Characterization of bioactive compounds in essential oils, fermented anchovy sauce, and edible plants, and, Induction of phytochemicals from edible plants using methyl jasmonate (MeJA) and chitosan.

摘要

Antioxidant capacities of three essential oils: tea tree (Melaleuca alternifolia) oil (TTO), nutmeg (Myristica fragrans Houttuyn) oil, and vetiver (Vetiveria zizanioides) oil (VO) and three edible plants (sweet basil, parsley, and radish sprout) were evaluated using various assays. It was investigated that their majority activities were attributed to alpha-terpinene, alpha-terpinolene, and gamma-terpinene in the crude TTO, eugenol, isoeugenol, and methoxyeugenol in the crude nutmeg oil, and beta-vetivenene, beta-vetivone, alpha-vetivone in the crude VO, rosmarinic acid, caffeic acid, and eugenol in sweet basil, and ferulic acid, methyl ferulate, isoferulic acid, sinapic acid, and methyl sinapate in radish sprout, respectively, but major antioxidants in parsley could not be identified except caffeic acid. To increase the amounts of phytochemicals including these antioxidants of sweet basil and radish sprout, methyl jasmonate (MeJA) and chitosan were treated on sweet basil and MeJA on radish sprout. The total amount of the phenolic and terpenic compounds in sweet basil increased after the chitosan and MeJA treatments. Especially, the amounts of rosmarinic acid (RA) and eugenol increased 2.5 times and 2 times, respectively, by 0.1% and 0.5% chitosan treatment, while the amounts of RA, caffeic acid (CA), and eugenol in the sweet basil treated with 0.5 mM MeJA were 1.5-fold, 3.8-fold, and 1.6-fold higher than those of control. Due to the significant induction of phenolic compounds, the corresponding antioxidant activity assayed by the DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging test increased at least 3.5-fold and 2.3-fold by chitosan and MeJA treatments, respectively. Also, the activity of PAL, a key regulatory enzyme for the phenylpropanoid pathway, increased 32 times by 0.5% chitosan solution. Moreover, after the elicitor chitosan treatment, the growth of the sweet basil significantly increased.; Like the effect of MeJA on sweet basil, the DPPH· free radical scavenging activity of the radish sprout extract increased due to the increased phenolic compounds induced by 1 mM MeJA treatment and the activity of PAL also increased 60% at 24 hr after MeJA treatment. However, the same treatment decreased the amount of 4-methylthio-3-butenylisothiocyanate (MTBITC), a major isothiocyanate in radish sprout and the activity of myrosinase, an enzyme related to produce isothiocyanates.; Besides the investigation of phytochemicals in essential oils and edible plants, the inhibitory activity of angiotensin I-converting enzyme (ACE), a key regulatory enzyme of blood pressure, from the fermented anchovy sauce was also investigated. Even though the activity of ACE significantly increased with increase in salt concentration and the activity maximally increased at 0.15 mg salt/muL and the activity was 40% higher than that of the reaction solution without salt, the ACE inhibitory activity of the fermented anchovy sauce containing high salt content (20-25%) significantly increased with increase in fermentation time. The activity reached a maximal value of 96% at 15 months after fermentation and then saturated. Although the identification of the ACE inhibitors in the fermented anchovy sauce was failed, it was confirmed that the ACE inhibitors in the fermented anchovy were peptides using enzymatic digestion of the crude anchovy sauce.