Sulphuric acid h2so4

Sulphuric acid H₂SO₄, malonic acid (MA) and 1,4-cyclohexanedione (CHD) were obtained from Sigma-Aldrich, 1,10-phenanthroline ferrous complex (ferroin) was from Fisher Scientific and sodium bromate NaBrO₃ from Acros Organics. BZ mixtures were prepared in glass vials by sequentially pipetting stock solutions of H₂SO₄, NaBrO₃, MA (or CHD) and ferroin (Supplementary Table S1). For the MA-CHD BZ mixture, CHD was added after the MA and the ferroin, because it was observed that the mixture usually failed to oscillate if CHD was added before the onset of MA BZ oscillations. The composition of MA BZ was 0.50 M H₂SO₄, 0.47 M NaBrO₃, 0.18 M malonic acid and 2 mM ferroin, with variations as described in the Results section. Unless otherwise stated, the composition of the 50/50% MA-CHD BZ mixture was 0.50 M H₂SO₄, 0.28 M NaBrO₃, 89 mM malonic acid, 93 mM CHD and 2 mM ferroin. With 4 mM ferroin the time to the start of wave propagation from droplet to droplet is up to 1 h shorter than with 2 mM.

For extraction, analytical grade solvents, Dichloromethane (DCM), Ethyl Acetate (EtOAc), and Ethanol (EtOH) were purchased from Carlo Erba Reactifs SDS (Val de Reuil, France). The aqueous solutions were prepared using deionized water. For TLC analysis, solvents were obtained from Fisher Scientific, while Sulphuric Acid (H₂SO₄) and Vanillin standard (98%) were purchased from Sigma-Aldrich (Steinheim, Germany). For HPLC analysis, MEthanol (MeOH), Acetonitrile (can), Water, and Acetic Acid were obtained from Fisher Scientific (Leicestershire, UK). ACN and Formic Acid used for LC–MS analysis were of LC–MS grade (Fisher Scientific, Loughborough, UK), while ultrapure water was obtained from a Milli-Q^® purification system (Merck Millipore, Darmstadt, Germany). Dimethyl sulfoxide (DMSO), DPPH (2,2-diphenyl-1-picrylhydrazyl), Gallic Acid used for DPPH Radical Scavenging assay, as well all reagents used for the three enzymatic assays, were purchased from Sigma-Aldrich. Kojic Acid (purity 99%), Elastatinal, and Phosphoramidon were used as the positive control for anti-tyrosinase, anti-elastase, and anti-collagenase assays, respectively, and were also purchased from Sigma-Aldrich.

The PP (Pisum sativum) is an ancient, economical, small sphere-shaped native seed or pod of fruit belonging to the Leguminosae family, mostly common in the northern part of Africa and the western part of Asia as well as other parts of the world. Like every other leguminous plant, PP encompasses symbiotic bacteria known as rhizobia inside the root lumps of their root arrangements. Rhizobia have the distinct capability of fixing nitrogen from molecular nitrogen into ammonia. It comprises a high proportion of consumable proteins, vitamin A and vitamin C, and it is also rich in some essential minerals like calcium and phosphorus (Singh et al. 2020 ). However, the PP used for this study was acquired from an indigenous market and was utilized for the production of the activated TETA-PP. Sulphuric acid (H₂SO₄, MW = 98.07 g, 99%) and potassium dichromate (K₂Cr₂O₇, MW = 294.19 g, 99 %) and TETA were obtained from Sigma-Aldrich. The standard stock solution of Cr⁶⁺ ions was prepared from K₂Cr₂O₇. 1,5-Diphenylcarbazide was obtained from BDHZ Chemicals LTD, Poole, UK, as a composite reagent for Cr⁶⁺ ion analysis. The “Analytik Jena SPEKOL 1300 UV/visible digital spectrophotometer” instrument with matching glass cells of a 1.00-cm optical path, a shaker (“JSOS-500”) and a pH meter (“JENCO 6173”) were used for the experiments and analysis.