates may well serve as lead structures for the development of new antimalarial drugs.     

Microbial products. VIII. Azinothricin, a novel hexadepsipeptide antibiotic

Azinothricin was isolated from the culture filtrate of Streptomyces sp. X-14950 in crystalline form. It represents a new type of hexadepsipeptide antibiotic as it contains a 19-membered cyclodepsipeptide ring composed of six unusual amino acids and bearing a novel C21 side chain. Azinothricin was identified as [(3S,4S,7R(S*),10S,17R,20S,23R)[2S(2'R*,5'S*, 6'S*)3S*]]-alpha-ethyl-6-(3-ethyl-1, 5-dimethyl-4-oxo-1,5-heptadienyl)- N-(1,8, 14,15,18,21,27-heptaaza-21-hydroxy-7-(1-hydroxyethyl)-2,6,9,16,19, 22-hexaoxo-4-isopropyl-20-(methoxy-methyl)-17,18-dimethyl-5-oxa tricyclo [21.4.0.0(10,15)]heptacosan-3-yl)tetrahydro-alpha, 2-dihydroxy-5-methyl-2H-pyran-2-acetamide and is primarily active against Gram-positive microorganisms.     

一种西沙掘海绵Dysidea sp.的化学成分研究

目的 对西沙掘海绵Dysidea sp.进行化学成分研究;方法 运用正相硅胶柱色谱、反相ODS柱色谱、凝胶Sephadex LH-20柱色谱以及高效液相色谱(HPLC)等多种分离手段对西沙掘海绵Dysidea sp.化学成分进行分离纯化;并通过理化性质、波谱学数据等结构信息鉴定其化合物的结构。结果发现：从西沙掘海绵Dysidea sp.中分离鉴定了8个化合物,分别为dictyoceratin C（1）、dactyloquinone B（2）、aminoquinone（3）、dictyoceratin A（4）、dactyloquinone D（5）、dactyloquinone E（6）、(1R*,2E,4R*,7E,10S*,11S*,12R*)-10,18-diacetoxydolabella-2,7-dien-6-one（7）和?,?-unsaturated ester（8）,结论 化合物1?6和8均为首次从该属海绵中分离得到。     

Lignans from the flower buds of Magnolia liliflora Desr

Six new lignans, 1- 6, along with six known compounds were obtained from the flower buds of Magnolia liliflora Desr. The new lignans were elucidated as (1 S*,2 R*,5 S*,6 S*)-2-(3,5-dimethoxyphenyl)-6-(3,4-methylenedioxyphenyl)-3,7-dioxabicyclo[3.3.0]octane (1), (1 R*,2 R*,5 R*,6 S*)-2-(3,5-dimethoxyphenyl)-6-(3,4-methylenedioxyphenyl)-3,7-dioxabicyclo[3.3.0]octane (2), (1 R*,?2 R*,5 R*,6 S*)-2,6-bis (3,5-dimethoxyphenyl)-3,7-dioxabicyclo[3.3.0]octane (3), (1 R*,2 S*,5 R*,6 R*)-2-(3,4-methylenedioxyphenyl)-6-(3,5-dimethoxyphenyl)-3,7-dioxabicyclo[3.3.0]octane ( 4), (7' S*,8 R*,8' R*)-3,5'-dimethoxy-3',4,9'-trihydroxy-7',9-epoxy-8,8'-lignan (5), and (7' R*,8' S*)-3,3',4,5'-tetramethoxy-7-en-7',9-epoxy-8,8'-lignan (6), by the analysis of 1D and 2D-NMR as well as HRESIMS data. The capacity of compound 1 to protect against damages to the DNA of rat lymphocyte cells induced by UV irradiation was assessed by the comet assay. It showed stronger antigenotoxicity than ascorbic acid from 6×10(-3)?mmol·L(-1) to 6×10(-6)?mmol·L(-1).     

