1. Spinach (Spinacia oleracea L.) leaf extracts catalyse the oxidation of formate to CO(2). 2. Two enzymic systems are responsible for this oxidation, the peroxidatic action of catalase (EC 1.11.1.6) and NAD-dependent formate dehydrogenase (EC 1.2.1.2). 3. Formate dehydrogenase is mainly, if not exclusively, located in the mitochondria. This enzyme has a pH optimum of 6-6.5 and a K(m) for forma...

Application of gibberellin A(53) (GA(53)) to short-day (SD)-grown spinach (Spinacia oleracea L.) plants caused an increase in petiole length and leaf angle similar to that found in plants transferred to long days (LD). [(2)H] GA(53) was fed to plants in SD, LD, and in a SD to LD transition experiment, and the metabolites were identified by gas chromatography with selected ion monitoring. After ...

Chloroplast phosphofructokinase from spinach (Spinacia oleracea L.) was purified approximately 40-fold by a combination of fractionations with ammonium sulfate and acetone followed by chromatography on DEAE-Sephadex A-50. Positive cooperative kinetics was observed for the interaction between the enzyme and the substrate fructose 6-phosphate. The optimum pH shifted from 7.7 toward 7.0 as the fru...

We investigated the effect of selenium form and dose on the total glutathione and non-protein -SH group contents in the edible spinach (Spinacia oleracea L.) and ground tomato (Lycopersicon esculentum Mill.) plants. Our experiments were carried out in a hydroponic culture. Selenium was added to the culture medium in its selenite (Na2SeO3 x 5H2O) and selenate (Na2SeO4) forms. Regardless of the s...

A shortage in the zinc supply to spinach (Spinacia oleracea L.) drastically reduced carbonic anhydrase levels with little effect on net CO(2) uptake per unit leaf area, except with the most severe zinc stresses. Under these conditions, carbonic anhydrase was below 10% and photosynthesis 60 to 70% of the control levels. When photosynthesis was measured at a range of CO(2) supply levels, zinc-def...

A glucosyl and a glucosyl-glucan transferase activity from spinach (Spinacia oleracea L. var. Matador) leaves have been partially purified and characterized. The latter activity (fraction 1 after diethylaminoethylcellulose chromatography) is responsible for the transfer of glucosyl as well as of maltosyl, maltotriosyl, and higher homologous residues to glucose giving rise to maltose and the cor...

In this study, a series of twelve ring-substituted salicylanilides and carbamoylphenylcarbamates were prepared and characterized. The compounds were analyzed using RP-HPLC to determine lipophilicity. They were tested for their activity related to the inhibition of photosynthetic electron transport (PET) in spinach (Spinacia oleracea L.) chloroplasts. Moreover, their site of action in the photos...

Abstract The use of plant extracts rich in primary and secondary metabolites as biostimulants agriculture is a modern approach for increasing the sustainability crops. Quinoa seeds ( Chenopodium quinoa Willd.) spinach leaves Spinacia oleracea L.) are valuable source biologically active compounds metabolism such polyphenolic ecdysteroids. An important producers – polysaccharides common chicory C...

Abstract Spinacia oleracea L., Amaranthaceae, leaves cultivated in Egypt demonstrated a potential antileukemic activity against the chronic myeloid leukemia, K562 cell line. Thus, aim of this study is to carry out phytochemical investigation S. as well isolation its phytoconstituents. Phytochemical resulted seventeen known compounds. The biological revealed that compounds hexaprenol, phytol, an...

The present study employed white (W), blue (B: 468 nm), red (R: 629 nm) and green (G: 524 monochromatic LED lights for 26 days, from 11:00 to 18:00 (7 h per day), with a average of photosynthetic photon flux density (PPFD) 26.00 m-2 s-1 on two baby leaves spinach (Spinacia oleracea L.) cultivars (Falcon F1 Viroflay) grown in hydroponic system. Regardless the cultivar, fresh dry weights were pos...