Geranylated 2-arylbenzofurans from Morus alba var. tatarica and their α-glucosidase and protein tyrosine phosphatase 1B inhibitory activities.

Abstract Ten new geranylated 2-arylbenzofuran derivatives, including two monoterpenoid 2-arylbenzofurans ( 1 and 2 ), two geranylated 2-arylbenzofuran enantiomers ( 3a and 3b ), and six geranylated 2-arylbenzofurans ( 4–9 ), along with four known 2-arylbenzofurans ( 10–13 ) were isolated from the root bark of Morus alba var. tatarica . Their structures and relative configurations were established on the basis of spectroscopic data analysis. Compounds 3–7 with one asymmetric carbon at C-7″ were supposed to be enantiomeric mixtures confirmed by chiral HPLC analysis, and the absolute configurations of each enantiomer in 3–7 were determined by Rh 2 (OCOCF 3 ) 4 -induced CD and Snatzke's method. The enantiomers with the substituting group at C-2′ exhibited better resolutions on a Chiralpak AD-H column than those with the substituting group at C-4′. Compounds 1–7 , 10 , 11 and 13 , showed α-glucosidase inhibitory activities with IC 50 values of 11.9 – 131.9  μ M, and compounds 1 and 9–13 inhibited protein tyrosine phosphatase 1B (PTP1B) with IC 50 values of 7.9 – 38.1  μ M.