多叶姜黄(Curcuma comosa Roxb.)的化学成分

目的对泰国产姜科姜黄属植物多叶姜黄(Curcuma comosaRoxb.)干燥根茎甲醇提取物的化学成分进行分离和结构鉴定。方法C.comosaRoxb.的甲醇提取物经乙酸乙酯-正丁醇-水依次萃取后,对各萃取部分采用正-反相硅胶柱色谱和制备型HPLC进行分离,经理化常数测定、核磁共振技术分析等方法鉴定了化合物的结构。结果分离得到8个化合物,分别被鉴定为异蓬莪术环二烯酮(isofuranodienone,1),蓬莪术环二烯酮(furanodienone,2),1(10)Z,4Z-蓬莪术二烯-6-酮[1(10)Z,4Z-furanodiene-6-one,3],泽泻醇(alismol,4),2,2,6-三甲基-1-氧螺[2,5]辛-5-烯-4-醇(2,2,6-trimethyl-1-oxaspiro[2,5]oct-5-en-4-ol,5),1-羟基-α,α,4-三甲基-3-环己烯-1-甲醇(1-hydroxy-α,α,4-trimethyl-3-cyclohexene-1-methanol,6),6-羟基-3(1-羟基-1-甲基乙基)-6-甲基-2-环己烯-1-酮(6-hydroxy-3(1-hydroxy-1-methylethyl)-6-methyl-2-cyclo-hexen-1-one,7),(1S,2S,4R)-1,8桉叶素-2-O-β-D-葡萄糖苷((1S,2S,4R)-2-hydroxy-1,8-cineoleβ-D-glucopyranoside,8)。结论化合物3~8为首次从该属植物中分离得到。     

温郁金挥发油的化学成分

目的对温郁金(Curcuma wenyujin)挥发油的化学成分进行研究。方法采用硅胶柱色谱、正反相MPLC及HPLC等进行分离纯化,通过波谱分析鉴定其结构。结果从温郁金挥发油中分离得到10个化合物,鉴定为莪术醇(1)、莪术二酮(2)、(4S,5S)-germacrone-4,5-epoxide(3)、germa-crone-1,10-epoxide(4)、新莪术二酮(5)、(5R,6R,7αR)-5-isopropenyl-3,6-dimethyl-6-vinyl-5,6,7α-tetrahydro-4H-enzofuran-2-one(6)、hydroxyisogermafurenolide(7)、(5R,6R,7aS)-5-isopropenyl-3,6-dimethyl-6-vinyl-5,6,7,7-αtetrahydro-4-Hbenzo-furan-2-one(8)、脱-氢1,8-桉叶素(9)、p-menth-2-ene-1,8-diol(10)。并通过核磁共振手段对其碳氢信号进行了全归属。结论化合物6、7为新的天然产物;化合物4、8、10为首次从该属植物中分离得到;化合物4、6、7、8、10为首次从该种植物中分离得到。     

Roles of phosphoinositide-dependent kinase-1 in α1B-adrenoceptor phosphorylation and desensitization

The role of phosphoinositide-dependent protein kinase-1 (PDK-1) activity on α(1B)-adrenoceptor phosphorylation and function was explored using pharmacological inhibitors and expression of a dominant-negative mutant of this enzyme. Noradrenaline-, phorbol myristate acetate-, lysophosphatidic acid- and epidermal growth factor-mediated α(1B)-adrenoceptor phosphorylation were markedly reduced by the two inhibitors used: UCN-01 [(7-hydroxystaurosporine; (3R*,8S*, 9R*, 10R*,12R*)-2,3,9,10,11,12-hexahydro-3-hydroxy-9-methoxy-8-methyl-10-(methylamino)-8,12-epoxy-1H, 8H-2,7b,12a-triazadibenzo[a,g]-cyclonona[cde]triden-1-one)] and OSU-03012 [(2-amino-N-[4-[5-(2-phenanthrenyl)-3-trifluoromethyl)-1H-pyrazol-1-yl]phenyl]-acetamide)]. A similar effect was observed in cells expressing a PDK-1 dominant-negative mutant. Phosphorylated PDK-1 (S241) and protein kinase C α (T497) were associated with cell membranes in the basal state which increased in response to the hormonal stimuli mentioned previously. UCN-01 essentially abolished phospho-PDK-1 membrane-association and markedly attenuated that of protein kinase C α. Consistent with the findings, UCN-01 reduced lysophosphatidic acid- and epidermal growth factor-induced α(1B-)adrenoceptor desensitization. Our data suggest that PDK-1 plays a permissive role in α(1B)-adrenoceptor desensitization and phosphorylation and participates in the formation of signaling complexes, which delicately modulate receptor function and regulation.     

