Jimei Liu

Probing the Catalytic Promiscuity of a Regio‐ and Stereospecific C‐Glycosyltransferase from Mangifera indica

The catalytic promiscuity of the novel benzophenone C-glycosyltransferase, MiCGT, which is involved in the biosynthesis of mangiferin from Mangifera indica, was explored. MiCGT exhibited a robust capability to regio- and stereospecific C-glycosylation of 35 structurally diverse druglike scaffolds and simple phenolics with UDP-glucose, and also formed O- and N-glycosides. Moreover, MiCGT was able to generate C-xylosides with UDP-xylose. The OGT-reversibility of MiCGT was also exploited to generate C-glucosides with simple sugar donor. Three aryl-C-glycosides exhibited potent SGLT2 inhibitory activities with IC50  values of 2.6×, 7.6×, and 7.6×10(-7)  M, respectively. These findings demonstrate for the first time the significant potential of an enzymatic approach to diversification through C-glycosidation of bioactive natural and unnatural products in drug discovery.

Pericoannosin A, a Polyketide Synthase–Nonribosomal Peptide Synthetase Hybrid Metabolite with New Carbon Skeleton from the Endophytic Fungus Periconia sp.

Four new polyketide synthase-nonribosomal peptide synthetase (PKS-NRPS) hybrid metabolites, pericoannosin A (1), with an unusual hexahydro-1H-isochromen-5-isobutylpyrrolidin-2-one skeleton, and three cytochalasans, periconiasins D-F (2-4), were isolated from the endophytic fungus Periconia sp. F-31. Their structures and absolute configurations were elucidated through extensive spectroscopic analyses, calculated ECD, and single-crystal X-ray diffraction (Cu Kα). A possible biogenetic pathway is proposed. Compounds 1 and 4 showed anti-HIV activity with IC50s of 69.6 and 29.2 μM, respectively.

Stachybotrysins A–G, Phenylspirodrimane Derivatives from the Fungus Stachybotrys chartarum

Seven new phenylspirodrimane derivatives named stachybotrysins A-G (2-8), together with five known compounds (1, 9-12), were isolated from Stachybotrys chartarum CGMCC 3.5365. Stachybotrysin D (5) is the first reported example of a naturally occurring alcoholic O-sulfation of a phenylspirodrimane, and stachybotrysins F and G (7 and 8) are the first examples possessing an isobenzotetrahydrofuran ring with an acetonyl moiety attached. The structures of these compounds were elucidated on the basis of extensive spectroscopic data analysis and by comparison with reported data. The absolute configurations of 1-8 were determined by X-ray single-crystal diffraction, electronic circular dichroism (ECD), and calculated ECD. Compounds 1 and 8 displayed anti-HIV activity with IC50 values of 15.6 and 18.1 μM, respectively, and 2, 7, 9, and 11 showed inhibitory effect on influenza A virus with IC50 values ranging from 12.4 to 18.9 μM.

Sesquiterpenoids from the cultured mycelia of Ganoderma capense

Eleven new sesquiterpenoids, including eight cadinane-type sesquiterpenoids, Ganodermanol A-H (1-8), and three eudesmane-type sesquiterpenoids, Ganodermanol I-K (9-11), together with three known compounds (12-14), were isolated from the cultured mycelia of Ganoderma capense. Their structures and absolute configurations were identified through combined extensive spectroscopic analysis, circular dichroism (CD), and Mo2(AcO)4-induced CD. Compounds 4 and 9 exhibited moderate cytotoxic activity against the human cancer cell line HCT116 with IC50 values of 16.6 and 12.2μM, respectively.

Eremophilane Sesquiterpenes from an Endophytic Fungus Periconia Species

Nine new polyoxygenated eremophilane sesquiterpenes, periconianones C-K (1-9), including one unusual isoeremophilane sesquiterpene, periconianone C (1), and four trinor-eremophilane sesquiterpenes, periconianones H-K (6-9), were isolated from the endophytic fungus Periconia sp. F-31. Compound 1 is the first furan-type isoeremophilane reported containing a linkage of C-8/C-11 and a 7,12-epoxy moiety. These compound structures, including absolute configurations, were elucidated through extensive spectroscopic data analysis, electronic circular dichroism, Mo2(AcO)4-induced circular dichroism, and single-crystal X-ray diffraction (Cu Kα). Compounds 2, 5, and 9 showed inhibition effects on lipopolysaccharide-induced NO production in BV2 cells by 10.2%, 18.3%, and 16.1% at a concentration of 1.0 μM, respectively, which is comparable to the positive control curcumin (12.9% at 1.0 μM).

