A compound of formula A, or a pharmaceutically acceptable salt, solvate, racemat, non-enantiomer, or geometric isomer thereof wherein: R 1 and R 2, are the same or different, selected from hydrogen; alkyl; optionally substituted saturate hydrocarbon rings containing 1 to 3 ring(s) and each ring containing 3 to 7 carbon atoms; alkoxy alkyl; alkyl amino alkyl; heterocycle; a straight chain or branched-chain alkyl group with 1 to 4 ethylenic bond(s) containing 2 to 20 carbon atoms; and a straight chain or branched-chain alkyl group with 1 to 4 acetylenic bond(s) containing 2 to 20 carbon atoms; whereinhydrocarbyl; alkoxy alkyl; alkyl amino alkyl and heterocycle are unsubstituted or optionally substituted, preferably substituted by halogen, hydroxyl, alkoxy, alkyl, alkoxy alkyl, optionally substituted saturate hydrocarbon ring containing 1 to 3 ring(s) and each ring containing 3 to 7 carbon atoms, and heterocycle; provided that R 1 or R 2 does not contain any unsaturated bond, or if R 1 and/or R 2 contain(s) unsaturated bond, the atom of the unsaturated bond cannot be directly connected with nitrogen atom; R 3 is selected from alkyl, an optionally substituted saturate hydrocarbon ring containing 1 to 3 ring(s) and each ring containing 3 to 7 carbon atoms; R 4 and R 5, are the same or different, selected from: hydrogen; hydroxyl; alkyl; optionally substituted saturate hydrocarbon rings containing 1 to 3 ring(s) and each ring containing 3 to 7 carbon atoms; alkoxy; alkoxy alkyl; heterocycle; a straight chain or branched-chain alkyl group with 1 to 4 ethylenic bond(s) containing 2 to 20 carbon atoms; a straight chain or branched-chain alkyl group with 1 to 4 acetylenic bond(s) containing 2 to 20 carbon atoms; wherein alkyl, a straight chain or branched-chain alkyl group with 1 to 4 ethylenic bond(s) containing 2 to 20 carbon atoms, a straight chain or branched-chain alkyl group with 1 to 4 acetylenic bond(s) containing 2 to 20 carbon atoms, optionally substituted saturate hydrocarbon ring containing 1 to 3 ring(s) and each ring containing 3 to 7 carbon atoms, alkoxy alkyl, alkyl amino alkyl and heterocycle are unsubstituted or optionally substituted, preferably substituted by halogen, hydroxyl, alkoxy, straight chain or branched-chain alkyl, alkoxy alkyl, an optionally substituted saturate hydrocarbon ring containing 1 to 3 ring(s) and each ring containing 3 to 7 carbon atoms and heterocycle; R 4 and R 5 form a closed ring via the connected atoms of R 4 and R 5; said ring may be a quaternary, pentabasic, hexahydric, heptabasic or octatomic ring; said ring is optionally condensed with other rings and optionally substituted, preferably substituted by halogen, hydroxyl, alkoxy, straight chain or branched-chain alkyl, alkoxy alkyl, an optionally substituted saturate hydrocarbon ring containing 1 to 3 ring(s) and each ring containing 3 to 7 carbon atoms and heterocycle. R 1 and R 2, are the same or different, selected from hydrogen; alkyl; optionally substituted saturate hydrocarbon rings containing 1 to 3 ring(s) and each ring containing 3 to 7 carbon atoms; alkoxy alkyl; alkyl amino alkyl; heterocycle; a straight chain or branched-chain alkyl group with 1 to 4 ethylenic bond(s) containing 2 to 20 carbon atoms; and a straight chain or branched-chain alkyl group with 1 to 4 acetylenic bond(s) containing 2 to 20 carbon atoms; whereinhydrocarbyl; alkoxy alkyl; alkyl amino alkyl and heterocycle are unsubstituted or optionally substituted, preferably substituted by halogen, hydroxyl, alkoxy, alkyl, alkoxy alkyl, optionally substituted saturate hydrocarbon ring containing 1 to 3 ring(s) and each ring containing 3 to 7 carbon atoms, and heterocycle; provided that R 1 or R 2 does not contain any unsaturated bond, or if R 1 and/or R 2 contain(s) unsaturated bond, the atom of the unsaturated bond cannot be directly connected with nitrogen atom; R 3 is selected from alkyl, an optionally substituted saturate hydrocarbon ring containing 1 to 3 ring(s) and each ring containing 3 to 7 carbon atoms; R 4 and R 5, are the same or different, selected from: hydrogen; hydroxyl; alkyl; optionally substituted saturate hydrocarbon rings containing 1 to 3 ring(s) and each ring containing 3 to 7 carbon atoms; alkoxy; alkoxy alkyl; heterocycle; a straight chain or branched-chain alkyl group with 1 to 4 ethylenic bond(s) containing 2 to 20 carbon atoms; a straight chain or branched-chain alkyl group with 1 to 4 acetylenic bond(s) containing 2 to 20 carbon atoms; wherein alkyl, a straight chain or branched-chain alkyl group with 1 to 4 ethylenic bond(s) containing 2 to 20 carbon atoms, a straight chain or branched-chain alkyl group with 1 to 4 acetylenic bond(s) containing 2 to 20 carbon atoms, optionally substituted saturate hydrocarbon ring containing 1 to 3 ring(s) and each ring containing 3 to 7 carbon atoms, alkoxy alkyl, alkyl amino alkyl and heterocycle are unsubstituted or optionally substituted, preferably substituted by halogen, hydroxyl, alkoxy, straight chain or branched-chain alkyl, alkoxy alkyl, an optionally substituted saturate hydrocarbon ring containing 1 to 3 ring(s) and each ring containing 3 to 7 carbon atoms and heterocycle; R 4 and R 5 form a closed ring via the connected atoms of R 4 and R 5; said ring may be a quaternary, pentabasic, hexahydric, heptabasic or octatomic ring; said ring is optionally condensed with other rings and optionally substituted, preferably substituted by halogen, hydroxyl, alkoxy, straight chain or branched-chain alkyl, alkoxy alkyl, an optionally substituted saturate hydrocarbon ring containing 1 to 3 ring(s) and each ring containing 3 to 7 carbon atoms and heterocycle.