gc 4

PK11000 是一种烷化剂，可通过共价半胱氨酸修饰来稳定野生型和突变型p53的 DNA 结合结构域。

BGC4是一种基于联苯的金 (III) 复合物，能够抑制人类重组硫氧还蛋白还原酶 (TrxR)，其IC50为10.7 μM。它对MDA-MB-231细胞具有细胞毒性，IC50为5.4 μM，并能诱导细胞凋亡 (apoptosis)。在小鼠模型中，BGC4显示出抗肿瘤活性。

GC-072是一种效力强大的4-oxoquinolizine类抗生素，具备选择性抑制细菌拓扑异构酶的能力。GC-072能够在体外对B. pseudomallei的敏感和耐药菌株展示效果，也能抑制Burkholderia mallei、Bacillus anthracis、Yersinia pestis和Francisella tularensis等危险病原体。在模拟小鼠类鼻疽感染的模型中，口服GC-072表现出剂量依赖性的生存优势，显示出其作为类鼻疽口服一线治疗方案的潜力。

13C15-Nivalenol is intended for use as an internal standard for the quantification of nivalenol by GC- or LC-MS. Nivalenol is a trichothecene mycotoxin that has been found inFusarium.1It is lethal to mice (LD50= 6.9 mg kg).2Nivalenol (5, 10, and 15 mg kg) also induces thymic, splenic, and Peyer's patch cell apoptosis in mice.3 1.Yang, Z., Concannon, J., Ng, K.S., et al.Tetrandrine identified in a small molecule screen to activate mesenchymal stem cells for enhanced immunomodulationSci. Rep.630263(2016) 2.Yoshizawa, T., and Morooka, N.Studies on the toxic substances in the infected cereals (part 3): Acute toxicities of new trichothecene mycotoxins: Deoxynivalenol and its monoacetateJ. Food Hyg.15(4)261-269(1974) 3.Poapolathep, A., Ohtsuka, R., Kiatipattanasakul, W., et al.Nivalenol-induced apoptosis in thymus, spleen and Peyer's patches of miceExp. Toxicol. Pathol.53(6)441-446(2002)

4-deoxy Nivalenol-13C15is intended for use as an internal standard for the quantification of 4-deoxy nivalenol by GC- or LC-MS. 4-deoxy Nivalenol is a trichothecene mycotoxin that has been found inFusarium.1It binds to eukaryotic ribosomes and inhibits protein synthesis in mice when administered at doses ranging from 5 to 25 mg kg. 4-deoxy Nivalenol (0.1 and 0.2 mg kg) induces emesis in pigs and decreases feed consumption in pigs when administered at a dose of 40 ppb in the diet.2It induces lethality in mice (LD50= 46-78 mg kg).34-deoxy Nivalenol has been found inF. graminearum-infected cereal grains such as wheat, barley, and corn. 1.Pestka, J.J., and Smolinski, A.T.Deoxynivalenol: Toxicology and potential effects on humansJ.Toxicol.Environ.Health B.Crit.Rev.8(1)39-69(2005) 2.Forsyth, D.M., Yoshizawa, T., Morooka, N., et al.Emetic and refusal activity of deoxynivalenol to swineAppl. Environ. Microbiol.34(5)547-552(1977) 3.Pestka, J.J.Deoxynivalenol: Mechanisms of action, human exposure, and toxicological relevanceArch. Toxicol.84(9)663-679(2010)

Aflatoxin B2-13C17(AFB2-13C17) is intended for use as an internal standard for the quantification of AFB2by GC- or LC-MS. AFB2is a mycotoxin that has been found inA. terricola.1It induces hepatic autophagy and apoptosis in broiler chickens when administered at doses of 0.2, 0.4, and 0.8 mg kg.2AFB2(0.5 and 1 mg animal) also induces parenchymal cell hyperplasia in rats.3 1.Moubasher, A.H., el-Kady, I.A., and Shoriet, A.Toxigenic Aspergilli isolated from different sources in EgyptAnn. Nutr. Aliment.31(4-6)607-615(1977) 2.Chen, B., Li, D., Li, M., et al.Induction of mitochondria-mediated apoptosis and PI3K Akt mTOR-mediated autophagy by aflatoxin B2 in hepatocytes of broilersOncotarget7(51)84989-84998(2016) 3.Wogan, G.N., Edwards, G.S., and Newberne, P.M.Structure-activity relationships in toxicity and carcinogenicity of aflatoxins and analogsCancer Res.31(12)1936-1942(1971)

