A UHPLC-QTOF-MS screening provides new insights into the phytochemical composition and biological properties of six Consolida species from Turkey

Abstract

The genus Consolida is one of the most important within the Ranunculaceae family and several members of this genus contain important biologically active compounds, such as phenolics and alkaloids. The present study attempts for the first time to assess the biological properties and phytochemical constituents of six Consolida species (C. glandulosa (Boiss. & A. Huet) Bornm, C. hellospontica (Boiss.) Chater, C. raveyi (Boiss.) Schrödinger, C. regalis (Boiss.) Schrödinger, C. staminosa P.H. Davis & Sorger and C. stenocarpa (P.H. Davis & M. Hossain) P.H. Davis) growing in Turkey. A comprehensive phytochemical profiling of the different species was achieved by using an ultra-high-performance liquid chromatography-quadrupole time-of-flight (UHPLC-QTOF) mass spectrometry, targeting polyphenols and diterpene alkaloids. Also, the in vitro antioxidant assays (2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), ferric reducing antioxidant power (FRAP), cupric reducing antioxidant capacity (CUPRAC), metal chelating and phosphomolybdenum) and enzyme inhibition (cholinesterases, tyrosinase, α-amylase, and α-glucosidase) potentials of the different Consolida methanolic extracts were evaluated. The UHPLC-QTOF profiling revealed 492 compounds, being 236 flavonoids, 93 phenolic acids, 78 tyrosol derivatives, 49 diterpene alkaloids, 29 lignans, and 7 stilbenes. The cumulative phenolic content ranged from 17.65 mg Eq./g for C. staminosa up to 43.04 mg Eq./g for C. glandulosa, whilst the total diterpene alkaloids content was exclusively found in C. glandulosa extracts (3.53 mg Eq./g). Consolida regalis (58. 61 mg trolox equivalent (TE)/g for DPPH and 65.38 mg TE/g for ABTS) and C. stenocarpa (46.81 mg TE/g for DPPH and 78.12 mg TE/g for ABTS) exhibited the highest anti-radical abilities, while the best reducing power values were recorded for C. glandulosa (129.46 mg TE/g for CUPRAC and 77.01 mg TE/g for FRAP) and C. raveyi (124.56 mg TE/g for CUPRAC and 78.36 mg TE/g for FRAP). Also, following the cholinesterases inhibition assays, C. hellospontica and C. glandulosa exhibited the highest inhibitory effects. Regarding tyrosinase inhibitory effects, C. raveyi showed the highest value, being 126.60 mg kojic acid equivalent (KAE)/g, followed by C. glandulosa (125.82 mg KAE/g) and C. stenocarpa (123.09 mg KAE/g). Besides, Consolida staminosa showed potential inhibition against α-amylase, but low glucosidase inhibitory properties. Therefore, the present findings could provide a starting point for further investigations to promote the industrial exploitation of these species with the aim of designing novel phyto-pharmaceuticals.