Bioactive constituents from the rhizomes of Atractylodes macrocephala.

Twelve undescribed compounds including five sesquiterpenes (1 – 5), one monoterpene (6), and four lignans (7a / 7b and 8a / 8b), along with two other types (9 and 10) were isolated from the rhizomes of Atractylodes macrocephala. Among them, two pairs of enantiomers (7a / 7b and 8a / 8b) were successfully separated by chiral-phase HPLC, while racemate 9 could not be resolved. Their structures and absolute configurations were unambiguously elucidated by spectroscopic data analysis and electronic circular dichroism (ECD) calculations. Notably, compounds 1 and 2 are rare sesquiterpene hybrids featuring an eudesmanolactam linked to a resorcinol or methyl 2-methylpentanoat through a C N bond. Compound 3 represents the first example of eudesmanolide sesquiterpene with an oxygen-bridge between C-8 and C-14. Compounds 7a and 7b are a pair of rare enantiomeric benzodioxane norneolignans. Additionally, compound 2 exhibited weak cytotoxicity against SGC-7901 cells. Compound 4 significantly promoted the proliferation of LPS-induced IEC-6 cells with the rate of 117.2%. [Display omitted] • Four types of undescribed compounds were obtained from A. macrocephala. • Atramacronoids S and T are rare hybrids of N -containing sesquiterpenes and others. • A pair of rare enantiomeric norneolignans were separated by chiral column. • Atramacronoid V had the capacity of promoting IEC-6 cells proliferation. [ABSTRACT FROM AUTHOR]