Accumulating evidences have shown that unfolded protein response (UPR) contributes to the increased survival of tumor cells under endoplasmic reticulum (ER) stress conditions. Malectin is an ER-resident lectin that selectively traps misfolded glycoproteins in ER for degradation, and its expression is upregulated upon ER stress. However, contribution of malectin to malignant behavior of tumor has not been reported.
View Article and Find Full Text PDF-Quinone methides (-QMs) are a class of highly reactive intermediates that serve as important nonisolable building blocks (NBBs) in organic synthesis and small-molecule library construction. Because of their instability and nonisolability, most reported -QMs are generated through chemical synthesis, and only a few natural -QMs have been reported due to the lack of directed discovery strategies. Herein, a new natural -QM precursor (trichophenol A, ) was identified from the fungal strain of sp.
View Article and Find Full Text PDFEnfumafungin-type antibiotics, represented by enfumafungin and fuscoatroside, belong to a distinct group of triterpenoids derived from fungi. These compounds exhibit significant antifungal properties with ibrexafungerp, a semisynthetic derivative of enfumafungin, recently gaining FDA's approval as the first oral antifungal drug for treating invasive vulvar candidiasis. Enfumafungin-type antibiotics possess a cleaved E-ring with an oxidized carboxyl group and a reduced methyl group at the break site, suggesting unprecedented C-C bond cleavage chemistry involved in their biosynthesis.
View Article and Find Full Text PDFChin J Nat Med
November 2023
Bisabosqual-type meroterpenoids are fungi-derived polyketide-terpenoid hybrids bearing a 2,3,3a,3a,9,9a-hexahydro-1-benzofuro[4,3,2-]chromene skeleton (6/6/6/5 ring system) or its -C-ring structure, and exhibit diverse bioactivities. Their unique structural architecture and impressive biological activities have led to considerable interest in discovering new analogues. However, to date, only nine analogues have been identified.
View Article and Find Full Text PDF19-Hydroxybrevianamide M (1) and 6 R-methoxybrevianamide V (2), two new alkaloids, were isolated from an extract of the endophytic fungus sp. JNU18HC0517J, together with six known analogues (). Their structures were elucidated by extensive spectroscopic analyses, NMR calculations, and ECD calculations.
View Article and Find Full Text PDFFernane-type triterpenoids are a small group of natural products mainly found in plants and fungi with a wide range of biological activities. Polytolypin is a representative fernane-type triterpenoid from fungi and possesses potent antifungal activity. So far, biosynthesis of fungal-derived fernane-type triterpenoids has not been characterized, which hinders the expansion of their structural diversity using biosynthetic approaches.
View Article and Find Full Text PDFTwenty new malabaricane triterpenoids, astramalabaricosides A-T (-), were isolated from the roots of var. (Astragali Radix). Their structures were determined by spectroscopic analysis, and the use of the circular dichroism exciton chirality method, quantum chemical calculations, and chemical methods.
View Article and Find Full Text PDFTo systematically study the susceptible genetic markers for liver injury induced by anti-tuberculosis drugs in the Chinese population, 109 genes related to drug metabolism, transport and immunity were captured by Haloplex capture technique from DNA samples of 41 patients with liver injury induced by anti-tuberculosis drugs and 39 healthy controls, and sequenced completely. Association study was conducted using Plink software. To verify the significant candidate SNPs, the study was expanded to the control group from the 1000-person Genome Project of the East Asian population.
View Article and Find Full Text PDFFusidane-type antibiotics are a group of triterpenoid antibiotics. They include helvolic acid, fusidic acid, and cephalosporin P, among which fusidic acid has been used clinically. We have recently elucidated the biosynthesis of helvolic acid and fusidic acid, which share an early biosynthetic route involving six conserved enzymes.
