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Objective To assess the effects of meal timing on the pharmacokinetics and pharmacodynamics of the dipeptidyl peptidase IV (DPP-4) inhibitor vildagliptin in Japanese patients with Type 2 diabetes. Methods In this open-label, single-center crossover study, 12 Japanese patients with Type 2 diabetes were randomized to twice-daily vildagliptin 50 mg, administered 30 min before or immediately before breakfast and dinner for 7 days. After a 7-day washout period, patients received the other regimen. Blood samples were collected for the determination of vildagliptin, DPP-4, glucagon-like peptide-1 (GLP-1) and glucose. Results Vildagliptin absorption appeared slower when administered 30 min before rather than immediately before meals (tmax absolute range: 1.00 - 2.00 h vs. 0.33 - 1.58 h). Vildagliptin Cmax and AUC0-8 h were essentially the same irrespective of meal timing (geometric mean ratio: Cmax 1.08 (90% CI; 0.92 - 1.26); AUC0-8 h 0.97 (90% CI; 0.91 - 1.05)). Meal timing did not affect pharmacodynamics; complete DPP-4 inhibition (> 90%) was sustained for 8 h post-dose, and plasma active glucagon-like peptide-1 levels increased 2 - 3-fold from baseline. Fasting plasma glucose (FPG) and postprandial plasma glucose (PPPG) reductions from baseline did not differ significantly with meal timing (30 min before vs. immediately before: FPG, -8.9 vs. -5.8 mg/dl; adjusted AUE0-4 h, -67.0 vs. -51.0 mg×h/dl). Vildagliptin was well tolerated. Conclusions Dosing 30 min or immediately before meals did not affect vildagliptin pharmacokinetics or pharmacodynamics in Japanese patients with Type 2 diabetes.

Aliskiren is a novel orally active renin inhibitor for the treatment of hypertension. This study evaluated the antihypertensive efficacy, safety and tolerability of aliskiren in Japanese patients with hypertension. Forty hundred and fifty-five Japanese men and women with a mean sitting diastolic blood pressure of 95-110 mmHg were randomized to receive once-daily double-blind treatment for 8 weeks with aliskiren 75, 150 or 300 mg or placebo. Aliskiren produced significant, dose-dependent reductions in mean sitting diastolic blood pressure (p0.0005 vs. placebo for each dose) and mean sitting systolic blood pressure (p0.001 vs. placebo for each dose). The placebo-corrected reductions in mean sitting systolic/diastolic blood pressure were 5.7/4.0, 5.9/4.5 and 11.2/7.5 mmHg in the aliskiren 75, 150 and 300 mg groups, respectively. After 8 weeks' treatment, 27.8%, 47.8%, 48.2% and 63.7% of patients in the placebo and aliskiren 75, 150 and 300 mg groups, respectively, achieved a successful treatment response (diastolic blood pressure90 mmHg and/or reduced byor =10 mmHg from baseline; p0.005 vs. placebo for each dose). Aliskiren treatment was well tolerated, with the incidence of adverse events reported in the active treatment groups (53-55%) being similar to that in the placebo group (50%). This study, which is the first to assess the antihypertensive efficacy and safety of aliskiren in Japanese patients with hypertension, demonstrates that the once-daily oral renin inhibitor aliskiren provides significant, dose-dependent reductions in blood pressure with placebo-like tolerability.

We were interested in RCS (rabbit aorta contracting substance) and SRS-A (slow reacting substance of anaphylaxis) and their involvement in human bronchial asthma. When we started our anti-asthmatic drug research in the 1970's. We synthesized a lot of chemical compounds and eventually discovered that AA-861 inhibited the generation of SRS-A from the lung tissue of actively sensitized guinea pigs. AA-861 was found to be a potent 5-lipoxygenase inhibitor. This compound reduced experimental allergic asthma in guinea pigs, but it is easily metabolized in the body. More recently, we found a novel compound, AA-2414 (seratrodast), which is not metabolized in the body. AA-2414 proved to be not a 5-lipoxygenase inhibitor, but a thromboxane A2 (TXA2) receptor antagonist. Seratrodast is the first receptor antagonist that is being developed as an anti-asthmatic drug. Seratrodast inhibits both immediate-, late asthmatic responses in guinea pigs, and also reduces airway hyperresponsiveness in dogs. The anti-asthmatic action of seratrodast in animal models indicates that the drug should be of use in the treatment of human asthmatics. In clinical studies, seratrodast showed a marked effect to improve clinical parameters in bronchial asthma. It is also reported that seratrodast is free from harmful aftereffects. Clinical trials are under way in the US.

