Offend again perhaps, producing plant extract (5)
I believe the answer is:
resin
'plant extract' is the definition.
(I've seen this before)
'offend again perhaps' is the wordplay.
I cannot quite understand how this works, but
'offend' could be 'sin' (sin can mean to commit an offence) and 'sin' is present in the answer.
'again' could be 're' (prefix meaning 'again') and 're' is located in the answer.
No letters remain.
This explanation may well be incorrect...
'producing' acts as a link.
Can you help me to learn more?
(Other definitions for resin that I've seen before include "Tree gum" , "Fiddler's need" , "Synthetic substance" , "Risen (anag.)" , "Lac" .)