Phytochemistry Reviews (v.17, #3)

Chemistry and medicinal uses of the subfamily Barnadesioideae (Asteraceae) by Gari V. Ccana-Ccapatinta; Marcelo Monge; Paola L. Ferreira; Fernando B. Da Costa (471-489).
The subfamily Barnadesioideae (Asteraceae) constitutes a group of spiny plants that are entirely restricted to South America and currently encompasses 92 species distributed in nine genera. Barnadesioideae is particularly interesting because this subfamily constitutes the sister group of all other Asteraceae, and provides insights into the early evolution of Asteraceae. The present work summarizes the current knowledge of the chemistry and medicinal uses of Barnadesioideae. The up-to-date phytochemical profile of Barnadesioideae is composed of phenolic compounds, flavonoids, and triterpenoids, representing 39 different compounds described in 45 species of the subfamily. The presumable absence of sesquiterpene lactones—the typical Asteraceae taxonomical markers—in members of Barnadesioideae is also discussed. A few members of the genera Barnadesia, Dasyphyllum, and more frequently, Chuquiraga, are reported in the traditional medicine of Argentina, Brazil, Bolivia, Chile, Colombia, Ecuador, and Peru, where they are known for their antitussive, expectorant, anti-inflammatory, and many other properties. Chuquiraga jussieui, Chuquiraga spinosa, and Chuquiraga weberbaueri are species frequently sold in medicinal plant markets of Ecuador and Peru, where they are commonly recommended for the relief of genitourinary and reproductive disorders in women and men. Some phytopharmaceuticals containing C. spinosa are also marketed in Europe and North America. Further phytochemical studies on the members of Barnadesioideae would be of great interest for the chemotaxonomy of the family Asteraceae. Moreover, profiling the phytochemical composition of those medically important Barnadesioideae would support their uses in traditional medicine.
Keywords: Barnadesioideae; Flavonoids; Triterpenoids; Traditional medicine

Recent trends and comprehensive appraisal for the biotechnological production of trans-resveratrol and its derivatives by MingYu Chu; Lorena Almagro; BaiHong Chen; Lorenzo Burgos; María Angeles Pedreño (491-508).
Grapevine is one of the most important fruit crops in the world, due to the production of wine and other beverages, the consumption of grapes as fresh fruits and in the form of raisins. Grapevine produces stilbenes, which are plant phenols characterized by a 1, 2-diphenylethylene backbone. Most plant stilbenes have phytoalexin activity and are derivatives of the monomeric unit trans-resveratrol (3,5,4′-trihydroxystilbene). The use of trans-resveratrol and its derivatives obtained from plants is increasing due to the high demand for these compounds as ingredients in the cosmetic, nutraceutical and pharmaceutical industries. However, the natural production of these compounds is insufficient to meet current market demand, for which reason, it is important to develop efficient methods to obtain them in abundance on a commercial scale. At present, the methods used for obtaining trans-resveratrol and derivatives can be divided into three types: extraction from plant raw materials, chemical synthesis and production by biotechnological processes. However, the yield of trans-resveratrol extracted from plants or obtained by chemical synthesis is low and insufficient to meet the increase in demand. As a result, the third option, plant in vitro culture, is increasingly used as an alternative biotechnological strategy to increase the production of these compounds. This review describes how the optimization of culture conditions and the different factors associated with cell growth, as well as elicitation strategies could increase the production of trans-resveratrol and its derivatives by using plant in vitro cultures. Special attention is paid to grapevine transformation technologies and the metabolic engineering necessary for the production of trans-resveratrol and its derivatives.
Keywords: Bioproduction; Elicitation; Metabolic engineering; Plant in vitro cultures; Stilbenes

Naphthoquinone pigments from sea urchins: chemistry and pharmacology by Alexander N. Shikov; Olga N. Pozharitskaya; Anna S. Krishtopina; Valery G. Makarov (509-534).
Due to their wide distribution, chemical diversity and scientifically confirmed pharmacological properties, sea urchin pigments have evoked renewed interest as a promising source material for the development of drugs that might be useful in clinical practice for the treatment of various human diseases. This review discusses advances in the chemistry, isolation, stability, and pharmacological and clinically proven activities of naphthoquinone pigments from sea urchins, as well as their safety uses. Recent decades have also witnessed studies concerning the anti-allergic, antidiabetic, antihypertensive, anti-inflammatory, antioxidant, cardioprotective, and hypocholesterolemic potential of pigments. Dimeric pigments are believed to be more active and largely responsible for observed pharmacological effects. The summarized data on observed pharmacological activity, coupled with a low toxicity profile, strongly support the view that naphthoquinone pigments could be potentially used in the development of agents possessing therapeutic benefits.
Keywords: Anhydroethylidene-trihydroxynaphthazarin; Echinochrome; Ethylidene-trihydroxynaphthazarin; Spinochrome; Isolation; Stability; Effects