Enantiomers of four potent nonprostanoid thromboxane A2 (TXA2) receptor antagonists, (+/-)-7-(4-fluorophenyl)-7-(2-hydroxyphenyl)heptanoic acids (1-4), were synthesized stereoselectively by direct ortho-alkylation of phenols under modified Mitsunobu conditions. The reaction of 5 eq of phenols (6a-c) with 1 eq of (S)- or (R)-methyl 7-(4-fluorophenyl)-7-hydroxyheptanoate ((S)- or (R)-7) afforded ortho-alkylated phenol derivatives (6a-c) enantioselectively in 33 to 42% chemical yield and 90 to 93% ee. In these compounds, the (R)-enantiomers (1-4) exhibited potent TXA2 receptor antagonistic activity and the (S)-isomer (3) was much less active. In particular, compound (R)-3 strongly inhibited U-46619-induced human platelet aggregation (IC50 = 48 nM), and also showed a very potent inhibitory effect with a minimum effective dose (MED) of 0.3 mg/kg (p.o.) on U-46619-induced bronchoconstriction in guinea pigs.

A novel series of (3-pyridylmethyl)benzoquinone derivatives was molecular designed and synthesized for the dual purpose of inhibiting thromboxane A2 and leukotriene biosynthesis enzymes and scavenging active oxygen species (AOS). They were evaluated for inhibition of TXA2 synthase, inhibition of 5-lipoxygenase, and for their scavenging activity of AOS using the thiobarbituric acid method. 2,3,5-Trimethyl-6-(3-pyridylmethyl)-1,4-benzoquinone (24, CV-6504) was the most promising derivative since it showed efficient AOS scavenging activity (inhibition of lipid peroxidation in rat brain homogenates: IC50 = 1.8 x 10(-6) M) as well as potent, specific, and well-balanced inhibitory effects on both enzymes (inhibitory effect on TXA2 synthase in human blood, IC50 = 3.3 x 10(-7) M; inhibitory effect on 5-lipoxygenase in human blood, IC50 = 3.6 x 10(-7) M). In adriamycin-induced proteinuria in a rat model, compound 24 at 10 mg/kg per day (po) suppressed proteinuria by more than 50%. The proteinuria, however, could not be reduced by single administration of an inhibitor specific for thromboxane A2 synthase [(E)-7-phenyl-7-(3-pyridyl)-6-heptenoic acid (2, CV-4151)] or for 5-lipoxygenase [2-(12-hydroxy-5,10-dodecadiynyl)-3,5,6-trimethyl-1,4-benzoquinone (1, AA-861)]. The proteinuria was also not reduced by administration of an AOS scavenger, 2-O-octadecylascorbic acid (4, CV-3611). Triple function compounds such as compound 24 that specifically inhibit both enzymes as well as scavenge AOS possess a variety of pharmacologically beneficial effects.

ortho-Substituted phenol derivatives with high optical purity have been obtained directly by Mitsunobu reaction between an appropriate phenol and an optically active benzyl alcohol. In this reaction, the chemical yield was well balanced with the optical purity of the ortho-substituted compound when 5 equiv. of phenol was allowed to react with 1 equiv. of alcohol in a solvent such as dichloroethane or toluene. In addition, it was confirmed by an X-ray analysis of the product that stereochemical inversion of the asymmetric centre took place in this reaction, as well as the usual Mitsunobu reaction. This reaction is useful in the preparation of optically active phenol derivatives possessing a diarylmethane moiety.

Enantiomers of four potent nonprostanoid thromboxane A2 (TXA2) receptor antagonists, (+/-)-7-(4-fluorophenyl)-7-(2-hydroxyphenyl)heptanoic acids (1-4), were synthesized stereoselectively by direct ortho-alkylation of phenols under modified Mitsunobu conditions. The reaction of 5 eq of phenols (6a-c) with 1 eq of (S)- or (R)-methyl 7-(4-fluorophenyl)-7-hydroxyheptanoate ((S)- or (R)-7) afforded ortho-alkylated phenol derivatives (6a-c) enantioselectively in 33 to 42% chemical yield and 90 to 93% ee. In these compounds, the (R)-enantiomers (1-4) exhibited potent TXA2 receptor antagonistic activity and the (S)-isomer (3) was much less active. In particular, compound (R)-3 strongly inhibited U-46619-induced human platelet aggregation (IC50 = 48 nM), and also showed a very potent inhibitory effect with a minimum effective dose (MED) of 0.3 mg/kg (p.o.) on U-46619-induced bronchoconstriction in guinea pigs.

