Incorrect NO2 group rendering in mol2 saving

Hi!i have a problem with nitro group as a substitution !i draw it with correct charge and valance (N+,O,O-)but when i open mol2 or sdf file that i saved it shows NH and OH instead of the correct form!i really appreciate if you can help me!

Hi! Could you specify the version of your MarvinSketch, please?  And may be your files as well - just to be on the safe side - so we can investigate on your problem.

Thank you very much!

Best regards,

Nikolett Mihala