Separation of lacquer polysaccharides and interaction with poly-l-lysine

A comprehensive review of medicinal Toxicodendron (Anacardiaceae): Botany, traditional uses, phytochemistry and pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Comprising of about 30 species, the genus Toxicodendron (Anacardiaceae) are mainly distributed in East Asia and North America. Among them, 13 species have been traditionally used as folk medicines in Asia and other parts of the world to treat blood diseases, abnormal bleeding, skin diseases, gastrointestinal diseases, liver diseases, bone injury, lung diseases, neurological diseases, cardiovascular diseases, tonic, cancer, eye diseases, menstrual irregularities, inflammation, rheumatism, diabetes mellitus, rattlesnake bite, internal parasites, contraceptive, vomiting and diarrhea.

AIM OF THE STUDY

To date, no comprehensive review on Toxicodendron has been published and the scientific basis of the traditional medicinal benefits of Toxicodendron have been less reported. Therefore, this review aims to provide a reference for further research and development on medicinal purpose of Toxicodendron by summarizing the works (from 1980 to 2023), and focusing on its botany, traditional uses, phytochemistry and pharmacology.

MATERIALS AND METHODS

The names of the species were from The Plant List Database (http://www.theplantlist.org), World Flora Online (http://www.worldfloraonline.org), Catalogue of Life Database (https://www.catalogueoflife.org/) and Plants for A Future Database (https://pfaf.org/user/Default.aspx). And the search terms "Toxicodendron" and "the names of 31 species and their synonyms" were used to search for information from electronic databases such as Web of Science, Scopus, Google Scholar, Science Direct, PubMed, Baidu Scholar, Springer, and Wiley Online Library. Moreover, PhD and MSc dissertations were also used to support this work.

RESULTS

These species on Toxicodendron are widely used in folkloric medicine and modern pharmacological activities. So far, approximately 238 compounds, mainly phenolic acids and their derivatives, urushiols, flavonoids and terpenoids, are extracted and isolated from Toxicodendron plants, commonly, T. trichocarpum, T. vernicifluum, T. succedaneum, and T. radicans. Among them, phenolic acids and flavonoids are the main compound classes that show pharmacological activities in Toxicodendron plants both in vitro and in vivo. Furthermore, the extracts and single compounds of these species show a wide range of activities, such as antioxidant, antibacterial, anti-inflammatory, anti-tumor, liver protection, fat reduction, nerve protection, and treatment of blood diseases.

CONCLUSIONS

Selected species of Toxicodendron have been used as herbal medicines in the Southeast Asian for a long time. Furthermore, some bioactive constituents have been identified from them, so plants in this genus may be potential new drugs. The existing research on Toxicodendron has been reviewed, and the phytochemistry and pharmacology provide theoretical basis for some of the traditional medicinal uses. Therefore, in this review, the traditional medicinal, phytochemical and modern pharmacology of Toxicodendron plants are summarized to help future researchers to find new drug leads or to get a better understanding of structure-activity relationships.

N-glycans in Toxicodendron vernicifluum lacquer laccase

The N-glycans in Toxicodendron vernicifluum (Rhus vernicifera) lacquer laccase was elucidated for the first time through a combination of enzymatic digestion and subsequent mass spectrometry measurements using LC-MS/MS and MALDI-TOF MS. Lacquer laccase was isolated from a Japanese lacquer acetone powder from consecutive Sephadex C-50 and DEAE A-50 column chromatography. Trypsin and chymotrypsin digestions of the lacquer laccase resulted in a mixture of peptides and N-glycopeptides, which were treated with peptide-N-glycosidases and then N^α-(aminooxyacetyl)tryptophanylarginine methyl ester (aoWR) to give the aoWR-labelled N-glycans. The MS measurements revealed that GlcNAc₄Hex₅Fuc₃Xyl₁ N-glycan was attached at 12 N-glycosylation sites (Asn 5, 14, 180, 194, 233, 274, 284, 347, 364, 381, 398, and 519), GlcNAc₃Hex₄Fuc₂Xyl₁ N-glycan at two sites (Asn 124 and 454), and GlcNAc₃Hex₆Fuc₁Xyl₁ N-glycan at one site (Asn 28). A database search (Mascot search) of the peptides also suggested the presence of N-glycans at the 15 potential N-glycosylation sites (Asn-X-Ser/Thr).

