STUDIES ON THE NUMEROUS MEDICINAL UTILITIES OF THE PLANT URGINEA INDICA: A COMPREHENSIVE OVERVIEW

Urginea indica, is an essential indigenous plant belonging to the family Liliaceae found in all parts of India on rocky and hilly areas. It is commonly known as Indian squill, True squill or Sea onion and popularly known as Bon Pollundu. A methodical literature survey from various scientific databases such as PubMed, Scopus, Web of science and Google Scholar was conducted and it has been reported that the plant, mainly its bulb contains varieties of bioactive constituents such as flavonoids, phytosterols, phenols, saponins, alkaloids, proteins, carbohydrates, steroids and tannins. The bulb and the rhizome also contains calcium, iron, commercial compounds, such as Bufadienolides, Quercetin, Allose, Mindererus spirit, Tartronic acid and Paraldehyde, which have a variety of health functional properties. Various scientific studies have proven that the plant has anticancer, antidiabetic, anthelmintic, analgesic, antibacterial, antifungal, anti-angiogenic, anti-arthritic, antioxidant, anti-inflammatory, spasmodic and cardiac stimulant activities. It also finds its use as an analgesic and in wound healing. Thus, the current review gives a comprehensive overview of the various medicinal activity of the plant Urginea indica.

Glycerol Waste Valorization to Mesoxalic Acid Over a Bimetallic Pt-Pd/CNT Catalyst in Alkaline Medium

Glycerol electro-oxidation offers a green route to produce the high value added chemicals. Here in, we report the glycerol electro-oxidation over a series of multi walled carbon nano tubes supported monometallic (Pt/CNT and Pd/CNT) and bimetallic (Pt-Pd/CNT) catalysts in alkaline medium. The cyclic voltammetry, linear sweep voltammetry and chronoamperometry measurements were used to evaluate the activity and stability of the catalysts. The Pt-Pd/CNT electrocatalyst exhibited the highest activity in terms of higher current density (129.25 A/m2) and electrochemical surface area (382 m2/g). The glycerol electro-oxidation products formed at a potential of 0.013 V were analyzed systematically by high performance liquid chromatography. Overall, six compounds were found including mesoxalic acid, 1,3-dihydroxyacetone, glyceraldehyde, glyceric acid, tartronic acid and oxalic acid. A highest mesoxalic acid selectivity of 86.42% was obtained for Pt-Pd/CNT catalyst while a maximum tartronic acid selectivity of 50.17% and 46.02% was achieved for Pd/CNT and Pt/CNT respectively. It was found that the introduction of Pd into Pt/CNT lattice facilitated the formation of C3 products in terms of maximum selectivity achieved (86.42%) while the monometallic catalysts (Pd/CNT and Pt/CNT) showed a poor performance in comparison to their counterpart.

Selective oxidation of glycerol to tartronic acid over Pt/N-doped mesoporous carbon with extra framework magnesium catalysts under base-free conditions

Pt/N-doped carbons with extra framework magnesium catalysts exhibit high activity and selectivity in glycerol oxidation to tartronic acid under base-free conditions.

Green oxidation of bio-lactic acid with H2O2 into tartronic acid under UV irradiation

Lactic acid was photochemically converted into tartronic acid via green oxidation by using H2O2.

The preparation of large surface area lanthanum based perovskite supports for AuPt nanoparticles: tuning the glycerol oxidation reaction pathway by switching the perovskite B site

Gold and gold alloys, in the form of supported nanoparticles, have been shown over the last three decades to be highly effective oxidation catalysts. Mixed metal oxide perovskites, with their high structural tolerance, are ideal for investigating how changes in the chemical composition of supports affect the catalysts' properties, while retaining similar surface areas, morphologies and metal co-ordinations. However, a significant disadvantage of using perovskites as supports is their high crystallinity and small surface area. We report the use of a supercritical carbon dioxide anti-solvent precipitation methodology to prepare large surface area lanthanum based perovskites, making the deposition of 1 wt% AuPt nanoparticles feasible. These catalysts were used for the selective oxidation of glycerol. By changing the elemental composition of the perovskite B site, we dramatically altered the reaction pathway between a sequential oxidation route to glyceric or tartronic acid and a dehydration reaction pathway to lactic acid. Selectivity profiles were correlated to reported oxygen adsorption capacities of the perovskite supports and also to changes in the AuPt nanoparticle morphologies. Extended time on line analysis using the best oxidation catalyst (AuPt/LaMnO3) produced an exceptionally high tartronic acid yield. LaMnO3 produced from alternative preparation methods was found to have lower activities, but gave comparable selectivity profiles to that produced using the supercritical carbon dioxide anti-solvent precipitation methodology.