Sadly got into a last bottle of juice (4)
I believe the answer is:
alas
'sadly' is the definition.
('alas' is used to express regret)
'into a last bottle of juice' is the wordplay.
I cannot quite see how this works, but
'a' is found in the answer.
The remaining letters 'las' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'got' is the link.
Can you help me to learn more?
(Other definitions for alas that I've seen before include "Sad expression" , "'- Poor Yorick' (Hamlet)" , "More's the pity" , "Regretfully!" , "Expression of grief or misfortune" .)