66791-71-7Relevant articles and documents
Synthesis and biological activities of 2α-chloro-1-epicalcitriol and 1- epicalcitriol
Schoenecker, Bruno,Reichenbaecher, Manfred,Gliesing, Sabine,Gonschior, Manuela,Griebenow, Sirid,Scheddin, Dietmar,Mayer, Hubert
, p. 28 - 36 (1998)
Anomalous diequatorial epoxide ring opening of 1β, 2β-oxido-cholesta- 5,7-diene-3β,25-diol 1 produces the 1β-hydroxy-2α-chloro-provitamin 2 and its corresponding 1β-hydroxy-provitamin 3. The provitamins 2 and 3 are transformed by irradiation and thermal isomerization to 2α-chloro-1- epicalcitriol NS3 (4) and 1-epicalcitriol NS8 (5), respectively. These two A- ring derivatives were tested for their in vitro biological activity in the mesenchymal, murine cell line C3H10T 1/4 , and their effects were compared with those of the native vitamin D3 derivatives 25(OH)D3 and 1,25(OH)2D3. NS3 and NS8 showed marked differences in their affinity for the vitamin D binding protein (DBP) and in their ability to inhibit cell proliferation. NS8 has the ability to bind to a high-affinity DBP-binding site for which 25(OH)D3 has none affinity. The 2α-chloro-substitution (NS3) prevents binding to the postulated noncompetitive, NS8-specific DBP-binding site and diminishes the affinity to the vitamin D receptor (VDR) and therefore diminishing NS3 's biological abilities. The elucidation of the structure-function relationships at the DBP-binding-sites could have major impact on the development of new vitamin D3 derivatives with extended serum half-life.
Characterization of rat and human CYP2J enzymes as Vitamin D 25-hydroxylases
Aiba, Isamu,Yamasaki, Tomoaki,Shinki, Toshimasa,Izumi, Shunsuke,Yamamoto, Keiko,Yamada, Sachiko,Terato, Hiroaki,Ide, Hiroshi,Ohyama, Yoshihiko
, p. 849 - 856 (2007/10/03)
vitamin D is 25-hydroxylated in the liver, before being activated by 1α-hydroxylation in the kidney. Recently, the rat cytochrome P450 2J3 (CYP2J3) has been identified as a principal vitamin D 25-hydroxylase in the rat [Yamasaki T, Izumi S, Ide H, Ohyama Y. Identification of a novel rat microsomal vitamin D3 25-hydroxylase. J Biol Chem 2004;279(22):22848-56]. In this study, we examine whether human CYP2J2 that exhibits 73% amino acid homology to rat CYP2J3 has similar catalytic properties. Recombinant human CYP2J2 was overexpressed in Escherichia coli, purified, and assayed for vitamin D 25-hydroxylation activity. We found significant 25-hydroxylation activity toward vitamin D3 (turnover number, 0.087 min-1), vitamin D2 (0.16 min-1), and 1α-hydroxyvitamin D3 (2.2 min-1). Interestingly, human CYP2J2 hydroxylated vitamin D2, an exogenous vitamin D, at a higher rate than it did vitamin D3, an endogenous vitamin D, whereas, rat CYP2J3 hydroxylated vitamin D3 (1.4 min-1) more efficiently than vitamin D2 (0.86 min-1). Our study demonstrated that human CYP2J2 exhibits 25-hydroxylation activity as well as rat CYP2J3, although the activity of human CYP2J2 is weaker than rat CYP2J3. CYP2J2 and CYP2J3 exhibit distinct preferences toward vitamin D3 and D2.
