Record ... Herd affected in Evans Head producing anti-asthma alkaloids (9)

I believe the answer is:

ephedrine

I'm a little stuck... Click here to teach me more about this clue!

'anti-asthma alkaloids' is the definition.
I can't tell whether this defines the answer.

'record herd affected in evans head' is the wordplay.
'record' becomes 'EP' (abbreviation for extended play record).
'affected' indicates anagramming the letters.
'head' suggests taking the first letters.
The initial letter of 'evans' is 'e'.
'herd' is an anagram of 'hedr'.
'ep'+'hedr'+'in'+'e'='EPHEDRINE'

'producing' acts as a link.

Can you help me to learn more?

(Other definitions for ephedrine that I've seen before include "Stimulant" , "Drug used for asthma and hay fever" , "Bronchitis/asthma drug" .)

I've seen this clue in the Sydney Morning Herald.

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