Three new tetralol analogs from soil-derived fungus Myrothecium verrucaria with anti-inflammatory activity.

Three new tetralol analogs, myrochromanols A-C (1-3), together with 11 known trichothecenes (4-14), were isolated from a soil fungus Myrothecium verrucaria HL-P-1. The structures of the three new compounds were elucidated by extensive spectroscopic analysis including HRESIMS, NMR, and ECD calculation. All of the new compounds were tested for their anti-inflammatory activity and cytotoxicity. Compounds 1 and 3 inhibited lipopolysaccharide (LPS)-induced NO production in BV2 cells with IC50 values of 26.04 and 25.80 µM, respectively.

One pair of new cyclopentaisochromenone enantiomer from Alternaria sp. TNXY-P-1 and their cytotoxic activity.

One pair of new cyclopentaisochromenone derivatives, (+)-(S)-6-hydroxy-1,8-dimethoxy-3a-methyl-3,3a-dihydrocyclopenta[c]isochromene-2,5-dione (1a) and (-)-(R)-6-hydroxy-1,8-dimethoxy-3a-methyl-3,3a-dihydrocyclopenta[c]isochromene-2,5-dione (1b), together with seven known analog 2‒8, were isolated from a rice solid culture of the endophytic fungus Alternaria sp. TNXY-P-1, obtained from fresh leaf of Arisaema heterophyllum. Their structures were elucidated on the basis of detailed 1D, 2D NMR, and HRESIMS analysis. Among them, compounds 1a and 1b were enantiomers separated from 1 by chiral HPLC. The absolute configurations of 1a and 1b were assigned by quantum chemical calculations of the electronic circular dichroic spectra. All isolated compounds were evaluated for cytotoxic activities. Interestingly, enantiomers (+)-1a and (-)-1b showed distinct selective antitumor activities against HL-60 cell lines with IC50 values of >200, 75.3 µM, respectively.

C21 steroidal glycosides from Cynanchum taihangense.

Two new C21 steroidal glycosides, cynataihosides E (1) and F (2), together with a known one, sublanceoside H2 (3), were isolated from Cynanchum taihangense. The aglycone of cynataihoside F (2) was also a new compound. Their structures were elucidated on the basis of NMR spectroscopic data, HR-ESI-MS analysis, and chemical evidence. Their cytotoxic activities against three human tumor cell lines (HL-60, THP1, and Caco2) were reported.

Structure determination of two new C21 steroidal glycosides from Cynanchum komarovii.

Two new 13,14:14,15-disecopregnane-type C21 steroidal glycosides, namely komarosides R (1) and S (2), along with four known compounds (3-6), were obtained from the 95% ethanol extract of the whole herbs of Cynanchum komarovii Al.Iljinski (Asclepiadaceae). The structures of new compounds were elucidated on the basis of 1D, 2D NMR spectroscopic data and acid hydrolysis. Compounds 1 and 2 showed potent inhibitory activities against human leukemia cell line (HL-60) with IC50 values being 6.2 and 17.6 µM, respectively, compared to the positive control 5-fluorouracil (6.4 µM).

α-Pyrone derivatives with cytotoxic activities, from the endophytic fungus Phoma sp. YN02-P-3.

Four new α-pyrone derivatives phomones C-F (1-4) together with four known compounds (5-8) were isolated from the endophytic fungus Phoma sp. YN02-P-3. Compound 1 is the first example of 6-α,ß-unsaturated ester-2-pyrone dimers via intermolecular symmetrical [2+2] cycloaddition. The chemical structures of these compounds were determined from spectroscopic data (1D/2D NMR, MS and IR). The acetylated product (9) of 1 along with compounds 1-8 were then tested for their cytotoxicity against HL-60, PC-3 and HCT-116 cell lines. Compounds 2, 3, 5 and 9 with acetyl groups showed significant inhibitory activities against the three cell lines with IC50 values in the range 0.52-9.85µM. while compounds 1, 4 and 6-8 that possess no acetyl group showed no inhibitory activity (IC50>50µM), indicating that the acetyl group at 10- or 12- are essential for their cytotoxic activities. The structure-activity relationships of these phomones were also reported.

A novel 3,4-dihydronaphthalen-1(2H)-one with spiro-butyrolactone and a new isocoumarin isolated from the endophytic fungus Phoma sp. YN02-P-3.

A novel 3,4-dihydronaphthalen-1(2H)-one with spiro-butyrolactone phomol (1) and a new isocoumarin phomasatin (2), together with two known compounds (3-4) were isolated from the solid culture of the endophytic fungus Phoma sp. YN02-P-3. Their structures including the absolute configurations were characterized on the basis of extensive 1D, 2D NMR (HSQC, HMBC, NOESY), MS, and CD spectral data. Compound 1 showed selective cytotoxic activity against HL-60 cell line with the IC50 value of 29.05 µM.

Three new amino acid derivatives from edible mushroom Pleurotus ostreatus.

