Lanostane-type C31 triterpenoid derivatives from the fruiting bodies of cultivated Fomitopsis palustris

Polyporenic Acids from the Mushroom Buglossoporus quercinus Possess Chemosensitizing and Efflux Pump Inhibitory Activities on Colo 320 Adenocarcinoma Cells

Polyporenic acids N-R (1-5), five novel 24-methylene lanostane triterpenes along with seven known polyporenic acids (6-12), were identified from the fruiting bodies of Buglossoporus quercinus. The isolation of compounds 1-12 was performed by a combination of multistep flash chromatography and reversed-phase high-performance liquid chromatography (HPLC). The structure determination was carried out by extensive spectroscopic analysis, including 1D and 2D nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS) experiments. The isolated fungal metabolites were investigated for their antiproliferative activity in vitro by 3-(4,5-dimethylthiazol2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on the resistant Colo 320 human colon adenocarcinoma cell line expressing P-glycoprotein (ABCB1). The lanostane triterpenes exerted moderate antiproliferative activity with IC50 values in the range of 20.7-106.2 μM. A P-glycoprotein efflux pump modulatory test on resistant Colo 320 cells highlighted that fungal metabolites 3, 5, 8, and 10-12 have the ability to inhibit the efflux pump activity of cancer cells. Moreover, the drug interactions of triterpenes with doxorubicin were studied by the checkerboard method. Compounds 3-4, and 7-12 interacted in a synergistic manner, while an outstanding potency was detected for compound 9, which was defined as strong synergism (CI = 0.276). The current study reveals that B. quercinus is a remarkable source of fungal steroids with considerable chemosensitizing activity on cancer cells.

Two new lanostanoid glycosides isolated from a Kenyan polypore Fomitopsis carnea

Chemical exploration of solid-state cultures of the polypore Fomitopsis carnea afforded two new C31 lanostane-type triterpenoid glycosides, forpiniosides B (1) and C (2) together with two known derivatives, namely 3-epipachymic acid (3) and (3α,25S)-3-O-malonyl-23-oxolanost-8,24(31)-dien-26-oic acid (4). The structures of the isolated compounds were established based on HRESIMS and extensive 1D and 2D NMR experiments. All the isolated compounds were assessed for their antimicrobial and cytotoxic activities. Among the tested compounds, forpinioside B (1) exhibited significant antimicrobial activity against Staphylococcus aureus and Bacillus subtilis at MIC values comparable to gentamycin and oxytetracycline (positive controls), respectively.

Lanostane triterpenoids from the fruiting bodies of Fomitopsis pinicola and their anti-inflammatory activities

Thirteen previously undescribed lanostane triterpenoids, as well as nine known lanostane triterpenoids, were isolated from the fruiting bodies of Fomitopsis pinicola (Sw.) P. Karst. Their structures and absolute configurations were characterized by extensive analysis of spectroscopic data and single-crystal X-ray diffraction. Nor-pinicolic acids A-F possess unusual C-25-C-27 nor-lanostane skeletons, which were first reported from F. pinicola. Anti-inflammatory assays indicated that pinicopsic acid F and 16α-hydroxy-3-oxolanosta-7,9(11),24-trien-21-oic acid showed moderate inhibitory activities against LPS-induced NO production in RAW 264.7 cells, with IC₅₀ values of 24.5 and 25.7 μM, respectively.

(±)-Caryopterisines A and B, dimeric monoterpene alkaloids with unprecedented 6/5/5/5/6 pentacyclic rings scaffold from Caryopteris glutinosa

(±)-Caryopterisines A (1) and B (2) featuring an unprecedented 6/5/5/5/6 pentacyclic rings system were isolated from Caryopteris glutinosa. The structures were determined by spectroscopic and X-ray crystallographic data analyses as well as theoretical calculations. Chiral HPLC resolution of both racemic 1 and 2 afforded their corresponding enantiotropic enantiomers. A plausible biogenesis for 1 and 2 may be originated from Diels-Alder reaction between pyridine-containing oxerine derivatives. The enantiotropic conversion mechanism of the enantiomers was demonstrated by H-D exchange and ¹⁸O incorporation studies. Compounds 1 and 2 showed moderate inhibition of estrogen E2 biosynthesis in human ovarian granulosa-like KGN cells. These two alkaloids reduced kynurenine biosynthesis at moderate level via inhibition of indoleamine 2,3-dioxygenase. Alkaloid 2 exhibited moderate inhibition of the release of interleukin-1β.