Aflatoxin G1-13C17is intended for use as an internal standard for the quantification of aflatoxin G1by GC- or LC-MS. Aflatoxin G1is a mycotoxin that has been found inA. terricola.1In vivo, aflatoxin G1is lethal to ducklings (LD50= 1.18 mg kg).2It induces hepatocellular carcinoma tumor formation and lethality in rats when administered at doses of 1.4 and 3 mg animal, respectively. Aflatoxin G1also inhibits liver and kidney succinate dehydrogenase and fumarase, as well as kidney cytochrome oxidase, NADH oxidase, α-glycerophosphate dehydrogenase, isocitrate dehydrogenase, and malate dehydrogenase in rats.3 1.Moubasher, A.H., el-Kady, I.A., and Shoriet, A.Toxigenic Aspergilli isolated from different sources in EgyptAnn. Nutr. Aliment.31(4-6)607-615(1977) 2.Wogan, G.N., Edwards, G.S., and Newberne, P.M.Structure-activity relationships in toxicity and carcinogenicity of aflatoxins and analogsCancer Res.31(12)1936-1942(1971) 3.Bai, N.J., Pai, M.R., and Venkitasubramanian, T.A.Mitochondrial function in aflatoxin toxicityIndian J. Biochem. Biophys.14(4)347-349(1977)

Guanfacine-13C,15N3is intended for us as an internal standard for the quantification of guanfacine by GC- or LC-MS. Guanfacine is an α2-adrenergic receptor (α2-AR) agonist with Kivalues of 93, 1,380, and 3,890 nM for α2A-, α2B-, and α2C-ARs, respectively, in a radioligand binding assay.1It has EC50values of 52, 288, and 602 nM for α2A-, α2B-, and α2C-ARs, respectively, for stimulated [35S]GTPγS binding. It also binds to imidazoline receptor 1 (Ki= 19 nM in a radioligand binding assay).2Guanfacine (0.3-5 mg kg) binds to adrenergic receptors in the central nervous system and lowers blood pressure in hypertensive rats in a dose-dependent manner.3It also improves spatial working memory deficits induced by hypobaric hypoxia in rats.4Formulations containing guanfacine are used in the treatment of high blood pressure and attention deficit hyperactivity disorder (ADHD). 1.Jasper, J.R., Lesnick, J.D., Chang, L.K., et al.Ligand efficacy and potency at recombinant α2 adrenergic receptors: Agonist-mediated [35S]GTPγS bindingBiochem. Pharmacol.55(7)1035-1043(1998) 2.Nikolic, K., Filipic, S., and Agbaba, D.QSAR study of imidazoline antihypertensive drugsBioorg. Med. Chem.16(15)7134-7140(2008) 3.Scholtysik, G.Pharmacology of guanfacineBr. J. Clin. Pharmacol.10(Suppl 1)21S-24S(1980) 4.Kauser, H., Sahu, S., Kumar, S., et al.Guanfacine is an effective countermeasure for hypobaric hypoxia-induced cognitive declineNeuroscience254110-119(2013)

