Chemical constituents of the roots of Scorzonera divaricata and their chemotaxonomic significance

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.

Terpenoid and Fatty Acid Profiling Along with Anti-tyrosinase and Anti-urease Potentials of Scorzonera pygmaea Sibth. & Sm. an Endemic Plant of Turkey

Petroleum ether (PE), chloroform (CH), ethyl acetate (EA) and n-butanol (BU) fractions were obtained from ethanol extracts of the roots (SPR) and the above ground (SPH) parts of S. pygmaea. PE fractions were evaluated by GC-MS for profiling the terpenoids and the fatty acids of the plant. 29 compounds in total including saturated (major palmitic acid), unsaturated (major linoleic acid) fatty acids and triterpenes were tentatively determined. Short-term extraction methods might be preferred to avoid esterification of fatty acids. Phytochemical profiles of SPR-PE and SPH-PE were found to be similar to each other and to other few Scorzonera species reported previously. These results will contribute to the chemotaxonomic studies about the genus which is considered taxonomically complex genus. Activity studies were carried out using kojic acid (87.10% inhibition) standard for tyrosinase and thiourea (95.83% inhibition) standard for urease. SPR-CH was determined as the most potent fraction with 55.94% and 55.10% inhibition of tyrosinase and urease respectively at the same concentration of the standards (200 microgram/mL). These moderate results might be considered encouraging for more detailed studies to determine the active compounds and to evaluate the plant's potential in pharmaceutical, food and cosmetic industries in terms of tyrosinase and urease inhibition.

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.