Aim: To confirm the efficacy of vildagliptin in patients with type 2 diabetes (T2D) by testing the hypothesis that glycosylated haemoglobin (HbA1c) reduction with vildagliptin is superior to that with voglibose after 12 weeks of treatment. Methods: In this 12-week, randomized, double-blind, active-controlled, parallel-group study, the efficacy and safety of vildagliptin (50 mg bid, n = 188) was compared with that of voglibose (0.2 mg tid, n = 192) in patients with T2D who were inadequately controlled with diet and exercise. Results: The characteristics of two groups were well matched at baseline. The mean age, body mass index (BMI) and HbA1c were 59.1 years, 24.9 kg/m2 and 7.6%, respectively. At baseline, fasting plasma glucose (FPG) and 2-h postprandial glucose (PPG) were 9.01 mmol/l (162.2 mg/dl) and 13.57 mmol/l (244.3 mg/dl), respectively. The adjusted mean change in HbA1c from baseline to endpoint was −0.95 ± 0.04% in the vildagliptin-treated patients and −0.38 ± 0.04% in those receiving voglibose (between-group change = 0.57 ± 0.06%, 95% confidence interval (CI) (−0.68 to −0.46%), p < 0.001), showing that vildagliptin was superior to voglibose. Endpoint HbA1c ≤ 6.5% was achieved in 51% vildagliptin-treated patients compared with 24% patients who were on voglibose (p < 0.001). Vildagliptin also exhibited significantly (p < 0.001) greater reduction compared with voglibose in both FPG [1.34 vs. 0.43 mmol/l (24.1 vs. 7.8 mg/dl)] and 2-h PPG [2.86 vs. 1.1 mmol/l (51.5 vs. 19.8 mg/dl)]. Overall adverse events (AEs) were lower in the vildagliptin-treated patients compared with that in the voglibose-treated patients (61.2 vs. 71.4%), with no incidence of hypoglycaemia and serious adverse events with vildagliptin. Gastrointestinal AEs were significantly lower with vildagliptin compared with that of the voglibose (18.6 vs. 32.8%; p = 0.002). Conclusions: Vildagliptin (50 mg bid) showed superior efficacy and better tolerability compared with voglibose in Japanese patients with T2D.

We were interested in RCS (rabbit aorta contracting substance) and SRS-A (slow reacting substance of anaphylaxis) and their involvement in human bronchial asthma. When we started our anti-asthmatic drug research in the 1970's. We synthesized a lot of chemical compounds and eventually discovered that AA-861 inhibited the generation of SRS-A from the lung tissue of actively sensitized guinea pigs. AA-861 was found to be a potent 5-lipoxygenase inhibitor. This compound reduced experimental allergic asthma in guinea pigs, but it is easily metabolized in the body. More recently, we found a novel compound, AA-2414 (seratrodast), which is not metabolized in the body. AA-2414 proved to be not a 5-lipoxygenase inhibitor, but a thromboxane A2 (TXA2) receptor antagonist. Seratrodast is the first receptor antagonist that is being developed as an anti-asthmatic drug. Seratrodast inhibits both immediate-, late asthmatic responses in guinea pigs, and also reduces airway hyperresponsiveness in dogs. The anti-asthmatic action of seratrodast in animal models indicates that the drug should be of use in the treatment of human asthmatics. In clinical studies, seratrodast showed a marked effect to improve clinical parameters in bronchial asthma. It is also reported that seratrodast is free from harmful aftereffects. Clinical trials are under way in the US.

Inhibition of renin, the first rate-limiting enzyme in the renin-angiotensin system, has long been a therapeutic goal for treatment of hypertension. Aliskiren, the first in a new class of oral direct renin inhibitors, has been shown to reduce blood pressure (BP) in several short-term studies. In this 52-week, open-label, multicenter, parallel-group study, the long-term safety, tolerability, and efficacy of aliskiren-based therapy were assessed in Japanese patients (N=345) with mild-to-moderate essential hypertension. The study had two periods: (i) an 8-week, dose-titration period and (ii) a 44-week, fixed-dose period with an optional addition of a diuretic or a calcium channel blocker (CCB). Safety was assessed by monitoring all adverse events (AEs), serious AEs (SAEs), vital signs, laboratory parameters, ECGs, and physical examinations. Efficacy was assessed by trough mean sitting BP and responder rate. Aliskiren alone or in combination with a diuretic or a CCB was well tolerated. No deaths were reported during this study. Nine SAEs were reported, and for three of these, a possible relation to the study drug could not be excluded. The overall incidence of AEs was 85.2%, and most of these were mild-to-moderate events such as nasopharyngitis. The incidence of suspected study drug-related AEs was 25.3%. A clinically meaningful reduction of 17.6/12.8 mm Hg from baseline was achieved in the mean sitting BP at the end point with aliskiren, irrespective of the dose and additional treatments. The overall responder rate was 73.3% at the end point. In conclusion, this first long-term study in Japanese patients showed the safety and efficacy of aliskiren-based therapy in mild-to-moderate essential hypertension.

