> are there any flavours that are totally made up, not derived or inspired from something natural?
There are three ways to make flavours, by extracting it from some living organism or existing mineral is often the cheapest. Synthesising it to match something familiar is a good way to generate sales.
Then there’s the “suck it and see” method of making a chemical and trying it out to smell what the flavour is.
MSG would be the most familiar completely synthetic flavour, but even that was first a natural product, found in sea kelp in 1908.
Artificial sweeteners are artificial flavours, but are still made in imitation of natural flavours. Completely artificial sweeteners include aspartame, saccharin and sucralose, and many others.
Wikipedia gives a list of aroma compounds (not to be confused with “aromatic”), keeping in mind that most of taste is actually aroma. https://en.wikipedia.org/wiki/Aroma_compound
These are:
1 Aroma-compounds classified by structure
1.1 Esters
1.2 Linear-terpenes
1.3 Cyclic-terpenes
1.4 Aromatic
1.5 Amines
2 Other aroma-compounds
2.1 Alcohols
2.2 Aldehydes
2.3 Esters
2.4 Ketones
2.5 Lactones
2.6 Thiols
2.7 Miscellaneous-compounds
Almost all the aroma compounds either occur naturally or roughly imitate a natural flavour. Or as used as “foul taste” agents.
Methyl formate is an aroma compound that does not imitate a natural flavour and does not occur naturally. Its aroma is described as “Ethereal”. A similar is Acetaldehyde.