The genus Scorzonera L. (Asteraceae): A comprehensive review on traditional uses, phytochemistry, pharmacology, toxicology, chemotaxonomy, and other applications

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Scorzonera L. comprises of approximately 175 species, which are mainly distributed in temperate and arid regions of Central Europe, Central Asia, and Africa. Twenty-nine Scorzonera traditional ethnomedicines have been used for treating colds and fevers, pulmonary diseases, asthma, dyspepsia, malignant stomach neoplasia, liver disorder, jaundice, kidney diseases, mastitis, women's vaginitis, herpes zoster, poisonous ulcers, rheumatic pain, diabetic, atherosclerosis, headache, hypertension, dysentery, pregnant vomiting, snakebites, etc. AIM OF THE REVIEW: This review aims to systematically evaluate the genus Scorzonera over its ethnomedicinal uses, phytochemistry, pharmacology, and toxicology, discuss the relationship between traditional uses, phytochemistry and pharmacological properties, and put forward some suggestions to promote further development and utilization of Scorzonera.

MATERIALS AND METHODS

This review is based on published scientific research works obtained from the following databases: Elsevier, Web of Science, PubMed, Springer, Wiley, Taylor & Francis, Google Scholar, CNKI, Baidu Scholar, ResearchGate, and others (the Flora of China, 1997 edition; Chinese herbal books, PhD dissertation and Master thesis in Chinese).

RESULTS

The genus 81 Scorzonera plants have been studied for their traditional usage, phytochemistry, and pharmacology. Altogether 421 chemical constituents are isolated from the 54 species of Scorzonera, which include sesquiterpenoids, monoterpenes, diterpenes, triterpenoids, steroids, quinic acid derivatives, flavonoids, cumarinoids, lignanoids, phenylpropanoids, stilbene derivatives, benzylphthalides, kava lactones, phenolics, aliphatic acids, phthalic acids, alkanes, vitamins, sugars, alkaloids, and other constitutes. Besides those listed above, there are also volatile oils, polysaccharides, tannins, amino acids, enzymes, and inorganic elements. The extracts and compounds extracted from 55 Scorzonera species exhibit extensive pharmacological activities, such as anti-inflammatory, antinociceptive, wound healing, anti-cancer, hepatoprotective, anti-microbial, anti-ulcerogenic, antidiarrheal, antidiabetic, hypolipidemic, antioxidant, repairing cerebral ischemia, antidepressant, immunomodulatory activities, enzyme inhibitory effects, etc. Clinical applications strongly indicate that certain species are effective in treating herpes zoster and pregnancy resistance. Certain species are studied over applicationssuch as pharmacokinetic and histological distribution, and toxicity, the product extraction process, quick-freezing processing technology, synthesized metabolites, etc. Chemotaxonomy is also discussed on Scorzonera.

CONCLUSION

This review provides information on traditional usage, phytochemistry, pharmacology, toxicology, chemotaxonomy, other applications aspects, and future prospects of the genus Scorzonera. However, only around one third of Scorzonera species have been studied so far. This review may be used as the basis for future endeavors, including further biological and chemical investigations, and efforts of seeking more applications.

Two new dihydroisocoumarins and terpenoids from Scorzonera longiana Sümbül an endemic species to Turkey and their antimicrobial activity

Two new dihydroisocoumarins (scorzolongin I (1), and scorzolongin II (2)) and nine known compounds (3',5'-dimethoxy hydrangenol (scorzolongin III, 3), cladantholide (4), dammar-24-ene-3β-ol (5), taraxasterol (6), β-sitosterol (7), mangifgerursanone (8), and a mixture of α-amyrenone (9a), β-amyrenone (9b), and dammar-24-ene-3-one (9c) in about 1:1:2 ratio) were identified from the dichloromethane fraction of Scorzonera longiana. The structure of all compounds (1-9a-c) were elucidated by extensive 1D and 2D NMR (¹H, ¹³C/APT, COSY, HMBC, HSQC, and NOESY) spectroscopy, UV, FT-IR, and LC-QTOF-MS data and by comparison of their NMR data with the literature. These compounds have been isolated from S. longiana for the first time. An antimicrobial assay against eight microorganisms was applied to isolated compounds 1-3. Scorzolongin I, and scorzolongin II, and scorzolongin III showed notable activity against gram (-) (Escherichia coli and Yersinia pseudotuberculosis) and fungi (Candida albicans, Saccharomyces cerevisiae) with 20 mm inhibition zone each. Scorzolongin II (2) exhibited strong activity against E. coli, Y. pseudotuberculosis, Mycobacterium smegmatis C. albicans, S. cerevisiae with MIC value of 33.8 μg/mL.

