02645nas a2200289   4500008004100000022001400041245018900055210006900244260007300313300001000386490000800396520149100404653003101895653001401926653003601940653004601976653002502022653002402047100001802071700002102089700002702110700002402137700001702161700002402178700002502202856012802227       2008                        eng d  a0022-286000aVitamin K-3 family members - Part II: Single crystal X-ray structures, temperature-induced packing polymorphism, magneto-structural correlations and probable anti-oncogenic candidature0 aVitamin K3 family members Part II Single crystal Xray structures  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcDEC  a74-830 v8923 a<p>Temperature-induced packing polymorphism is observed for vitamin K-3 (menadione, 3-methyl-1,4-naphthoquinone, 1). Form la crystallizes at 300 K and 1b at 277 K both in the same space group P2(1)/c. Form 1b contains one molecule per asymmetric unit, performing anisotropy in g-factor viz. g(z) = 2.0082, g(y) = 2.0055 and g(x) = 2.0025, whereas form 1a contains two molecules in its asymmetric unit. Vitamin K-3 family members 2, [2-hydroxy vitamin K-3] and 3, [2-hydroxy-1-oximino vitamin K-3] also perform intrinsic neutral active naphthosemiquinone valence tautomers even in dark having spin concentrations due to hydrogen bonding and aromatic stacking interactions which are compared to vitamin K-3. The significant lateral C-H center dot center dot center dot O and O-H center dot center dot center dot pi bifurcated or pi-pi(center dot) interactions are discussed for molecular associations and radical formations. X-ray structure of 3 revealed pi-pi(center dot) stack dimers as radicals signatured in PR as triplet with five hyperfine splits [(A) over bar(N-14) = 11.9 G]. The centrosymmetric biradicals in 3 show diamagnetism at high temperature but below 10 K it shows paramagnetism with mu(eff) as 0.19 B.M. Vitamin K-3 and its family members inhibit biological activities of acid phosphatase (APase), which are proportional to their spin concentrations. This may relate to their probable anti-oncogenic candidature in future. (C) 2008 Elsevier B.V. All rights reserved.</p>10aAnti-oncogenic candidature10aH-bonding10aMagneto-structural correlations10aNaphthosemiquinones in vitamin K-3 family10aPacking polymorphism10aSpin concentrations1 aRane, Sandhya1 aAhmed, Khursheed1 aSalunke-Gawali, Sunita1 aZaware, Santosh, B.1 aSrinivas, D.1 aGonnade, Rajesh, G.1 aBhadbhade, Mohan, M.  uhttps://library.ncl.res.in/content/vitamin-k-3-family-members-part-ii-single-crystal-x-ray-structures-temperature-induced-0