6-(10-Hydroxydecyl)-2, 3-dimethoxy-5-methyl-1, 4-benzoquinone (idebenone) has been found to have a membrane-stabilizing activity in studies using lysosomes. Using dimyristoyl L-α-phosphatidylcholine (DMPC) as a substrate, the effects of idebenone and related benzoquinones on phospholipid digestion by phospholipase A2 (PLA2) was investigated. Free myristic acid, released from DMPC upon PLA2 treatment, was anthrylmethylated with 9-anthryldiazomethane (ADAM) and determined by reversed-phase HPLC. Idebenone and a related benzoquinone, 2, 3-dimethoxy-5-methyl-6-(10-morpholinodecyl)-1, 4-benzoquinone hydrochloride (QS-10·Mor), inhibited the hydrolysis of the substrate with PLA2 in a dose-dependent manner. It is suggested that the effect of idebenone on PLA2, in addition to its antioxidant activity against lipid peroxidation, can be attributed to membrane-stabilizing activity.

In order to elucidate the mode of the thromboxane A2 (TXA2) receptor-ligand interaction at the molecular level, a model for the human TXA2 receptor, a member of the G protein-coupled receptor family with seven transmembrane segments, was constructed on the basis of its amino acid sequence, which was determined recently (Hirata, M.; et al. Nature 1991, 349, 617-620). First, we made a model for the human beta 2-adrenergic receptor using its amino acid sequence and the known helix arrangement of bacteriorhodopsin. Then, a TXA2 receptor model was constructed based on the beta 2 receptor model and was used to analyze the receptor-ligand interaction. The ligand-binding pocket of the TXA2 receptor includes a serine residue from segment V, an arginine residue from segment VII, and a large hydrophobic pocket between these two residues. These results are consistent with the known properties of TXA2 and TXA2 antagonists having a hydrogen-bonding group such as hydroxyl, a carboxyl group, and a hydrophobic moiety. This model should be helpful for rational design of potent TXA2 antagonists.

A novel series of (3-pyridylmethyl)benzoquinone derivatives was molecular designed and synthesized for the dual purpose of inhibiting thromboxane A2 and leukotriene biosynthesis enzymes and scavenging active oxygen species (AOS). They were evaluated for inhibition of TXA2 synthase, inhibition of 5-lipoxygenase, and for their scavenging activity of AOS using the thiobarbituric acid method. 2,3,5-Trimethyl-6-(3-pyridylmethyl)-1,4-benzoquinone (24, CV-6504) was the most promising derivative since it showed efficient AOS scavenging activity (inhibition of lipid peroxidation in rat brain homogenates: IC50 = 1.8 x 10(-6) M) as well as potent, specific, and well-balanced inhibitory effects on both enzymes (inhibitory effect on TXA2 synthase in human blood, IC50 = 3.3 x 10(-7) M; inhibitory effect on 5-lipoxygenase in human blood, IC50 = 3.6 x 10(-7) M). In adriamycin-induced proteinuria in a rat model, compound 24 at 10 mg/kg per day (po) suppressed proteinuria by more than 50%. The proteinuria, however, could not be reduced by single administration of an inhibitor specific for thromboxane A2 synthase [(E)-7-phenyl-7-(3-pyridyl)-6-heptenoic acid (2, CV-4151)] or for 5-lipoxygenase [2-(12-hydroxy-5,10-dodecadiynyl)-3,5,6-trimethyl-1,4-benzoquinone (1, AA-861)]. The proteinuria was also not reduced by administration of an AOS scavenger, 2-O-octadecylascorbic acid (4, CV-3611). Triple function compounds such as compound 24 that specifically inhibit both enzymes as well as scavenge AOS possess a variety of pharmacologically beneficial effects.

ortho-Substituted phenol derivatives with high optical purity have been obtained directly by Mitsunobu reaction between an appropriate phenol and an optically active benzyl alcohol. In this reaction, the chemical yield was well balanced with the optical purity of the ortho-substituted compound when 5 equiv. of phenol was allowed to react with 1 equiv. of alcohol in a solvent such as dichloroethane or toluene. In addition, it was confirmed by an X-ray analysis of the product that stereochemical inversion of the asymmetric centre took place in this reaction, as well as the usual Mitsunobu reaction. This reaction is useful in the preparation of optically active phenol derivatives possessing a diarylmethane moiety.

