“…Toxicity to humans prevented by vitamin B 6 supplementation (Epstein et al, 1958(Epstein et al, -1959; behaves as a pyridoxine antagonist in vitro (Braunstein et al, 1962;Dann and Carter, 1964;Cedrangolo, 1963;Khomutov et al, 1963;Karpeisky et al, 1963).…”