The invention provides a method of producing a host cell, plant cell or plant with increased trilobatin content or increased N 4′-O-glycosyltransferase activity, the method comprising transformation of the host cell or plant cell with a polynucleotide encoding a polypeptide with 4′-O-glycosyltransferase activity. The invention also provides host cells, plant cells and plants, genetically modified to contain and or express the polynucleotides.