Effect of various culture conditions on shoot multiplication and GC–MS analysis of Plumbago zeylanica accessions for plumbagin production

Abstract

Plumbago zeylanica, a pharmaceutically important medicinal plant, contains a wide range of phytocompounds. Culture parameters like carbon source, nitrogen source, and culture media are essential for the development and growth of explants. In this investigation, the influence of various carbon sources (sucrose, glucose, and fructose at 3% concentration), nitrogen source (ammonium nitrate, sodium nitrate, and potassium nitrate) and plant tissue culture media (MS medium, Gamborg’s B5 medium, White medium and Nitsch medium) on shoot multiplication of five different accessions was studied. Optimum growth of all five accessions was observed in MS media containing 3% sucrose and ammonium nitrate as a source of carbon and nitrogen. Out of five accessions, IC-524441 showed the highest shoot multiplication. Further, methanolic extracts of all accessions (grown in MS media containing 3% sucrose and ammonium nitrate as nitrogen source) were prepared and comparison of extracts in DPPH assay indicated that accession number IC-524441 was the most effective free radical scavenging agent. Total phenolic, flavonoid and tannin content ranges were from 20 to 70 µg/ml, 40 to 100 µg/ml and 55 to 120 µg/ml, respectively, and the highest amount was found in accession number IC-524441. Sucrose and ammonium nitrate content may be responsible for increased antioxidant activity, flavonoids content, phenolic content, and tannin content in accession number IC-524441. GC–MS of ethyl acetate extract of all five accessions of P. zeylanica was conducted (grown in MS media containing 3% sucrose and ammonium nitrate as nitrogen source). GC–MS analysis of the aerial part showed the presence of various phytocompounds, which include 1,4-naphthalenedione, 3-eicosene, 5-eicosene, phthalic acid, o-anisic acid, thioctic acid, 1-octadecene, 5-t-butyl-cycloheptene, 2-benzoyl-1,2-dihydro-1-isoquinolinecarbonitrile, octadecanal, silane, 3-methoxy-2-methyl-2-(1-phenyl-ethylamino)-propionic acid, and 1-nonadecene. Accession number IC-524441 contains the highest amount of plumbagin, i.e. 14.19 ± 0.5 µg/ml as compared to the others.