The inventions disclosed herein relate to genuses of non-naturally occurring small molecule compounds which comprise two or optionally three organic moieties of limited size “linked” by certain structurally related “linker” functional groups. Suitable linker groups include ester, amine, ether, keto, imino, thioamide, thioether, sulfonamide, sulfonate ester, sulfone, guanidine, and thiourea groups. The compounds are capable, when contacted with comestible food or drinks or pharmaceutical compositions, at concentrations preferably on the order of about 100 ppm or lower, of serving as savory (“umami”) or sweet taste modifiers, savory or sweet flavoring agents and savory or sweet flavor enhancers, for use in foods, beverages, and other comestible or orally administered medicinal products or compositions, optionally in the presence of or in mixtures with conventional flavoring agents such as monosodium glutamate or known natural or artificial sweeteners.