Phytochemical characterization of low-caffeine and high-theobromine wild tea Camellia yungkiangensis var. yuanbaoshanica reveal its special compositions.

Yuanbaoshancha (Camellia yungkiangensis var. yuanbaoshanica, YBSC), a novel wild tea with low caffeine and high theobromine/polyphenol content, shows promise for breeding low-caffeine tea varieties. To elucidate its phytochemical basis, we performed metabolite profiling, isolation, and structural analysis of YBSC leaves. UPLC/ESI-Q-TOF/MS identified 190 metabolites across eight categories. Comparative metabolomics with tea cultivars (BXZ, YNDY) and wild relatives (RJC, TLC) revealed YBSC-specific differential metabolites. K-means clustering confirmed its unique metabolic profile. Eleven enriched components were structurally characterized, including theobromine (1), hydrolysable tannins (2, 6, 7), strictinin (4), catechins (3, 8, 9), and flavonols (10,11). Notably, 1,3-di-O-galloyl-4,6-O-hexahydroxydibenzoyl-β-d-glucopyranose (5) was identified as the unknown HPLC peak in YBSC. This study provides the first comprehensive metabolic profile and chemical characterization of YBSC, establishing a foundation for its biosynthetic exploration and potential application in low-caffeine tea production.