Is commerical lease valid after property sold?

My son has a 3 year lease on a Florida commercial property with 6 months remaining. Business is down and he wants to close the business now. The property sold to a new owner six months ago and we find nothing in the lease to suggest the lease commitment will extend to a new owner. Would my son most likely be free to give a 30 day notice and move out?

The only item that remotely suggests to me the lease contract might apply to a new owner is the following:

"Item # 33. BINDING EFFECT. Except as otherwise provided herein, the terms, covenants, conditions and agreements of this lease shall be binding upon and shall inure to the benefit of the parties and their respective heirs, personal representatives, successors, and assigns."

Would the terms "successors" and "assigns" refer to a new owner, or is the contract valid only for my son and the original owner named in the lease?

Good for you for reading the contract and catching what your son apparently didn't. That's exactly what it means: your son's agreement is now transferred to the new owner. The lease was most likely assigned at the time the new owner purchased the property or shortly thereafter.