No abstract

The aim of the present study was to quantify selected phenolic compounds, determine antioxidant activity and enzyme inhibitory effects of the aerial parts of Alkanna trichophylla Hub.‐Mor. (A. trichophylla) and Convolvulus galaticus Rost.ex Choisy (C. galaticus) extracts prepared by homogenizer‐assisted extraction (HAE), maceration (MAC) and infusion techniques. This is the first time such study has been designed to validate the phytochemical composition and bioactivity of these plants. Multivariate analysis was conducted on collected data. Rutin and caffeoylquinic acid derivatives were the most significant compounds in A. trichophylla and C. galaticus, respectively. The highest antioxidant activity of A. trichophylla was mostly exhibited by HAE/methanolic extracts as determined by DPPH, ABTS, FRAP (51.39, 112.70 and 145.73 mg TE/g, respectively) and phosphomolybdenum (2.05 mmol TE/g) assays. However, significant antioxidant activities varied within the extracts of C. galaticus. HAE/methanolic extract of A. trichophylla significantly depressed AChE (2.70 mg GALAE/g), BChE (5.53 mg GALAE/g) and tyrosinase (26.34 mg KAE/g) activities and that of C. galaticus inhibited AChE (2.04 mg GALAE/g), tyrosinase (31.25 mg KAE/g) and α‐amylase (0.53 mmol ACAE/g) activities significantly. We concluded that HAE was the most efficient extraction technique as high yield of compounds and promising bioactivities were recorded from extracts prepared. Multivariate analysis showed that types of solvents influenced recovery of compounds and biological activities. This research study can be used as one methodological starting point for further investigation on these plants as all results are clearly promising and open the door to further research challenges such as cytotoxicity evaluation, molecular docking analysis, and more screening of pharmacological actions.

Micromorphology and anatomy of six Onosma L. species, viz. O. argentata Hub.-Mor., O. neglecta Riedl, O. proballanthera Rech. f., O. rechingeri Riedl, O. sericea Willd. and O. stenoloba Hausskn. ex Riedl from Turky were investigated. Stem anatomy revealed that cuticle layer ranged from 0.6 µm in O. argentata to 1.7 µm in O. proballanthera. Parenchymatous cells of O. neglecta and O. stenoloba possessed more intense starch than the other species studied. In leaf anatomy, the longest palisade parenchyma was found in O. neglecta, while the smallest was noted in O. argentata. Mesophyll structure of O. argentata, O. sericea and O. rechingeri was equifacial (isobilateral), while O. neglecta, O. proballanthera and O. stenoloba presented bifacial (dorsiventral) structure. Rugose nutlet ornamentation was observed in O. argentata, O. neglecta and O. sericea, whereas reticulate type was found in O. proballanthera, O. rechingeri and O. stenoloba. Onosma stenoloba could easily be distinguished from other species by its aesterotrichous indumentum, and in contrary, other species possessed haplotrichous type of indumentum. Micromorphological features of nutlet surface, anatomical features of epidermal surface (trichomes and stomata), and lamina mesophyll structure (dorsiventral and isobilateral) could be useful in solving taxonomic problem of the genus.

The study aimed at the metabolite profiling and evaluation of antioxidant and enzyme inhibitory properties of methanol extracts from flowers, leaves, and tubers of unexplored Eminium intortum (Banks & Sol.) Kuntze and E. spiculatum (Blume) Schott (Araceae). A total of 83 metabolites, including 19 phenolic acids, 46 flavonoids, 11 amino, and 7 fatty acids were identified by UHPLC-HRMS in the studied extracts for the first time. E. intortum flower and leaf extracts had the highest total phenolic and flavonoid contents (50.82 ± 0.71 mg GAE/g and 65.08 ± 0.38 RE/g, respectively). Significant radical scavenging activity (32.20 ± 1.26 and 54.34 ± 0.53 mg TE/g for DPPH and ABTS) and reducing power (88.27 ± 1.49 and 33.13 ± 0.68 mg TE/g for CUPRAC and FRAP) were observed in leaf extracts. E. intortum flowers showed the maximum anticholinesterase activity (2.72 ± 0.03 mg GALAE/g). E. spiculatum leaves and tubers exhibited the highest inhibition towards α-glucosidase (0.99 ± 0.02 ACAE/g) and tirosinase (50.73 ± 2.29 mg KAE/g), respectively. A multivariate analysis revealed that O-hydroxycinnamoylglycosyl-C-flavonoid glycosides mostly accounted for the discrimination of both species. Thus, E. intortum and E. spiculatum can be considered as potential candidates for designing functional ingredients in the pharmaceutical and nutraceutical industries.

The genus Opopanax W. Koch (Apiaceae) is represented by four species in Turkey. The composition of the essential oil of Opopanax genus members (Apiaceae) growing in Turkey was investigated in this study. GC-MS was used to analyze the composition of Opopanax essential oil samples that were taken from their natural environments. The Clevenger apparatus was used to hydrodistill the plant’s aerial parts, and the yields were determined to be between 0.2% v/w (for O. siifolius) and 0.4% (for O. hispidus, O. chironium, and O. persicus). The results and the chemical data provided some information and clues on the chemotaxonomy of the genus Opopanax. In this study, γ-elemene, butanoic acid octyl ester, and cylopropane were the main compounds identified in the essential oils of O. chironium, O. hispidus, and O. persicus. In particular, hexynyl n-valerate was most abundant in the essential oil of O. chironium, cyclopropane in that of O. hispidus, γ-elemene in that of O. persicus, and n-hexadecanoic acid/palmitic acid in that of O. siifolius. In a chemotaxonomic approach, the essential oil analysis of the Opopanax species revealed that these species conformed in a cluster analysis with their morphological classification. The constituents of the essential oils of all examined in the genus Opopanax were determined in this study, which is the most thorough one to date. This study provides new information about the composition of the essential oils of the investigated species.