Modulation of [3H]MK-801 binding to NMDA receptors in vivo and in vitro

[3H]MK-801 binding in vivo was used to determine the occupancy of NMDA receptor ligands shown to allosterically modulate binding in vitro. ED(50) values (mg/kg) were obtained for the channel blockers (+)-5-methyl-10,11-dihydro-5,4-dibenzo[a,d]cyclohepten-5,10-imine maleate ((+)-MK-801, 0.2), 1-(1-phenylcyclohexyl)piperidine (phencyclidine, PCP, 1.7) and ketamine (4.4). Antagonists at the glutamate (DL-(2-carboxypiperazine-4-yl)propyl-1-phosphonate (DL-CPP, 5.7)) and glycine site (7-Chloro-4-hydroxy-3-(3-phenoxy)-phenyl-2(H)quinolinone (L-701,324, 14.1), 3R(+)cis-4-methyl-pyrrollid-2-one (L-687,414, 15.1)) inhibited [3H]MK-801 binding in vivo to varying maximum levels (69%, 103% and 45%, respectively). NR2B subunit-selective compounds acting at the ifenprodil site inhibited [3H]MK-801 in vivo by a maximum of 52-72% and gave ED(50) values (mg/kg) of: (+/-)-(1S*, 2S*)-1-(4-hydroxyphenyl)-2-(4-hydroxy-4-phenylpiperidino)-1-propanol ((+/-)CP-101,606), 1.9; (+/-)-(3R, 4S)-3-[4-(4-fluorophenyl)-4-hydroxypiperidin-1-yl]chroman-4,7-diol ((+/-)CP-283,097), 1.8; (+/-)-(R*, S*)-alpha-(4-hydroxyphenyl)-beta-methyl-4-(phenylmethyl)-1-piperidine propanol ((+/-)Ro 25-6981), 1.0; ifenprodil, 6.0. The glycine site agonist D-serine stimulated binding to 151% of control with an ED(50) of 1.7 mg/kg. Results show that [3H]MK-801 binding in vivo may be used to measure receptor occupancy of ligands acting not only within the ion channel but also at modulatory sites on the NMDA receptor complex.     

Effect of beraprost sodium on peripheral circulation insufficiency in rats and rabbits

Beraprost sodium (sodium (+/-)-(1R*,2R*,3aS*,8bS*)-2,3,3a,8b-tetrahydro-2- hydroxy-1-[(E)-(3S*)-3-hydroxy-4-methyl-1-octen-6-ynyl]-1H- cyclopenta[b]benzofuran-5-butyrate, TRK-100) is a chemically and biologically stable epoprostenol analogue which possesses both potent antiplatelet and peripheral vasodilating actions. Its effect on obstruction of the peripheral artery was studied in three different models: 1. acute thrombosis induced by electrical-stimulation of the femoral artery in rabbits, 2. occlusion induced by intra-arterial injection of sodium laurate in rats and 3. tail gangrene induced by subcutaneous injections of both ergotamine and epinephrine in rats. Oral administration of beraprost sodium resulted in suppression of thrombus formation in the acute thrombosis model, marked improvement of macroscopic and histological observations in the laurate-occlusion model and inhibition of tail gangrene extension. In contrast, ticlopidine improved thrombus formation in the acute thrombosis model and slightly improved histological observation in the laurate-occlusion model, but not in the tail gangrene model. Cilostazol suppressed lesions in the acute thrombosis model, but not in the tail gangrene model. These findings suggest that beraprost sodium may be very useful clinically for the therapy of peripheral circulation insufficiency diseases such as Buerger's disease and Raynaud's disease.     