Leukotrienes C4 (LTC4) and D4 (LTD4), major components of slow-reacting substances of anaphylaxis (SRS-A), caused dose-dependent contractions of rabbit coronary arteries in concentrations of 10−9 to 10−7 M and 10−10 to 10−7 M, respectively. The potency of LTC4 and LTD4, when compared with the concentration that elicits half of the contraction induced by 25 mM KCl, was 17 and 76 times, respectively, greater than that of histamine. In contrast, other blood vessels from rabbits were either unresponsive (renal artery and vein, mesenteric artery and thoracic aorta) or only weakly responsive (pulmonary artery and vein and portal vein) to both leukotrienes even at 10−7 M. The LTD4-induced coronary contraction was inhibited by FPL 55712 (10−7 and 10−6 M), a selective SRS-A inhibitor, in a dose-dependent manner, but not by diphenhydramine (10−7 M), a histamine H1-receptor blocker or by indomethacin (10−5 M), a prostaglandin synthetase inhibitor, suggesting that LTD4 has a direct effect on the coronary arteries. These results indicate that the leukotrienes may act as potent, selective coronary vasoconstrictors and that SRS-A responsive receptors exist in the rabbit coronary artery.

An immunoassay for thromboxane B2 was developed in which the hapten molecule was labeled with beta-galactosidase. The immunoprecipitate formed after competition between enzyme-labeled and unlabeled thromboxane B2 was subjected to a fluorometric assay of beta-galactosidase. Thromboxane B2 was detectable in the range of 0.1-30 pmol. Both enzyme immunoassay and radioimmunoassay showed essentially the same cross-reactivities with other prostaglandins and their metabolites when the same antibody was used. Known amounts of thromboxane B2 were added to human plasma, and the sample was applied to an octadecyl silica column. The extract was analyzed by enzyme immunoassay to examine the correlation between the added (x) and measured (y) thromboxane B2 (y = 1.09x + 11.07 pmol/ml, r = 0.99). A satisfactory correlation was observed between radioimmunoassay (x) and enzyme immunoassay (y) (y = 0.92x + 4.64 pmol/ml, r = 0.96). The validity of enzyme immunoassay was also confirmed by gas chromatography-mass spectrometry of a dimethylisopropylsilyl ether derivative of thromboxane B2 methyl ester. The method was applicable to the assay of thromboxane B2 produced from endogenous precursor during thrombin-induced aggregation of human platelets.

Inhibitory effects of 3-hydroperoxy-3-methyl-2-phenyl-3H-indole(HPI) on prostaglandin endoperoxide synthase(EC 1.14.99.1) and prostaglandin I 2 (PGI 2 ) synthetase were compared with those of 15-hydroperoxy-5,8,11,13-eicosatetraenoic acid, namely, 15-hydroperoxyarachidonic acid(15-HPAA) and tranylcypromine (TCP). Sheep seminal vesicle microsomes were used as a source of prostaglandin endoperoxide synthase and bovine aortic microsomes as that of PGI 2 synthetase. 15-HPAA and HPI inhibited PGI 2 synthetase with IC 50 s of 5 × 10 −7 and 3.5 × 10 −6 M, respectively, whereas neither compound had effect on prostaglandin endoperoxide synthase at the concentration inhibiting PGI 2 synthetase by 90%. TCP was a weak(IC 50 = 5 × 10 −4 M) PGI 2 synthetase inhibitor with low specificity.

A new series of omega-phenyl-omega-quinonylalkanoic acids and related compounds was synthesized. The compounds were tested for their inhibitory effects on U-44069-induced contraction of the rabbit aorta. (+/- )-7-(3,5,6-Trimethyl-1,4-benzoquinon-2-yl)-7-phenylheptanoic acid (4d) (AA-2414) with pA2 value of 8.28 was one of the most potent compounds. Compound 4d inhibited U-46619-induced contraction of the guinea pig lung (pA2 = 8.29) and U-44069-induced aggregation of the guinea pig platelet (IC50 = 3.5 x 10(-7) M). Compound 4d displaced the binding of [3H]U-46619 to guinea pig platelets (IC50 = 7.4 x 10(-9) M). Compound 4d also showed very potent inhibitory effects with an MED of 0.3 mg/kg (po) on U-46619-, LTD4-, PAF-, or IgG1-induced bronchoconstriction in guinea pigs. The enantiomers of 4d were prepared. The R-(+) isomer 8a was active in both in vitro and in vivo tests, but the S-(-) isomer 8b was much less active. We concluded that the antiasthmatic effects of 4d were based mainly on the TXA2 receptor antagonistic action. In addition, compound 4d showed potent inhibitory effects on PGD2-, PGF2 alpha-, and 11-epi-PGF2 alpha-induced contraction of the guinea pig tracheal strips. The diverse inhibitory effects might be expressed in terms of eicosanoid-antagonistic activity.

