| Summary: | 碩士 === 國立中興大學 === 食品暨應用生物科技學系所 === 105 === 10-oxo-trans-8-decenoic acid (10-ODA) is an important growth-regulating substances of mushroom. The biotransformation reaction is the incorporation of oxygen into the linoleic acid (LA) by a lipoxygenase, producing the intermediate, subsequently, a hydroperoxide lyase cleaves the intermediate generating 1-octen-3-ol and 10-ODA. Many studies indicated that 10-ODA stimulates mushroom growth and has antifungal activity, yet very few biological activitues of 10-ODA have been reported in open literatures. In the present study, urea complex fractionation of soybean oil was carried out to purify linoleic acid from the the oil, and then extract was produced with different purity linoleic acid and Agrocybe cylindracea. The antioxidant properties and activity of various extracts containing 10-ODA upon animal cells were also studied.
The separation and purification of linoleic acid from soybean oil by urea complex fractionation was studied. At the same condition of urea-to-fatty acids ratio, ethanol-urea ratio, and crystallization time, the LA recovery/purity on different crystallization temperature were different, which were 47.15%/78.54% at 4℃, 82.82%/63.25% at 18℃, and 86.59%/53.95% at 25℃. The isolated LA from the group of crystallization temperature at 18℃ was using for enzymatic reaction.
Using 99%, 65% LA and Isolated LA conducted enzymatic reaction with in Agrocybe cylindracea fruiting bodies, then partitioned with ethyl ether to produce ether extract. The yield of 10-ODA in 99% LA ether extract (99% LA-EE)、65% LA ether extract (65% LA-EE) and Isolated LA ether extract (Isolated LA-EE) evaluated by HPLC-UV and quantified by 10-ODA isolated compounds.The content of 10-ODA in 99% LA-EE, 65% LA-EE, and Isolated LA-EE was 302.83, 191.80 and 163.10 µg/mg extract, respectively.
In the antioxidant activities, the results showed that each ether extracts only had activities in scavenging ability on DPPH radicals and trolox equivalent actioxidant capacity (TEAC). The reducing power and scavenging ability on superoxide anions of these ether extracts had no significantly positive effects. None of these extracts had the chelating ability on ferrous ion. According to the results, there was high correlation between antioxidant activities and content of total phenols and flavonoids, but the correlations between antioxidant activities and the amount of 10-ODA was very low. In other words, 10-ODA might did not have antioxidant activities.
Moreover, each ether extracts inhibited the growth of RAW 264.7 macrophages, and also had a slightly cytostatic effect on Hs68 human skin fibroblast cells. Besides, 99% LA-EE with high 10-ODA content did not inhibit MRC-5 human lung fibroblast cells, whereas it stimulated A549 lung carcinoma cells proliferation. In accorance with the above results, 10-ODA might has cytotoxic and slightly promote cancer cell proliferation.
In conclusion, soybean oil can be used as a material for the purification of linoleic acid. 10-ODA does not have antioxidant activity, bus has the possibility of inhibiting cell growth and promoting cancer cell proliferation.
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