KT5926, a potent and selective inhibitor of myosin light chain kinase

KT5926, (8R*,9S*,11S*)-(-)-9-hydroxy-9-methoxycarbonyl-8-methyl-14-n-propoxy-2,3 ,9, 10-tetrahydro-8,11-epoxy, 1H,8H, 11H-2,7b,11a-triazadibenzo[a,g]cycloocta[cde] trinden-1-one, was found to be a potent and selective inhibitor of myosin light chain kinase. The compound inhibited both Ca2+/calmodulin-dependent and -independent smooth muscle myosin light chain kinases to a similar extent. The inhibition was not affected by the concentration of calmodulin. Kinetic analyses showed that the mode of inhibition was of the competitive type with respect to ATP (Ki, 18 nM) and of the noncompetitive type with respect to myosin light chain (Ki, 12 nM). These results indicated that KT5926 directly interacted with the enzyme at the catalytic site. KT5926 also inhibited other protein kinases, but with relatively high Ki values; the values for protein kinase C, cAMP-dependent protein kinase, and cGMP-dependent protein kinase were 723, 1200, and 158 nM, respectively. Ca2(+)-ATPase, Na+/K(+)-ATPase, hexokinase, and 5'-nucleotidase were not inhibited by KT5926 at less than 10 microM. The effect of KT5926 on serotonin secretion and protein phosphorylation induced by platelet-activating factor or phorbol ester was examined in rabbit platelets. KT5926 inhibited the phosphorylation of a 20-kDa protein but had no effect on the phosphorylation of a 40-kDa protein, thereby indicating that the compound exerts its selective inhibition of myosin light chain kinase in intact cells. The compound inhibited serotonin secretion induced by platelet-activating factor, but its potency was significantly less than that of K-252a, (8R*,9S*,11S*)-(-)-9-hydroxy-9-methoxycarbonyl-8-methyl-2,3,9, 10-tetrahydro-8,11-epoxy-1H,8H,11H-2,7b, 11a-triazadibenzo[a,g]cycloocta [cde]trinden-1-one, which inhibited the phosphorylation of both the 20-kDa protein and the 40-kDa protein. Phorbol ester-induced secretion was not suppressed by KT5926. These results provide the evidence that both the 20-kDa protein phosphorylation by myosin light chain kinase and the 40-kDa protein phosphorylation by protein kinase C substantially contribute to the secretion response in platelets.     

Sesquiterpene lactones from Inula hookeri

Four new sesquiterpene lactones, (1 S,5 R,6 S,7 S,8 R,9 R,10 S,11 S)-6-acetoxy-9-hydroxy-4-oxo-pseudoguai-2(3)-en-12,8-olide, (1 S,2 R,5 R,6 S,7 R,8 S,10 R)-6-acetoxy-2-ethoxy-4-oxo-pseudoguai-11(13)-en-12,8-olide, (1 S,2 R,5 R,6 S,7 R,8 S,10 R)-6-acetoxy-2-hydroxy-4-oxo-pseudoguai-11(13)-en-12,8-olide, and 14-acetoxy-1 β,5 α,7 αH-4 β-hydroxy-guai-9(10),11(13)-dien-12,8 α-olide, along with 26 known sesquiterpene lactones, were isolated from the whole plants of Inula hookeri C. B. Clarke. Their structures were established based on spectroscopic methods including HRESIMS, 1D and 2D NMR, and CD techniques. All compounds were evaluated for their cytotoxic activities against HepG2, HeLa, PC-3, and MGC-803 cell lines by CCK-8 assay. Some of the isolates, especiallly pseudoguaianolides and guaianolides, exhibited significant cytotoxicities against these four examined cell lines.     

6-hydroxy-4-en-3-one sterols from the marine sponge Iotrochoto birotulata

Five sterols with a nucleus skeleton of 6-hydroxy-4-en-3-one, namely cholesta-6beta-hydroxy-4-en-3-one (1), ergosta-6beta-hydroxy-4,24(28)-dien-3-one (2), ergosta-6alpha-hydroxy-4,24(28)-dien-3-one (3), ergosta-6alpha-hydroxy-4,22-E-dien-3-one (4), and ergosta-28-methyl-6beta-hydroxy-4,24(28)-dien-3-one (5) have been isolated from the marine sponge Iotrochoto birotulata, collected from the southern China sea. Sterols 2-4 are new compounds, and 1 has been isolated from marine organisms for the first time. The structures have been elucidated on the basis of extensive spectroscopic and chemical properties.     

Isolation, synthesis, and biological activity of five metabolites of danazol.

Metabolites of danazol (17 alpha-pregna-2,4-dien-20-yno[2,3-d]isoxazol-17-ol), an orally effective pituitary gonadotropin inhibitory agent devoid of estrogenic and progestational activites, were isolated from urine of a female subject who had taken danzol orally at a dose of 800 mg/day for 7 days, The metabolites isolated were 17-hydroxy-17alpha-pregn-4-en-20-yn-3-one (11), 17-hydroxy-2alpha-(hydroxymethyl)-17alpha-pregn-4-3n-20-yn-3-one (5), 17-hydroxy-2-(hydroxymethyl)-17alpha-pregna-1,4-dien-20-yn-3-one(7), 6beta,17-dihydroxy-2alpha-(hydroxymethyl)-17alphapregn-4-en-20-yn-3-one(8), and 6beta, 17-dihydroxy-2(hydroxymethyl)-17alphapregna-1,4-dien-20yn-3-one(10). None of these metabolites exhibited pituitary inhibiting activity comparable to danazol.     