2-deoxy-D-Glucose-13C6is intended for use as an internal standard for the quantification of 2-deoxy-D-glucose by GC- or LC-MS. 2-deoxy-D-Glucose is a glucose antimetabolite and an inhibitor of glycolysis.1,2It inhibits hexokinase, the enzyme that converts glucose to glucose-6-phosphate, as well as phosphoglucose isomerase, the enzyme that converts glucose-6-phosphate to fructose-6-phosphate.32-deoxy-D-Glucose (16 mM) induces apoptosis in SK-BR-3 cells, as well as inhibits the growth of 143B osteosarcoma cells cultured under hypoxic conditions when used at a concentration of 2 mg ml.4,5In vivo, 2-deoxy-D-glucose (500 mg kg) reduces tumor growth in 143B osteosarcoma and MV522 non-small cell lung cancer mouse xenograft models when used alone or in combination with doxorubicin or paclitaxel .6 1.Kang, H.T., and Hwang, E.S.2-Deoxyglucose: An anticancer and antiviral therapeutic, but not any more a low glucose mimeticLife Sci.78(12)1392-1399(2006) 2.Aft, R.L., Zhang, F.W., and Gius, D.Evaluation of 2-deoxy-D-glucose as a chemotherapeutic agent: Mechanism of cell deathBr. J. Cancer87(7)805-812(2002) 3.Ralser, M., Wamelink, M.M., Struys, E.A., et al.A catabolic block does not sufficiently explain how 2-deoxy-D-glucose inhibits cell growthProc. Natl. Acad. Sci. USA105(46)17807-17811(2008) 4.Liu, H., Savaraj, N., Priebe, W., et al.Hypoxia increases tumor cell sensitivity to glycolytic inhibitors: A strategy for solid tumor therapy (Model C)Biochem. Pharmacol.64(12)1745-1751(2002) 5.Zhang, X.D., Deslandes, E., Villedieu, M., et al.Effect of 2-deoxy-D-glucose on various malignant cell lines in vitroAnticancer Res.26(5A)3561-3566(2006) 6.Maschek, G., Savaraj, N., Priebe, W., et al.2-deoxy-D-glucose increases the efficacy of adriamycin and paclitaxel in human osteosarcoma and non-small cell lung cancers in vivoCancer Res.64(1)31-34(2004)

Oleic acid-13C is intended for use as an internal standard for the quantification of oleic acid by GC- or LC-MS. Oleic acid is a monounsaturated fatty acid and a major component of membrane phospholipids that has been found in human plasma, cell membranes, and adipose tissue.1,2 It contributes approximately 17% of the total fatty acids esterified to phosphatidylcholine, the major phospholipid class in porcine platelets.1 Oleic acid inhibits collagen-stimulated platelet aggregation by approximately 90% when used at a concentration of 10 μg ml. It also inhibits fMLF-induced neutrophil aggregation and degranulation by 55 and 68%, respectively, when used at a concentration of 5 μM, similar to arachidonic acid .3 Oleic acid (60 μM) induces release of intracellular calcium in human platelets.4

Octanoic acid-13C is intended for use as an internal standard for the quantification of octanoic acid by GC- or LC-MS. Octanoic acid is a medium-chain saturated fatty acid. It has been found in Teleme cheeses made from goat, ovine, or bovine milk.1 Octanoic acid is active against the bacteria S. mutans, S. gordonii, F. nucleatum, and P. gingivalis (IC80s = <125, <125, 1,403, and 2,294 μM, respectively).2 Levels of octanoic acid are increased in the plasma of patients with medium-chain acyl-CoA dehydrogenase (MCAD) deficiency, an inborn error of fatty acid metabolism characterized by hypoketotic hypoglycemia, medium-chain dicarboxylic aciduria, and intolerance to fasting.3,4 |1. Mallatou, H., Pappa, E., and Massouras, T. Changes in free fatty acids during ripening of Teleme cheese made with ewes', goats', cows' or a mixture of ewes' and goats' milk. Int. Dairy J. 13(1-3), 211-219 (2003).|2. Hyang, C.B., Alimova, Y., Myers, T.M., et al. Short- and medium-chain fatty acids exhibit antimicrobial activity for oral microorganisms. Arch. Oral Biol. 56(7), 650-654 (2011).|3. Onkenhout, W., Venizelos, V., van der Poel, P.F.H., et al. Identification and quantification of intermediates of unsaturated fatty acid metabolism in plasma of patients with fatty acid oxidation disorders. Clin. Chem. 41(10), 1467-1474 (1995).|4. Rinaldo, P., O'Shea, J.J., Coates, P.M., et al. Medium-chain acyl-CoA dehydrogenase deficiency. Diagnosis by stable-isotope dilution measurement of urinary n-hexanoylglycine and 3-phenylpropionylglycine. N. Engl. J. Med. 319(20), 1308-1313 (1988).

