IPA: /ˌæl.kəˈlɔɪ.dəl/
KK: /ælˈkeɪlɔɪdəl/
Relating to a group of natural compounds that often have strong effects on living organisms, commonly found in plants.
The researchers studied the alkaloidal properties of the plant extracts.
Alkaloidal → It is formed from 'alkaloid' (from the Greek 'alkali', meaning ashes or alkaline substances) and the suffix '-al' (meaning pertaining to). The word 'alkaloidal' refers to substances that are related to or characteristic of alkaloids, which are a class of naturally occurring organic compounds that mostly contain basic nitrogen atoms.
Think of 'alkaloid' as relating to 'alkaline substances' and remember that 'alkaloidal' means pertaining to those substances.