Phenylbenzofuran-type stilbenoids from Stemona species

Stilbenoids and Phenols in Acanthopanax brachypus

“…Helv eticaChimica Acta -V ol. 98 (2015)1 467 Theobserved signals are consistent with those of a-(3'-hydroxy-5'-methoxyphenyl)-2methoxy-3-methylbenzofuran (stemofuran W) [8]. Aromatic H-atoms HÀC (5) and HÀC(6')w ere used to identify C(1),C (3), C(4)a nd C(6)( 2 J(C,H)) as well as C(1'), C(2'), C(4'), C(5'), and C(a)( 3 J(C,H)),respectively.Moreover,the HMBCsofMe(7)/ C(2); Me(3)/C(3),C(2), and C(4); HÀC(6')/C(2'); and Me(7')/C(5')were also helpful to identifythe connected aromatic moieties.The coupling constant (J ¼ 7.…”

“…0.8 Hz was observed between HÀC(5) (d(H)6 .98 (dd, J ¼ 7. 8, 0.8)) and the isolated HÀC(b)( d(H)7 .10 (d, J ¼ 0.8)) of the furan ring, indicating the presence of benzofuranr ing [7] [8].I nt he HMBCs pectrum, HÀC(b) (d(H)7 .10 (d, J ¼ 0.8)) shows 2 J(C,H)t oC ( a)( d(C)1 57.2)a nd C(1) (d(C)1 21.1) as well as 3 J(C,H)t oC (2)( d(C)1 59.9), C(6)( d(C)1 54.2), and C(1')( d(C)1 27.2), indicating the central annulated heterocyclic moiety of a-phenylbenzofuran skeleton.…”

Antioxidation of 2-phenylbenzofuran derivatives: structural-electronic effects and mechanisms

“…Despite the fact that experimental UV-visible spectra of almost all isolated compounds are now available, the calculation procedure has not yet been performed, to the best of our knowledge. 4,6,29 We continue to provide quantum analytical results to achieve a detailed comparison between theoretical and experimental results. Utilizing a reliable time-dependent density functional theory (TD-DFT) method at the B3LYP/6-311++G(d,p) level to predict the UV spectra of polyphenolic derivatives, 10,11 the observed (in methanol) and the predicted (in gas and methanol) electronic excitations (energy, wavelength, oscillator and transition assignment) of stemofurans 1-16 are presented in Fig.…”

“…1). [4][5][6] 2-Phenylbenzofurans are now available in nature and have been found to indicate various pharmacological activities, but they are mostly applied to radical scavenging examinations. 7 As examples, artopithecins A-D, four new prenylated 2-phenylbenzofurans derived from Artocarpus pithecogallus twigs, showed signicant inhibition of mushroom tyrosinase.…”

“…4 Furthermore, ve other members, stemofurans S (12), T-V (13)(14)(15), and W (16), were chemical constituents of S. collinsiae, S. burkillii, and S. lucida species, respectively. 6 With methylation occurring on rings A and/or B, stilbenoid-type methylated 2-phenylbenzofurans are characteristic of the medicinal plant Stemona. However, extensive antioxidant experimental assays for these compounds have not yet been performed.…”