To date, a number of mannose-binding lectins have been isolated and characterized from plants and fungi. These proteins are composed of different structural scaffold structures which harbor a single or multiple carbohydrate-binding sites involved in the specific recognition of mannose-containing glycans. Generally, the mannose-binding site consists of a small, central, carbohydrate-binding pocket responsible for the "broad sugar-binding specificity" toward a single mannose molecule, surrounded by a more extended binding area responsible for the specific recognition of larger mannose-containing N-glycan chains. Accordingly, the mannose-binding specificity of the so-called mannose-binding lectins towards complex mannose-containing N-glycans depends largely on the topography of their mannose-binding site(s). This structure⁻function relationship introduces a high degree of specificity in the apparently homogeneous group of mannose-binding lectins, with respect to the specific recognition of high-mannose and complex N-glycans. Because of the high specificity towards mannose these lectins are valuable tools for deciphering and characterizing the complex mannose-containing glycans that decorate both normal and transformed cells, e.g., the altered high-mannose N-glycans that often occur at the surface of various cancer cells.

https://hal-amu.archives-ouvertes.fr/hal-02388775/document

Overview of the Structure–Function Relationships of Mannose-Specific Lectins from Plants, Algae and Fungi

Current challenges to antiretroviral therapy have opened new vistas in the search for novel drugs from natural products. This review focusses on plants as sources of inhibitors for human immunodeficiency virus type 1 (HIV-1) reverse transcriptase. Based on a systematic search of the literature, anti-HIV-1 reverse transcriptase activity was recorded for 132 plant species in 100 genera and 51 families. Seven families comprise 52.6% of plant species with anti-reverse transcriptase activity: Lamiaceae (13.7%), Fabaceae (10.7%), Euphorbiaceae (9.9%), Clusiaceae (6.1%), Asteraceae (4.6%), Combretaceae (4.6%), and Moraceae (3.0%). The repertoire of anti-reverse transcriptase active compounds includes (-)-catechin, 1,8-cineole, 3,4-di-O-caffeoylquinic acid, 5,7-dimethoxy-6-methylflavone, apigenin, baicalein, betulinic acid, caffeic acid, cis-3-hexene-1-ol, eugenol, euscaphic acid, gallic acid, hoslunddiol, limonene, naringenin, oleanolic acid, p-cymene, pomolic acid, quinic acid, rosmarinic acid, stigmasterol, thymol, ursolic acid, α-bergamotene, α-pinene, and γ-terpinene. Among the IC50 values are 0.10 μg/ml (Uvaria angolensis), 3 μg/ml (Hemidesmus indicus), 2. 3μg/ml (Adansonia digitata), 6.24 μg/ml (Caesalpinia coriaria), 7.2 μg/ml (Terminalia sericea), 17.4 μg/ml (Hypoxis hemerocallidea), and 79 μg/ml (Moringa oleifera). The chemical diversity and activity profiles of HIV-1 reverse transcriptase inhibitors from plants reveal two recurring motifs: the structure of several active anti-reverse transcriptase compounds mimics nucleoside analogues, and numerous anti-reverse transcriptase phytochemicals have pleiotropic effects and heterogenous pharmacological benefits during infection and disease. To accelerate drug discovery and development, this review recommends the urgent need to tap into the rich vein of indigenous knowledge of putative anti-HIV/AIDS medicinal plants (reverse pharmacology), determine pan-assay interference compounds, analyze structure-activity relationships, and conduct more clinical trials.

/pdf/chemical-diversity-and-activity-profiles-of-hiv-1-reverse-tpjslj8133.pdf

Chemical diversity and activity profiles of HIV-1 reverse transcriptase inhibitors from plants

Dioscorea species, known as "Yams," belong to family Dioscoreaceae. This genus consists of more than 600 species distributed from Africa, Asia, the Caribbean's South America, and the South Pacific islands. Their organoleptic properties make them the most widely used carbohydrate food and dietary supplements. The underground and/or aerial tubers represent valuable sources of proteins, fats, and vitamins for millions of people in West Africa. This review gives a shot of secondary metabolites of Dioscorea plants, including steroids, clerodane diterpenes, quinones, cyanidins, phenolics, diarylheptanoids, and nitrogen-containing compounds. This review collected the evidence on biological properties of description Dioscorea, including in-vitro and in-vivo studies. Dioscorea species contain promising bioactive molecules i.e. diosgenin that support their different biological properties, including antioxidant, hypoglycaemic, hypolipidemic, anti- antimicrobial, inflammatory, antiproliferative, androgenic, estrogenic, and contraceptive drugs. Indeed, besides its nutrient values, Dioscorea is a potential source of bioactive substances of interest in the prevention/treatment of several diseases, and thus represents a great challenge in developing countries. However, ethnomedicinal potential should be validated and further researches on pharmacological properties and phytochemical composition should be carried out. Particularly, doing some studies to convert the preclinical results to clinical efficacy should be guaranteed. Dioscorea, Food plant, Traditional use, Phytochemistry, Pharmacological activities.

http://ijpr.sbmu.ac.ir/article_1100987_1897b6db9e9b87efd827dc147f6a771a.pdf

Dioscorea Plants: A Genus Rich in Vital Nutra-pharmaceuticals-A Review.

Seed storage proteins play a fundamental role in plant reproduction and human nutrition. They accumulate during seed development as reserve material for germination and seedling growth and are a major source of dietary protein for human consumption. Storage proteins encompass multiple isoforms encoded by multi-gene families that undergo abundant glycosylations and phosphorylations. Two-dimensional electrophoresis (2-DE) is a proteomic tool especially suitable for the characterization of storage proteins because of their peculiar characteristics. In particular, storage proteins are soluble multimeric proteins highly represented in the seed proteome that contain polypeptides of molecular mass between 10 and 130 kDa. In addition, high-resolution profiles can be achieved by applying targeted 2-DE protocols. 2-DE coupled with mass spectrometry (MS) has traditionally been the methodology of choice in numerous studies on the biology of storage proteins in a wide diversity of plants. 2-DE-based reference maps have decisively contributed to the current state of our knowledge about storage proteins in multiple key aspects, including identification of isoforms and quantification of their relative abundance, identification of phosphorylated isoforms and assessment of their phosphorylation status, and dynamic changes of isoforms during seed development and germination both qualitatively and quantitatively. These advances have translated into relevant information about meaningful traits in seed breeding such as protein quality, longevity, gluten and allergen content, stress response and antifungal, antibacterial, and insect susceptibility. This review addresses progress on the biology of storage proteins and application areas in seed breeding using 2-DE-based maps.

https://www.mdpi.com/1420-3049/23/10/2462/pdf

Vishwanathreddy Hotpet

Papers

Purification, characterization and biological significance of mannose binding lectin from Dioscorea bulbifera bulbils