Anti-first-pass effect compounds

A method for preparing an edible product providing reliable first-pass effect inhibiting activity, comprising adding a compound of Formulae I-IV to a natural or commercial edible product:

• wherein in each of the above structures, R is, independently, H or an optionally substituted C1-C15 alkyl group,
• L is an optionally substituted C1-C15 linear or branched, saturated, monounsaturated or polyunsaturated alkyl group optionally terminated at one or both ends by oxygen,
• HAr is an optionally substituted C6-C24 aromatic group or heteroaromatic group optionally containing one or plural ring atoms selected from the group consisting of N, O, S, and P,
• and E is —OH, —COOH, —COOR where R is defined above or an optionally substituted C1-C8 linear or branched, saturated, monounsaturated or polyunsaturated alkyl group optionally interrupted by one or plural nonadjacent oxygen or sulphur atoms, or E is a C3-C8 optionally substituted cyclic saturated, monounsaturated or polyunsaturated alkyl group optionally interrupted by one or plural nonadjacent oxygen or sulphur atoms, or E is optionally substituted HAr,
• wherein the optional substituents for the groups R, L, HAr and E are selected from the group consisting of a C1-C6 linear, branched or cyclic alkyl group, —OH, halogen, a C1-C5 alkoxy group, a C1-C5 carbonyloxy group and a C1-C5 alkoxycarbonyl group.