Essential oil and polyphenolic composition in Nardostachys jatamansi influenced by different plant parts and drying conditions

Nardostachys jatamansi (D. Don) DC., is an important threatened herbaceous aromatic plant species from Indian Himalayan Region (IHR). Present investigation determined composition of essential oil and polyphenolics in different drying conditions. Higher oil yield obtained in fibrous mantle of leaf base (1.06%) as compared to pooled root and rhizomes (0.5%). A total of 41 compounds were recorded in the essential oil of species using GC–MS analysis. Among them, monoterpene hydrocarbons (5.38%) and sesquiterpene hydrocarbons (33.74%) were the dominant compounds in fibre plant portion, while, oxygenated sesquiterpenes (64.02%) was dominated in both root and rhizome portions of species. Among different drying conditions, sun-drying with ethanolic extraction exhibited better results of different composition of polyphenolics such as ‘m-coumaric acid’(0.363 mg/g DW), chlorogenic acid (1.99 mg/g DW), gallic acid (0.38 mg/g DW), as compared to shade drying conditions. In addition, shade dried samples (fibre) showed maximum amount of ‘m-coumaric acid’ (0.05 mg/g DW), chlorogenic acid (0.26 mg/g DW), gallic acid (0.04 mg/g DW), except catechin (1.16 mg/g DW) which found maximum in oven drying conditions of both root and rhizome parts. Amongst different drying conditions, sun drying process was best for obtaining higher phenolics from species. Ethanol extraction showed better recovery of phenolic compounds from both the plant parts and thus be used effectively for extraction of these compounds. Therefore, use of compound specific drying conditions and solvents during extraction of these active constituents are required. This study suggests that standardization of appropriate harvesting and extraction conditions are necessary to obtain maximum active compounds of pharmaceutical value that can be exploited by the industries to reap higher commercial benefits.