title: Selective chemiluminescence method for monitoring of vitamin K homologues in rheumatoid arthritis patients.
abstract: Vitamin K is a fat-soluble vitamin involved in blood coagulation and bone metabolism. The detection and monitoring of vitamin K homologues in rheumatoid arthritis (RA) patients is a challenging problem due to the smaller concentrations of vitamin K and the presence of several interfering medications. Therefore, this study aimed to develop a new highly sensitive and selective chemiluminescence (CL) method designated to quantify vitamin K homologues in plasma of RA patients including phylloquinone (PK, vitamin K(1)), menaquinone-4 (MK-4, vitamin K(2)) and menaquinone-7 (MK-7, vitamin K(2)). The method was based on the unique photochemical properties of vitamin K homologues that were exploited for selective luminol CL reaction. The correlation coefficients of 0.998 or more were obtained in the concentration ranges of 0.1-100 ng mL(-1) vitamin K homologues. The detection limits were 0.03-0.1 ng mL(-1) in human plasma for vitamin K homologues. The developed HPLC-CL system was successfully applied for selective determination of vitamin K homologues in plasma of RA patients. The developed method may provide a useful tool for monitoring vitamin K homologues in different clinical studies such as RA, osteoporosis and hepatocellular carcinoma in which vitamin K is intervented.
authors.affiliation: Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Assiut University, Assiut 71526, Egypt. sameh_aa@yahoo.com
authors.forename: Sameh
authors.initials: S
authors.lastname: Ahmed
authors.forename: Naoya
authors.initials: N
authors.lastname: Kishikawa
authors.forename: Kaname
authors.initials: K
authors.lastname: Ohyama
authors.forename: Takahiro
authors.initials: T
authors.lastname: Imazato
authors.forename: Yukitaka
authors.initials: Y
authors.lastname: Ueki
authors.forename: Naotaka
authors.initials: N
authors.lastname: Kuroda
mesh_terms: D001172:Arthritis, Rheumatoid / Q000378:metabolism*; D006528:Carcinoma, Hepatocellular; D004347:Drug Interactions; D006801:Humans; D057230:Limit of Detection; D008113:Liver Neoplasms; D008163:Luminescent Measurements / Q000379:methods*; D008165:Luminol; D008722:Methods; D010024:Osteoporosis; D014812:Vitamin K / Q000031:analogs & derivatives / Q000097:blood*
chemical_list: D014812:Vitamin K; D008165:Luminol