Effect of methionine on production of naphthoquinones in Impatiens balsamina root cultures and detection of some secondary metabolites

Figures & data

Figure 1.   Chemical structures of naphthoquinones: (a) lawsone (b) lawsone methyl ether, and (c) 3,3′-methylenebislawsone.

Table 1.  Naphthoquinone production in I. balsamina root cultures after adding methionine at various concentrations to the culture medium at day 0.

Concentration (mg/L)	Naphthoquinone content (mg/g dry weight) Mean ± SE (n = 6)
	1*	2*	3*	Total naphthoquinone
Control	1.45 ± 0.393a	0.07 ± 0.037a	0.32 ± 0.045b	1.85 ± 0.455a
50	1.58 ± 0.241a	0.10 ± 0.040a	0.46 ± 0.094b	2.14 ± 0.311a
100	1.36 ± 0.374a	0.09 ± 0.032a	0.51 ± 0.100a	1.96 ± 0.402a
300	1.49 ± 0.298a	0.06 ± 0.026a	0.63 ± 0.103a	2.26 ± 0.365a
500	n/a	n/a	n/a	n/a
1000	n/a	n/a	n/a	n/a

1 = lawsone, 2 = lawsone methyl ether, 3 = 3,3′-methylenebislawsone.

*Significant difference (p < 0.05) when compared within the same column. Mean values followed by the same letter within the column are not significantly different.

n/a = data not available.

Figure 2.   Intracellular and extracellular content of (a) lawsone, (b) lawsone methyl ether and (c) 3,3′-methylenebislawsone after feeding with various concentrations of methionine to 21-day old root cultures. Data are mean value ± SE of n = 5 (M-300, M-500 and M-1000 = methionine concentrations at 300, 500 and 1000 mg/L, respectively).

Figure 3.   Structures of (1) luteolin, (2) phthalic acid, (3) phthalic anhydride, (4) methyl linolenate, (5) spinasterol, (6) p-hydroxybenzoic acid, (7) isofraxidin, (8) scopoletin, (9) 2,3-dihydroxy-1,4-naphthoquinone and (10) echinocystic acid.