Cal. Prob. Code § 1875

A transaction that affects real property of the conservatorship estate, entered into by a person acting in good faith and for a valuable consideration and without knowledge of the establishment of the conservatorship, is not affected by any provision of this article or any order made under this article unless a notice of the establishment of the conservatorship or temporary conservatorship has been recorded prior to the transaction in the county in which the property is located.