Isolation and characterization of secondary metabolites from the leaves of Sauropus spatulifolius Beille and their potential biological assays

Eight new compounds (1–8), along with three known related compounds (9–11) were isolated from the leaves of Sauropus spatulifolius Beille. Their structures and configurations were elucidated by means of spectrometric and the modified Mosher's method. Among the new compounds, compounds 1 and 2 were identified as ethyl 3, 6-anhydro-2-deoxy-β-D-arabino-hexofuranoside (1) and ethyl 3, 6-anhydro-2-deoxy- hexofuranoside (2). Compounds 3–5 were the 2-acetylpyrrole derivatives and identified as 2-(2-acetyl-1H-pyrrol-1-yl)-4-hydroxybutyric acid (3), methyl 4-(2-acetyl-lH-pyrrol- 1-yl) butanoate (4) and 1, 4-bis (2-acetyl-1H-pyrrol-1-yl) butane (5), respectively. Compound 6 was elucidated as 7-megastigmane-3, 8, 9-triol. Compounds 7, 8 were identified as kaempferol-3-O-2-deoxy-β-D-glucoside (7) and kaempferol-3-O-β-D- glucopyranosyl-(1–6)-2-deoxy-β-D-glucoside (8). In addition, the cytotoxic activities of all the compounds were also evaluated, where compounds 3, 5, 7, 9\10 and 11 exhibited the magnificent inhibition activity on lung fibroblast differentiation induced by TGF-β1with low toxicity against the RLE-6TN cell.