| Fungi are widely distributed all over the world,such as in water,soil,vegetation,etc.,in large numbers and rich in variety,and are a huge treasure trove of natural product sources.Due to the characteristics of special habitat and genetic instability,fungi can generate many small molecules with significant activity,which have a great role in human medicine and health.In the metabolites of fungi,many drug molecules used in clinical practice are obtained,such as antibacterial drugs:penicillin,cephalosporin,echinocandins,etc.;antitumor drugs:doxorubicin,bleomycin,mitomycin,etc.;hypoglycemic drugs such as acarbose;lipid-lowering drugs such as statins,etc.,which shows that fungal resources are worth developing.Studies have yielded endophytic fungi from yew that can produce paclitaxel,suggesting that researchers should study endophytic fungi to reduce over-exploitation of endangered plants.After investigation,it was found that fungi from animals can also generate many active molecules,so it is meaningful to study fungi from various animal and plant sources,which not only enriches the understanding of fungi,but also protects plant resources from being destroyed in large quantities,and also obtains various compound molecules with rich activity.This article studyed two endophytic fungus,Xylaria sp.(LCSS1a)and Exophiala sp.NH1238(CC-8),which was derived from lichens and Buthus martensii.,including their chemical composition studies and activity assessments.These two strains were amplified fermented with rice medium,and the product was extracted with ethyl acetate.The crude extract was separated and purified by purification techniques such as silica gel column chromatography,gel column chromatography,ODS reversed-phase column chromatography,Flash column chromatography and high performance liquid chromatography(HPLC),and a total of 53 compounds were obtained,including 14 new compounds.The absolute configuration of these compounds was determined by means of nuclear magnetic resonance(NMR),mass spectrometry(MS),ultraviolet(UV),infrared(IR),Circular Dichroism(CD)calculations,etc.The endogenous fungus Xylaria sp.(LCSSla)was isolated from the lichen of the genus Meiyi,and the rice fermentation metabolites of this strain were isolated and purified,and a total of 32 compounds of configuration were identified,including 11 new compounds:Xylarione A(5),Xylarione B(10),Xylarione C(11),Xylarione D(13),Xylarione E(16),Xylarione F(17),Xylarione G(18),Xylarione H(19)、Xylarione I(21)、Xylarione J(28)、Xylarione K(31).These new compounds,in addition to compounds 5 and 31,were derivatives of xanthone compounds,wherein compound 5 belongs to the aromatic lactone class,compound 31 had a novel structure,has a polycyclic fused skeleton,like a tricyclic[4,3,3,1]undecylone benzofuran.Fungus Exophiala sp.NH1238(CC-8)from Buthus martensii,from its rice fermentation products,we obtain 21 compounds,including 2 isocoumarin compounds(33,35),4 chromone compounds(41,45,49,51),1 alkaloid compound(47),7 peptide compounds(36-38,42-44,53),3 steroidal compounds(34,40,48),1 glyceric acid compound(46),1 glycoside compound(50),2 phenyl ether compounds(39,52),of which compounds 45,49,51 were new compound.The activity results showed that compounds 34 and 44 exhibited inhibitory activity against ACTT29213 Staphylococcus aureus,with MIC80 values of 4 μg/mL and 8μg/mL,respectively.Compound 44 had a certain inhibitory effect on wild-type Candida albicans SC5314 and candida albicans CA632,and the MIC80 values were 8 μg/mL,and compound 44 showed certain inhibitory activities on B16F10,CT26,huh-7 cells,IC50 values were 5.97,23.97,and 22.13 μM,respectively.In this paper,the chemical composition and biological activity of two endophytic fungi were studied,and 14 new compounds were found,and some compounds exhibited antibacterial activity and cytotoxic activity,proving the research value of secondary metabolites from endophytic fungi,but it needed to be used to explore active molecules more specifically and efficiently. |
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