Callus Culture of Scorzonera radiata as a New, Highly Productive and Stable Source of Caffeoylquinic Acids

During our ongoing efforts to investigate biotechnological sources of caffeoylquinic acid (CQA) metabolites, we discovered the plant Scorzonera radiata Fisch. (Asteraceae), which is able to produce callus cultures with high yield and extremely high stability. An actively growing callus line, designated as Sr-L1, retained the ability to produce 11 CQAs during long-term cultivation (more than 20 years). A total of 29 polyphenolic compounds were identified in the leaves and Sr-L1 callus culture of S. radiata, including CQAs, lignol derivatives, flavonoids, and dihydrostilbenes. The composition of CQAs in the Sr-L1 culture was identical to that in the S. radiata leaves. Sr-L1 calli did not produce flavonoids and dihydrostilbenes, but produced lignol derivatives, which were absent in leaves. The HPLC-UV-HRMS determination showed the presence of monoacyl derivatives of CQAs such as 5-CQA, 4-CQA, cis-5-CQA, and 5-O-p-coumaroylquinic acid in the Sr-L1 culture. Among diacyl derivatives, 3,4-diCQA, 3,5-diCQA, cis-3,5-diCQA, 4,5-diCQA, 3-O-p-coumaroyl-5-O-CQA, and 3-O-caffeoyl-5-O-p-coumaroylquinic acid were found. The content of 5-CQA reached 7.54 mg/g dry weight and the content of 3,5-diCQA was as high as 18.52 mg/g dry weight. 3,5-diCQA has been reported to be of high nutritional and pharmacological value, as it alleviates inflammatory pain, reverses memory impairment by preventing neuronal apoptosis, and counteracts excessive adipose tissue expansion, serving as an attractive treatment option for obesity. The high content of 3,5-diCQA and the exceptional stability of biosynthesis make callus cultures of S. radiata a promising source for the development of drugs and nutraceuticals.

Assessment of Correlation Analysis, Phytochemical Profile, and Biological Activities of Endemic Scorzonera Species from Turkey

Scorzonera species belong to the Asteraceae family comprising more than 25000 species. The present study aimed to examine the phytochemical profiles and biological activities of S. sandrasica Hartvig et Strid, S. coriacea A. Duran&Aksoy, and S. ahmet-duranii Makbul&Coskuncelebi which are endemic species to Turkey. Flavonoids such as hyperoside, isoquercitrin, rutin, isoorientin, orientin, 7-O-methyl isoorientin, luteolin-7-O-β-glycoside, apigenin-7-O-β-glucoside, vitexin, isovitexin as well as caffeoylquinic acid derivatives including chlorogenic acid, 4,5-O-dicaffeoylquinic acid, and 1,5-O-dicaffeoylquinic acid contents were analyzed to clarify phytochemical content of the extracts. Aerial parts of the investigated extracts were determined as contain flavonoids in high amounts. Chlorogenic acid and its derivatives were detected in all investigated species, in varying amounts, both in the roots and aerial parts. S. coriacea aerial parts contained the highest total phenolic and flavonoids. The strongest inhibitory activities on ABTS and DPPH radicals were also observed with S. coriacea aerial parts by 8.07±0.28 and 13.94±0.53 μg/ml of IC50 values, respectively. Total phenolic contents of the extracts were significantly correlated with DPPH (r=-0.9842, p=0.0004) and ABTS free radical scavenging (r=-0.9870, p=0.0003) and total antioxidant capacity (r=0.8173, p=0.0470), as well as total flavonoid contents (r=0.8820, p=0.0201). S. sandrasica aerial parts and S. ahmet-duranii roots exhibited the greatest red blood cell membrane protection and protein denaturation inhibition, respectively. From the phytochemical point of view, all the selected species were analyzed for the first time.

