左炔诺孕酮Levonorgestrelcas：797-63-7左炔诺孕酮杂质BLevonorgestrelImpurityB：13-Ethyl-17-hydroxy-18,19-dinor-17α-pregn-5(10)-en-20-yn-3-one(LevoNorgestrelImpurity)规格1mg左炔诺孕酮杂质CLevonorgestrelImpurityC:13-Ethyl-3-ethynyl-18,19-dinor-17α-pregna-3,5-dien-20-yn-17-ol(LevoNorgestrelImpurity)规格2.5mg左炔诺孕酮杂质DLevonorgestrelImpurityD：13-Ethyl-18,19-dinor-17α-pregn-4-en-20-yn-17-ol(LevoNorgestrelImpurity)规格2.5mg)