Harzianic acids and oxazolidinone from the endophytic fungus Ilyonectria sp. and their cytotoxicity activity.

Four undescribed compounds including three harzianic acids (1, 3 and 4) and one oxazolidinone (2), along with three known ones (5-7) were isolated from the solid fermented product of endophytic fungus Ilyonectria sp., their structures were elucidated as 1-amino-harzianic acid (1), ilyonectria-oxazolidinone (2),10'-nor- isoharzianic acid (3), isohomoharzianic acid (4), harzianic acid (5), isoharzianic acid (6), homoharzianic acid (7) by means of detailed chemical evidences and spectroscopic data analysis. All the compounds were evaluated for cytotoxicity against SMMC-7721 human cancer cell lines by MTS assay. Among the seven tested compounds, 1-amino-harzianic acid (1) demonstrated well cytotoxic activity against SMMC-7721 with IC50 value of 26.84 µM. The results of molecular docking indicated that compound exhibited moderate anti-tumor activity may through binding to apoptosis related proteins.

Boerelasins A-D, Four Unprecedented Cytochalasins from the Endophytic Fungus Boeremia Exigua.

Four undescribed cytochalasins (1-4) were isolated from the endophytic fungus Boeremia exigua. Structurally, boerelasin A (1) represents the first example of a cytochalasin with a rare 5/5 bicyclic carbon core. Boerelasin B (2) possesses an unprecedented 5/6/5/6/8 pentacyclic ring system. Boerelasin C (3), a derivative from the common biosynthetic intermediate to 1, is a macrocyclic ring-opening cytochalasin, and boerelasin D (4) contains an uncommon six-carbon alkyl acid side chain. The structures were elucidated based on spectroscopic methods, electronic circular dichroism, spin-spin coupling constants, and calculated nuclear magnetic resonance with DP4+ analysis. These compounds exhibited significant cytotoxicity against the tumor cells.

Oblongolides from endophytic fungus Phoma bellidis Neerg. harbored in Tricyrtis maculata (D. Don) J.F.Macbr.

Five previously undescribed oblongolides, namely phomaones A-E, along with four known compounds, were isolated from the endophytic fungus Phoma bellidis Neerg.. Their structures and absolute configurations were determined by extensive experimental spectroscopic methods as well as single crystal X-ray diffractions, ECD calculations and GIAO 13C NMR calculations. Phomaone A represent the first example of oblongolides with glycol directly linked by two C-C bonds, and its biosynthetic pathway were proposed. The cytotoxicity of obtained compounds was evaluated against human cancer cell lines MCF-7, DU145, and SW480. All compounds except phomaone A showed the cytotoxicity against MCF-7 with IC50 value ranging from 12.45 to 49.84 µM.

Structure and cytotoxicity of trichothecenes produced by the potato-associated fungus Trichothecium crotocinigenum.

Seven previously undescribed trichothecenes, named trichothecrotocins M-S (1-7), along with five known compounds, were isolated from rice cultures of the potato-associated fungus Trichothecium crotocinigenum. Their structures and absolute configurations were determined through spectroscopic methods, single-crystal X-ray diffraction, and quantum chemistry calculations on ECD. Compound 1 possesses a rare 6,11-epoxy moiety in the trichothecene family. Compound 6 exhibited strong cytotoxic activity against MCF-7 cancer cell lines with an IC50 value of 2.34 ± 0.45 µM. It promoted apoptosis induction in MCF-7 cells. Moreover, cell cycle analysis showed cell cycle arrest caused by compound 6 at the G2/M phase which resulted to cell proliferation inhibition and pro-apoptotic activity. Further quantitative real-time PCR (qRT-PCR) analysis confirmed that the G2/M arrest was accompanied by upregulation of p21 and down regulation of cyclins B1 in 6-treated MCF-7 cells.

Depsidones and diaryl ethers from potato endophytic fungus Boeremia exigua.

