saving ObservableCollection to SQLite or similar, Xamarin Forms

I'm having multiple ObservableCollections in my app, which I would like to save, edit and so on. But since they're a collection of my own type of class, SQLite doesn't recognizes them. What would be the best way to save theses? Or what am I doing wrong.

Sort of looks something like this:

In my App: (Of course there's more code inside)

public partial class App : Application
{
  static MyDatabase database;

  public static MyDatabase Database
  {
    get
    {
      if (database == null)
      {
        database = new MyDatabase(DependencyService.Get
<IFileHelper>().GetLocalFilePath("MyListSQLite.db3"));
      }
      return database;
    }
  }
}

MyDatabase:

public class MyDatabase
{
  readonly SQLiteAsyncConnection database;

  public MyDatabase(string dbPath)
  {
    database = new SQLiteAsyncConnection(dbPath);
    database.CreateTableAsync<MyClass>().Wait();
  }

  public Task<List<MyClass>> GetItemsAsync()
  {
    return database.Table<MyClass>().ToListAsync();
  }

    public Task<MyClass> GetItemAsync(int id)
    {
        return database.Table<MyClass>().Where(i => i.ID == id).FirstOrDefaultAsync();
    }

    public Task<int> SaveItemAsync(MyClass item)
    {
        if (item.ID != 0)
        {
            return database.UpdateAsync(item);
        }
        else
        {
            return database.InsertAsync(item);
        }
    }

    public Task<int> DeleteItemAsync(MyClass item)
    {
        return database.DeleteAsync(item);
    }

}

MyClass:

public class MyClass : ObservableCollection<MyOtherClass>
{
  [PrimaryKey, AutoIncrement]
  public int ID { get; set; }
}

MyOtherClass:

public class MyOtherClass : BindableObject
    {
        [PrimaryKey, AutoIncrement]
        public int ID { get; set; }


        public static readonly BindableProperty ListNbrProperty =
            BindableProperty.Create("ListNbr", typeof(int), typeof(MyOtherClass), default(int));

        public int ListNbr
        {
            get { return (int)GetValue(ListNbrProperty); }
            set { SetValue(ListNbrProperty, value); }
        }

        public bool IsMaster { get; set; }

        public static readonly BindableProperty ResizedPathProperty =
            BindableProperty.Create("ResizedPath", typeof(String), typeof(MyOtherClass), default(String));

        public String ResizedPath
        {
            get { return (String)GetValue(ResizedPathProperty); }
            set { SetValue(ResizedPathProperty, value); }
        }
...
}