Thromboxane A2 synthase is a cytochrome P450-type enzyme and its interaction with imidazole or pyridinebased inhibitors could be studied by absolute and difference spectroscopy with the solubilized as well as the purified enzyme. Nitrogenous bases shift the 418-nm Soret absorption by 4–6 nm to the red and among them the best inhibitors of enzyme activity showed a stoichiometric binding to the enzyme. The structural and energetic prerequisites for such high binding affinities were primarily the liganding of the basic nitrogen to the hemin but also the attachment of a hydrophobic carboxylic side chain to the active site at an about 1 nm distance from the nitrogen. In addition, the side chain seemed to be oriented almost parallel to the plane of the heme. If this geometry was changed, a decrease in affinity was observed and if the ligand binding was sterically hindered, a spectral shift to a five-coordinated complex absorbing at 390 nm occured. This is best explained by the displacement of an endogenous oxygen ligand, presumably water, from the sixth coordination position of the heme. From these results it can be concluded that the inhibitors mimic the binding of prostaglandin H2 (PGH2) with its carboxylic group at the carboxyl side chain and the endoperoxide oxygen atom at C9 as previously reported. The methyl side chain of PGH2 does not seem to play a role in the formation of the enzyme-substrate complex.

As successive discoveries were made of thromboxane A2, prostacyclin, and the leukotrienes from 1975 to 1979, the physiological and pathological roles of the arachidonate cascade metabolites were clarified. With these discoveries as a turning point, novel concepts for designing new drugs which specifically control and manipulate the metabolites have rapidly grown and developed.Any new approach to treating and preventing cardio- and cerebro- vascular diseases requires urgent and careful evaluation. Recent research into thromboxane synthetase inhibitors (TXSI) and thromboxane receptor antagonists (TXRA) has focussed attention mainly on platelets and blood vessel walls, and the interaction between the two. Some TXSI and TXRA have been studied in a variety of in vitro systems and animal models, and are now in various stages of clinical evaluation.In the present review, TXSI, TXRA, and the structure-activity relationships are described together with the results of our experiments on this subjects.

The anti-asthmatic activity of AA-2414 [(±)-7-(3,5,6-trimethyl-1,4-benzoquinon-2-yl-7-phenylheptanoic acid)] has been studied in vivo and in vitro . Experimental allergic asthma was inhibited by orally administered AA-2414 in a dose-dependent manner. AA-2414, 0.08∼1.25 mg/kg (p.o.), inhibited the bronchoconstriction in guinea pigs induced by a prostaglandin endoperoxide analogue (U-46619), leukotriene D 4 (LTD 4 ), and platelet activitating factor (PAF) with a long duration of action. The compound did not inhibit histamine-induced bronchoconstriction. AA-2414 reduced the induction of pulmonary inflation caused by LTD 4 aerosol inhalation. AA-2414 competitively inhibited the contractile response to U-46619 in guinea pig tracheal and parenchymal strips and dog saphenous vein strips with pA2 values of 7.69, 8.29 and 6.79, respectively. Furthermore, the contractile responses of guinea pig tracheal strip to PGD 2 , 9 a , 11s-PGF 2 and PGF 2 a were inhibited with pA2 values of 7.20, 7.79 and 5.71, respectively. These results suggest that AA-2414, a quinone derivative, is a novel, potent and orally active antagonist of a variety of spasmogenic prostanoids.

Several linear and branched all-trans-multiprenylacetic acids were synthesised, and introduced to the 6 position of the sugar moiety of muramyl dipeptide and its analog, via an amino acid as a linking unit. Compared with the saturated stearoyl derivative, all the compounds having a multiprenylacetyl group exhibited more potent adjuvant activity on the induction of delayed-type hypersensitivity to N-acetyl-3-(4-arsonophenylazo)-L-tyrosine. The derivatives with larger branched side chains tended to have increased activity.

