Antiviral and cytotoxic indole diterpenoids from the antarctic sponge-derived fungus Aspergillus candidus HDN15-152.

One new indole diterpenoid, ascandinine T (1), and three known analogues (2-4) were isolated from an Antarctic sponge-derived fungus Aspergillus candidus HDN15-152. The structures, including absolute configurations, were established based on NMR, HRESIMS, and electronic circular dichroism (ECD) calculations. All isolated compounds were tested for antiviral and anticancer activity. Compound 4 displayed antiviral activity against influenza A virus (IAV) of A/PR/8/34(H1N1) strain with an IC50 value of 39.2 µM, while compound 2 showed cytotoxicity against NCI-H446, NCI-H446/EP and L-02 cells with IC50 values ranging from 9.77 to 13.91 µM.

Overexpression of Global Regulator SCrp Leads to the Discovery of New Angucyclines in Streptomyces sp. XS-16.

Six angucyclines including three unreported compounds (1-3) were isolated from Streptomyces sp. XS-16 by overexpressing the native global regulator of SCrp (cyclic AMP receptor). The structures were characterized based on nuclear magnetic resonance (NMR) and spectrometry analysis and assisted by electronic circular dichroism (ECD) calculations. All compounds were tested for their antitumor and antimicrobial activities, and compound 1 showed different inhibitory activities against various tumor cell lines with IC50 values ranging from 0.32 to 5.33 µM.

Chemical constituents and their biological activities from the mushroom Pyropolyporus fomentarius.

The chemical constituents and their biological activities of the mushroom Pyropolyporus fomentarius were investigated in this study. Two previously undescribed pentacyclic lupane-type triterpenes, 3-formyloxybetulin and 3-formyloxybetulinic acid, two rare degraded ergosterols, pyropolincisterols A and B, along with ten known triterpenoids and four known ergosterols were isolated from the fruiting bodies of P. fomentarius. Their chemical structures were determined using a combination of spectroscopic analysis. Nine compounds exhibited certain cytotoxicities to human cancer cell lines, while polyporenic acid showed significant cytotoxicities to SMMC-7721 and A-549 with IC50 values less than 10 µM. Four compounds showed inhibitory activities against nitric oxide (NO) production in LPS-activated RAW264.7 macrophages with IC50 values of 36.3, 25.1, 21.4, and 34.2 µM, respectively. The results of this assessment suggested that the lanostane triterpenoids and ergosterols in fruiting bodies of P. fomentarius played key roles in its folk usages.

Illudane Sesquiterpenoids from Edible Mushroom Agrocybe salicacola and Their Bioactivities.

To comprehensively understand the chemical constituents of the edible mushroom Agrocybe salicacola and their biological functions, a phytochemical separation of the cultural broth of A. salicacola led to the isolation of four new illudane sesquiterpenoids, agrocybins H-K (1-4), along with 10 known analogues (5-14). Compounds 2-4 were racemates of which 2 and 3 were further separated into single enantiomers as 2a/2b and 3a/3b. All new structures with absolute configurations were elucidated on the basis of an extensive spectroscopic analysis and quantum chemistry calculations. Compound 1 possesses a new carbon skeleton that might be derived from the protoilludane backbone. Compounds 1, 5, 8, and 9 show a certain degree of cytotoxicity to five human cancer cell lines. Compound 1 shows a mild inhibitory effect on nitric oxide production with an IC50 value of 31.4 µM. It is concluded that A. salicacola is rich in illudin derivatives with potential bioactivity prospects, which would make A. salicacola a good material of medicine and food homology.

Chemical constituents and their cytotoxicities from mushroom Tricholoma imbricatum.

Two undescribed triterpenes, tricholimbrins A and B, three undescribed steroids, tricholimbrins C‒E, one undescribed 4-chromanone derivative, along with 27 known compounds were isolated from fruiting bodies of the mushroom Tricholoma imbricatum. Tricholimbrins A and B are two polycyclic triterpenoids with a carbon degradation, while tricholimbrin C is a ring-rearranged steroid containing an aromatic moiety that might be derived from an ergosterol. Isocyathisterol, 3ß,15α-dihydroxyl-(22E,24R)-ergosta-5,8(14),22-trien-7-one, demethylincisterol A3, and volemolide showed cytotoxicities to six human cancer cell lines. 3ß-Hydroxyl-(22E,24R)-ergosta-5,8,22-trien-7,15-dione and 3ß-hydroxyl-(22E,24R)-ergosta-5,8,22-trien-7-one showed preferable cytotoxicities against HL-60 while chaxine C and volemolide showed preferable cytotoxicities against A-549, with IC50 values less than 10 µM.

Melodinines Y1-Y4, four monoterpene indole alkaloids from Melodinus henryi.

Melodinines Y1-Y4 (1-4), four undescribed alkaloids were isolated from Melodinus henryi. Their structures were elucidated by extensive NMR, mass spectroscopic analyses, theoretical NMR and electronic circular dichroism (ECD) calculations. Compounds 1 and 2 are the first examples of bisindole alkaloids possessing an eburnamine-leuconoxine combination. Compound 3 is a rare 2,3-seco pleiocarpamine type monoterpene indole alkaloid. Compound 1 showed cytotoxic activities against six human cancer cell lines with IC50 values of 0.5-15.2 µM.

Monoterpenoid indole alkaloids from the bark of Melodinus henryi.

Four new alkaloids, melodinines W1-W4 (1-4), together with twenty one known alkaloids (5-25) were isolated from Melodinus henryi. The structures with absolute configurations were elucidated by extensive MS and NMR spectroscopic methods, as well as the single crystal X-ray diffraction and ECD calculations. All compounds were evaluated for their cytotoxicities to five human cancer cell lines. Many compounds showed certain cytotoxicities to five human cancer cell lines with an IC50 range of 1.4-29.4 µM.