New Convergent Synthesis of 1α,25-Dihydroxyvitamin D3 and Its Analogues by Suzuki-Miyaura Coupling between A-Ring and C,D-Ring Parts
Hanazawa, Takeshi,Koyama, Akiko,Nakata, Kunio,Okamoto, Sentaro,Sato, Fumie
, p. 9767 - 9772 (2007/10/03)
A new convergent method for the synthesis of 1α,25 -dihydroxyvitamin D3 and its analogues has been developed that involves efficient preparation of the A-ring part 1a, (Z)-(3S,5R)-1-bromom-ethylene-3,5-bis(tert-butyldimethylsilyloxy) -2-methylenecyclohexane, starting from epichlorohydrin (4) and its Suzuki-Miyaura coupling reaction with the C,D-ring part 12. Thus, (R)-4 was converted to (3S,5R)-5-(tert-butyldimethylsilyloxy)-8-(trimethylsilyl)-oct-l-en-7-yn-3-ol (3a) through a ten-step reaction sequence in 49% overall yield. Compound 3a thus obtained was treated with a Ti(O-i-Pr)4/2 i-PrMgCl reagent and then with NBS to afford (Z)-(1S,2S,5R)-2-bromomethyl-3-[bromo-(trimethylsilyl)methylene] -5-(tert-butyldimethylsilyloxy)cyclohexanol (10a) in 51% yield, from which la was obtained in 87% yield by sequential treatment with TBSCl/imidazole, DBU, and Cs2CO3. The resulting A-ring intermediate 1a was reacted with alkenylboronate 12 in the presence of a PdCl2(dppf) catalyst to furnish 1α,25 -dihydroxyvitamin D3 in 82% yield after protodesilylation. Similarly, all of the other three possible stereoisomers of A-ring parts 1b, 1c, and 1d were prepared, from which 1-epi-, 3-epi-, and 1,3-di-epi-1α,25-dihydroxyvitamin D3 were synthesized by coupling with 12 in excellent yield, respectively. Starting from 1a and 1c, des-C,D-1α,25-dihydroxyvitamin D3 analogues, retiferol 13 and its 3-epi derivative, were also prepared, respectively.
Efficient synthesis and biological evaluation of all A-ring diastereomers of 1α,25-dihydroxyvitamin D3 and its 20-epimer
Fujishima, Toshie,Konno, Katsuhiro,Nakagawa, Kimie,Kurobe, Mayuko,Okano, Toshio,Takayama, Hiroaki
, p. 123 - 134 (2007/10/03)
An improved synthesis of the diastereomers of 1α,25-dihydroxyvitamin D3 (1) was accomplished utilizing our practical route to the A-ring synthon. We applied this procedure to synthesize for the first time all possible A- ring diastereomers of 20-epi-1α,25-dihydroxyvitamin D3 (2). Ten-step conversion of 1-(4-methoxyphenoxy)but-3-ene (6), including enantiomeric introduction of the C-3 hydroxyl group to the olefin by the Sharpless asymmetric dihydroxylation, provided all four possible stereoisomers of A- ring enynes (3), i.e., (3R,5R)-, (3R,5S)-, (3S,5R)- and (3S,5S)-bis[(tert- butyldimethylsilyl)oxy]oct-1-en-7-yne, in good overall yield. Palladium- catalyzed cross-coupling of the A-ring synthon with the 20-epi CD-ring portion (5), (E)-(20S)-de-A,B-8-(bromomethylene)cholestan-25-ol, followed by deprotection, afforded the requisite diastereomers of 20-epi-1α,25- dihydroxyvitamin D3 (2). The biological profiles of the synthesized stereoisomers were assessed in terms of affinities for vitamin D receptor (VDR) and vitamin D binding protein (DBP), HL-60 cell differentiation- inducing activity and in vivo calcium-regulating potency in comparison with the natural hormone. (C) 2000 Elsevier Science Ltd.
A novel and practical route to A-ring enyne synthon for 1α,25-dihydroxyvitamin D3 analogs: Synthesis of A-ring diastereomert of 1α,25-dihydroxyvitamin D3 and 2-methyl-1,25-dihydroxyvitamin D3
Konno, Katsuhiro,Maki, Shojiro,Fujishima, Toshie,Zhaopeng, Liu,Miura, Daishiro,Chokki, Manabu,Takayama, Hiroaki
, p. 151 - 156 (2007/10/03)
A novel and practical route to the A-ring enyne synthon (2), which can be versatile far a variety of A-ring analogs of 1α,25-dihydroxyvitamin D3 (1), was developed. This novel method led to an improved synthesis of the A-ring diastereomers of 1, the compounds 13-15, and synthesis of the new analogs, 2-methyl-1,25-dihydroxyvitamin D3 (4) with its all possible diastereomers. The biological evaluation of the 2-methyl analogs showed the ααβ-isomer to be more potent than 1.
