Pinosylvin monomethyl ether

In October 2018, the fresh leaves of the S. fruticosa were collected from Naher Ibrahim, Lebanon. The botanical identification was made by Dr. Marc El Beyrouthy, chairman and general manager of the company Nature by Marc Beyrouthy. The samples were deposited in the Herbarium of Botany, Medicinal Plants and Malherbology, School of Engineering, Holy Spirit University of Kaslik, Lebanon under the registry number MNIIIb177a. The analytical standards used for the identification and quantification of the main phenolic compounds found in the plant extracts were as follows: 3-amino-4-hydroxybenzoic acid; 3,4-dihydroxy-5-methoxybenzoic acid; rutin; polydatin; 5′,3′-dihydroxyflavone; 5,7-dihydroxy-4-phenylcoumarine; 3-benzyloxy-4,5-dihydroxy-benzoic acid methyl ester; 4′,5-dihydroxy-7-methoxyflavone; pinosylvin monomethyl ether; and 3, 6,3′-trimethoxyflavone, all of which were obtained from Sigma-Aldrich (St Louis, MO, USA).

The stilbenoid derivatives to be tested (1–19, Table 1) were isolated from natural sources or obtained commercially. The naturally occurring stilbenoids trans-resveratrol (1), pinostilbene (2), thunalbene (3), piceatannol (4), piceatannol-3’-O-β-glucopyranoside (5), batatasin III (6), pinostilbenoside (7), 1-(2,4-dihydroxyphenyl)-2-(4-hydroxyfenyl)-ethanone (10), 3,5-dimethoxystilbene (11), pterostilbene (15), pinosylvin monomethyl ether (17), and isorhapontigenin (18) were obtained from Sigma-Aldrich, synthetic compounds trans-stilbene (12), cis–stilbene (13), 4-stilbenecarboxylic acid (14), trans-α-methylstilbene (16), and 2,4,3´,5´-tetramethoxystilbene (19) were purchased from Sigma-Aldrich (Steinheim, Germany). The compounds 2-carboxyl-3-O-methyl-4´-β-d-glucopyranosyl-dihydroresveratrol (8) and 3-O-caffeoyl-(9→5)-β-apiosyl-(1→6)-β-glucopyranosyl-5,3´-O-dimethyldihydropiceatannol (9) were kindly provided by Dr. Sebastian Granica (Medical University of Warsaw, Warsaw, Poland) who had isolated them from Tragopogon tommasinii Sch.Bip. (Asteraceae, Cichorieae) [7 (link)].

All chemicals used were of analytical reagent grade. All reagents were purchased from Sigma, Aldrich: Ascorbic acid, Acetic acid, acetylcholinesterase (AChE), acetylthiocholine (ACTHI) acetonitrile (ACN), N, O-bis (trimethylsilyl) trifluoroacetamide (BSTFA), cyclohexane (CYH), dichloromethane (DCM), Dulbecco's modified eagle medium (DMEM), dimethyl sulfoxide (DMSO), 1-1-diphenyl-2-picryl hydrazyl (DPPH), 5, 5-dithiobis-2-nitrobenzoic acid (DTNB), Folin-Ciocalteu reagent (2 N), methanol (MeOH), human colon cancer cells (HCT116), human breast cancer cells (MCF-7), 3- [4, 5-dimethylthiazol-2yl]-2, 5-diphenyl tetrazolium bromide (MTT), Roswell Park Memorial Institute (RPMI), Chlorotrimethylsilane (TMCS), and tetrahydrofuran (THF).
The analytical standards used for the identification and quantification of the principal phenolic compounds found in the extracts: 3-amino-4-hydroxybenzoic acid, Gallic acid, 3, 4-dihydroxy-5 methoxybenzoic acid, 7-hydroxycoumarin-3-carboxylic acid, rutin hydrate, Butyl gallate, 4-hydroxytamoxifen, cardamonin, phenoxodiol, pinostilbene hydrate, 3-benzyloxy-4, 5-dihydroxy-benzoic acid methyl ester, ethyl trans-2-hydroxycinnamate, 4′, 5-dihydroxy-7-methoxyflavone, pinosylvin monomethyl ether, 3, 6, 3′-trimethoxyflavone, shikonin, 5-hydroxy-3′-methoxyflavone, and 3′-hydroxy-b-naphthoflavone were also purchased from Sigma, Aldrich.