One that may ring pop star, extracting money, implying poison (10)

I believe the answer is:
belladonna
'poison' is the definition.
(I've seen this before)
'one that may ring pop star extracting money' is the wordplay.
I cannot really understand how this works, but
'one' could be 'a' (a thing is one thing) and 'a' is located in the answer.
'ring' could be 'bell' (both can mean to call on the phone) and 'bell' is found within the answer.
The remaining letters 'donna' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'implying' acts as a link.
Can you help me to learn more?
(Other definitions for belladonna that I've seen before include "Could it poison" , "Deadly nightshade or atropine" , "Boy in Lebanon destroyed" , "drug supplier" , "brought a sparkle to the eye" .)
