Notoginsenoids, a new class of hexa-nortriterpenoids from biotransformation of Panax notoginseng saponins

• Notoginsenoids T1−T7, a new class of hexa-nortriterpenoids, were obtained. • Spectral, single-crystal X-ray, Mo 2 (AcO) 4 -induced CD and ECD analyzes were applied. • T1-T7 possess an unprecedented 9-en-5-ketone tricyclic hexa-nordammar skeleton. • A plausible biotransformed pathway for T1−T7 by degradation from PNS was proposed. • T1−T5 showed growth inhibitory effects on probiotic and pathogenic fungi of sanqi. Notoginsenoids T1−T7, a new class of hexa-nortriterpenoids including two dimers and five monomers, possessing an unprecedented 9-en-5-ketone tricyclic hexa-nordammar skeleton and a variable side chain at C-17, were obtained from biotransformation of PPD-type dammarane saponins by the soil harvested with Panax notoginseng (Araliaceae), a famous traditional Chinese medicinal herb. Their structures were unambiguously determined by spectroscopic, single-crystal X-ray diffraction, Mo 2 (AcO) 4 -induced CD and ECD analyzes. A plausible biotransformed pathway for T1−T7 was proposed. Notoginsenoids T1−T5 showed growth inhibitory effects on the probiotic and pathogenic fungi of P. notoginseng .