h-4 receptor antagonist 1

H4 Receptor antagonist 1 is a potent and selective histamine H4 receptor inverse agonist with an IC50 of 19 nM.

Napyradiomycin A1is a fungal metabolite originally isolated fromC. rubraand has diverse biological activities.1,2It is active againstS. aureus,M. luteus,B. anthracis,C. bovis, andM. smegmatis(MICs = 1.56-12.5 μg/ml).1Napyradiomycin A1is an estrogen receptor antagonist (IC50= 4.2 μM in rat uterine homogenates).2It also inhibits mitochondrial NADH:ubiquinone oxidoreductase (complex I) and succinate:ubiquinone oxidoreductase (complex II) activities in bovine heart homogenates (IC50s = 20 and 9.7 μM, respectively).3 1.Shiomi, K., Iinuma, H., Hamada, M., et al.Novel antibiotics napyradiomycins. Production, isolation, physico-chemical properties and biological activityJ. Antibiot. (Tokyo)39(4)487-493(1986) 2.Hori, Y., Abe, Y., Shigematsu, N., et al.Napyradiomycins A and B1: Non-steroidal estrogen-receptor antagonists produced by a StreptomycesJ. Antibiot. (Tokyo)46(12)1890-1893(1993) 3.Yamamoto, K., Tashiro, E., Motohashi, K., et al.Napyradiomycin A1, an inhibitor of mitochondrial complexes I and IIJ. Antibiot. (Tokyo)65(4)211-214(2012)

Emestrin, a mycotoxin originally isolated from *E. striata*, exhibits antimicrobial, immunomodulatory, and cytotoxic activities. It is effective against fungi *C. albicans* and *C. neoformans*, and bacteria *E. coli*, *S. aureus*, and methicillin-resistant *S. aureus* (MRSA; IC50s = 3.94, 0.6, 2.21, 4.55, and 2.21 μg ml, respectively). Emestrin acts as a chemokine (C-C motif) receptor 2 (CCR2) antagonist (IC50 = 5.4 μM in a radioligand binding assay using isolated human monocytes). At 0.1 μg ml, it induces apoptosis in HL-60 cells and causes necrosis in heart, thymus, and liver tissues in mice at doses of 18-30 mg kg.

PMX-205 is a cyclic hexapeptide that acts as a potent antagonist of C5a receptor (C5aR; IC50= 31 nM).1It is orally active and blocks inflammatory signaling and symptoms in animal models of colitis and allergic asthma.2,3PMX-205 is also brain penetrant and reduces neuroinflammation and neurodegeneration in an animal model of Alzheimer's disease.4 1.March, D.R., Proctor, L.M., Stoermer, M.J., et al.Potent cyclic antagonists of the complement C5a receptor on human polymorphonuclear leukocytes. Relationships between structures and activityMol. Pharmacol.65(4)868-879(2004) 2.Jain, U., Woodruff, T.M., and Stadnyk, A.W.The C5a receptor antagonist PMX205 ameliorates experimentally induced colitis associated with increased IL-4 and IL-10Br. J. Pharmacol.168(2)488-501(2013) 3.Staab, E.B., Sanderson, S.D., Wells, S.M., et al.Treatment with the C5a receptor/CD88 antagonist PMX205 reduces inflammation in a murine model of allergic asthmaInt. Immunopharmacol.21(2)293-300(2014) 4.Fonseca, M.I., Ager, R.R., Chu, S.-H., et al.Treatment with a C5aR antagonist decreases pathology and enhances behavioral performance in murine models of Alzheimer's diseaseJ. Immunol.183(2)1375-1383(2009)

