Minor protopanaxadiol type sapogenins from the alkali hydrolysate of stems-leaves of Panax notoginseng

Two new protopanaxadiol type sapogenins, (3β,12β)-3,12,20-trihydroxydammar-24-en-26-al (1) and (3β,12β)-3,12,20-trihydroxydammar-24-en-26-oic acid (2), were isolated from the alkali hydrolysate of stems-leaves of Panax notoginseng, along with seven known analogues (3–9). Their structures were elucidated by spectroscopic analyses and single-crystal X-ray diffraction. Compound 2 and the known sapogenins 5–8 displayed weak to moderate inhibition of NO production in LPS-induced RAW264.7 macrophages with IC₅₀ values from 44.5 to 143.6 μM, respectively.