Are there any chiral centres in these compounds??

Nicotine, 有chiral centre,因為在N對下的Carbon 就是chiral centre
http://chemfinder.cambridgesoft.com/result.asp
Adrenaline 有chiral centre,因為在OH group 中的Carbon 就是chiral centre
http://chemfinder.cambridgesoft.com/result.asp?mol_rel_id=51-43-4
& Thyroxine 有chiral centre,因為有NH2 group黏住的Carbon 就是chiral centre
http://chemfinder.cambridgesoft.com/result.asp
And also is chiral centre only restricted to sp3 hybridization state?? Of course NOT, double bond cpd can also be optically active. They are called allene. See HKAL Chemistry examination paper 2003 paper I for answer.
I hope you will find my answer helpful.

I saw the structures from google.
All of them have chiral centres.
For more detail, you can find the pictures of their structures from google.

do you have the structure, i don' t know the structure, so can't answer you.
but if the compound have chiral centre, the chiral atom must bonded with 4 different groups. because the chiral atom must bonded with 4 different groups, so it must be sp3