Bioactive steroids and sorbicillinoids isolated from the endophytic fungus Trichoderma sp. Xy24.

Abstract A new steroid glucoside (1), along with nine known steroids (2–10) and four known sorbicillinoids (11–14), were isolated from the endophytic fungus Trichoderma sp. Xy24. Their structures were elucidated on the basis of spectroscopic data analyses and by comparison with reported data. Compounds 3, 5–7, 9, 10, and 13 exhibited significant inhibitory effects on HIV-1 virus with IC50 values ranging 1.9–9.3 μM; compounds 10, 13, and 14 showed potent inhibitory activity on LPS-induced NO production in BV2 microglia cells with inhibitory rates of 108.2, 100, and 75.1% at 10 μM, respectively. In addition, compound 10 displayed moderate cytotoxicity against BCG823 and HePG2 cell lines with IC50 values of 11.1 and 17.7 μM, respectively.

Two Furanharzianones with 4/7/5/6/5 Ring System from Microbial Transformation of Harzianone

Furanharzianones A and B (2 and 3), two new harziane-type diterpenoids with a tetrahydrofuran and unusual 4/7/5/6/5 ring system, were obtained from the microbial transformation of harzianone (1) by a bacterial strain Bacillus sp. IMM-006. The structures, including the stereochemistry, of the two new compounds were elucidated by extensive spectroscopic analysis. The absolute configuration of 2 was unambiguously determined by single-crystal X-ray diffraction. In addition, a plausible bioconversion pathway was proposed.

Data on eleven sesquiterpenoids from the cultured mycelia of Ganoderma capense

The data included in this paper are associated with the research article entitled “Sesquiterpenoids from the cultured mycelia of Ganoderma capense” [1]. 1H NMR, 13C NMR, DEPT, HSQC, 1H–1H COSY, HMBC, NOESY, HRESIMS, and IR spectra of Ganodermanol A–H (1–11), together with Mo2(AcO)4-induced CD spectrum of Ganodermanol A, CD spectra of Ganodermanol D–E were included in the Data in Brief article. In addition, the cytotoxicities and anti-HIV-1 activity of isolated compounds were also included in the Data in Brief article.

Bistachybotrysins A–C, three phenylspirodrimane dimers with cytotoxicity from Stachybotrys chartarum

Bistachybotrysins A-C (1-3), three phenylspirodrimane dimers representing an unusual [6,6,7,6]-tetracyclic skeleton with a central 2,10-dioxabicyclo[4.3.1]decan-7-ol core fused with two phenyl units, were isolated from a fungal strain, Stachybotrys chartarum CGMCC 3.5365. The structures of 1-3 were elucidated through extensive spectroscopic data analysis, including Mo2(AcO)4-induced and calculated electronic circular dichroism (ECD). 1 and 2 exhibited potent cytotoxicity against four human tumor cell lines with IC50 values in the range of 2.8-7.5 μM. Furthermore, a possible biogenesis for 1-3 is proposed.

Neural anti-inflammatory sesquiterpenoids from the endophytic fungus Trichoderma sp. Xy24

Abstract Three new sesquiterpenoids trichoacorenols B–C and cyclonerodiol B (1–3), along with three known ones (4–6), were isolated from the mangrove plant endophytic fungus Trichoderma sp. Xy24 using various column chromatography techniques. The structures of these compounds were determined on the basis of extensive spectroscopic data analyses. Compounds 1, 2, 4, and 5 were four acorane sesquiterpenes, 3 and 6 were two monocyclic sesquiterpenediols. Compounds 3 and 5 exhibited significant neural anti-inflammatory activity by inhibiting LPS-induced NO production in BV2 cells with the inhibitory rates of 75.0% and 39.2% at 0.1 μM, respectively, which are more potent than curcumin, a positive control with the inhibitory rate of 21.1% at 0.1 μM.