Carrageenans and carrageenases: versatile polysaccharides and promising marine enzymes by Mehri Ghanbarzadeh; Asma Golmoradizadeh; Ahmad Homaei (535-571).
Carrageenans are sulfated polysaccharides isolated from marine red algae that share a common backbone of D-galactose alternately linked by α(1,3) and β(1,4) glycosidic linkages. They are classified based on the number and the position of the sulfate ester groups and the occurrence of a 3,6 anhydro-ring in the α-linked galactose. Accordingly the three most commercially exploited carrageenans are κ-, ι-, and λ-carrageenans. Because of their biocompatibility, exceptional physicochemical features and emulsifying, thickening, gelling and stabilizing abilities, they have found several industrial application, especially in food, pharmaceutical and cosmetic industries. Moreover, carrageenans can be degraded into lower molecular weight oligosaccharides, which have been reported to have promising pharmacological properties and potential therapeutic applications. Enzymes which degrade carrageenans are called carrageenases and are produced only by marine bacterial species. These enzymes all are endohydrolases that hydrolyze the internal β 1,4 linkages in carrageenans and produce a series of homologous even-numbered oligosaccharides with various biological and physiological activities including anti-tumor, anti-inflammation, anti-viral, anti-coagulation, etc. Carrageenase enzymes have also other applications related to the biomedical field, bioethanol production, prevention of red algal bloom, obtaining algal protoplasts, etc. In the first part of this review, general information regarding structure, physicochemical properties, biological activities and potential applications of carrageenans is summarized. The second part deals with research and development works on some aspects of carrageenase enzymes like the source, characterization, the kinetics and biochemical properties and their applications in various industries.
Keywords: Carrageenan; Carrageenan-degrading enzymes; Bacterial carrageenases; Biochemical properties; Industrial applications

Rheum australe (Himalayan Rhubarb) is a multipurpose, endemic and endangered medicinal herb of North Western Himalayas. It finds extensive use as a medicinal herb since antiquity in different traditional systems of medicine to cure a wide range of ailments related to the circulatory, digestive, endocrine, respiratory and skeletal systems as well as to treat various infectious diseases. The remedying properties of this plant species are ascribed to a set of diverse bioactive secondary metabolite constituents, particularly anthraquinones (emodin, chrysophanol, physcion, aloe-emodin and rhein) and stilbenoids (piceatannol, resveratrol), besides dietary flavonoids known for their putative health benefits. Recent studies demonstrate the pharmacological efficacy of some of these metabolites and/or their derivatives as lead molecules for the treatment of various human diseases. Present review comprehensively covers the literature available on R. australe from 1980 to early 2018. The review provides up-to-date information available on its botany for easy identification of the plant, and origin and historical perspective detailing its trade and commerce. Distribution, therapeutic potential in relation to traditional uses and pharmacology, phytochemistry and general biosynthesis of major chemical constituents are also discussed. Additionally, efficient and reproducible in vitro propagation studies holding vital significance in preserving the natural germplasm of the plant and for its industrial exploitation have also been highlighted. The review presents a detailed perspective for future studies to conserve and sustainably make use of this endangered plant species at a commercial scale.
Keywords: Rheum australe ; Anthraquinone; Stilbenoid; Flavonoid; Anticancer; Antidiabetic; Antimicrobial; Antioxidative; Anti-inflammatory

The antioxidant properties of plant flavonoids: their exploitation by molecular plant breeding by Vincenzo D’Amelia; Riccardo Aversano; Pasquale Chiaiese; Domenico Carputo (611-625).
Flavonoids are a large group of plant secondary metabolites that have a high popularity as nutraceuticals. Further, they contribute to food quality, acting as preservatives, pigments and strong antioxidants. Flavonoids also play an important role in plant stress tolerance, with consequent contribution to crop productivity. The enhancement of flavonoid content is an alluring goal that meets the food requirements of an increasing and more demanding world population. After illustrating the relevance of flavonoids for human nutrition, food technology and plant protection, this review covers breeding and molecular strategies used to exploit flavonoid biodiversity present among plant species. Highlighted here are also recent advances in genome sequencing and -omics tools that facilitate the identification of genetic regions influencing flavonoid production in relevant agricultural species. Finally, the review outlines established and new biotechnological techniques which can help to functionalize and use flavonoid genes to improve both the quality and the quantity of these outstanding compounds. The final message of this review is that flavonoids can be an interesting target for molecular plant breeding that can greatly impact both primary agricultural products and food technology.
Keywords: Agricultural production; Antioxidant activity; Phenylpropanoids; Plant biochemistry; Plant biotechnology

Therapeutic properties of lectins in herbal supplements by K. M. Mbae; S. Umesha; H. M. Manukumar (627-643).
Medicinal plants host numerous therapeutic low molecular weight phytochemicals and macromolecules such as polysaccharides and proteins. Lectins are glycan binding proteins ubiquitous in the cell and the extracellular surface of all living organisms. Plant parts contain lectins with diverse glycan binding specificities. This review highlights the occurrence of lectins in herbal remedies, their persistence, and bioactivity. Lectins’ roles in plants include signaling, defense, and stress responses. The species, plant part, biotic and abiotic factors influence the type and concentration of lectins. Many lectins withstand herbal portions preparation procedures, resist degradation in the alimentary canal and crossover to the circulatory system. Exogenous plant lectins bind glycans with high specificity eliciting cellular responses that include antimicrobial, antitumor and immunomodulation effects. Some lectins are deleterious to normal physiology.
Keywords: Lectins; Medicinal herbs; Antitumor; Immunomodulation