Phytochemical Composition and Biological Activities of Scorzonera Species

The genus Scorzonera comprises nearly 200 species, naturally occurring in Europe, Asia, and northern parts of Africa. Plants belonging to the Scorzonera genus have been a significant part of folk medicine in Asia, especially China, Mongolia, and Turkey for centuries. Therefore, they have become the subject of research regarding their phytochemical composition and biological activity. The aim of this review is to present and assess the phytochemical composition, and bioactive potential of species within the genus Scorzonera. Studies have shown the presence of many bioactive compounds like triterpenoids, sesquiterpenoids, flavonoids, or caffeic acid and quinic acid derivatives in extracts obtained from aerial and subaerial parts of the plants. The antioxidant and cytotoxic properties have been evaluated, together with the mechanism of anti-inflammatory, analgesic, and hepatoprotective activity. Scorzonera species have also been investigated for their activity against several bacteria and fungi strains. Despite mild cytotoxicity against cancer cell lines in vitro, the bioactive properties in wound healing therapy and the treatment of microbial infections might, in perspective, be the starting point for the research on Scorzonera species as active agents in medical products designed for miscellaneous skin conditions.

Comprehensive bioactivity and chemical characterization of the endemic plant Scorzonera hieraciifolia Hayek extracts: A promising source of bioactive compounds

Members of Scorzonera genus are known for their potential application in both food and pharmaceutical industries. The present study reports the chemical component and bioactivity of the dichloromethane, ethyl acetate, hexane, methanol and infused extracts of Scorzonera hieraciifolia Hayek aerial parts and roots. The methanolic extracts of both aerial parts and roots were good sources of total phenolic and flavonoid content. For the aerial parts, the infused and methanolic extracts showed highest (p < 0.05) free radical scavenging (2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS)), reducing (cupric reducing antioxidant capacity (CUPRAC))and ferric reducing antioxidant power (FRAP)) and metal chelating capacities. Whilst, for the root extracts, overall most remarkable free scavenging and reducing activity was observed for the methanolic extracts (p < 0.05) while the hexane extracts showed highest metal chelating activity. The inhibitory activity of the extracts was evaluated against key enzymes. Overall, the hexane extracts of both aerial parts (acetylcholinesterase (AChE): 2.27 ± 0.04 and butyrlcholinesterase (BChE): 5.75 ± 0.48 mg galantamine equivalent (GALAE)/g) and roots (AChE: 2.44 ± 0.35 and BChE: 53.17 ± 0.22 mg GALAE/g) were most potent against AChE and BChE, suggesting a role for the more lipophilic compounds in this regard. The highest inhibitory activity against tyrosinase was displayed by methanolic extracts of aerial parts (64.70 ± 0.26 mg kojic acid equivalent (KAE)/g) and roots (63.63 ± 0.20 mg KAE/g). Modest activity was observed against α-amylase and α-glucosidase, two major enzymes implicated in the pathology of diabetes. Liquid chromatography-mass spectrometry (LC-MS) and nuclear magnetic resonance (NMR) analysis showed the presence of 40 compounds such as caffeic, ursolic, betulinic and oleanolic acid and their derivatives in the studied extracts. Multivariate analysis showed that the biological activities were dependent on the plant parts used as well as on the type of solvent used. Overall, the results showed that S. hieraciifolia is a valuable source of phytochemicals for both the nutraceutical and pharmaceutical sectors.

