Phenolic Compounds from the Roots of Rhodiola crenulata and Their Antioxidant and Inducing IFN-γ Production Activities

Abstract

Abstract:In the present study, two new phenolic compounds 1 and 11, a pair of lignan isomers 12 and 13 with their absolute configurations established for the first time, were isolated from the ethanol extract of the roots of Rhodiola crenulata, together with 13 known phenolic compounds, and their structures were elucidated via NMR, HRESIMS, UV, IR and CD analyses. All the isolated compounds were evaluated for their in vitro antioxidant activities using the 2,2-diphenyl-1-picryhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging assays. Ten of them exhibited significant antioxidant activities compared to ascorbic acid. Furthermore, the inducibilities of the isolated compounds to IFN-γ production were also assessed. Compounds 1, 8, 9, 12, 13, 14 and 15 could moderately stimulate IFN-γ expression.

Rhodiola species: A comprehensive review of traditional use, phytochemistry, pharmacology, toxicity, and clinical study

“…Gallic acid (Compound 77 ) is frequently identified across Rhodiola species, such as R. crenulata , R. rosea , R. sachalinensis , R. sacra , R. kirilowii , R. quadrifida , and R. quadrifida . Nine gallic acid derivatives isolated from R. crenulata are as follows: 3‐ O ‐methylgallic acid (Compound 78 ), methyl gallate (Compound 79 ), gallic acid ethyl ester (Compound 80 ), 4‐ O ‐β‐ d ‐glucopyranosyloxy‐3,5‐dimethoxybenzoic acid (Compound 82 ), 1,2,3,4,6‐penta‐ O ‐galloylglucose (Compound 85 ), 2‐(4‐hydroxyphenyl)ethyl ester‐3,4,5‐trihydroxy‐benzoic acid (Compound 88 ), 6‐ O ‐galloylsalidroside (Compound 89 ), crenulatin (Compound 90 ), and sachalinoside A (Compound 91 ) . From R. rosea , five gallic acid derivatives are isolated, namely Compound 79 , 1,2,6‐tri‐ O ‐galloyl‐β‐ d ‐glucoside (Compound 83 ), 1,2,3,6‐tetra‐ O ‐galloyl‐β‐ d ‐glucopyranose (Compound 84 ), 1,2,3,6‐tetra‐ O ‐galloyl‐4‐ O ‐p‐hydroxybenzoyl‐β‐ d ‐glucopyranoside (Compound 86 ), and Compound 89 .…”

“…From R. crenulata , a caffeic acid derivative, ferulaic acid (Compound 111 ), and a p ‐coumaric acid glycoside, p ‐coumaric acid 4‐ O ‐β‐ d ‐glucopyranoside (Compound 112 ), have been isolated. Structurally, the carboxyl group of four caffeic acid derivatives (Compounds 113‐117 ) is esterified with their chemical names as follows: Rhodiolate (Compound 113 ), octacosyl ferulate (Compound 114 ), chlorogenic acid (Compound 115 ), and caffeic acid phenethyl ester (Compound 116 ) . Among them, Compounds 113 and 114 are found in R. crenulata .…”

“…In addition, rosmarinci acid (Compound 117 ) is a trans ‐caffeic acid derivative from R. rosea , in whose structure the carboxyl group of trans ‐caffeic acid is esterified with the branched hydroxyl group of benzenepropanoic acid. There are two other caffeic acid derivatives found in R. crenulata , namely 3‐[(2 R, 3 R )‐2,3‐dihydro‐3‐(4‐hydroxy‐3‐methoxyphenyl)‐2‐(hydroxymethyl)‐1,4‐benzodioxin‐6‐yl]‐2‐propenoic acid (Compound 118 ) and arteminorin D (Compound 119 ) . The two phenolic hydroxyl groups of their caffeic acid unit are substituted by the branched carbons of dihydroconiferyl alcohol.…”

Chemical Constituents from the Stems of Tinospora sinensis and Their Bioactivity

“…This was further confirmed by the key HMBC correlations from δ H 3.67 (OCH 3 ) to 173.9 (C-1′), from δ H 4.19 (H-6′) to δ C 167.5 (C-9), and 28.1 (C-5′), as shown in Figure 4. Therefore, compound 16 was confirmed as rhodiolate by comparison of its spectral data with those reported [24]. Compound 17 displayed closely related 1D NMR spectroscopic and mass spectrometric characteristics to 16 and was determined to have a similar structure to 16 .…”

“…Among the isolated compounds, 1 , 11 , and 17 were new compounds. The other fifty-four known compounds were identified, including eight lignans, (+)-pinoresinol ( 2 ) [14], syringaresinol ( 3 ) [15], medioresinol ( 4 ) [16], (+)- epi -syringaresinol ( 5 ) [15], (+)-pinoresinol monomethyl ether ( 6 ) [17], (+)-glaberide I ( 7 ) [18], sesamin ( 8 ) [19], and sesamolin ( 9 ) [20]; five pyrrole alkaloids, 5-(hydroxymethyl)-1 H -pyrrole-2-carbaldehyde ( 10 ) [21], methyl 4-[formyl-5-(hydroxymethyl)-1 H -pyrrol-1-yl] butanoate ( 12 ) [22,23], methyl 4-[formyl-5-(methoxymethyl)-1 H -pyrrol-1-yl] butanoate ( 13 ) [22,23], 4-[formyl-5-(methoxymethyl)-1 H -pyrrol-1-yl] butanoic acid ( 14 ) [22,23], and 4-[formyl-5-(hydroxymethyl)-1 H -pyrrol-1-yl] butanoic acid ( 15 ) [23]; seventeen benzenoids, rhodiolate ( 16 ) [24], methyl ferulate ( 18 ) [25], β-hydroxypropiovanillone ( 19 ) [26], 2-methyl-4,5-dimethoxybenzoic acid ( 20 ) [27], vanillic acid ( 21 ) [28], p -hydroxyl phenethanol ( 22 ) [29], tachioside ( 23 ) [30], icariside D 2 ( 24 ) [31], salidroside ( 25 ) [32], syringin ( 26 ) [33], cordifolioside A ( 27 ) [34], p -hydroxybenzoic acid ( 28 ) [35], 4-(2-hydroxyethyl)benzoic acid ( 29 ) [36], syringic acid-4- O -α- l -rhamnoside ( 30 ) [37], isovanillic acid ( 31 ) [38], syringic acid ( 32 ) [39]; ten terpenoids, loliolide ( 33 ) [40], abscisic acid ( 34 ) [41], 3(17)-phytene 1,2-diol ( 35 ) [42], malabarolide ( 36 ) [43], lupeol ( 37 ) [44], 3- O -acetyloleanolic acid ( 38 ) [45], cycloeucalenol ( 39 ) [46], cycloabyssinone ( 40 ) [47], cycloartane-3β,25-diol ( 41 ) [48], and cycloart-22-ene-3β,25-diol ( 42 ) [49]; eight steroids, β-sitosterol ( 43 ) [50], st...…”