- Method for the determination of vitamin K homologues in human plasma using high-performance liquid chromatography-tandem mass spectrometry
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We report here the development of a precise and sensitive method for the determination of vitamin K homologues including phylloquinone (PK), menaquinone-4 (MK-4), and menaquinone-7 (MK-7) in human plasma using HPLC-tandem mass-mass spectrometry with atmospheric pressure chemical ionization (LC-APCI-MS/MS). The method involves the use of stable isotope 18O-labeled internal standard compounds, which were synthesized in our laboratory, and the selection of a precursor and product ion with a MS/MS multiple reaction monitoring method. The average intraassay and interassay variation values for PK, MK-4, and MK-7 were 10%. Average spiked recoveries from authentic compounds added to normal human plasma samples for PK, MK-4, and MK-7 were 98-102%. Mean plasma concentrations of PK, MK-4, and MK-7 from healthy subjects (n = 20) were 1.22 ± 0.57, 0.39 ± 0.46, and 6.37 ± 7.45 ng/mL, respectively. We conclude that this novel LC-APCI-MS/MS method should be useful for the evaluation of vitamin K status in postmenopausal women and elderly subjects and provides useful information for the treatment and prevention of osteoporosis with vitamin K.
- Suhara, Yoshitomo,Kamao, Maya,Tsugawa, Naoko,Okano, Toshio
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- Organocatalytic Asymmetric Formal [4 + 2] Cycloaddition of in Situ Oxidation-Generated ortho-Quinone Methides and Aldehydes
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An unprecedented chiral secondary amine-catalyzed formal [4 + 2] annulation of aldehydes and oxidation-generated β-unsubstituted o-QMs is reported. This asymmetric protocol allows direct functionalization of the benzylic C-H bonds and furnishes [4 + 2] cycloadducts, chromanols, with excellent enantioselectivity and in up to 92% yield. The usability of this approach was further demonstrated by the enantioselective synthesis of anticancer Rhinacanthins derivative NKPLS8.
- Zhou, Ding,Yu, Xueting,Zhang, Jian,Wang, Wei,Xie, Hexin
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- Functional investigation and applications of the acetylesterase activity of the Citrus sinensis (L.) Osbeck peel
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The hydrolysis of acetyl moieties on a set of commercially relevant substrates was performed by employing the whole tissue of Citrus sinensis (L.) Osbeck peel as an efficient biocatalyst in mild reaction conditions with high degree of regioselectivity. The reaction is done in aqueous media and the product is easily recovered. Optimal reaction conditions were deduced and two practical applications were investigated: the elaboration of acetylglicerols and the preparation of vitamin K1 precursor. Peel waste (flavedo and albedo) from orange juice manufacturing was successfully employed as a biocatalyst.
- Fontana, Gianfranco,Bruno, Maurizio,Maggio, Antonella,Rosselli, Sergio
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supporting information
p. 4502 - 4507
(2020/03/16)
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- METHOD OF MAKING VITAMIN K1
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This invention discloses a method of making vitamin K1. The mentioned method of making vitamin K1 comprises performing a first one-pot synthesis with base catalyst, performing a first hydrolysis, performing a substitution, and performing a second one-pot synthesis without metal oxidant. The starting material of this invention is stable 2-methyl-1,4-naphthoquinone. Preferably, this invention provides a method of making vitamin K1 efficiently on simplifying the operation and decreasing the side-product. More preferably, without metal residue, the vitamin K1 of this invention is without metal residue and more safety for clinical application.
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Paragraph 0045-0048
(2016/12/12)
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- A METHOD OF MAKING VITAMIN K1
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This invention discloses a method of making vitamin K1. The mentioned method of making vitamin K1 comprises performing a first one-pot synthesis with base catalyst, performing a first hydrolysis, performing a substitution, and performing a second one-pot synthesis for oxidation reaction without using metal oxidant. The starting material of this invention is stable 2-methyl-1,4-naphthoquinone. Preferably, this invention provides a method of making vitamin K1 efficiently on simplifying the operation and decreasing the formation of side-product. More preferably, without the usage of metal residue in this invention results that the vitamin K1 is more safety for clinical application.
