Head of acquisitions donated tequila ingredient (5)
I believe the answer is:
agave
'tequila ingredient' is the definition.
(I've seen this in another clue)
'head of acquisitions donated' is the wordplay.
'head of' indicates taking the first letters.
'donated' becomes 'gave' (give can mean to donate).
The initial letter of 'acquisitions' is 'a'.
'a'+'gave'='AGAVE'
(Other definitions for agave that I've seen before include "source of tequila" , "Succulent plant" , "Spiky succulent" , "Tropical plant" , "Succulent; daughter of Cadmus" .)