高圧水銀ランプ照射のもとにテストステロンアセテートと12種のオレフィンとの反応を行ない,シクロブタノ[1',2':4,5]アンドロスタン-3-オン誘導体を合成した。本反応では常に4α-cis付加体が得られる。しかし,オレフィンとしてビあるいはアクリロニトリルを用いた場合には通常の付加体(4α-cis体)のほかに4α-trans付加体が生成した。これらの4α-体は定量的に熱または塩基性触媒のもとで容易に4β-cis体に異性化した。表1にtrans体およびcis体の特性を示す分光学的データを記載し,表3にそれらの興味ある知見をまとめた。4α-trans体に1molの臭素を作用させると4α-モノブロモシクロブタノケトステロイドが得られる。一方,4α-cisおよび4β-cis体に同様の反応を行なうと2β-および2α-プロム体がそれぞれ得られる。このように臭素化による方向性が異なることは興味がある。幼若去勢ラットにテストステロンプロピオネートを投与し,その精のう,腹部および背部前立腺の重量の変化を指標として,抗男性ホルモン作用を調べた結果,N-アリルアセトアミドおよびN,N'-ジメチルアリルアミンの付加体は抗男性ホルモン作用を示した。

As successive discoveries were made of thromboxane A2, prostacyclin, and the leukotrienes from 1975 to 1979, the physiological and pathological roles of the arachidonate cascade metabolites were clarified. With these discoveries as a turning point, novel concepts for designing new drugs which specifically control and manipulate the metabolites have rapidly grown and developed.Any new approach to treating and preventing cardio- and cerebro- vascular diseases requires urgent and careful evaluation. Recent research into thromboxane synthetase inhibitors (TXSI) and thromboxane receptor antagonists (TXRA) has focussed attention mainly on platelets and blood vessel walls, and the interaction between the two. Some TXSI and TXRA have been studied in a variety of in vitro systems and animal models, and are now in various stages of clinical evaluation.In the present review, TXSI, TXRA, and the structure-activity relationships are described together with the results of our experiments on this subjects.

(E)-7-Phenyl-7-(3-pyridyl)-6-heptenoic acid (CV-4151) inhibited horse platelet crosomal thromboxane (TX) A2synthetase with an IC50 of 2.6 × 10−8 M, but even at a high concentration of 10−4 M it had little effect on cyclooxygenase, PGI2 synthetase and 5-lipoxygenase in vitro enzymatic assays. CV-4IB1 did not affect PGI2 release from rat and rabbit aortic tissues in in vitro (10 M) and ex vivo (10 and 100 mg/kg, p.o.) experiments, whereas aspirin (10−4M or 10 and 100 mg/kg, p.o.) markedly inhibited PGI2 release in these preparations. When given orally to rats and dogs, CV-4151 markedly inhibited blood TXA2 synthetase activity: the ID50 values (mg/kg, 2 hr later) were 0.05 in rats and 0.17 in dogs. The inhibitory effects at an oral dose of 1 mg/kg lasted more than 24 hr in both species; the inhibition was 41% in rats and 32 % in dogs 24 hr after the administration. When injected i.v. to rats and dogs, CV-4151 caused inhibitory effects on TXA2 synthetase equipotent to those observed with the oral administration. In both species, CV-4151 given orally increased concentration of serum immunoreactive 6-keto-PGF1 concomitant with a decrease of serum TXB2 concentration. CV-415 was equipotent to OKY-1580 (IC50: 2.3 × 10−8 M), a well documented TXA2 synthetase inhibitor, in an in vitro TXA2 synthetase assay. However, CV-4151, given orally or i.v. to rats and dogs, was much more potent and longer acting in inhibition of blood TXA2 production than OKY-1580. Dazoxiben was less potent than these compounds in vitro. In rats, serial oral administration of CV-4151 (10 mg/kg) once daily for 14 days produced a constant and marked reduction of serum TXB2 concentration with concomitant increase of serum immunoreactive 6-Keto-PGF1α concentration. No rebound phenomenon in inhibition of TXA2 synthetase was observed after the dosing was stopped. These findings indicate that CV-4151 is a potent and long acting selective inhibitor of TXA2 synthetase and may reorient the metabolism of PG endoperoxides to PGI2.

A novel series of 2-O-alkylascorbic acids (5a-u) was synthesized, and their scavenging activities against active oxygen species as well as their suppressive effects on the arrhythmias in rat heart ischemia-reperfusion models were evaluated. Some 2-O-alkylascorbic acids (5e-1) exhibited potent inhibiting activities against lipid peroxidation in rat brain homogenates and in alleviating effects in the ischemia-reperfusion models. Studies on the structure-activity relationship demonstrated that a free 3-enolic hydroxyl group and the longer alkyl chains substituted on the 2-hydroxyl group of ascorbic acid were beneficial for the biological and pharmacological activities. 2-O-Octadecylascorbic acid (5k, CV-3611), one of the most potent and promising compounds, markedly inhibited lipid peroxidation (IC50 = 4.3 X 10(-6) M) and alleviated myocardial lesions induced by ischemia-reperfusion at an oral dose of 1 mg/kg in rats.

