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Subject: Chemistry × Author: Chaubey, Pinky × End date: 2019 × Start date: 2013 × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Chemical diversity, genetic profiling and antioxidant activity of Acorus calamus L. accessions from different altitudinal regions of Uttarakhand
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2017-08) Chaubey, Pinky; Om Prakash
    In present study the chemical composition of essential oils, total phenol analysis, antioxidant activity, elemental profiling, and genetic variability among the twenty collections of Acorus calamus from different altitudinal zones were evaluated. GC-MS analysis of essential oils of Acorus calamus exhibited the presence of various phenylpropanoids, monoterpenoids and sesquiterpenoids. The yields of essential oils varied from 0.2-1.4% and 0.7- 5.4 % (v/w) the oils of A. calamus leaves and rhizomes respectively. The major components identified in A. calamus essential oils from leaves and rhizomes were β-asarone, α-asarone, Z-methyl isoeugenol, Z-isoelimicin, and shyobunone. The presence of asaronaldehyde could be detected only in the rhizome samples from Chhoi, Nainital (2.4%) and Palpur, Almora collections (0.6%). Several minor constituents were also identified in the oils investigated. The antioxidant activity of rhizomes essential oil was studied by their ability to scavenge free radicals (IC50=22.27 to 61.96 µg/mL), metal chelating activity (29.55 to 159.26 µg/mL) and reducing power activity (21.41 to 61.19 µg/mL) whereas the antioxidant activity of leaf essential oil were evaluated by DPPH radical scavenging method with different IC50 values ranging from10.79 to 106.44 µg/mL in comparison to standard antioxidant. The methanol and hexane extracts were screened for their in vitro antioxidant activity and biochemical assay. All the extracts were also subjected to quantitative analysis of total phenols, flavonoids and orthodihydric phenolic contents. The total phenols, flavonols and orthodihydric phenols in all the methanolic extracts were ranged from 1.67 to 10.42 mg/g gallic acid equivalent, 0.50-27.25 mg/g catechin equivalent and 0.43- 5.50 mg/g catechol equivalent respectively. The antioxidant activity of methanolic extracts of A. calamus were evaluated by the three methods viz. DPPH radical scavenging, metal chelating and reducing power activity in terms of IC50 values were 143.55 to 919.55 µg/mL, 308.57 to 1439.35 µg/mL, 104.62 to 241.81 µg/mL respectively. The antioxidant activity of the hexane extracts also exhibited DPPH radical scavenging activity (IC50 = 113.05 to 1671.05 µg/mL), metal chelating activity (IC50 = 298.46 to 1141.46 µg/mL) and reducing power activity (IC50 = 105.86 to 307.50 µg/mL). In all the cases the activity observed were less than standard compounds BHT, catechin, EDTA and citric acid. The elemental analysis of leaves and rhizomes of A. calamus were studied with the help of atomic absorption spectrometry (AAS). The results exhibited the presence of P, K, Ca, Na, Mg, Mn, Fe, Cu, Cr, Pb, Ni, and Zn. The genetic diversity by simple sequence repeat revealed the monomorphic behaviour of the plant.