PMID-sentid Pub_year Sent_text comp_official_name comp_offsetprotein_name organism prot_offset 11233209-5 2000 The ratio of second-order rate constants, kfast/kslow, with kfast being rate constant k for the faster reacting pair of enantiomers and vice versa, lies in the range 1.0-3.0, depending on the nature of the N-alkyl groups in NiA2 and organic groups attached to the ethylene bridge in the salen ligands H2B. ethylene 264-272 H2B clustered histone 21 Homo sapiens 301-304