HT-2 toxin-13C22is intended for use as an internal standard for the quantification of HT-2 toxin by GC- or LC-MS. HT-2 toxin is a type A trichothecene mycotoxin and an active, deacetylated metabolite of the trichothecene mycotoxin T-2 toxin .1,2Like T-2 toxin, HT-2 toxin inhibits protein synthesis and cell proliferation in plants.2HT-2 toxin also reduces viability of HepG2, A549, HEp-2, Caco-2, A-204, U937, Jurkat, and RPMI-8226 cancer cells with IC50values ranging from 3.1 to 23 ng ml and human umbilical vein endothelial cells with an IC50value of 56.4 ng ml.1It induces oxidative stress, DNA damage, and autophagy in, as well as halts the development of, cultured mouse embryos when used at a concentration of 10 nM.3HT-2 toxin has been found in cereal grains and food products.4,5 1.Nielsen, C., Casteel, M., Didier, A., et al.Trichothecene-induced cytotoxicity on human cell linesMycotoxin Res.25(2)77-84(2009) 2.Nathanail, A.V., Varga, E., Meng-Reiterer, J., et al.Metabolism of the fusarium mycotoxins T-2 toxin and HT-2 toxin in wheatJ. Agric. Food Chem.63(35)7862-7872(2015) 3.Zhang, L., Li, L., Xu, J., et al.HT-2 toxin exposure induces mitochondria dysfunction and DNA damage during mouse early embryo developmentReprod. Toxicol.85104-109(2019) 4.Langseth, W., and Rundberget, T.The occurrence of HT-2 toxin and other trichothecenes in Norwegian cerealsMycopathologia147(3)157-165(1999) 5.Al-Taher, F., Cappozzo, J., Zweigenbaum, J., et al.Detection and quantitation of mycotoxins in infant cereals in the U.S. market by LC-MS MS using a stable isotope dilution assayFood Control72(Part A)27-35(2017)

Palmitic acid-13C is intended for use as an internal standard for the quantification of palmitic acid by GC- or LC-MS. Palmitic acid is a 16-carbon saturated fatty acid. It comprises approximately 25% of human total plasma lipids.1 It increases protein levels of COX-2 in RAW 264.7 cells when used at a concentration of 75 μM.2 Palmitic acid is involved in the acylation of proteins to anchor membrane-bound proteins to the lipid bilayer.2,3,4,5,6 |1. Santos, M.J., López-Jurado, M., Llopis, J., et al. Influence of dietary supplementation with fish oil on plasma fatty acid composition in coronary heart disease patients. Ann. Nutr. Metab. 39(1), 52-62 (1995).|2. Lee, J.Y., Sohn, K.H., Rhee, S.H., et al. Saturated fatty acids, but not unsaturated fatty acids, induced the expression of cyclooxygenase-2 mediated through toll-like receptor 4. J. Biol. Chem. 276(20), 16683-16689 (2001).|3. Dietzen, D.J., Hastings, W.R., and Lublin, D.M. Caveolin is palmitoylated on multiple cysteine residues. Palmitoylation is not necessary for localization of caveolin to caveolae. J. Biol. Chem. 270(12), 6838-6842 (1995).|4. Robinson, L.J., and Michel, T. Mutagenesis of palmitoylation sites in endothelial nitric oxide synthase identifies a novel motif for dual acylation and subcellular targeting. Proc. Nat. Acad. Sci. USA 92(25), 11776-11780 (1995).|5. Topinka, J.R., and Bredt, D.S. N-terminal palmitoylation of PSD-95 regulates association with cell membranes and interaction with K+ channel Kv1.4. Neuron 20(1), 125-134 (1998).|6. Miggin, S.M., Lawler, O.A., and Kinsella, B.T. Palmitoylation of the human prostacyclin receptor. Functional implications of palmitoylation and isoprenylation. J. Biol. Chem. 278(9), 6947-6958 (2003).

