Ent-labdane-type diterpene glycosides obtained from Rubus chingii Hu and their inhibitory effects on PDE5A activity.

ABSTRACT

In this study, 16 new ent-labdane-type diterpene glycosides, designated as goshonosides J1-J16 (1-16), along with nine previously known diterpene glycosides (17-25) were extracted from the fruits of Rubus chingii Hu. The structures of goshonosides J1-J16 were elucidated using various analytical techniques, such as nuclear magnetic resonance, electron capture detector ECD, high-resolution electrospray ionization mass spectrometry HREIMS, single-crystal X-ray diffraction, and hydrolysis. Furthermore, the isolates' efficacy in inhibiting the activity of phosphodiesterase type 5 A was evaluated. Goshonosides J1, J2, and G effectively inhibited the activity of the aforementioned enzyme (IC50 values 6.15 ± 1.76, 3.27 ± 0.65, and 9.61 ± 2.36 µM, respectively). Our findings highlight the remarkable structural diversity of bioactive compounds in R. chingii Hu and offer insights into the use of this shrub.