antioxidants Article Caffeoylquinic Acids and Flavonoids of Fringed Sagewort (Artemisia frigida Willd.): HPLC-DAD-ESI-QQQ-MS Profile, HPLC-DAD Quantification, in Vitro Digestion Stability, and Antioxidant Capacity Daniil N. Olennikov 1,* , Nina I. Kashchenko 1 , Nadezhda K. Chirikova 2, Aina G. Vasil’eva 2, Aydan I. Gadimli 3, Javanshir I. Isaev 3 and Cecile Vennos 4 1 Laboratory of Medical and Biological Research, Institute of General and Experimental Biology, Siberian Division, Russian Academy of Science, 6 Sakh’yanovoy Street, Ulan-Ude 670047, Russia 2 Department of Biochemistry and Biotechnology, North-Eastern Federal University, 58 Belinsky Street, Yakutsk 677027, Russia 3 Department of Pharmacognosy, Azerbaijan Medical University, Anvar Gasimzade Street 14, Baku AZ1022, Azerbaijan 4 Regulatory and Medical Scientific Affairs, Padma AG, 1 Underfeldstrasse, CH-8340 Hinwil, Switzerland * Correspondence: [email protected]; Tel.: +7-9021-600-627 Received: 5 July 2019; Accepted: 12 August 2019; Published: 14 August 2019 Abstract: Fringed sagewort (Artemisia frigida Willd., Compositae family) is a well-known medicinal plant in Asian medical systems. Fifty-nine hydroxycinnamates and flavonoids have been found in A. frigida herbs of Siberian origin by high-performance liquid chromatography with diode array and electrospray triple quadrupole mass detection (HPLC-DAD-ESI-QQQ-MS). Their structures were determined after mass fragmentation analysis as caffeoylquinic acids, flavone O-/C-glycosides, flavones, and flavonol aglycones. Most of the discovered components were described in A. frigida for the first time. It was shown that flavonoids with different types of substitution have chemotaxonomic significance for species of Artemisia subsection Frigidae (section Absinthium). After HPLC-DAD quantification of 16 major phenolics in 21 Siberian populations of A. frigida and subsequent principal component analysis, we found substantial variation in the selected compounds, suggesting the existence of two geographical groups of A. frigida. The antioxidant activity of A. frigida herbal tea was determined using 2,2-diphenyl-1-picrylhydrazyl free radical (DPPH•) and hydrophilic/lipophilic oxygen radical absorbance capacity (ORAC) assays and DPPH•-HPLC profiling, revealing it to be high. The effect of digestive media on the phenolic profile and antioxidant capacity of A. frigida herbal tea was assessed under simulated gastrointestinal digestion. We found a minor reduction in caffeoylquinic acid content and ORAC values, but remaining levels were satisfactory for antioxidant protection. These results suggest that A. frigida and its food derivate herbal tea could be recommended as new plant antioxidants rich in phenolics. Keywords: Artemisia frigida; Compositae (Asteraceae); caffeoylquinic acids; flavonoids; HPLC; mass spectrometry; chemotaxonamy; antioxidant capacity; ORAC 1. Introduction Traditional healing treatments refer to the collective knowledge, skills and practices that are based on the theories, values and personal experiences developed and used by indigenous people of different cultures to improve health, avoid and reduce diseases and their spread, or as complete cures Antioxidants 2019, 8, 307; doi:10.3390/antiox8080307 www.mdpi.com/journal/antioxidants Antioxidants 2019, 8, x 2 of 22 1. Introduction Traditional healing treatments refer to the collective knowledge, skills and practices that are Antioxidantsbased on the2019 theories,, 8, 307 values and personal experiences developed and used by indigenous people2 of of 23 different cultures to improve health, avoid and reduce diseases and their spread, or as complete cures of both physical and mental health conditions [1,2]. The investigation of traditional healing ofprocedures both physical in unique and mental regions health such conditionsas Siberia is [1 ,of2]. particular The investigation interest due of traditional to the large healing variety procedures of ethnic ingroups. unique The regions territory such of Siberia as Siberia extends is of eastwards particular from interest the dueUral toMountains the large to variety the watershed of ethnic between groups. Thethe territoryPacific and of SiberiaArctic extendsdrainage eastwards basins. The from local the Uralresidents Mountains mostly to thepassed watershed traditional between healing the Pacificknowledge and Arcticon orally drainage from one basins. generation The local of residents healers to mostly the next. passed The traditional study of the healing use of knowledge local flora onof orallya particular from oneregion generation or culture of by healers native to people the next. is termed The study ethnobotany of the use [3]. of The local native flora populations of a particular of regiondifferent or regions culture of by