View Article and Find Full Text PDFFuranosteroids, represented by wortmannin, viridin, and demethoxyviridin, are a special group of fungal-derived, highly oxygenated steroids featured by an extra furan ring. They are well-known nanomolar-potency inhibitors of phosphatidylinositol 3-kinase and widely used in biological studies. Despite their importance, the biosyntheses of these molecules are poorly understood.
View Article and Find Full Text PDFA novel valerenane sesquiterpenoid sinulaspirolactam A (1), together with five known compounds, was isolated from the soft coral Sinularia sp. Their structures were determined by spectroscopic analyses. The absolute configuration of 1 was established by ECD calculation.
View Article and Find Full Text PDFFour new phenylisotertronic acids (1a/1b, 2a, and 3a) were isolated from a TCM endophytic fungal strain Phyllosticta sp. J13-2-12Y obtained from the leaves of Acorus tatarinowii, along with two known ones (2b and 3b). Compounds 1-3 all existed as mixtures of enantiomers, and their corresponding optically pure enantiomers were successfully isolated by chiral HPLC.
View Article and Find Full Text PDFPhyllomeroterpenoids A-C (1-3), multi-biosynthetic pathway derived meroterpenoids from amino acid/pentose phosphate/terpenoid pathways, were isolated from the TCM endophytic fungus Phyllosticta sp. J13-2-12Y, together with six biosynthetically related compounds (4-9). All structures were determined by extensive spectroscopic analysis, chemical derivatization, and ECD experiments.
View Article and Find Full Text PDFDimericbiscognienyne A (1), an unusual diisoprenyl-cyclohexene-type meroterpenoid dimer, was isolated from Biscogniauxia sp. together with three new monomeric diisoprenyl-cyclohexene-type meroterpenoids (2-4) and one new isoprenyl-benzoic acid-type meroterpenoid (5). All structures were determined by extensive NMR spectroscopic methods, quantum chemical calculations, chemical derivatization, and X-ray crystallography.
View Article and Find Full Text PDFThree pairs of new isopentenyl dibenzo[b,e]oxepinone enantiomers, (+)-(5S)-arugosin K (1a), (-)-(5R)-arugosin K (1b), (+)-(5S)-arugosin L (2a), (-)-(5R)-arugosin L (2b), (+)-(5S)-arugosin M (3a), (-)-(5R)-arugosin M (3b), and a new isopentenyl dibenzo[b,e]oxepinone, arugosin N (4), were isolated from a wetland soil-derived fungus Talaromyces flavus, along with two known biosynthetically-related compounds 5 and 6. Among them, arugosin N (4) and 1,6,10-trihydroxy-8-methyl-2-(3-methyl-2-butenyl)-dibenz[b,e]oxepin-11(6H)-one (CAS: 160585-91-1, 5) were obtained as the tautomeric mixtures. The structures of isolated compounds were determined by detailed spectroscopic analysis.
View Article and Find Full Text PDFBackground: Contrast-induced acute kidney injury (CI-AKI) is typically defined by an increase in serum creatinine after intravascular administration of contrast medium. Because creatinine is an unreliable indicator of acute changes in kidney function, we assessed whether circulating microRNAs (miRNAs) could serve as biomarkers for early detection of CI-AKI.
Methods And Results: Using a rat model of CI-AKI, we first evaluated the miRNA profile of rat plasma and kidney.
Fusarins G1/G2 (1/2) and G3/G4 (3/4), two sets of interesting examples of diastereoisomers with substantially identical NMR data, were discovered from natural products. The reason was discussed and the generally applicable determinant conditions were proposed. The minimum interval for stereoclusters to be entirely segregated was also discussed.
View Article and Find Full Text PDFLeguminous lectins have a conserved carbohydrate recognition site comprising four loops (A-D). Here, we randomly mutated the sequence and length of loops C and D of peanut agglutinin (PNA) and expressed the proteins on the surface of mouse green fluorescent protein (GFP)-reporter cells. Flow cytometry, limiting dilution, and cDNA cloning were used to screen for several mutated PNAs with distinct properties.
View Article and Find Full Text PDF