Sesquiterpene Lactams and Lactones With Antioxidant Potentials From Atractylodes macrocephala Discovered by Molecular Networking Strategy

Abstract

<i>Atractylodes macrocephala</i> rhizome (called Bái-zhú in China) has a long history as a functional food and herbal medicine in East Asia, especially China. Sesquiterpenoids are one of the main active compounds of <i>Atractylodes macrocephala</i> rhizome. This study aimed to explore the unknown sesquiterpenoids of <i>A. macrocephala</i> rhizome using a molecular networking strategy. Two new nitrogen-containing sesquiterpenoids, atractylenolactam A (<b>1</b>) and atractylenolactam B (<b>2</b>), and 2 new sesquiterpene lactones, 8-methoxy-atractylenolide V (<b>6</b>) and 15-acetoxyl atractylenolide III (<b>7</b>), along with 12 known analogs (<b>3-5</b> and <b>8-16</b>) were discovered and isolated. All the structures were assigned based on detailed spectroscopic analyses. The absolute configurations of <b>1</b>, <b>2</b>, <b>6</b>, and <b>7</b> were established by time-dependent density functional theory ECD (TDDFT-ECD) calculations. All these compounds had different degrees of concentration-dependent activating effects on nuclear-factor-E2-related factor-2 (Nrf2).