Analysis of interaction between sulfated polysaccharides and HIV oligopeptides by surface plasmon resonance

This study aims to quantitatively investigate the interaction between sulfated polysaccharides with potent anti-HIV activity, dextran and curdlan sulfates with negatively charged sulfate groups, and poly-L-lysine as a model protein and oligopeptides from a HIV surface glycoprotein gp120 with positively charged amino acids using surface plasmon resonance (SPR) and dynamic light scattering (DLS) to elucidate the anti-HIV mechanism of sulfated polysaccharides. The apparent association- (k_a) and dissociation rate (k_d) constants of dextran and curdlan sulfates against poly-L-lysine were k_a = 6.92 × 10⁴-2.17 × 10⁶ 1/Ms and k_d = 4.29 × 10^-5-2.22 × 10^-4 1/s; these kinetic constants were dependent on the molecular weights and degree of sulfation of sulfated polysaccharides. For interaction, the three oligopeptides from the HIV gp120 were peptide A ²⁹⁷TRPNNNTRKRIRIQRGPGRA³¹⁶ with several lysine (K) and arginine (R) in the V3 loop region, peptide B ⁴⁹³PLGVAPTKAKRRVVQREKR⁵¹¹ with several K and R in the C-terminus region, and oligopeptide C ³⁶²KQSSGGDPEIVTHSFNCGG³⁸⁰ with few basic amino acids in the CD4 binding domain. Sulfated polysaccharides exhibited strong interaction against oligopeptides A and B, (k_a = 5.48 × 10⁴-2.96 × 10⁶ 1/Ms. and k_d = 1.74 × 10^-4-6.24 × 10^-3 1/s), no interaction was noted against oligopeptide C. Moreover, the particle size and zeta potential by DLS indicated the interaction between sulfated polysaccharides and oligopeptides A and B, suggesting the anti-HIV mechanism of sulfated polysaccharides to be the electrostatic interaction of negatively charged sulfated polysaccharides and HIV at the positively charged amino acid regions.

Effect of repeat unit structure and molecular mass of lactic acid bacteria hetero-exopolysaccharides on binding to milk proteins

Interactions of exopolysaccharides and proteins are of great importance in food science, but complicated to analyze and quantify at the molecular level. A surface plasmon resonance procedure was established to characterize binding of seven structure-determined, branched hetero-exopolysaccharides (HePSs) of 0.14-4.9MDa from lactic acid bacteria to different milk proteins (β-casein, κ-casein, native and heat-treated β-lactoglobulin) at pH 4.0-5.0. Maximum binding capacity (RU_max) and apparent affinity (K_A,app) were HePS- and protein-dependent and varied for example 10- and 600-fold, respectively, in the complexation with native β-lactoglobulin at pH 4.0. Highest RU_max and K_A,app were obtained with heat-treated β-lactoglobulin and β-casein, respectively. Overall, RU_max and K_A,app decreased 6- and 20-fold, respectively, with increasing pH from 4.0 to 5.0. K_A,app was influenced by ionic strength and temperature, indicating that polar interactions stabilize HePS-protein complexes. HePS size as well as oligosaccharide repeat structure, conferring chain flexibility and hydrogen bonding potential, influence the K_A,app.

Isolation and antiviral activity of water-soluble Cynomorium songaricum Rupr. polysaccharides

The plant, Cynomorium songaricum Rupr., is used as a traditional medicine in China and Mongolia. In the present study, two new water-soluble polysaccharides isolated from C. songaricum Rupr. were purified by successive Sephadex G-75 and G-50 column chromatographies and then characterized by high resolution NMR and IR spectroscopies. The molecular weights of two polysaccharides were determined by an aqueous GPC to be [Formula: see text] = 3.7 × 10(4) and 1.0 × 10(4), respectively. In addition, it was found that the polysaccharide with the larger molecular weight was an acidic polysaccharide. It was found that the iodine-starch reaction of both isolated polysaccharides was negative and the methylation analysis gave 2, 4, 6-tri-O-methyl alditol acetate as a main product. NMR and IR measurements and sugar analysis revealed that both polysaccharides had a (1 → 3)-α-d-glucopyranosidic main chain with a small number of branches. After sulfation, the sulfated C. songaricum Rupr. polysaccharides were found to have a potent inhibitory effect on HIV infection of MT-4 cells at a 50% effective concentration of 0.3-0.4 μg/ml, a concentration that has almost the same high activity as standard dextran and curdlan sulfates, EC50 = 0.35 and 0.14 μg/ml, respectively. The 50% cytotoxic concentration was low, CC50>1000 μg/ml. In addition, the interaction between the sulfated polysaccharides and poly-l-lysine as a model protein compound was investigated by a surface plasmon resonance to reveal the anti-HIV mechanism.

Enzymatic Digestion and Mass Spectroscopies of N-Linked Glycans in Lacquer Stellacyanin fromRhus vernicifera

Lacquer stellacyanin was isolated and purified from lacquer acetone powder by continuous Sephadex column chromatographies using Sephadex C-50, DEAE A-50, and C-50 gels. The purified lacquer stellacyanin had a blue color with one major and three minor bands around 26 k Dain SDS PAGE. Trypsin- and chymotrypsin-treated lacquer stellacyanins were examined by LC/MS/MS to determine three N-glycosylation sites (N28, N60, and N102) and were further analyzed by MALDI TOF MS, indicating that the N-linked glycans were attached to the three asparagine (Asn) sites, respectively. In addition, after trypsin digestion and PNGase A and PNGase F treatments to cleave N-linked glycans from the Asn sites, it was found that lacquer stellacyanin had a xylose containing a biantennary N-linked glycan with core fucosylation consisting of 13 sugar residues (a complex type N-linked glycan) by MALDI TOF MS analysis. This is the first report on the structure of an N-linked glycan in lacquer stellacyanin.