Ravendra KumarUpadhyay, Pringal2022-08-122022-08-122022-06https://krishikosh.egranth.ac.in/handle/1/5810186285The present study aimed to investigate the chemical variation in essential oils composition and evaluation of biological properties of Strobilanthes species. Strobilanthes species viz. S.pentastemonoides (Nees), S. glutinosa (Nees), S. angustifrons C. B. Clarke, T. Anderson, S. attenuata (Wall. ex Nees) Jacq. ex Nees and S. tomentosa (Nees) J.R.I.Wood were collected in the month of August-January (2019–2021) at flowering stage from different location of Kumaun region, Uttarakhand. Essential oils were extracted by hydro-distillation using Clevenger type apparatus. Essential oils yield (% v/w) was found to vary from 0.006 to 0.01% in different Strobilanthes species. Essential oils isolated from different Strobilanthes species were analyses by GC-MS to check the chemical variations. Biological activities (in vitro antioxidant, anti-inflammatory and anti-diabetic) were also performed for different Strobilanthes species essential oils by using reported protocols. Fenchyl acetate was the marker molecule of Strobilanthes glutinosa oil, collected from Kill, Pithoragarh (SGPEO) and Strobilanthes angustifrons oil, collected from Kausani, Bageshwar (SABEO) in variable amount, respectively. Guaiol was the dominant constituent of Strobilanthes pentastemonoid oil, collected from Sirkuch of Pithoragarh (SPPEO) and Strobilanthes attenuta essential oil, collected from Saktipur, Champawat (SACEO) in different amount, respectively. Labda-7,13 diene-15-ol (51.84%), a diterpenoid molecule was identified as the major secondary metabolite in Strobilanthes tomentosa essential oil, collected from Kainchi Dham, Nainital (STNEO). The antioxidant activity was performed by three different methods which include DPPH radical scavenging activity, H2O2 scavenging activity and metal chelating activity. BHT and Na2-EDTA were used as standard antioxidants. Antioxidant activity of SPPEO, in terms of DPPH scavenging activity (IC50=15.32 μL/mL) and metal chelating activity (IC50= 23.29μL/mL) was found to be higher than those of the others. In terms of H2O2 scavenging activity, the highest antioxidant activity was observed for SACEO (IC50 = 21.83μL/mL). The in-vitro anti-inflammatory activity was performed by using denaturation of egg albumin protein method. Diclofenac sodium was the standard for anti-inflammatory activity. Among all tested samples, STNEO showed high anti-inflammatory activity with an IB50 value of 9.6±0.57 μL/mL. The antidiabetic activity was analysed by α-amylase inhibition assay. Acarbose was used as standard antidiabetic agent. STNEO showed significant α-amylase inhibition an IC50 value of 30.15±1.96 μL/mL. In conclusion, results revealed that all the studied essential oils possess good to moderate antioxidant, anti-inflammatory and antidiabetic properties at different dose levels, and this could be due to the differences in the composition and concentration of biological active compounds.EnglishThesis