Benzothiazole derivatives substituted in position 2 as biologically active substances with plant growth regulation activity

Abstract

Thirteen of the new synthetized 2-R substituted benzothiazole derivatives have been tested for plant growth regulatory (PGR) activity. The effect on growth elongation was studied on wheat coleoptile segments Triticum aestivum L. cv. Blava, and on the hypocotyl and roots in cucumber Cucumis sativum L. cv. Evita. The formation and number of adventitious roots and the length of hypocotyl in Vigna radiata (L.) Wilczek and, the effect on the length of stem, fresh and dry mass in buckwheat Fagopyrum esculentum Moench. cv. Pyra were evaluated. Cytokinin activity was determined on segments of barley leaves Hordeum vulgare L. cv. Jubilant on the basis of senescence inhibition and chlorophyll content. The benzothiazole derivatives were tested in the range of 10<sup>–3</sup>–10<sup>–7</sup>M concentrations, and PGR activity was compared with indole-3-acetic acid, indole-3-butyric acid and 6-furfurylaminopurine. All tested derivatives showed different auxine-like effects on elongation growth of plants and the stimulative effects were found to depend on applicable concentrations. At higher concentration rates, derivatives acted as growth retardants and inhibited the length of cucumber hypocotyl and roots. The derivatives increased the formation of adventitious roots of mung bean hypocotyl cuttings, as well as stem elongation and production of fresh and dry mass of buckwheat. Cytokinin activity was confirmed in one derivate only with a significant effect on the inhibition of leaf senescence and higher chlorophyll content. The tested benzothiazole derivatives may be characterized as biologically active substances with dominant auxine-like growth promoting activity

Study of regulating activity of synthetic low molecular weight heterocyclic compounds, derivatives of pyrimidine on growth of tomato(Solanum lycopersicum L.) seedlings

“…Similar studies were conducted in a work [85] that showed that synthetic 2-R substitutedbenzothiazole derivatives demonstrated dominant auxine-like plant growth promoting activity.Based on obtained results, showing that the plant growth promoting activity of synthetic benzothiazole compounds can be correlated with the activity of IAA synthetase, the authors have proposed that the mode of action ofsynthetic 2-R substitutedbenzothiazole derivatives as auxine-like substances is due to their possible regulation of synthesis or degradation of endogenous auxin indole-3-acetic acid (IAA) in plants.…”

“…The assumptions discussed in the works [82][83][84][85] are consonant with our early published work [86], which testified in favor of theindirect, mediated through endogenous phytohormonesaction of synthetic LMWHC, derivatives of pyridinelutidine N-oxide (Ivin) and pyrimidine -6-methylthiouracil(Methyur)on plant cell extension, and published works of other authors [87 -92]thatshowed the effect of exogenously applied synthetic multi-dimensional plant growth regulator Thidiazuron (TDZ; N-phenyl-1,2,3-thidiazole-5ylurea) on increase in concentrations of endogenous cytokinins, auxin, ethylene and ABA in plant cells.…”

Study of auxin-like and cytokinin-like activities of derivatives of pyrimidine, pyrazole, isoflavones, pyridine, oxazolopyrimidine and oxazole on haricot bean and pumpkin plants

“…As is known, the major plant hormones auxins are involved in control of plant embryogenesis, seed germination, cell elongation and division in plant hypocotyls and coleoptiles, apical dominance, cambium cell division, plant tropisms, growth and development of root system, promotion of fruit setting, prevention of leaf abscission, plant-pathogen interactions, and in vitro morphogenesis in plants [30][31][32][33][34][35][36][37][38][39][40][41] .…”

“…The most well-known bioassays include bioassays specific for auxin-like and cytokinin-like activities based on a stimulating effect of natural or chemical compounds on the basic processes of plant growth such as acceleration of the germination of plant seeds and growth of plant seedlings, elongation of hypocotyl or coleoptile on the plant seedlings, formation of the adventitious roots on the plant seedlings or on the isolated stem and leaf cuttings, increasing of growth of biomass of cotyledons isolated from plant seeds, delaying of leaf senescence, and in vitro morphogenesis in plants [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45] .…”

Iodobenzene-Promoted Pd-Catalysed ortho-Directed C–H Activation: The Synthesis of Benzothiazoles via Intramolecular Coupling

“…2 2-Aminobenzothiazoles can be obtained through either intermolecular transformations, which are dominated by condensation reactions, [3][4][5][6][7] or intramolecular transformations, which include cross-coupling reactions [8][9][10] starting from ortho-haloaryl thioureas, and oxidative coupling reactions. [11][12][13][14][15] Herein, we present an iodobenzenepromoted Pd-catalysed synthesis of benzothiazoles via intramolecular coupling.…”