Parse this person name:

Sebastiaan van den Wittenboer, 1426-1503, flourished 1452-1474
user
first_name: Sebastiaan
last_name: van den Wittenboer
middle_names: []
temporal:
- start: 1426
  end: 1503
  type: life_span
- start: 1452
  end: 1474
  type: flourished
titles: []
extra_info: []
assistant