Corollary 2
Tag 0ALG, permanent. Cite it as [Bourbaki, Tag 0ALG].
Lie Groups and Lie Algebras, chapter III, § 10. The automorphism group of a Lie group
Let G be a semi-simple connected real or complex Lie group. The group Int G is the identity component of Aut G.
The mapping is an isomorphism of Aut G onto a Lie subgroup of Aut (Theorem 1). The image of Int G under this isomorphism is Ad G. But Ad G is the identity component of Aut (, no. 8, Proposition 30 (ii)).
Bourbaki puts the proof directly after the statement, so what is above is the statement and its proof together.