Three depsidones boremexins A-C (1-3), two diaryl ethers boremexins D (4) and E (5), together with four known compounds were obtained from cultures of potato endophytic fungus Boeremia exigua. Their structures with absolute configurations were established by extensive spectroscopic methods and electronic circular dichroism (ECD) calculations. Compounds 1-4, 6, and 9 displayed anti-inflammatory properties on nitric oxide production in LPS-induced RAW264.7 macrophages with an IC50 range of 19.4-34.4 µM. Compounds 2 and 5 exhibited cytotoxicities to human breast cancer cell line (MCF-7) with IC50 values of 33.1 and 4.0 µM, respectively.

Novel Metabolites from the Endophytic Fungus Chaetomium subaffine L01.

One natural p-terphenyl glycoside, gliocladinin C, and two furano-polyene derivatives, chaetominins A and B, were isolated from potato endophytic fungus Chaetomium subaffine. The absolute configurations of these compounds were elucidated by HR-ESI-MS, NMR, the DP4+ probabilities and electronic circular dichroism (ECD) spectra. Furthermore, gliocladinin C and chaetominin A showed cytotoxic activity against two selected human tumor cell lines (Hep-2 and HepG-2).

Xylarichalasin A, a Halogenated Hexacyclic Cytochalasan from the Fungus Xylaria cf. curta.

A cytochalasan, xylarichalasin A, was obtained from the endophytic fungus Xylaria cf. curta harbored in Solanum tuberosum. Its structure was elucidated by comprehensive spectroscopic methods including HRESIMS, 1D/2D NMR, and residual dipolar coupling analysis as well as quantum chemistry calculations including DFT GIAO 13C NMR and ECD calculation. It has an unprecedented 6/7/5/6/6/6 fused polycyclic structure. In bioassay, xylarichalasin A showed cytotoxicity against human cancer cell lines with IC50 value ranging from 6.3-17.3 µM.

Cytotoxic 19,20-epoxycytochalasans from endophytic fungus Xylaria cf. curta.

Nine new 19,20-epoxycytochalasans (1-9) were isolated from the rice fermentation extracts of endophytic fungus Xylaria cf. curta, along with four known compounds 19,20-epoxycytochalasin C (10), 18-desoxy-19,20-epoxycytochalasin C (11), 19,20-epoxycytochalasin D (12) and 5,6-dihydro-7-oxo-19,20-epoxycytochalasin C (13). Their structures and absolute configurations were determined by 1D and 2D NMR, HRESIMS, X-ray diffraction and ECD calculation. The cytotoxicity of obtained compounds (1-13) was evaluated against human cancer cell lines HL-60, A549, SMMC-7721, MCF-7, and SW480. Remarkably, compound 10 showed significant specific cytotoxicity against HL-60 cell lines with IC50 value of 1.11 µM.

Vibralactone Z4, the first chain-like vibralactone derivative from cultures of the basidiomycete Boreostereum vibrans.

The first chain-Like vibralactone derivative, vibralactone Z4 (1), together with three known ones (2-4), were isolated from cultures of the basidiomycete Boreostereum vibrans. Vibralactone Z4 (1) is likely to be a key intermediate from 3 to 4 in their biosynthetic pathway. It showed a weak cytotoxicity to human cancer cell line SW480 (IC50 29.2 ± 1.38 µM).

Piperidine alkaloids and xanthone from the roots of Caulophyllum robustum Maxim.

Two undescribed piperidine racemates, (±)-caulophines A and B (1 and 2), a new N-containing xanthone derivative (3), together with six known piperidines, were isolated from the roots of Caulophyllum robustum Maxim. Their structures were determined by extensive spectroscopic techniques. Compounds 3 and 7 exhibited weak cytotoxicities against human palace cancer hela cell line with inhibitory rates of 32.2% and 39.7%, respectively, at the concentration of 40 µM.

Ophiorrhines A and B, Two Immunosuppressive Monoterpenoid Indole Alkaloids from Ophiorrhiza japonica.