Cytotoxic triterpenoids and triterpene sugar esters from the medicinal mushroom Fomitopsis betulina

Thirteen undescribed 24-methylene lanostane triterpenoids, named polyporenic acids E-M and fomitosides L-O, as well as seventeen known analogues, were isolated from the fruiting bodies of the mushroom Fomitopsis betulina. Their structures were determined using 1D, 2D NMR, IR, and HRESIMS. Fomitoside L and fomitoside N exhibited cytotoxicity against HL60 leukemia cells (IC₅₀ = 15.8 and 23.7 μM, respectively). Among the known compounds, notable cytotoxicities against HL60 leukemia cells and selectivity with respect to MRC-5 healthy cells were noticed for dehydropachymic acid (IC₅₀ = 10.9 μM, SI 8.6), pachymic acid (IC₅₀ = 11.0 μM, SI 9.8), 3-epi-dehydrotumulosic acid (IC₅₀ = 19.9 μM, SI 5.8) and 12α-hydroxy-3α-(3'-hydroxy-4'-methoxycarbonyl-3'-methylbutyryloxy)-24-methyllanosta-8,24 (31)-dien-26-oic acid (IC₅₀ = 19.2 μM, SI 2.2).

Lanostane Triterpenoids with PTP1B Inhibitory and Glucose-Uptake Stimulatory Activities from Mushroom Fomitopsis pinicola Collected in North America

A chemical investigation on the fruiting bodies of Fomitopsis pinicola led to the isolation and identification of 28 lanostane triterpenoids including 11 new compounds (1-11) and 17 known analogues (12-28). Their structures were elucidated by extensive one-dimensional NMR, two-dimensional NMR, and MS spectra. All isolates were tested for their anti-inflammatory activity, protein tyrosine phosphatase 1B (PTP1B) inhibitory activity in vitro, and effect on glucose uptake in insulin-resistant HepG2 cells. Compounds 1, 4, 22, 23, and 27 inhibited the nitric oxide released from the LPS-induced RAW 264.7 cell assay with IC₅₀ values in the range of 21.4-27.2 μM. Compounds 18, 22, 23, and 28 showed strong PTP1B inhibitory activity with IC₅₀ values in the range of 20.5-29.9 μM, comparable to that of the positive control of oleanolic acid (15.0 μM). Compounds 18 and 22 were confirmed to be good competitive inhibitors of PTP1B by kinetic analysis. In addition, compounds 18, 22, and 28 were found to stimulate glucose uptake in the insulin-resistant HepG2 cells in the dose from 6.25 to 100 μM. These findings indicated the potential of F. pinicola in the development of functional food or medicine for the prevention and treatment of diabetes.

C30 and C31 Triterpenoids and Triterpene Sugar Esters with Cytotoxic Activities from Edible Mushroom Fomitopsis pinicola (Sw. Ex Fr.) Krast

Fomitopsis pinicola (Sw. Ex Fr.) Krast has been commonly used as a health food source and antitumor agent. To uncover bioactive key composition of F. pinicola, in our study, we investigated the chemical constituents of a methanol extract of F. pinicola and thirty-five lanostane-type tritetpenoids; 13 new compounds (1-13) and twenty-two known analogues (14-35) were isolated. Among them, compounds 1-9 were C30 lanostane triterpenoids and triterpene sugar esters, while compounds 10-13 were C31 triterpenoids and triterpene sugar esters. Their structures and absolute configurations were elucidated by extensive 1D, 2D NMR, MS, and IR spectra. Furthermore, cytotoxic activities of all isolates against five human tumor cell lines (HL-60, A549, SMMC-7721, MCF-7, and SW480) were evaluated. The results showed that compounds 12, 14, 17, 18, 22, and 23 displayed cytotoxic effects against five human tumor cell lines with IC₅₀ values ranging from 3.92-28.51 μM. Meanwhile, compounds 9 and 35 exhibited selected inhibitory activities against HL-60, SMMC-7721, and MCF-7 with IC₅₀ values in the range of 13.57-36.01 μM. Furthermore, the flow cytometry analysis revealed that compounds 17, 22, and 35 induced apoptosis in HL-60 cell lines. Their structure-activity relationships were preliminarily reported. These findings indicate the vital role of triterpenoids and their glycosides in explaining antitumor effects of F. pinicola and provide important evidence for further development and utilization of this fungus.