Study On Anti-fungal Activities Of Lactarius Deliciosus Extract And GA-Na

In this dissertation, a compound in the fruiting bodies of Lactariusdeliciosus was separated and purified by a series of techniques containing solventextraction, column chromatography. The compound was identified as ergosterolperoxide by nuclear magnetic resonance, mass spectrometry, UV scanners andinfrared scanners, along with reviewing the literatures. The inhibition tests ofergosterol peroxide shown it had lower inhibitory activity against S. sclerotiorum andF. graminearum. Therefore, ergosterol peroxide from L. deliciosus is not the maincompound against plant pathogenic fungi, and the antifungal compound in thismushroom may be other compounds. Hence, the antifungal constituents of L.deliciosus still need to be further studied.Secondly, a diterpenoid compound grandiflorenic acid which was isolated fromWedalia trilobata was reacted with NaOH to give its sodium salt (named as GA-Na),which had strong antifungal activities. Involved by the19phytopathogenic fungi, themycelia growth rate tests of GA-Na was demonstrated effective on phytopathogenicfungi at the concentration of500μg/mL. All the values of inhibition rates were rangedfrom19.3%to98%, and the inhibition rates of15phytopathogenic fungus were morethan50%. Moreover, the inhibition rates of GA-Na against19phytopathogenic fungiwere decreased with the concentration decreased. The inhibition rates of GA-Naagainst10phytopathogenic fungi were higher than the same concentration ofcarbendazim, such as A. pluriseptata, F. oxysporum f. Sp., C. personata Berk. et Curt,A. solani (Ell. et Mart) Jones et Grout, B. carbonum Wilson, C. ladosporium sp., C.arachidicola Hori, C. gloeosprioides (Peng.) Sacc, Gloeosporium sp.; The inhibitionrates of3phytopathogenic fungi were close to carbendazim, such as S. sclerotiorum,C. orbiculare (Berk. et Mont.) Arx, C. capsici f. Nicotianae;The inhibition rates of6phytopathogenic fungi were lower than carbendazim, such as F. graminearum Schw, F.graminearum, G. theae-sinensis Miyake, G. cingulate, C. gloeosporioides (Penz.) Sacc, C. gloeosporioides Penz. et Sacc. Thus, GA-Na was regarded as an effectivecomponent more than carbendazim.Thirdly, F. graminearum was selected for the studies of the inhibitory mechanism.When they were inoculated on GA-Na PDB medium at concentration of300μg/mL,The results showed that:1. The mycelia of F. graminearum was short and few.2. Thecell membrane was damaged, and substances within the cell was extravasated,resulting the conductivity increased.3. Mycelia couldn’t absorb glucose and solubleprotein well.4. The oxidation-reduction system of mycelia was unbalanced, and thebiosynthesis of mycelia proteins was affected further even to be destroyed. It is ofgreat practical significance that GA-Na has the strong activities againstphytopathogenic fungi, which provides some preliminary information to develop newplant-derived fungicides.