Deltorphin II is a peptide agonist of δ2-opioid receptors.1,2It is selective for δ-opioid receptors over μ- and κ-opioid receptors in radioligand bindings assays (Kis = 0.0033, >1, and >1 μM, respectively) and induces [35S]GTPγS binding in mouse brain membrane preparations (EC50= 0.034 μM). Deltorphin II (0.12 mg/kg) decreases the infarction zone:risk zone ratio in a rat model of myocardial ischemia-reperfusion injury induced by coronary occlusion, an effect that can be reversed by the δ2-opioid receptor antagonist naltriben but not the δ1-opioid receptor antagonist BNTX.3Intrathecal administration of deltorphin II (15 μg/animal) increases latency to withdraw in the paw pressure and tail-flick tests in rats.4 1.Raynor, K., Kong, H., Chen, Y., et al.Pharmacological characterization of the cloned κ-, δ-, and μ-opioid receptorsMol. Pharm.45(2)330-334(1994) 2.Scherrer, G., Befort, K., Contet, C., et al.The delta agonists DPDPE and deltorphin II recruit predominantly mu receptors to produce thermal analgesia: A parallel study of mu, delta and combinatorial opioid receptor knockout miceEur. J. Neurosci.19(8)2239-2248(2004) 3.Maslov, L.N., Barzakh, E.I., Krylatov, A.V., et al.Opioid peptide deltorphin II simulates the cardioprotective effect of ischemic preconditioning: role of δ2-opioid receptors, protein kinase C, and KATP channelsBull. Exp. Biol. Med.149(5)591-593(2010) 4.Labuz, D., Toth, G., Machelska, H., et al.Antinociceptive effects of isoleucine derivatives of deltorphin I and deltorphin II in rat spinal cord: A search for selectivity of delta receptor subtypesNeuropeptides32(6)511-517(1998)

Eltoprazine(DU28853) is a serenic or antiaggressive agent which as an agonist at the 5-HT1A and 5-HT1B receptors and as an antagonist at the 5-HT2C receptor.IC50 value:Target: 5-HT1A/1B agonist; 5-HT2C antagonistin vitro: The binding of [3H]eltoprazine to whole tissue sections was saturable and revealed an apparent dissociation constant (Kd) of 11 nM. Specific [3H]eltoprazine binding was completely displaced by 5-HT; conversely, unlabelled eltoprazine reduced [3H]5-HT binding to the levels of non-specific binding [1]. Eltoprazine evoked membrane changes that were similar to but much weaker than those induced by 5HT. Both the 5HT- and eltoprazine-evoked membrane hyperpolarizations were largely suppressed in the presence of spiperone [2].in vivo: eltoprazine is extremely effective in suppressing dyskinesia in experimental models, although this effect was accompanied by a partial worsening of the therapeutic effect of l-dopa. Interestingly, eltoprazine was found to (synergistically) potentiate the antidyskinetic effect of amantadine. The current data indicated that eltoprazine is highly effective in counteracting dyskinesia in preclinical models [3]. Rats were chronically treated with mianserin (10 mg/kg i.p.) or eltoprazine (1 mg/kg i.p.) and were tested in the elevated plus-maze test for anxiety. Mianserin and eltoprazine displayed opposite effects in the elevated plus-maze: mianserin induced anxiolytic-like effects, while eltoprazine showed anxiogenic-like ones [4]. [1]. Sijbesma H, et al. Eltoprazine, a drug which reduces aggressive behaviour, binds selectively to 5-HT1 receptor sites in the rat brain: an autoradiographic study. Eur J Pharmacol. 1990 Feb 20;177(1-2):55-66. [2]. Joels M, et al. Eltoprazine suppresses hyperpolarizing responses to serotonin in rat hippocampus. J Pharmacol Exp Ther. 1990 Apr;253(1):284-9. [3]. Bezard E, et al. Study of the antidyskinetic effect of eltoprazine in animal models of levodopa-induced dyskinesia. Mov Disord. 2013 Jul;28(8):1088-96. [4]. Rocha B, et al. Chronic mianserin or eltoprazine treatment in rats: effects on the elevated plus-maze test and on limbic 5-HT2C receptor levels. Eur J Pharmacol. 1994 Sep 1;262(1-2):125-31.

Histamine H4 receptor antagonist-1 is a potent antagonist of the histamine H4 receptor (hydrochloride).