A novel series of omega-pyridylalkenoic acids has been prepared by applying the Wittig reaction. Modifications were made in the omega-aryl moiety, the alkylene chain length, the alpha-methylene group adjacent to the carbonyl group, and the carboxyl group of the molecule. The compounds were tested as inhibitors of thromboxane synthetase in an in vitro assay and in ex vivo experiments with the rat. Most members of this new class of thromboxane synthetase inhibitors (TXSI) showed good activity in both assay systems. (E)-7-Phenyl-7-(3-pyridyl)-6-heptenoic acid (9c; CV-4151) was one of the most potent compounds in in vitro enzyme inhibition (IC50 = 2.6 X 10(-8) M) and, when orally administered, the most potent and long acting in the inhibition of blood thromboxane A2 production in the rat. New conceptual models I-III for the enzyme-substrate (prostaglandin H2, PGH2) and the enzyme-TXSI interactions are proposed for understanding the molecular design and structure-activity relations.

Ausgehend von dem aus der Vorstufe (I) dargestellten Alkohol (IIa) werden durch verschiedene Folgereaktionen bzw. deren Wiederholung die Analogen (IIb) und (IIc) dargestellt; die aus (IIa)-(IIc) erhaltlichen Bromderivate (IId)-(IIf) werden in die Ester (IV) und (V) und weiter in die Sauren (VIa)-(VIc) bzw. (VIIa)-(VIIc) ubergefuhrt.

Endothelin (ET) caused transient and sustained elevations of cytosolic free Ca2+ concentrations ({Ca2+}i) in cultured rat and rabbit vascular smooth muscle cells (VSMC). Specific platelet activating factor (PAF) antagonists (CV-6209 and WEB-2086) and arachidonic acid (AA) cascade blockers (chlorpromazine, indomethacin, CV-4151 and AA-2414) potently inhibited the ET-induced increase in {Ca2+}i. Additionally, these compounds inhibited the PAF-induced increase in {Ca2+}i. These results suggest that PAF and throm☐ane A2 (TXA2) may be involved in the mechanism of ET-induced mobilization of Ca2+ in cultured rat and rabbit VSMC.

General synthetic routes to quinone acids (8), quinone amides (9), quinone alcohols (10), and quinone methylketones (11) with polyprenyl side chains, in which allylic alcohols (3) are employed as the key intermediates, are described. The Claisen rearrangements and the Carrot reactions of the allylic alcohols (3) with ethyl orthoacetate and diketen produced the ethyl esters (4) and the methylketones (5), respectively. Quinone products (8), (10), and (11) were recovered by oxidative demethylation of hydroquinone dimethyl ethers (4), (5), and (7) or by acid hydrolysis of hydroquinone bis(methoxymethyl) ethers (4) and (5) followed by ferric chloride oxidation. Amidation of quinone acids (8) led to the formation of quinone amides (9). Inhibitory effects of these quinone derivatives on the generation of the slow reacting substance of anaphylaxis (SRS-A) in the lungs of sensitised guinea pigs are evaluated.

A new series of quinone derivatives with alkenyl and alkynyl groups in the side chain has been synthesised. A ready and novel synthetic method for the preparation of quinone derivatives via application of a 4-hydroxybutylation reaction discovered in our laboratory has been developed. Oxidative demethylation of the hydroquinone dimethyl ethers (5), (9), and (10) with cerium (IV) ammonium nitrate selectively leads to the formation of the desired quinone derivatives (11)–(13) in good yield, in spite of the presence of double or triple bonds, hydroxy groups in the side chains, and/or four methoxy groups on the same phenyl ring. Inhibitory effects of these quinone derivatives on the formation of leukotrienes [LTC4, LTD4, LTB4, and (5S,12S)- and (5S,12R)-6-trans-LTB4] and 5-hydroxyicosa-6,8,11,14-tetraenoic acid (5-HETE) in rat basophilic leukaemia (RBL-1) cells were evaluated. It was found that quinone derivatives such as 2-(12-hydroxydodeca-5,10-diynyl)-3,5,6-trimethyl-1,4-benzoquinone (AA-861)(12d) proved to be potent and specific inhibitors of leukotrienes and 5-HETE formation from arachidonic acid.