Stability of adenine-based cytokinins in aqueous solution

Abstract

Since the isolation of the first cytokinin almost 60 yr ago, cytokinins have become critically important for ornamental and agricultural crops in plant tissue culture. Despite the extensive research on this class of compounds, little information is available on the chemical stability of cytokinins in solution or following an autoclave cycle with Murashige and Skoog (MS) basal medium. This work describes the stability in aqueous solutions of five widely used adenine-based cytokinins: trans-zeatin (tZ), 6-(γ,γ-dimethylallylamino) purine (2iP), kinetin, benzyladenine (BA), and m-topolin. High pressure liquid chromatography (HPLC) and electrospray ionization-mass spectrometry (ESI-MS) were used to quantify and identify their degradation. BA, kinetin, 2iP, and m-topolin were stable at 1.0 mg mL−1 in 0.05 N KOH, with no statistically significant concentration changes (p > 0.05) after 90 d of storage at temperatures of −20°C, 2−6°C, or 25°C. The cytokinin tZ was used as a model compound to evaluate stability under alkaline and acid conditions as well as after repeated freeze-thaw cycles. Trans-zeatin retained >90% of the initial concentration of 1.0 mg mL−1 when dissolved in 0.01 N KOH and stored at −20°C and 2–6°C for 90 d, with only the 2–6°C temperature treatment showing a statistical significant concentration change (p = 0.03). The 1.0 mg mL−1 tZ solution in 0.01 N KOH was stable through six repeated freeze-thaw cycles over 90 d without any significant change in concentration compared to the initial freeze-thaw. Yet, tZ showed highly significant concentration changes when dissolved at 50 mg mL−1 and 0.5 N KOH. All of these adenine-based cytokinins showed exceptional stability following an autoclave cycle at 121°C, 110 kPa for 30 min when in solutions of 1.0 mg mL−1 in 0.05 N KOH, with no significant degradation detected. Trans-zeatin was also found to be stable after one autoclave cycle with 1× MS-basal salts.Electronic supplementary materialThe online version of this article (doi:10.1007/s11627-015-9734-5) contains supplementary material, which is available to authorized users.

Simultaneous Determination of Multiclass Phytohormones in Submilligram Plant Samples by One-Pot Multifunctional Derivatization-Assisted Liquid Chromatography–Tandem Mass Spectrometry

“…We investigated the stability of CKs in the derivatization condition because the derivatization condition might have influenced the stability of the CKs, leading to inaccurate results. 24 The peak areas of CKs had no significant difference after derivatization (Figure S6), indicating that CKs were stable in the proposed derivatization condition. We also investigated the stability of DEED derivatives and 2-methyl-4-PAMBA derivatives.…”

“…As aforementioned, the derivatization strategy was used to detect phytohormones with the carboxyl group and BRs with the cis -diol group; while CKs were directly analyzed without derivatization. We investigated the stability of CKs in the derivatization condition because the derivatization condition might have influenced the stability of the CKs, leading to inaccurate results . The peak areas of CKs had no significant difference after derivatization (Figure S6), indicating that CKs were stable in the proposed derivatization condition.…”

First Report of Krymsk® 5 (cv. VSL 2) Cherry Rootstock In Vitro Propagation: Studying the Effect of Cytokinins, Auxins and Endogenous Sugars

“…Medium autoclaving has no significant impact on the physical stability of all of the four adenine cytokinins assayed (Hart et al, 2016). Therefore any difference in the effectiveness among cytokinins could be partly attributed to the different metabolism of them within the plant.…”

Synthesis and biological activity of N⁶-mannopyranosyladenines

“…Значительный интерес представляют углевод-замещенные аденины [3], что связано, вероятно, с биологической активностью, проявляемой их природными аналогами [4]. При этом гликозилированные аденины обладают достаточной в сравнении с классическими препаратами (кинетин, 6-бензиламинопурин) водорастворимостью и относительной стабильностью в растворах [5]. Вопросы синтеза указанных веществ и природа их биоактивности в научной литературе освещены в незначительной степени.…”

“…Спектры отражения модельных растворов гликозиладенинов (1%), регистрируемые через 4 суток после приготовления, не обнаруживают полос, характерных для свободного аденина в области 1250-1110 см -1 [5], что свидетельствует о достаточной устойчивости синтезированных продуктов к гидролитическому расщеплению в условиях эксперимента (рис. 4).…”