Combining Activity Profiling with Advanced Annotation to Accelerate the Discovery of Natural Products Targeting Oncogenic Signaling in Melanoma

Abstract

The discovery of bioactive natural products remains a time-consuming and challenging task. The ability to link high-confidence metabolite annotations in crude extracts with activity would be highly beneficial to the drug discovery process. To address this challenge, HPLC-based activity profiling and advanced UHPLC-HRMS/MS metabolite profiling for annotation were combined to leverage the information obtained from both approaches on a crude extract scaled down to the submilligram level. This strategy was applied to a subset of an extract library screening aiming to identify natural products inhibiting oncogenic signaling in melanoma. Advanced annotation and data organization enabled the identification of compounds that were likely responsible for the activity in the extracts. These compounds belonged to two different natural product scaffolds, namely, brevipolides from a Hyptis brevipes extract and methoxylated flavonoids identified in three different extracts of Hyptis and Artemisia spp. Targeted isolation of these prioritized compounds led to five brevipolides and seven methoxylated flavonoids. Brevipolide A (1) and 6-methoxytricin (9) were the most potent compounds from each chemical class and displayed AKT activity inhibition with an IC50 of 17.6 ± 1.6 and 4.9 ± 0.2 μM, respectively.

A Dimerosesquiterpene and Sesquiterpene Lactones from Artemisia argyi Inhibiting Oncogenic PI3K/AKT Signaling in Melanoma Cells

“…Eupatilin (20): yellow solid; 1 H and 13 C NMR were reported recently; 6 Cell Lines and Cell Culture. Details on cell line construction and culture conditions have been reported.…”

“…In the course of a metabolomic analysis of several plant extracts, which aimed at establishing a workflow for efficient prioritization of active features in an extract, flavonoids were annotated as being responsible for at least part of the activity of the A. argyi extract. These compounds subsequently were isolated to confirm the annotation . Minor clusters containing sesquiterpene lactones were also highlighted as active (data not shown).…”

Dimerosesquiterpene and sesquiterpene lactones from Artemisia argyi inhibiting oncogenic PI3K/AKT signaling in melanoma cells

“…(IC 50 of 4.9 ± 0.2 µM). 6 In A2058 cells, compound 22 was also the most active flavonoid (IC 50 of 26 ± 1.8 μM; Figure S86, Supporting Information). The difference in activity in the two cell lines might be due to their mutational landscape.…”

“…These compounds were subsequently isolated to confirm the annotation. 6 Minor clusters containing sesquiterpene lactones were also highlighted as active (data not shown). Recently, A. argyi has been shown to contain a diverse set of sesquiterpene lactones.…”

“…Information). The absolute configuration at C-2' in artemdubolide C(6) was not assigned. ECD spectra were measured for 12, 13a, and 13b.…”