Palmitic acid-13C (C1, C2, C3, and C4 labeled) is intended for use as an internal standard for the quantification of palmitic acid by GC- or LC-MS. Palmitic acid is a common 16-carbon saturated fat that represents 10-20% of human dietary fat intake and comprises approximately 25 and 65% of human total plasma lipids and saturated fatty acids, respectively.1,2Acylation of palmitic acid to proteins facilitates anchoring of membrane-bound proteins to the lipid bilayer and trafficking of intracellular proteins, promotes protein-vesicle interactions, and regulates various G protein-coupled receptor functions.1Red blood cell palmitic acid levels are increased in patients with metabolic syndrome compared to patients without metabolic syndrome and are also increased in the plasma of patients with type 2 diabetes compared to individuals without diabetes.3,4 1.Fatima, S., Hu, X., Gong, R.-H., et al.Palmitic acid is an intracellular signaling molecule involved in disease developmentCell. Mol. Life Sci.76(13)2547-2557(2019) 2.Santos, M.J., López-Jurado, M., Llopis, J., et al.Influence of dietary supplementation with fish oil on plasma fatty acid composition in coronary heart disease patientsAnn. Nutr. Metab.39(1)52-62(1995) 3.Yi, L.-Z., He, J., Liang, Y.-Z., et al.Plasma fatty acid metabolic profiling and biomarkers of type 2 diabetes mellitus based on GC/MS and PLS-LDAFEBS Lett.580(30)6837-6845(2006) 4.Kabagambe, E.K., Tsai, M.Y., Hopkins, P.N., et al.Erythrocyte fatty acid composition and the metabolic syndrome: A National Heart, Lung, and Blood Institute GOLDN studyClin. Chem.54(1)154-162(2008)

Palmitic acid-13C is intended for use as an internal standard for the quantification of palmitic acid by GC- or LC-MS. Palmitic acid-13C contains 13C at the C2 position and has been used in the study of free fatty acid incorporation into phospholipid fatty acids in soil microbes.1 Palmitic acid is a 16-carbon saturated fatty acid. It comprises approximately 25% of human total plasma lipids.2 It increases protein levels of COX-2 in RAW 264.7 cells when used at a concentration of 75 μM.3 Palmitic acid is involved in the acylation of proteins to anchor membrane-bound proteins to the lipid bilayer.3,4,5,6,7

Flumequine-13C3is intended for use as an internal standard for the quantification of flumequine by GC- or LC-MS. Flumequine is a fluoroquinolone antibiotic.1It is active againstS. aureus, S. pyogenes, B. subtilis, E. coli, P. aeruginosa, S. faecalis, andK. pneumoniae(MICs = 1-100 μg ml). Flumequine is also active against field isolates of B. hyodysenteriae (MICs = 6.25-200 μg ml).2It inhibits DNA gyrase, disrupting supercoiling of bacterial DNA to block transcription and replication.3In vivo, flumequine (50 mg kg) increases survival in rat models ofP. vulgaris-induced urinary tract infection andP. mirabilis-induced prostatitis.1Formulations containing flumequine have been used in the treatment of urinary tract infections in veterinary medicine. 1.Rohlfing, S.R., Gerster, J.R., and Kvam, D.C.Bioevaluation of the antibacterial flumequine for urinary tract useAntimicrob. Agents Chemother.10(1)20-24(1976) 2.Aller-Morán, L.M., Martínez-Lobo, F.J., Rubio, P., et al.Evaluation of the in vitro activity of flumequine against field isolates of Brachyspira hyodysenteriaeRes. Vet. Sci.10351-53(2015) 3.Smith, J.T.The mode of action of 4-quinolones and possible mechanisms of resistanceJ. Antimicrob. Chemother.18 (Suppl. D)21-29(1986)

