convert json tree structure to list : i am new in json.  i have a json list in tree structure  like bellow

        {"complaint@simulator.amazonses.com":{"time":"2018-01-02T20:45:46.650Z","type":"Complaint","bounceType":"null","bounceSubType":"null"},
    "struax@afb.net":{"time":"2018-01-02T20:53:03.000Z","type":"Bounce","bounceType":"Permanent","bounceSubType":"Suppressed"},
    "bounce-test@service.socketlabs.com":{"time":"2018-01-02T21:06:40.097Z","type":"Bounce","bounceType":"Permanent","bounceSubType":"Suppressed"},
    "bounce@simulator.amazonses.com":{"time":"2018-01-02T21:08:02.000Z","type":"Bounce","bounceType":"Permanent","bounceSubType":"General"},
    "jstrechay@afb.net":{"time":"2018-01-05T06:31:39.000Z","type":"Bounce","bounceType":"Permanent","bounceSubType":"General"},
    "leematt45@hotmail.com":{"time":"2018-01-05T06:49:13.000Z","type":"Bounce","bounceType":"Permanent","bounceSubType":"Suppressed"},
    "afbweb@afb.net":{"time":"2018-01-07T12:50:38.000Z","type":"Bounce","bounceType":"Transient","bounceSubType":"General"},
    "rushjenacath@gmail.com":{"time":"2018-01-05T06:32:42.000Z","type":"Bounce","bounceType":"Permanent","bounceSubType":"Suppressed"},
    "Kerryhoskins0925@gmaiil.com":{"time":"2018-01-02T09:18:20.000Z","type":"Bounce","bounceType":"Transient","bounceSubType":"General"},

how to extract data  form the json list and save in db.
please help 