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Paragraph 0058-0060
(2017/03/28)
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- CANNABINOID RECEPTOR MODULATOR
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A cannabinoid receptor modulator containing a compound represented by Formula (I0) wherein, X is an oxygen atom, etc., R° is an optionally substituted acylamino group, ring A0 is a benzene ring which may further have a substituent in addition to R°, and ring B is an optionally substituted 5-membered heterocycle, or a salt thereof or a prodrug thereof.
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Page/Page column 81
(2008/06/13)
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- Synthesis and cytotoxicity of 9-substituted benzo[de]chromene-7,8-dione and 5-benzyl-9-substituted benzo[de]chromene-7,8-dione
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New Mansonone analogues of 9-substitued benzo[de]chromene-7,8-dione 5b-e and 5-benzyl-9-substitued benzo[de]chromene-7,8-dione 6a-e were prepared through a modified route. The first step involved a bulky base t-butylamine mediated regioselective deacetylation of 2-substituted-1,4-naphth-diyl diacetate, resulting in obtaining of monoacetate 4-acetate 2 in high yield. The mechanism of cyclization, debenzylation, and oxidation for the formation of 5a-e and 6a-e were discussed. The cytotoxicity of the prepared compounds 5 and 6 were comparable with naturally occurring Mansonone F. Copyright Taylor & Francis Group, LLC.
- Huang, Shi-Liang,Luo, Yi,Huang, Zhi-Shu,Wang, Xing-Yuan,Bu, Xian-Zhang,Liu, Pei-Qing,Ma, Lin,Xie, Bing-Fen,Liu, Zong-Chao,Li, Yue-Ming,Chan, Albert S. C.,Gu, Lian-Quan
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p. 2667 - 2684
(2007/10/03)
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- Regioselective hydrolysis of diacetoxynaphthalenes catalyzed by Pseudomonas sp. lipase in an organic solvent
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Depending on the relative positions of the acetyl groups in the aromatic rings, the Pseudomonas sp. lipase-catalyzed hydrolysis of diacetoxynaphthalenes in tert-butylmethyl ether proceeds regioselectively to afford the corresponding monoacetates.
- Ciuffreda, Pierangela,Casati, Silvana,Santaniello, Enzo
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p. 317 - 321
(2007/10/03)
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- Thermochemical investigation of the oxygenation of vitamin K
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Discovery of a new oxygenation reaction of naphthohydroquinone anions makes possible a determination of the heat of reaction (ΔHox) of oxygen with the potassium salt derived from deprotonation of the hydroquinone form of vitamin K. From that value (-33.52 ± 0.60 kcal/mol), the heat of deprotonation of vitamin KH2 (-30.03 ± 1.20 kcal/mol), and the heat of deprotonation of water (-6.05 ± 0.3 kcal/mol), the enthalpy change for converting vitamin KH2 to vitamin K oxide is established to be -57.5 kcal/mol, in reasonable agreement with our previous estimate of -62.4 kcal/mol for the oxygenation of the parent naphthohydroquinone. Indeed, in similar fashion the heat of oxygenation of the parent naphthohydroquinone was determined to be -58.47 kcal/mol, and this permits the assignment of a heat of formation to naphthoquinone epoxide of ΔHf° = -47.6 kcal/mol. Heats of oxygenation and deprotonation of a variety of related phenols and naphthols provide perspective on cation and substitution effects. These data provide strong support for the base strength amplification mechanism for the biological action of vitamin K proposed by two of us (P.D. and S.W.H.).
- Flowers II, Robert A.,Naganathan, Sriram,Dowd, Paul,Arnett, Edward M.,Ham, Seung Wook
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p. 9409 - 9416
(2007/10/02)
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