Nitisinone-13C6is intended for use as an internal standard for the quantification of nitisinone by GC- or LC-MS. Nitisinone is an inhibitor of 4-hydroxyphenylpyruvate dioxygenase (HPPD), which converts 4-hydroxyphenylpyruvate (HPPA) to homogentisate in the tyrosine catabolic pathway.1Nitisinone increases urinary levels of HPPA and 4-hydroxyphenyllactate (HPLA) in rats when administered at a dose of 10 mg kg. Nitisinone (3 mg kg) prevents the neonatal lethality of fumarylacetoacetate hydrolase (FAH) deficiency in mice when administered to pregnant dams.2It exhibits hepatoprotective effects inFAH- -mice, such as prevention of increases in plasma levels of aspartate serine aminotransferase (AST) and conjugated bilirubin, when administration is continued following birth at a dose of 1 mg kg. Nitisinone (100 μg) decreases urinary excretion of homogentisate and increases urinary excretion of HPPA, HPLA, and 4-hydroxyphenylacetate in a mouse model of alkaptonuria induced by ethylnitrosourea.3Formulations containing nitisinone have been used in the treatment of hereditary tyrosinemia type 1 (HT-1). 1.Ellis, M.K., Whitfield, A.C., Gowans, L.A., et al.Inhibition of 4-hydroxyphenylpyruvate dioxygenase by 2-(2-nitro-4-trifluoromethylbenzoyl)-cyclohexane-1,3-dione and 2-(2-chloro-4-methanesulfonylbenzoyl)-cyclohexane-1,3-dioneToxicol. Appl. Pharmacol.133(1)12-19(1995) 2.Grompe, M., Lindstedt, S., al-Dhalimy, M., et al.Pharmacological correction of neonatal lethal hepatic dysfunction in a murine model of hereditary tyrosinaemia type INat. Genet.10(4)453-460(1995) 3.Suzuki, Y., Oda, K., Yoshikawa, Y., et al.A novel therapeutic trial of homogentisic aciduria in a murine model of alkaptonuriaJ. Hum. Genet.44(2)79-84(1999)

Nitrofurantoin-13C3is intended for use as an internal standard for the quantification of nitrofurantoin by GC- or LC-MS. Nitrofurantoin is a nitrofuran antibiotic.1In vivo, nitrofurantoin (25-100 mg kg) reducesE. colireplication and abscess formation in the renal medulla of infected rats in a dose-dependent manner. It prevents kidney and bladder infection in rats following bladder inoculation with clinical isolates ofP. mirabilis. Nitrofurantoin also prevents alkalization of urine, as well as calculi and abscess formation, in a rat model ofP. vulgarisurinary tract infection.2Formulations containing nitrofurantoin have been used to treat urinary tract infections. 1.Rocha, H., Da Silva Teles, E., and Barros, M.Site of action of nitrofurantoin in experimental urinary tract infectionAppl. Microbiol.18(4)547-549(1969) 2.Hossack, D.J.N.Proteus vulgaris urinary tract infections in rats; treatment with nitrofuran derivativesBr. J. Pharmacol. Chemother.19(2)306-312(1962)

Olsalazine-13C6is intended for use as an internal standard for the quantification of olsalazine by GC- or LC-MS. Olsalazine is an orally bioavailable prodrug form of the anti-inflammatory agent 5-aminosalicylic acid that is cleaved by bacterial azo reductases in the gut to generate active 5-ASA.1In vitro, olsalazine increases ion transport in isolated rabbit distal ileum when applied to the luminal side (ED50= 0.3 mM) and stimulates fluid transport in rat jejunum when used at a concentration of 5 mM.2,3Olsalazine (150 mg/kg for 8 days) improves stool consistency and decreases occult and gross bleeding as well as myeloperoxidase (MPO) activity and leukotriene B4levels in colon tissue in a mouse model of acute colitis induced by dextran sulfate .4Olsalazine also inhibits bovine xanthine oxidasein vitro(IC50= 3.4 mg/L) and lowers serum uric acid levels in a mouse model of hyperuricemia induced by oxonic acid when administered at a dose of 20 mg/kg.5Formulations containing olsalazine have been used in the treatment of inflammatory bowel disease (IBD) and ulcerative colitis. 1.Nugent, S.G., Kumar, D., Rampton, D.S., et al.Intestinal luminal pH in inflammatory bowel disease: Possible determinants and implications for therapy with aminosalicylates and other drugsGut48(4)571-577(2001) 2.Pamukcu, R., Hanauer, S.B., and Chang, E.B.Effect of disodium azodisalicylate on electrolyte transport in rabbit ileum and colon in vitro. Comparison with sulfasalazine and 5-aminosalicylic acidGastroenterology95(4)975-981(1988) 3.Mohsen, A.Q.M., Mulvey, D., Priddle, J.D., et al.Effects of olsalazine in the jejunum of the ratGut28(3)346-352(1987) 4.Murthy, S., Murthy, N.S., Coppola, D., et al.The efficacy of BAY y 1015 in dextran sulfate model of mouse colitisInflamm. Res.46(6)224-233(1997) 5.Niu, Y., Li, H., Gao, L., et al.Old drug, new indication: Olsalazine sodium reduced serum uric acid levels in mice via inhibiting xanthine oxidoreductase activityJ. Pharmacol. Sci.135(3)114-120(2017)

