This answer has been challenged previously though- I recall it was argued that the word that fits the clue (but not the letters) is LUPULIN and that LUPULINE means something else.
I'm sure JimJools is right.
Here is the thread though that I meant to add- in this foxwall strongly challenged the validity of LIPULINE given by the ever reliable bibblebub
http://www.theanswerb...s/Question925805.html