- Method of preparing butyl betaine
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The invention relates to betaine and especially relates to a method of preparing butyl betaine, which can avoid generation of butyrolactone, increase product purity and reduce cost, wherein 4-dimethylamino butyric acid, methanol, alkali and an ionic liquid are used as raw materials and are reacted with monochloromethane and diluted hydrochloric acid to obtain the butyl betaine. The raw materials are commercial products and have broad raw materials in abundant supply, so that raw material cost is low and production cost is effectively controlled. During the reaction, generation of impurities, such as butyrolactone, is prevented, so that the produced butyl betaine is high in quality.
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Paragraph 0020; 0022; 0024; 0026; 0028; 0030
(2018/04/26)
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- Synthesis and in vitro characterization of drug conjugates of l-carnitine as potential prodrugs that target human Octn2
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The objective was to evaluate the potential of drug conjugates with l-carnitine as prodrugs that target organic cation/carnitine transporter (OCTN2). Twenty-two l-carnitine analogues were evaluated for human organic cation/carnitine transporter (hOCTN2) inhibition; the 3'-hydroxyl group was found to be the only functional group not contributing to l-carnitine interaction with hOCTN2 among the three functional groups on l-carnitine (i.e., 3'-hydroxyl, amine, and carboxylate). The 3'-hydroxyl group on l-carnitine was therefore chosen as the conjugate site. Three drug-l-carnitine conjugates (i.e., valproyl-l-carnitine, naproxen-l-carnitine, and ketoprofen-l-carnitine) were synthesized along with two ketoprofen analogues that incorporated a linker group (glycolic acid or glycine) between ketoprofen and l-carnitine (i.e., ketoprofen-glycolic acid-l-carnitine and ketoprofen-glycine-l-carnitine). These potential prodrugs were evaluated for their in vitro inhibition, transport, and metabolism properties. All three drug-l-carnitine conjugates and ketoprofen-glycine-l-carnitine were OCTN2 inhibitors, as well as substrates. For valproyl-l-carnitine, Ki = 155± 19μM, Km = 132± 23μM, and normalized Jmax = 0.467± 0.028; for naproxen-l-carnitine, Ki = 5.97± 0.81μM, Km = 257± 57μM, and normalized Jmax = 0.141± 0.012; for ketoprofen-l-carnitine, Ki = 82.2± 5.3μM, Km = 77.0± 4.0μM, and normalized Jmax = 0.412± 0.015; for ketoprofen-glycine-l-carnitine, Ki = 14.4± 1.4μM, Km = 58.5± 8.7μM, and normalized Jmax = 0.0789± 0.0037. Ketoprofen-glycolic acid-l-carnitine was unstable in metabolic buffers and chemical buffers. On the contrary, naproxen-l-carnitine, ketoprofen-l-carnitine, and ketoprofen-glycine-l-carnitine were stable in chemical and metabolic buffers. The results demonstrate the potential of drug-l-carnitine conjugates to serve as prodrugs that target OCTN2.
- Diao, Lei,Polli, James E.
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experimental part
p. 3802 - 3816
(2012/06/30)
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