The leaves, stem and root of sweet potato cultivated in China have been analysed qualitatively for chlorogenic acids by structure-diagnostic LC–MS3. Chlorogenic acids were not detected in the root. Caffeoylquinic acids were quantitativ--ely the major subgroup of chlorogenic acids detected in the stem and the only subgroup detected in the leaves. This subgroup was dominated by 5-caffeoylquinic acid.The stem also contained three feruloylquinic acids, 3,5- and 4,5-dicaffeoylquinic acid, and small amounts of at least four caffeoyl-feruloylquinic acids. This is the first report of ferulo---ylquinic and caffeoyl-feruloylquinic acids from sweet potato. Two chemically unrelatedand coeluting substances with the same molecular mass (Mr = 530) extracted from the Chinese sweet potato interfered with the characterisation of the caffeoyl-feruloylquinic acids. At least five caffeoyl-feruloylquinic acids were detected in the peel of sweet potato cultivated in Tanzania that lacked these interfering substances.

Keywords: Caffeoylquinic acids; Caffeoyl-feruloylquinic acids; Chlorogenic acids; Dicaffeoylquinic acids; Feruloylquinic acids; Ipomoea batatas; Sweet potato