Natural Phenyldihydroisocoumarins: Sources, Chemistry and Bioactivity

The present review gives an overview about naturally occurring phenyldihydroisocoumarins, their sources, and bioactivities. In total, 54 compounds are covered, including eight substances which are in fact alkaloids or protoalkaloids. These nitrogen containing compounds were exclusively found in the Papaveraceae family. The remaining 46 compounds have been reported from twelve different source families, ranging from mosses to angiosperms. Six of the nitrogen free compounds feature additional rings, while 40 are simple phenyldihydroisocoumarins with substituents in all possible positions, except 3, 2’, and 6’. Common substituents of these simple phenyldihydroisocoumarins are hydroxy groups, methoxy groups, and glucosyloxy groups; on the other hand, acuminosyloxy and rutinosyloxy groups have so far been found only in one and two naturally occurring phenyldihydroisocoumarins, respectively. Though a number of bioactivities have been proven for phenyldihydroisocoumarins, ranging from anticancer and antidiabetic to antimicrobial and anti-inflammatory activities, so far only one taxon, Hydrangea macrophylla var. thunbergii, is widely used. Moreover, the usage of this taxon is mainly due to the sweet taste properties of the contained phenyldihydroisocoumarin phyllodulcin and less based on the alleged health-promoting effects of its constituents.

A Rapid and Cost-Effective Method for DNA Extraction from Archival Herbarium Specimens

Here we report a rapid and cost-effective method for the extraction of total DNA from herbarium specimens up to 50-90-year-old. The method takes about 2 h, uses AMPure XP magnetic beads diluted by PEG-8000- containing buffer, and does not require use of traditional volatile components like chloroform, phenol, and liquid nitrogen. It yields up to 4 µg of total nucleic acid with high purity from about 30 mg of dry material. The quality of the extracted DNA was tested by PCR amplification of 5S rRNA and rbcL genes (nuclear and chloroplast DNA markers) and compared against the traditional chloroform/isoamyl alcohol method. Our results demonstrate that the use of the magnetic beads is crucial for extraction of DNA suitable for subsequent PCR from herbarium samples due to the decreasing inhibitor concentrations, reducing short fragments of degraded DNA, and increasing median DNA fragment sizes.

Antioxidant and free radical-scavenging activity of constituents from two Scorzonera species

The aim of this study was to investigate the secondary metabolites content of Scorzonera papposa DC., an edible plant eaten in the desert region of Jordan and to assess its antioxidant and free radical-scavenging activity. By using this bioassay-oriented approach nine compounds, including the new natural compounds (6-trans-p-coumaroyl)-3-O-β-D-glucopyranosyl-2-deoxy-D-riburonic acid (1), (6-cis-p-coumaroyl)-3-O-β-D-glucopyranosyl-2-deoxy-D-riburonic acid (2a), (6-trans-p-coumaroyl)-3-O-β-D-glucopyranosyl-2-deoxy-D-riburonic acid methyl ester (3), and (6-trans-p-coumaroyl)-3-O-β-D-glucopyranosyl-(5-acetyl)-2-deoxy-D-riburonic acid (4), having the rare deoxy-D-riburonic acid moiety, were isolated. Their structures were elucidated by UV, MS, (1)H and (13)C NMR and 2D NMR. The antioxidant activity of the S. papposa pure compounds and of related derivatives isolated from another Scorzonera species (S. judaica Eig.) was also tested. The Relative Antioxidant Capacity Index (RACI) was applied as an integrated method to compare the antioxidant activities obtained using different chemical methods.

Radical scavenging activity and cytotoxicity of active quinic acid derivatives from Scorzonera divaricata roots

Five new quinic acid derivatives and two known 3-O-feruloylquinic acids were isolated from the roots of Scorzonera divaricata Turcz. The new compounds were elucidated as (-)-1,4-di-O-feruloyl-3-O-dihydrocaffeoylquinic acid, (-)-1-O-feruloyl-4-O- dihydrocaffeoylquinic acid, (-)-3,5-di-O-feruloylquinic acid, (-)-1-O-feruloyl-3-O-dihydro- caffeoylquinic acid, and (-)-1-O-feruloyl-5-O-dihydrocaffeoylquinic acid based on extensive spectroscopic studies, including one- and two-dimensional NMR, HRESIMS, UV, and IR results. Five compounds were assessed for antioxidant activity by ABTS and DPPH radical-scavenging assays and for their cytotoxicity against HL-60 and Hep-G2 cell lines by the MTT assay. Three quinic acid derivatives exhibited strong antioxidant activity, with IC(50) values of 3.95, 5.87, and 7.45 μg/mL against ABTS(+) and 11.7, 13.6, and 50.1 μg/mL against DPPH(). (-)-1,4-Di-O-feruloyl-3-O-dihydrocaffeoylquinic acid also exhibited moderate activity against Hep-G2 cell lines with an IC(50) value of 14.6 μg/mL.

