How to rotate the UV coordinates?

This is the code i am using to assign the UV values.

void setUV()
	for(int i = 0; i<originalUV.Length; i++)
		updatedUV<em>.x = originalUV_.x * 0.25f;_</em>

updatedUV.y = originalUV_.y * 0.5f;
* }
mesh.uv = updatedUV;

Now i just want to rotate the UV on pressing a button.
Can somebody help? I am fairly new to unity and would appreciate it very much._

Vector2 source_uv = new Vector2(someX, someY);
Vector2 rotated_uv = Quaternion.AngleAxis(30f,Vector3.up) * source_uv;

end then use rotated_uv.x and rotated_uv.y

Thanks, but i solved it already.