Look for "real extracts" in your product search as most juices use articial flavors. They are not easy to find. Most e-juices promoted as natural fruit flavors are, in fact, lab produced "natural" flavors. Contact the manufacturer and talk to them about it if there is any doubt. A real natural will state "no artificial flavors" but the e-juice industry is based upon artificial flavors almost exclusively.
Those of us that don't vape artificial flavors go to more trouble than most vapers to find our liquids. We also work a little harder to vape as we have to change our wicks and clean our coils more often but it is worth it for real natural flavors IMHO. Some atomizers are better better suited to the natural flavors as well.
added:
Fadora Vapor
Five Pawns
Vape Dudes
EC Blends
None of the vendors listed above are natural flavors based upon their website info. I just sent off a customer request to Five Pawns asking them to clarify their ingredients statement.