Amino acid profile of two exemplary plant species: Campanula trachelium and Agrimonia eupatoria. C. trachelium hosts oligolectic bees unlike A. eupatoria. All measured amino acids and their derivates are displayed, separated into free and protein-bound fractions. (Arg = arginine, His = histidine, Ile = isoleucine, Leu = leucine, Lys = lysine, Met = methionine, Phe = phenylalanine, Thr = threonine, Trp = tryptophan, Val = valine, α-AAA = α-aminoadipic acid, α-ABA = α-aminobutyric acid, Ala = alanine, Asn = asparagine, Asp = aspartic acid, β-AIBA = β-aminoisobutyric acid, β-Ala = β-Alanine, Car = carnosine, Citr = citrulline, Cys = cysteine, Cyst = cystathionine, GABA = γ-aminobutyric acid, Gln = glutamine, Glu = glutamic acid, Gly = Glycin, 1-Meth = 1-methylhistidine, 3-Meth = 3-methylhistidine, OH-Pro = hydroxyproline, Orn = ornithine, P-Eta = phosphoethanolamine, Pro = proline, P-Ser = phosphoserine, Ser = serine, Tau = taurine, Tyr = tyrosine).