Discovery of unusual phloroglucinol–triterpenoid adducts from Leptospermum scoparium and Xanthostemon chrysanthus by building blocks-based molecular networking

The first phloroglucinol-triterpenoid hybrids, myrtphlotritins A–E (1–5), were rapidly recognized and isolated from two species of Myrtaceae by employing the building blocks-based molecular network (BBMN) strategy. Compounds 1–5 featured new carbon skeletons in which phloroglucinol derivatives were coupled with lupane- and dammarane-type triterpenoids through different linkage patterns. Their structures and absolute configurations were elucidated by comprehensive analysis of spectroscopic data and quantum chemical calculations. Biosynthetic pathways for compounds 1–5 were proposed on the basis of the coexisting precursors. Guided by the biogenetic pathways, the biomimetic synthesis of compound 1 was also achieved. Additionally, compounds 2, 3, and 5 exhibited potent antiviral activities against herpes simplex virus type-1 (HSV-1) infection, and compounds 2 and 5 displayed significant anti-inflammatory activities on RAW 264.7 cells.