Influence of the growth phenophases on the phenolic composition and anti-oxidant properties of Roscoea procera Wall. in western Himalaya

Abstract

Roscoea procera Wall. is one of the important Himalayan medicinal plant used in traditional as well as in modern health care system. The present study aimed to find out the influence of different phenophases on the phenolic compounds and anti-oxidant properties by analysing after every week for over 4 months from shoot bud initiation to the preparation of senescence. Concentration of total phenolic content were found to be about 1.5 times higher in preparation of senescence phase (6.10 mg GAE/g dry weight or dw) as compared to vegetative growth phase. Similarly, total flavonoid concentration ranged from 4.36 to 5.65 mg querectin equivalents/g dw. The concentration of selected phenolic compounds, i.e., gallic acid, catechin and p-coumaric acid was quantified by reverse phase-high performance liquid chromatography and varied significantly among the different phenophases. While, anti-oxidant activity was found 2-3 times higher in preparation of senescence phase as compared to vegetative phase. Thus, these results concluded that in R. procera, November month (preparation of senescence phase) could be recommended for extracting optimum level of total phenolics, flavonoids and anti-oxidant activity. These results will be further helpful for obtaining maximum benefits from the species and to reduce pressure on reproductive phase while ensuring its conservation.

Keywords: Anti-oxidant activity; Medicinal plants; Phenolic acids; Phenophases; Roscoea procera; Seasonal variation.

Fig. 1

Schematic diagram of different phenophases in Roscoea procera life cycle

Fig. 2

Variation in anti-oxidant activity in R. procera during different harvesting times and phenophases

Fig. 3

Rhizome of Roscoea procera in different phenophases. a Rhizome in shoot bud initiation phase, b new tuberous rhizome emerged during the vegetative growth phase, c in flowering phase, new tubers started developed and older rhizome degenerating, d in fruiting phase, new tuberous rhizome attained its full size and secondary metabolite content started to stored in it, e during preparation of senescence phase, translocation of nutrients occurs from degrading aerial parts to newly developed rhizomes and it attained maximum level of secondary metabolites