Аннотация:We derive explicit expressions for the elements of the {β}-expansion for the nonsinglet Adler D_A-function and Bjorken polarized sum rules S^{Bjp} in the N^4LO using recent results by Chetyrkin for these quantities computed within extended QCD including any number of fermion representations. We discuss the properties of the {β}-expansion for D_A and S^{Bjp} at higher orders which follow from the Crewther [1] and the Broadhurst-Kataev [2] relation.