Three new amino acid derivatives, oxalamido-L-phenylalanine methyl ester (1), oxalamido-L-leucine methyl ester (2), and lumichrome hydrolyzate (3), together with nine known compounds (4-12), were isolated from the solid culture of edible mushroom Pleurotus ostreatus. Their structures were elucidated on the basis of extensive spectroscopic analysis. The absolute configurations of 1 and 2 were established by the chiral synthesis and confirmed by circular dichroism (CD) analysis of their total synthesis products and natural isolates. All new compounds were evaluated for their antioxidant effects, antimicrobial activities, and cytotoxic activity. Compounds 1-3 showed weak antifungal activities against Candida albicans with minimum inhibitory concentration (MIC) value of 500 µg/ml.

Two new asterriquinols from Aspergillus sp. CBS-P-2 with anti-inflammatory activity.

Two new bisindolylbenzenoid alkaloids asterriquinol E (1) and asterriquinol F (2), together with four known compounds (3-6) were isolated from the fermentation products of the fungus Aspergillus sp. CBS-P-2. Their structures were established on the basis of extensive spectroscopic analysis, including HR-ESI-MS, UV, IR, 1D, and 2D NMR (HSQC, HMBC, and NOESY) methods. The stereochemical structure of 2 was confirmed via the CD data of the in situ formed [Rh2(OCOCF3)4] complex method. All of the isolated compounds were tested for inhibitory activity against LPS (lipopolysaccharide)-induced nitric oxide production in microglia.

Two new pregnane steroidal glycosides from Cynanchum taihangense.

As our ongoing chemical investigation, two new pregnane steroidal glycosides, cynataihosides G (1), with a new aglycone, and H (2) were isolated from the 95% ethanol extract of Cynanchum taihangense. Their structures were elucidated on the basis of 1 D and 2 D NMR spectral data, HR-ESI-MS analysis and qualitative chemical methods. The compounds were subjected to detect the cytotoxicity against three human tumor cell lines (HL-60, THP-1 and PC-3). The compounds displayed no significant cytotoxicity.Supplemental data for this article can be accessed at https://doi.org/10.1080/14786419.2019.1672682.

Two new C21 steroidal glycosides isolated from Cynanchum komarovii.

The present study was designed to further investigate the C21 steroidal glycosides in Cynanchum plants. Two new steroidal glycosides based on a 13, 14:14, 15-disecopregnane-type aglycone, komaroside P (1) and komaroside Q (2), together with three known compounds (3-5) were isolated from the whole herbs of Cynanchum komarovii. The aglycones of compounds 1 and 2 were two new disecopregnane. Their structures were elucidated on the basis of 1D, 2D NMR spectroscopic data and acid hydrolysis. All the compounds (1-5) showed potent inhibitory activities against human leukemia cell lines (HL-60) with IC50 values ranging from 16.6 to 26.3 µmol·L-1, compared to the positive control 5-fluorouracil (6.4 µmol·L-1).

Two new 14, 15-secopregnane-type steroidal glycosides from the roots of Cynanchum limprichtii.

Two new steroidal glycosides 1 and 2, along with three known ones (3-5), were isolated from the 95% ethanol extract of the roots of Cynanchum limprichtii Schltr. The structure of the new compounds was elucidated as 3-O-α-L-diginopyranosyl-(1→4)-ß-D-digitoxopyranosyl-(1→4)-ß-D-cymaropyranosyl-(1→4)-ß-D-thevetopyranosyl-14, 16:15, 20:18, 20-triepoxy-14, 15-secopregn-4, 6, 8 (14)-triene (1) and 3-O-α-L-cymaropyranosyl-(1→4)-ß-D-digitoxopyranosyl- (1→4)-ß-D-3-demethyl-2-deoxythevetopyranosyl-14, 16: 15, 20: 8, 20-triepoxy-14, 15-secopregn-5, 8 (14)-diene (2) on the basis of spectroscopic analysis together with acidic hydrolysis. All compounds showed cytotoxic activity against the human cancer cell line HL60, with IC50 values of 55.36, 65.41, 17.88, 17.68 and 33.5 µM, respectively. While, only compound 3 showed cytotoxicity against the Caco-2 cell line, with an IC50 value of 67.47 µM.

Isolation and identification of two new compounds from marine-derived fungus Acremonium fusidioides RZ01.

Two new compounds, (22E)-25-carboxy-8ß,14ß-epoxy-4α,5α-dihydroxyergosta-2,22-dien-7-one (1) and fusidione (3), along with two known compounds, 5α,8α-epidioxy ergosta-6,22-diene-3ß-ol (2) and microperfuranone (4), were isolated from the fermentation products of the marine-sourced fungus Acremonium fusidioides RZ01. The structures of compounds 1 and 3 were elucidated by extensive spectroscopic methods, especially 2D NMR, and their absolute configurations were suggested on the basis of the circular dichroism spectral analysis and the NOESY data. Both new compounds showed inhibitory activity against HL-60 cells with IC50 values being16.6 and 44.9 µmol·L-1, respectively.