Study On Diversity Of Caryophyllene Transformation Products And Two Penicillium Sp. Metabolites

Natural products, their synthetic analogues and semisynthetic derivatives are widely used clinical treatment and agricultural production. But the rise in resistance to disease becomes a major threat to human health and agriculture. Thus, there is an urgent need to discover new bioactive compounds. Novel bioactive small molecules can serve as a useful research tools for probing complex biological systems through perturbation of function of biopolymers, which leads to phenotypic changes. However, molecular structurally diversity is extremely important for phenotypic bioactive screening because of the lack of structural and functional knowledge of target biopolymers or ligands.To harvest chemical diversity and screen out lead compounds with high bioactivity, the content in this thesis includes（1） β-caryophyllene and the derivatives were explored with chemical diversity based on the high rearrangement reactivity of caryophyllene structure, and the rearrangement products were isolated;（2） The metabolites of Penicillium minioluteum were induced by chemical epigenetic manipulation;（3） The bioactive metabolites of Penicillium brasilianum were studied using OSMAC. 59 compounds, including 33 novel skeletal compounds, 9 new compounds and 3 new natural products, were isolated via various chromatographic methods（MPLC, HPLC, Sephadex LH-20 and silica and RP-silica column） and elucidated with advanced spectroscopic analysis（1D, 2D NMR, IR, HRMS）. A part of new compounds in absolute configuration is confirmed by biogenetics, ECD, XRD, chemical reaction and chiral analysis. And most of the compounds were screened with bioactivity. To explore and establish a method of harvesting complex and diverse cyclic skeleton is one of the highlight of this dissertation. The library is contained with a novel skeleton confused with a bicyclo [2.2.1] heptane moiety and 22 nitrogen-containing C₁₆ caryophyllene derivatives. The results are showed as follows:1, With the catalysis of Aspergillus tubingensis, a endophytic fungus from Media azedarach, twelve compounds, including eight new compounds were isolated from the rearrangenment products of β-carophyllene. Compound 1 and 2 are novel skeletons confused with a bicyclo [2.2.1] heptane moiety. Another,（4-ethoxy-3-methoxyphenyl）propane-1,2-diol（9） is a phenylpropanoid compound isolated as a new natural products and a funan derivate, aspericin B（12）, was isolated from terrestrial microbial at the first time. Compound 1 and 3-9 showed weak inhibition of the growth of Lactuca sativa in the allelopathic assay.2, Twenty-two novel skeletal nitrogen-containing caryophyllene derivations were isolated from the rearrangement study on caryophyllene β lactam（13, 14）. Six formamide substituted new compounds（15-20） were produced from the catalysis by proton acid. Forteen new compounds（21-34）, including 3 polycyclic and caged structures（31-33） with a γ lactam and a 2-pyridone derived polycycles（34） were isolated from biocatalysis by Aspergillus tubingensis. The stereochemical structures of Compound 14, 16, 20, 24, 26, 28, 30, 31, 32 were certificated by XRD and the absolute configuration of 27 and 31 were proved by the well match of calculated ECD curves with the corresponding experimental ECD spectra. Compound 16, 19, 30 showed different growth inhibition of rice blast fungus（Magnaporthe grisea）, 19 and 30 dispalyed a clear inhibitory zone on the plate. Meanwhile, 17 inhibites α-glucosidase well which exceeded to the drug acarbose and comparable to the positive control 1-deoxynojirimycin.3, Six new norsesquiterpenoid were isolated from rearrangement products of caryophyllene oxide decarbonic compound kobusone（35）. The stereochemical structure of Compound 36 and 37 were proved by the XRD. All isolated products were evaluated in vitro anti HeLa cell lines assay and α-glucosidase inhibitory assay. But the results show no or weak activities.4, Four novel funan dimer skeleton miniolion A-D（43-46）, their monomer precusor aspertetronin A（42） and a new compound（13Z）-vermistatin（49）, a new natural product ent-gregatin B（47） together with six known natural products were isolated from metabolites of Penicillium minioluteum induced by azacitidine, a DNA methyltransferase inhibitor. The cytotoxic assay showed the improved moderate activity of miniolion A-C（43-45）（IC50, 33.3, 28.7, 21.4 μM） compared to the monomer precusor aspertetronin A（42） against HeLa cell lines.5, A new natural product（Z）-isoroquefortine C（55）, together with a toxin griseofulvin（56） and ergosterol peroxide（11）, ergosta-5,8,22-triene-3β-ol（57）, cerevisterol（58）, 6-methoxycerevisterol（59） were isolated from matabolites of Penicillium brasilianum. All the compounds were evaluated in vitro against phytopathogenic fungi, pathogenetic bacteria and allelopathic assay.（Z）-isoroquefortine C（55） displayed a moderate antifungal activity against Colletotrichum gloeosporiodes and Alternaria solani. griseofulvin（56） showed the potent antifungal activity against Fusarium solani and Alternaria solani, and moderate to strong activity against G+ bacteria（Bacillus subtilis, Staphyloccocus aureus, Bacillus cereus）, but none activity against G- bacteria（E. coli）. Meanwhile, griseofulvin（56） showed a potent growth inhibitory activity against root and shoot of Raphanus sativus which exceeded to the positive control glyphosate.