脚骨脆的化学成分研究

目的研究脚骨脆小枝和叶的化学成分。方法采用乙醇提取,提取物经萃取后以硅胶、凝胶和MCI等柱色谱法及高效液相色谱法进行分离纯化,采用波谱法进行结构鉴定。结果从该植物共分离得到8个化合物,其结构鉴定为:(6R,7E,9R)-9-hydroxymegastigm-4,7-dien-3-one,(6S,7E)-6-hydroxy-4,7-megastig-madiene-3,9-dione,(3S,5R,6S,7E)-5,6-epoxy-3-hydroxymegastigm-7-en-9-one,(6E,9S)-9-hydroxymegastigm-4,6-dien-3-one,caseamembrin A,casearlucin B,β-谷甾醇和胡萝卜苷。结论前6种化合物为首次从该植物中分离得到。     

海洋来源真菌Hypocrea virens的次级代谢产物研究

目的研究海洋来源真菌Hypocrea virens发酵液的化学成分。方法采用硅胶柱色谱、Sepha-dex LH-20凝胶柱色谱、开放ODS柱色谱以及HPLC等方法进行分离纯化,通过理化性质和波谱数据鉴定化合物的结构。结果分离得到10个化合物,分别鉴定为bisdethiobis-(methylthio)glio-toxin(1)、胶霉毒素(gliotoxin,2)、5-羟基-3-羟甲基-2-甲基-7-甲氧基色原酮(5-hydroxy-3-hydroxymethyl-2-methyl-7-methoxychromone,3)、6-甲基苯-1,2,4-三醇(6-methyl-benzene-1,2,4-triol,4)、3β-羟基-胆甾-5-烯(3β-hydroxy-cholesta-5-ene,5)、3-异丁基-8-羟基吡咯并哌嗪-2,5-二酮(3-isobutyl-8-hydroxypyrrolopiperazine-2,5-dione,6)、3-苄基哌嗪-2,5-二酮(3-benzylpiperazine-2,5-dione,7)、3-苄基-8-羟基吡咯并哌嗪-2,5-二酮(3-benzyl-8-hydroxypyrrolopiper-azine-2,5-dione,8)、3S*,4R*-二羟基-3-甲基戊烷-2-酮(3S*,4R*-dihydroxy-3-methylpentan-2-one,9)、3R*,4R*-二羟基-3-甲基戊烷-2-酮(3R*,4R*-dihydroxy-3-methylpentan-2-one,10)。结论化合物1、3、4、8～10均为首次从Hypocrea属真菌中分离得到,化合物5为首次从真菌Hypocrea virens中分离得到。     

Norsesquiterpenoid glucosides and a rhamnoside of pyrrolizidine alkaloid from Tephroseris kirilowii

Four new glycosylated compounds have been isolated from the whole plant of Tephroseris kirilowii, including (-)-(1R,5R,6S,7R,8S)-8-O-beta-D-glucopyranosyloxy-7-hydroxy-6-(2-hydroxypropan-2-yl)-9-methylenebicyclo[4.3.0]non-3-one (tephroside A, 1), (-)-(1R,5R,6R,8R)-6-(2-O-beta-D-glucopyranosyloxypropan-2-yl)-8-hydroxy-9-methylenebicyclo[4.3.0]non-3-one (tephroside B, 2), thesinine-4'-O-alpha-L-rhamnoside (3), and p-coumaric acid 4-O-alpha-L-rhamnoside (4), together with the known roseoside. The structures of the new compounds were established by means of spectroscopic analysis.     

Studies on the antiplatelet effect of the stable epoprostenol analogue beraprost sodium and its mechanism of action in rats

