Evaluations of plant sites and extraction methods on compositions and bioactivities of essential oils from Citrus grandis Osbeck cv. 'Mato Peiyu'

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Because the pruning or the glut of fruit would produce a lot of agricultural wastes, we attempted to take advantage of those potential wasted materials. The experiment used steam distillation(SD) and solvent-free microwave extraction(SFME) from discarded pruned Mato Paiyu Leaves and obsolete Mato Paiyu Peel to extract essential oils. Afterwards, we analyzed the composition by using the gas chromatography-mass spectrometry (GC-MS) and evaluated antibacterial, anti-oxidation, anti-inflammatory, and whitening activities on the cosmetic to increase the economic value. The results showed that the main components of the Mato Paiyu Leaves extracted by SD method is Citronellal (34.54%), Citronellol (16.17%), extracted by SFME method were Citronellal (30.87%), Citronellol (28.95%). The highest content of essential oils in both of them is all mainly Aldehyde. Extracted by the method SD, the primary components in the essential oil of Mato Paiyu Peel were Limonene (82.74). Furthermore, the essential oil of Mato Paiyu Peel that used the way SFME are Limonene (82.13) as a primary component. Both of them of the highest content in the essential oil are monoterpenes. On the part of bacteriostatic, generally, the essential oil of Mato Paiyu Leaves obviously had more influences on P. aeruginosa、C. albicans、E. coli compare to the essential oil of Mato Paiyu Peel. However, the essential oils of Mato Paiyu Peel had better anti S. aureus activities than the essential oils of Mato Paiyu Leaves. In the anti-oxidation test, the essential oils of Mato Paiyu Leaves is superior on the DPPH radical scavenging activity and β-Carotene-oxidation inhibition assay. In the anti-inflammatory test, the essential oils extracted by the way SFME were better than the method SD on NO radical scavenging activity and 5-LOX inhibition assay. In the whitening activity examination, the essential oil of Mato Paiyu Peel is better than the essential oil of Mato Paiyu Leaves on Tyrosinase inhibition assay.