2,3-dinor-11β-Prostaglandin F2α (2,3-dinor-11β-PGF2α) was recovered from the urine of both normal monkeys and humans when infused with radiolabeled PGD2, where it represented approximately 1% and 4% of the infused radiolabeled dose, respectively. 2,3-dinor-11β-PGF2α has also been recovered from the urine of mastocytosis patients, where it is excreted in large amounts. In human asthmatic patients, 2,3-dinor-11β-PGF2α represents about 40% (as determined by GC/MS) of the immunoreactive 11β-PGF2α when measured using 's 11β-PGF2α EIA Kit . The excretion rate for 2,3-dinor-11β-PGF2α is approximately 200-250 ng/24 hours in a normal adult.

Zonisamide-13C2,15N is intended for use as an internal standard for the quantification of zonisamide by GC- or LC-MS. Zonisamide is an antiepileptic agent.1 It selectively inhibits the repeated firing of sodium channels (IC50 = 2 μg ml) in mouse embryo spinal cord neurons and inhibits spontaneous channel firing when used at concentrations greater than 10 μg ml.2 In rat cerebral cortex neurons, zonisamide (1-1,000 μM) inhibits T-type calcium channels with a maximum reduction of 60% of the calcium current.3 Zonisamide inhibits H. pylori recombinant carbonic anhydrase (CA) and the human CA isoforms I, II, and V with Ki values of 218, 56, 35, and 21 nM, respectively.4,5 In mice, it has anticonvulsant activity against maximal electroshock seizure (MES) and pentylenetetrazole-induced maximal, but not minimal, seizures (ED50s = 19.6, 9.3, and >500 mg kg, respectively). Zonisamide (40 mg kg, p.o.) prevents MPTP-induced decreases in the levels of dopamine , but not homovanillic acid or dihydroxyphenyl acetic acid , and increases MPTP-induced decreases in the dopamine turnover rate in mouse striatum in a model of Parkinson's disease.6 Formulations containing zonisamide have been used in the treatment of partial seizures in adults with epilepsy. |1. Masuda, Y., Ishizaki, M., and Shimizu, M. Zonisamide: Pharmacology and clinical efficacy in epilepsy. CNS Drug Rev. 4(4), 341-360 (1998).|2. Rock, D.M., Macdonald, R.L., and Taylor, C.P. Blockade of sustained repetitive action potentials in cultured spinal cord neurons by zonisamide (AD 810, CI 912), a novel anticonvulsant. Epilepsy Res. 3(2), 138-143 (1989).|3. Suzuki, S., Kawakami, K., Nishimura, S., et al. Zonisamide blocks T-type calcium channel in cultured neurons of rat cerebral cortex. Epilepsy Res. 12(1), 21-27 (1992).|4. Nishimori, I., Vullo, D., Minakuchi, T., et al. Carbonic anhydrase inhibitors: Cloning and sulfonamide inhibition studies of a carboxyterminal truncated α-carbonic anhydrase from Helicobacter pylori. Bioorg. Med. Chem. Lett. 16(8), 2182-2188 (2006).|5. De Simone, G., Di Fiore, A., Menchise, V., et al. Carbonic anhydrase inhibitors. Zonisamide is an effective inhibitor of the cytosolic isozyme II and mitochondrial isozyme V: Solution and X-ray crystallographic studies. Bioorg. Med. Chem. Lett. 15(9), 2315-2320 (2005).|6. Yabe, H., Choudhury, M.E., Kubo, M., et al. Zonisamide increases dopamine turnover in the striatum of mice and common marmosets treated with MPTP. J. Pharmacol. Sci. 110(1), 64-68 (2009).