Baraprost sodium (sodium (+/-)-(1R*,2R*,3aS*,8bS*)-2,3,3a.8b- tetrahydro-2-hydroxy-1-[(E)-(3S*)-3-hydroxy-4-methyl-1-octen-6- 1H-cyclopenta[b]benzo-furan-5-butyrate, TRK-100) is a novel stable epoprostenol (prostaglandin I2, PGI2) analogue having antiplatelet and vasodilating actions. Its effect on platelet aggregation in whole blood ex vivo and platelet suspension in vitro, formation of cyclic AMP(cAMP), production of malondialdehyde(MDA), and 45Ca++-influx into platelets were studied in rats. Oral administration of TRK-100 (0.3-1 mg/kg) showed a dose-dependent inhibition of platelet aggregation induced by ADP and collagen in whole blood and also inhibited in vitro thrombin-induced aggregation of platelet suspension in the presence or absence of external Ca++. Oral TRK-100 (0.3-3 mg/kg) dose-dependently increased plasma cAMP levels and this action was confirmed in vitro with platelet rich plasma in the presence or absence of theophylline. 45Ca++-influx into platelets stimulated by thrombin was dose-dependently inhibited by TRK-100 (3-100 nmol/l). TRK-100 (3-100 nmol/l) also suppressed MDA production induced by thrombin in platelet suspension but not that induced by arachidonic acid. From these results, TRK-100 which is orally active was suggested to exert its antiplatelet action through the increase of cAMP in platelets by activation of adenylate cyclase, concomitantly followed by the inhibition of Ca++-influx and thromboxane A2 formation.     

Effects of the natural and unnatural isomers and degradation products of enprostil on gastric acid secretion and gastrointestinal motility in the rat

The gastric antisecretory and gastrointestinal (GI) motility activity of the natural and unnatural allenic isomers and degradation products of enprostil (methyl(+/-)-7-[(1R*,2R*,3R*)-3-hydroxy-2-[(E)-(3R*)-3-hydroxy-4-phenoxy - 1-butenyl]-5-oxocyclopentyl]-4,5-heptadienoate, RS-84135-004) were studied in the rat. The natural R-allenic isomer of enprostil was the most potent antisecretory compound. The 8-iso-enprostil, enprostil free acid, and the 5-acetylene isomer had somewhat less activity while the other compounds were relatively inactive. The natural and unnatural allenic isomers increased intestinal dye transit with the same rank potency as the gastric antisecretory activity. Enprostil, 8-iso-enprostil, prostaglandin A-enprostil and enprostil free acid, all increased intestinal dye transit.     

杜仲叶中倍半萜及降碳倍半萜的分离与鉴定

目的 研究植物杜仲(Eucommia ulmoides Oliver)叶中的化学成分.方法 综合运用硅胶柱色谱、反相硅胶柱色谱和Sephadex LH-20凝胶柱色谱以及制备型高效液相色谱等方法进行系统分离,根据化合物的理化性质及其波谱数据确定化合物的结构.结果 从杜仲叶80％(体积分数)乙醇提取物中分离得到了12个倍...     

Characterization of beta-adrenoceptor subtypes in the ferret urinary bladder in vitro and in vivo

In the present study, the beta-adrenoceptor subtypes distributed in the detrusor of the ferret were investigated in functional experiments in vitro and in vivo using a variety of beta-adrenoceptor agonists and antagonists. All the beta-adrenoceptor agonists tested relaxed the isolated detrusor strip, the rank order of potency being (+/-)-(R*, R*)-[4-[2-[[2-(3-chlorophenyl)-2-hydroxyethyl]-amino]propyl]phenoxy]- acetic acid sodium (BRL 37344A)>(+/-)-4-(3-t-butylamino-2-hydroxypropoxy) benzimidazol-2-one (CGP-12177A), isoprenaline and (R, R)-5-[2-[[2-(3-chlorophenyl)-2-hydroxyethylamino]propyl]-1, 3-benzodioxole-2,2-dicarboxylate (CL 316,243)>dobutamine and procaterol. In antagonist experiment, 3-(2-allylphenoxy)-1-[(1S)-1,2, 3,4-tetrahydro-naphth-1-ylamino]-(2S)-2-propanol hydrochloride (SR 58894A), but neither 2-hydroxy-5(2-((2-hydroxy-3-(4-((1-methyl-4-trifluoromethyl)1H-imidaz ole-2-yl)-phenoxy)propyl)amino)ethoxy)-benzamide monomethane sulphonate (CGP-20712A) nor erythro-(+/-)-1-(7-methylindan-4-yloxy)-3-isopropylaminob utan-2-ol hydrochloride (ICI-118,551), caused a rightward shift of the concentration-relaxation curve for isoprenaline. In in vivo experiments, isoprenaline and CL 316,243 each reduced bladder pressure in a dose-dependent manner. CL 316,243 was the only drug that did not produce any significant influences on blood pressure and heart rate at doses that reduced bladder pressure. The present functional study provides the first evidence that relaxation of the ferret detrusor by beta-adrenoceptor activation is mediated mainly via the beta(3)-adrenoceptor, as in the human detrusor.