Ethnopharmacological evaluation of some Scorzonera species: in vivo anti-inflammatory and antinociceptive effects

ETHNOPHARMACOLOGICAL RELEVANCE

Scorzonera species are mainly used against inflammation and to relieve pain in Turkish traditional medicine. Therefore, we aimed to assess in vivo anti-inflammatory and antinociceptive activities of the aerial part and root extracts of Scorzonera acuminata, Scorzonera cana var. alpina, Scorzonera cana var. jacquiniana, Scorzonera cana var. radicosa, Scorzonera cinerea, Scorzonera eriophora, Scorzonera incisa, Scorzonera laciniata ssp. laciniata, Scorzonera parviflora and Scorzonera sublanata.

MATERIALS AND METHODS

For the anti-inflammatory activity evaluation carrageenan, PGE(2) and serotonin-induced hind paw edema and 12-O-tetradecanoyl-13-acetate (TPA)-induced mouse ear edema models were used. p-Benzoquinone-induced abdominal constriction test was employed in mice for the assessment of antinociceptive activity. Furthermore chemical composition of the tested extracts was investigated qualitatively and quantitatively by using RP-HPLC method. Some phenolic acids and flavonoids were used as standards.

RESULTS

Extracts prepared from the aerial parts of Scorzonera cana var. jacquiniana, Scorzonera cinerea, Scorzonera eriophora, Scorzonera incisa and Scorzonera parviflora showed significant inhibitory effect on carrageenan and PGE(2)-induced hind paw edema model as well as on p-benzoquinone-induced abdominal constriction test. The extracts did not show any remarkable activity on serotonin-induced hind paw edema and TPA-induced mouse ear edema models. Chlorogenic acid was detected as major compounds in all the species investigated. Additionally, among the tested flavonoids, luteolin-7-glucoside, hyperoside and rutin were found to be in different amounts in Scorzonera species.

CONCLUSION

The experimental data revealed that Scorzonera cana var. jacquiniana, Scorzonera cinerea, Scorzonera eriophora, Scorzonera incisa and Scorzonera parviflora possess significant anti-inflammatory and antinociceptive activity. It has been suggested that flavonoids and chlorogenic acid are partly responsible for mentioned activities of Scorzonera species.

A new triterpene from Scorzonera latifolia (Fisch. and Mey.) DC

A novel triterpene 1 (3-β-hydroxy-fern-7-en-6-one-acetate) together with four known compounds, urs-12-en-11-one-3-acetyl (2), 3-β-hydroxy-fern-8-en-7-one-acetate (3), olean-12-en-11-one-3-acetyl (4) and leucodin (5) were obtained from the S. latifolia roots. All compounds were isolated from the n-hexane extract of S. latifolia roots using several chromatographic techniques. The structure of the isolated compounds was elucidated on the basis of (1)H-NMR, (13)C-NMR and 2D NMR data (HMBC, HMQC, COSY, TOCSY, NOESY, DEPT) as well as GC EITOF-HRMS.

Phenolic compounds from Scorzonera latifolia (Fisch. & Mey.) DC

A new 3-benzylphthalide, scorzoveratrin 4'-O-β-glucoside (1), together with the known 3-benzylphthalides, scorzoveratrin (2) and scorzoveratrozit (3), the caffeoyl derivatives, chlorogenic acid methyl ester (4), 4,5-dicaffeoylquinic acid (5), 4,5-dicaffeoylquinic acid methyl ester (6), 3,5-dicaffeoylquinic acid (7) and caffeic acid (8) were isolated from the subaerial parts of Scorzonera latifolia (Fisch. & Mey.) DC. All secondary metabolites were assigned using physicochemical and spectroscopic data. The known compounds 2-8 were isolated for the first time from this species.

