Micropropagation and GC–MS analysis of bioactive compounds in bulbs and callus of white squill

Abstract

Medicinal herbs are the main source of bioactive compounds used in the medical industry. White squill (Urginea maritima) is an important medicinal and ornamental plant cultivated in the Mediterranean region. This study reports an efficient protocol for in vitro propagation of Urginea and investigates important bioactive compounds present in the bulbs and in vitro–produced callus. The least number of days for callus induction and shoot regeneration was achieved with Murashige and Skoog (MS) basal media supplemented with 1.0 mg L−1 1-naphthaleneacetic acid (NAA) plus 0.1 mg L−1 6-benzylaminopurine (BAP) and 1.0 mg L−1 NAA plus 0.4 mg L−1 BAP, respectively, while the highest number of shoots and fresh weight were obtained at medium supplemented with 1.0 mg L−1 NAA plus 0.5 mg L−1 BAP. Gas chromatography-mass spectrometry (GC–MS) analysis of Urginea bulb methanol extract showed the existence of important secondary metabolites, such as palmitic acid (C16H32O2), 9-hexadecenoic acid (C16H30O2), phthalic acid 2-ethylhexyl propyl ester (C19H28O4), tetradecanoic acid (C14H28O2), undecanoic acid (C11H22O2), and oleic acid (C18H34O2), in addition to other important compounds, such as 13-heptadecyn-1-ol, 9,12-octadecadienoic acid, 1-monolinoleoylglycerol trimethylsilyl ether, 2-methyl-1-hexadecanol, and octadecanoic acid. Callus methanol extracts showed a reduction in the percentages of most phyto-components compared to bulb extract except for oleic acid, 3-(octadecyloxy) propyl ester and 3-hydroxydodecanoic acid; on the other hand, some important compounds were detected only in callus extract possessing anti-cancer, antiviral, and anti-inflammatory effects, such as farnesol (C15H26O), 7-methyl-Z-tetradecen-1-ol acetate (C17H32O2), ethyl iso-allocholate (C26H44O5), 4-trifluoroacetoxypentadecane (C17H31F3O2), and 2-hydroxyhexadecanoic acid (C16H32O3).