Nitrosoguanidines structure

A comparison of structures of V-methyl-V-nitroso-p-nitrobenzamide, N,N -dimethyl-V-nitrosourea, V-methyl-V-nitrosourea, 2-nitroso-2-azabicyclo[2.2.2]octan-3-one to those of V-methyl-V -nitro-V-nitrosoguanidine and V,V -dimethyl-V"-cyano-V-nitrosoguanidine shows that the N—N and C—NNO bond lengths in the nitroguanidines44 are similar to those found in the nitrosoamides, but that the corresponding bonds in... 

Figure 22.12. Structures of simple alkylating agents frequently used in the laboratory. MMS, methyl methanesulfonate EMS, ethyl methanesulfonate MNNG, iV-methyl-lV -mtro-jV-nitrosoguanidine MNU, methylnitrosourea.

To obtain further information on enzyme structure and the biosynthetic mechanisms of gramicidin S formation, mutants with defective multienzymes have been isolated. Mutants producing no detectable gramicidin, or less than normal amounts were isolated with very low frequency from B. brevis after treatment with N-methyl-N-nitro-N-nitrosoguanidin (NTG) (6), or with very high frequency (10 %) after treatment of the parental strain with acridine orange or ethidium-bromide. The screening of the mutants was carried out as follows ... 

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