Chemical Constituents of <i>Mangifera indica</i> and Their Antiausterity Activity against the PANC‑1 Human Pancreatic Cancer Cell Line

Human pancreatic cancer cell lines such as PANC-1 have an altered metabolism, enabiling them to tolerate and survive under extreme conditions of nutrient starvation. The search for candidates that inhibit their viability during nutrition starvation represents a novel antiausterity strategy in anticancer drug discovery. A methanol extract of the bark of <i>Mangifera indica</i> was found to inhibit the survival of PANC-1 human pancreatic cancer cells preferentially under nutrient-deprived conditions with a PC₅₀ value of 15.5 μg/mL, without apparent toxicity, in normal nutrient-rich conditions. Chemical investigation on this bioactive extract led to the isolation of 19 compounds (<b>1</b>–<b>19</b>), including two new cycloartane-type triterpenes, mangiferolate A (<b>1</b>) and mangiferolate B (<b>2</b>). The structures of <b>1</b> and <b>2</b> were determined by NMR spectroscopic analysis. Among the isolated compounds, mangiferolate B (<b>2</b>) and isoambolic acid (<b>12</b>) exhibited potent preferential cytotoxicity against PANC-1 human pancreatic cancer cells under the nutrition-deprived condition with PC₅₀ values of 11.0 and 4.8 μM, respectively