Chemical Composition, Antimicrobial, and DNA Protection Activity of Essential Oils from Citrus Species of Northeast India

Essential oils from the citrus peels of Citrus grandis, Citrus indica, Citrus jambhiri, Citrus macroptera, and Citrus reticulata collected from various locations in Mizoram were analyzed for their chemical composition using gas chromatography–mass spectrometry (GC–MS). In comparative profiling, 18 compounds were identified, with d-limonene as a major constituent that varied from 87.27% in C. reticulata to 58.43% in Citrus limon. The other terpene compounds include α-pinene, β-myrcene, and β-pinene and nonterpenes like hexadecanoic acid, octadecanoic acid, decanal, and nootkatone. The extracted essential oils were evaluated for their antimicrobial activity. All of the essential oils showed excellent antifungal activity against Fusarium oxysporum f. sp. cubense, Macrophomina phaseolina, Sclerotium rolfsii, and Rhizoctonia solani at 750 and 1000 ppm; however, no antibacterial activity was observed for the essential oils even at 50,000 ppm against Xanthomonas oryzae pv oryzae and Ralstonia solanacearum. All of the essential oils exhibited DNA protection activity from ultraviolet (UV) light at a minimum concentration of 10,000 ppm