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An unusual proaporphine alkaloid bearing an isopropanenitrile group at isoquinoline nitrogen, named epiganine A ( 1 ) and a new aporphine alkaloid, epiganine B ( 2 ), together with eight known alkaloids, pronuciferine ( 3 ), dehydrodicentrine ( 4 ), romerine ( 5 ), romeline ( 6 ), N -methylcalycinine ( 7 ), phanostenine ( 8 ), dicentrine ( 9 ), and N -methyllaurotetanine ( 10 ), were isolated from the roots of Stephania epigaea . The absolute configuration of 1 was determined by calculating electronic circular dichroism (ECD) and comparing with experimental data. Compounds 2 and 4 showed strong acetylcholinesterase (AChE) inhibitory effects with the IC 50 values of 4.36 and 2.98 μM, respectively. Compounds 5 – 9 also exhibited potent AChE inhibitory activities. [ABSTRACT FROM AUTHOR]

One new phenanthrene, aphyllone A ( 1 ) and four new bibenzyl derivatives, aphyllone B ( 2 ) and aphyllals C–D ( 3 – 5 ), together with nine known compounds ( 6–14 ), were isolated from the stems of Dendrobium aphyllum (Roxb.) C. E. Fischer. The structures of these new compounds were elucidated by means of extensive spectroscopic analyses, and the absolute configuration of compound 1 was determined by single crystal X-ray diffraction and quantum calculations. Compounds 6 , 8 and 14 inhibited NO production at the concentration of 25 μM in LPS-stimulated RAW264.7 cells with the inhibition (%) of 32.48, 35.68, and 38.50. Compound 2 possessed significant DPPH radical scavenging activity with scavenging percentage of 87.97% at the concentration of 100 μg/mL. [ABSTRACT FROM AUTHOR]