The influence of n-(2-hydroxyphenyl)-β-alanines and products of their interaction with 2,3-dichlor-1,4-naphthoquinone on barley (Hordeum vulgare L.) growth and flavonoids formation


  • R. Stankevičienė Kaunas University of Technology
  • I. Jonuškienė
  • R. Baranauskaitė
  • V. Mickevičius


Naphthoquinones are largely found in plants, microorganisms, and some animals. These compounds have been widely used for various purposes as colorants for cosmetics, fabrics, foods, and for medicinal purposes, including antitumor, anti-inflammatory, and antimicrobial agents. They are biologically active.

Barley (Hordeum vulgare L.) is one of the oldest corn varieties in the world. Barley is widely used in the production of beer and in confectionery, textile, pharmacy industries. Barley seedlings contain significant quantities of calcium, iron, magnesium, potassium, vitamins C and E, flavonoids. However, the nutrient contents of all barley varieties depend on where the plants are grown, the soil quality, the average rainfall, and the harvest technique. It is known that the highest concentrations of nutrients are present for just a few days. Barley is promoted as a source of antioxidants. Studies have shown that an extract from young barley leaves helps to suppress a number of health disorders.

The barley variety ‘Barke’ was used in the experiments. Growth regulators were examined at different concentration: 0.5 mg/l, 1.0 mg/l, 1.5 mg/l, 2.0 mg/l, 2.5 mg/l, 5.0 mg/l, 10 mg/l and 15 mg/l. The naphthoquinone derivatives were synthesized at the Department of Organic Chemistry. The results of the experiments were compared with control variants: sterile distilled water, growth regulator 3-(2-oxo-1,3-benzoxazol-3(2H)-yl) propanoic acid sodium salt and 2-methyl-1,4-naphthoquinone (vitamin K3). Young green parts of barley plants, as a potential source of nutritionally valuable substances, were analysed for the content of flavonoids.

3-(6,11-Dioxo-6H-benz[b]phenoxazin-12(11H)-yl)butanoic acid was found to stimulate the growth of barley at a concentration of 1.5 mg/l. A solution of this compound (1.5 mg/l) also increased the content of flavonoids. The results of this study provide information that can help in the utilisation of barley seedlings as a unique and fully natural source of valuable nutritional substances – flavonoids.

Author Biographies

R. Stankevičienė, Kaunas University of Technology

I. Jonuškienė

R. Baranauskaitė

V. Mickevičius