Siberia native (yakuts, people isburyats, termed tuvans ethnobotany, soyots) [3 have]. The used native the populationsplants in their of environs different regionsfor different of Siberia purposes (yakuts, since buryats, ancient tuvans, times. soyots) have used the plants in their environs for different purposesArtemisia since frigida ancient Willd. times. (fringed sagewort) is one of the plant species most used by nomadic peopleArtemisia for its frigidatherapeuticWilld. (fringedproperties sagewort) (Figure is one1). As of thea member plant species of the most Compositae used by nomadic family, people it is forwidespread its therapeutic in the steppe properties regions (Figure of Siberia1). As and a member Mongolia, of the as well Compositae as on the family, prairies it of is widespreadNorth America in the[4]. steppeThere are regions reports of Siberiaof both andexternal Mongolia, and internal as well uses as on of the A. frigida prairies herbs of North by nomads America [5–9], [4]. as There well are as reportsthe addition of both of externalA. frigida and to cold internal baths uses with of waterA. frigida takenherbs from by mineral nomads hot [5– 9and], as cold well springs as the addition known as of A.“arshans” frigida to [7]. cold Cold baths spring with water water is takenheated from in barrels mineral using hot hot and stones, cold springs then A. known frigida herbs as “arshans” are added. [7]. ColdThis treatment spring water is believed is heated to in prevent barrels usingcolds. hotThe stones, application then A. of frigida fringedherbs sagebrush are added. as an This herbal treatment tea is isof believedthe greatest to preventinterest. colds.Herbal The tea applicationfrom aerial parts of fringed of A. sagebrushfrigida is referred as an herbal to as sagaan tea is aya of the tea. greatest Sagaan interest.aya tea is Herbalused to tea treat from many aerial diseases, parts ofin A.particular frigida is those referred caused to as bysagaan oxidative aya teastress—a. Sagaan process aya tea that is usedcan trigger to treat cell many damage diseases, [10]. in In particular particular, those during caused surveys by oxidative of nomadic stress—a populations, process thatwe found can trigger that cellsagaan damage aya tea [10 was]. In used particular, to treat during a number surveys of diseas of nomadices in the populations, pathogenesis we of foundwhich thatoxidative sagaan stress aya teais thought was used to treatbe ainvolved, number ofsuch diseases as inhyperten the pathogenesission, diabetes, of which cardiova oxidativescular stress diseases, is thought etc. to be(supplementary involved, such mate as hypertension,rials Table S1). diabetes, cardiovascular diseases, etc. (supplementary materials Table S1). (a) (b) Figure 1. (a) Artemisia frigida frigida plants plants in in their their natural natural habitat habitat (Sel (Selenginskiienginskii Region, Region, Buryatia Buryatia Republic, Republic, Eastern Siberia); (b) dried herb, herbal powderpowder andand herbalherbal teatea ofof A.A. frigida.frigida. Chemical investigations of Artemisia species often focus on on artemisinin artemisinin and and other other sesquiterpenes, sesquiterpenes, ignoring phenolicphenolic compounds compounds despite despite their their well-known well-known potent antioxidantpotent antioxidant properties properties [11]. According [11]. toAccording literature to data, literature a chemical data, a study chemical of phenolic study of compoundsphenolic compounds was carried was out carried on A. out frigida on A.growing frigida ingrowing North in America North America [12,13], [12,13], China China [14–17 [14–17],], Inner Inner Mongolia Mongolia [18,19 [18,19]] and and Russia Russia [20 [20].]. As As aa result, only 37 37 substances, substances, such such as as flavonoids flavonoids of ofthe the flavone, flavone, flavonol flavonol and and biflavone biflavone groups; groups; coumarins coumarins and andphenylpropanoids, phenylpropanoids, were wereisolated isolated and andcharacterized characterized (Table (Table S2). S2). Derivatives Derivatives of luteolin, of luteolin, 6- 6-hydroxyluteolinhydroxyluteolin and and 3’,5’-demethoxytricin 30,50-demethoxytricin in inthe the form form of of aglycones aglycones and and glycosides glycosides are are the main structural types ofof flavonesflavones inin A.A. frigidafrigida.. RareRare OO-glucuronides-glucuronides andand 2200′′--OO-glucuronyl-glucuronides-glucuronyl-glucuronides were detected only in raw materials collected in China and Inner Mongolia [17–19]. In specimens of Russian origin, only C-glycosides of apigenin were found [20], and luteolin-7-O-glucoside (cynaroside) was revealed in North American samples [12,13]. The only biflavone glycoside (8-O-8000-biluteolin-7, 7000-O-glucuronide) was detected in