Two monoterpenoid indole alkaloids, ophiorrhines A (1) and B (2), were obtained from plant Ophiorrhiza japonica BI. Their structures were elucidated by extensive spectroscopic methods and single crystal X-ray diffraction. Compounds 1 and 2 possess a novel spirocyclic ring system. Its biosynthesis pathway is proposed. Compound 2 exhibits potent inhibitory activity against concanavalin A (Con A) induced T cell proliferation and lipopolysaccharide (LPS) induced B lymphocyte cell proliferation with IC50 values 13.3 and 7.5 µM, respectively. Compound 1 exhibits significant inhibition specifically against the LPS-induced proliferation of B lymphocyte cells with IC50 value 18.6 µM.

Polyellisin, a novel polyketide from cultures of the basidiomycete Polyporus ellisii.

Polyellisin (1), an unprecedented polyketide possessing a tricyclic system sharing a spiroketal carbon, was isolated from cultures of the basidiomycete Polyporus ellisii. The structure with absolute configuration was elucidated by means of spectroscopic methods and the single crystal X-ray diffraction. Polyellisin showed NO production inhibition with an IC50 value of 17.2 µM.

Nicotabin A, a Sesquiterpenoid Derivative from Nicotiana tabacum.

Nicotabin A (1), a sesquiterpenoid derivative possessing a fused 5/6/5/5/5 ring system, was isolated from leaves of Nicotiana tabacum. The structure was elucidated by extensive spectroscopic methods and confirmed by single crystal X-ray diffraction. The plausible biosynthetic pathway for 1 was proposed. Compound 1 inhibited nitric oxide production in LPS-activated RAW264.7 macrophages with an IC50 of 22.1 µM.

Seco-sativene and Seco-longifolene Sesquiterpenoids from Cultures of Endophytic Fungus Bipolaris eleusines.

Two new seco-sativene sesquiterpenoids, bipolenins D (1) and E (2), a new seco-longifolene sesquiterpenoid, bipolenin F (3), together with three known analogues (4-6), were obtained from cultures of endophytic fungus Bipolaris eleusines. Their structures were established by MS and NMR data. Compounds 1-6 showed no activity to five human cancer cell lines.

Two new phenolic compounds and antitumor activities of asparinin A from Asparagus officinalis.

Two new phenolic acid compounds, asparoffin C (1) and asparoffin D (2), together with four known compounds, asparenyol (3), gobicusin B (4), 1-methoxy-2-hydroxy-4-[5-(4-hydroxyphenoxy)-3-penten-1-ynyl] phenol (5), and asparinin A (6), have been isolated from the stems of Asparagus officinalis. The structures were established by extensive spectroscopic methods (MS and 1D and 2D NMR). Compound 6 has obvious antitumor activities both in vitro and in vivo.

Two new acetylenic compounds from Asparagus officinalis.

Two new acetylenic compounds, asparoffins A (1) and B (2), together with two known compounds, nyasol (3) and 3″-methoxynyasol (4), were isolated from stems of Asparagus officinalis. The structures of two new compounds were elucidated on the basis of detailed spectroscopic analyses (UV, IR, MS, 1D, and 2D NMR). All compounds were evaluated for their cytotoxicities against three human cancer cell lines.

Three new sativene sesquiterpenoids from cultures of endophytic fungus Bipolaris eleusines.

Three new sativene sesquiterpenoids, bipolenins A-C (1-3), together with two known analogs (4 and 5), were obtained from cultures of endophytic fungus Bipolaris eleusines. The structures of new compounds were elucidated on the basis of extensive spectroscopic analyses. Compound 2 showed weak inhibitory activities against lung cancer A-549 and breast cancer MCF-7 with IC50 values of 33.2 and 19.1 µmol, respectively.

Three New Triterpenoids from European Mushroom Tricholoma terreum.

Three rare triterpenoids, saponaceolides Q-S (1-3), have been isolated from fruiting bodies of the mushroom Tricholoma terreum. Their structures were characterized based on extensive spectroscopic data. Compound 1 showed certain cytotoxicities against four human tumor cell lines.