Phenolic compounds from the roots of Jordanian viper's grass, Scorzonera judaica

Nine new phenolic compounds, 3S-hydrangenol 40-O-R-L-rhamnopyranoysl-(1-->3)-β-D-glucopyranoside (1), thunberginol F 7-O-β-D-glucopyranoside (2), 2-hydroxy-6-[2-(4-hydroxyphenyl)-2-oxo-ethyl]benzoic acid (3), 2-hydroxy-6-[2-(3,4-dihydroxyphenyl)-2-oxo-ethyl]benzoic acid (4), 2-hydroxy-6-[2-(3,4-dihydroxyphenyl-5-methoxy)-2-oxoethyl]benzoic acid (5), hydrangeic acid 40-O-β-D-glucopyranoside (6), E-3-(3,4-dihydroxybenzylidene)-5-(3,4-dihydroxyphenyl)dihydrofuran-2-one (7), Z-3-(3,4-dihydroxybenzylidene)-5-(3,4-dihydroxyphenyl)-2(3H)-furanone (8), and 4-[β-D-glucopyranosyl)hydroxy]-pinoresinol (9), and nine known compounds were isolated from the roots of Scorzonera judaica. Structures of 1-9 were elucidated by mass spectrometry, extensive 1D and 2D NMR spectroscopy, and CD spectroscopy.All compounds were evaluated for cytotoxic activity.

Cytotoxic Bibenzyls, and Germacrane- and Pinguisane-type Sesquiterpenoids from Indonesian, Tahitian and Japanese Liverworts

Cytotoxic bibenzyls, and germacrane- and pinguisane-type sesquiterpenoids have been isolated from unidentified Indonesian and Tahitian Frullania sp. and Japanese Porella perrottetiana by using a combination of chromatographic methods. The structure activity relationship (SAR) study showed that the presence of a phthalide group in bibenzyls, an α-methylene-γ-lactone in germacrane-type sesquiterpenoids, and β-hydroxycarbonyl in pinguisane-type sesquiterpenoids play an important role in providing cytotoxic activity against both human promyelocytic leukemia (HL-60) and human pharyngeal squamous carcinoma (KB) cell lines. The structure of each isolated compound was elucidated by using spectroscopic methods and the cytotoxicity was determined by using the WST-8 colorimetric assay.

Natural Products from Scorzonera aristata (Asteraceae)

The aerial parts of Scorzonera aristata Ramond ex DC., collected in the South Tyrolean Dolomites, yielded the flavonoids quercetin 3- O-glucoside, rutin, and isoorientin, and the caffeic acid derivatives chlorogenic acid, 4,5-dicaffeoyl quinic acid, and 3,5-dicaffeoyl quinic acid. Sub-aerial parts contained caffeic acid methyl ester, 3,5-dicaffeoyl quinic acid, and the triterpenes 3α-hydroxyolean-5-ene, lupeol, and magnificol. Chemosystematic implications of the isolated compounds are discussed briefly.

Two new 3-benzylphthalides from Scorzonera veratrifolia Fenzl

A phytochemical investigation of Scorzonera veratrifolia Fenzl (Asteraceae) yielded two new 3-benzylphthalides, scorzoveratrin (1) and scorzoveratrozit (2), together with five known compounds, chlorogenic acid (3), chlorogenic acid methyl ester (4), cryptochlorogenic acid (5), 4,5-dicaffeoylquinic acid (6) and 3,5-dicaffeoylquinic acid (7). All secondary metabolites were assigned using physicochemical and spectroscopic data. The known compounds 3-7 were isolated for the first time from this species.

Dihydrostilbene derivatives from the Mongolian medicinal plant Scorzonera radiata

Chromatographic separation of a crude extract obtained from aerial parts of the Mongolian medicinal plant Scorzonera radiata yielded five new dihydrostilbenes, scorzodihydrostilbenes A-E (1-5). The structures were unambiguously elucidated on the basis of one- and two-dimensional NMR ((1)H, (13)C, COSY, HMBC, HMQC, and ROESY) and mass spectrometric data. Compounds 1-5 exhibited antioxidative activity when analyzed in the DPPH (2,2-diphenyl-1-picrylhydrazyl) assay. For 1 and 5 the antioxidant activities were stronger than that of the well-known naturally occurring stilbene antioxidant resveratrol.