Yersiniabactin is still identified as a unique siderophore encoded by the high-pathogenicity island (HPI) in uropathogenic Escherichia coli (UPEC). This does not fully describe the HPI as directing the biosynthesis of siderophores. We aimed to discover and identify new siderophores in the HPI-dependent biosynthetic pathway using a combinational strategy of metabolomics and genetics. A global metabolome assay of wild-type UTI89, UTI89ΔybtS and UTI89ΔybtS involving salicylic acid found numerous unknown metabolite features that were encoded by the HPI with an obvious substrate dependency on salicylic acid. One metabolite feature with a mass-to-charge ratio of 307.0206 was shown to have a similar phenotype as yersiniabactin. Furthermore, isotope mass spectrum calculations and ms/ms annotations were combined to identify this metabolite as 2’-(2-hydroxyphenyl)-4’-thiazolyl-2,4-thiazolinyl-4-carboxylicacid (HPTzTn-COOH), and our study is the first to identify HPTzTn-COOH in UPEC UTI89. HPTzTn-COOH was verified as a new siderophore in this study, and it was observed to have a robust capacity to chelate different metals, including Al3+, Ni2+ and Ca2+, in addition to binding Fe3+. Our data revealed that HPTzTn-COOH has a much stronger diagnostic ability, characterized by a high production throughout the selected UPEC strains harboring the HPI. Altogether, our discoveries revise the siderophore family, and HPTzTn-COOH can be classified as an additional key siderophore along with yersiniabactin.