Ribavirin-13C5is intended for use as an internal standard for the quantification of ribavirin by GC- or LC-MS. Ribavirin is an antiviral guanosine nucleoside analog.1,2Upon entry into cells, ribavirin is metabolized to an active triphosphate form that induces viral RNA chain termination and inhibits viral polymerases. It reduces replication in a panel of seven RNA and four DNA viruses in Vero cells (EC50s = 2-95 μg/ml).3Ribavirin also reduces replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Vero cells (EC50= 109.5 μM).4Aerosol administration of ribavirin (30 mg/kg) reduces mortality in a mouse model of influenza A infection.5Formulations containing ribavirin have been used in the treatment of respiratory syncytial virus (RSV), hepatitis C virus (HCV), and viral hemorrhagic fevers. 1.Gilbert, B.E., and Knight, V.Biochemistry and clinical applications of ribavirinAntimicrob. Agents Chemother.30(2)201-205(1986) 2.Gordon, C.J., Tchesnokov, E.P., Woolner, E., et al.Remdesivir is a direct-acting antiviral that inhibits RNA-dependent RNA polymerase from severe acute respiratory syndrome coronavirus 2 with high potencyJ. Biol. Chem.295(20)6785-6797(2020) 3.Kirsi, J.J., North, J.A., McKernan, P.A., et al.Broad-spectrum antiviral activity of 2-β-D-ribofuranosylselenazole-4-carboxamide, a new antiviral agentAntimicrob. Agents Chemother.24(3)353-361(1983) 4.Wang, M., Cao, R., Zhang, L., et al.Remdesivir and chloroquine effectively inhibit the recently emerged novel coronavirus (2019-nCoV) in vitroCell Res.30(3)269-271(2020) 5.Wilson, S.Z., Knight, V., Wyde, P.R., et al.Amantadine and ribavirin aerosol treatment of influenza A and B infection in miceAntimicrob. Agents Chemother.17(4)642-648(1980)

1,2-Dipalmitoyl-13C-sn-glycero-3-PC is intended for use as an internal standard for the quantification of 1,2-dipalmitoyl-sn-glycero-3-PC by GC- or LC-MS. 1,2-Dipalmitoyl-sn-glycero-3-PC (DPPC) is a zwitterionic glycerophospholipid commonly used in the formation of lipid monolayers, bilayers, and liposomes for use in a variety of applications.1,2,3,4 It has been used in the formation of proteoliposomes for implantation of γ-glutamyl transpeptidase into human erythrocyte membranes.3 Incorporation of glycosphingolipid antigens into DPPC-containing liposomes increases the immunogenicity of the antigens in mice.4 |1. Ege, C., and Lee, K.Y.C. Insertion of Alzheimer's Aβ40 peptide into lipid monolayers. Biophys. J. 87(3), 1732-1740 (2004).|2. Leekumjorn, S., and Sum, A.K. Molecular simulation study of structural and dynamic properties of mixed DPPC/DPPE bilayers. Biophys. J. 90(11), 3951-3965 (2006).|3. Kalra, V.K., Sikka, S.C., and Sethi, G.S. Transport of amino acids in γ-glutamyl transpeptidase-implanted human erythrocytes. J. Biol. Chem. 256(11), 5567-5571 (1981).|4. Uemura, A., Watarai, S., Iwasaki, T., et al. Induction of immune responses against glycosphingolipid antigens: Comparison of antibody responses in mice immunized with antigen associated with liposomes prepared from various phospholipids. J. Vet. Med. Sci. 67(12), 1197-1201 (2005).

Chlorhexidine-d8 is intended for use as an internal standard for the quantification of chlorhexidine by GC- or LC-MS. Chlorhexidine is a bis(biguanide) antimicrobial disinfectant and antiseptic agent. It inhibits growth of clinical methicillin-resistant S. aureus (MRSA) isolates (MIC90 = 4 μg ml). It is also active against canine isolates of MRSA, methicillin-susceptible S. aureus (MSSA), methicillin-resistant S. pseudintermedius (MRSP), and methicillin-susceptible S. pseudintermedius (MSSP; MIC90s = 4, 2, 2, and 1 mg L, respectively). Chlorhexidine inhibits growth of E. faecium strains (MICs = 1.2-19.6 μg ml) and C. albicans (MIC = 5.15 μg ml). It generates cations that bind to and destabilize the bacterial cell wall to induce death.6 Chlorhexidine also completely inhibits matrix metalloproteinase-2 (MMP-2) and MMP-9 when used at concentrations of 0.0001 and 0.002%, respectively, in a gelatin degradation assay. Formulations containing chlorhexidine have been used in antisept......