Functional Characterization and Molecular Basis of a Multi-Site Halogenase in Naphthacemycin Biosynthesis.

Halogenases are spurring a growing interest in the fields of biosynthesis and biocatalysis. Although various halogenases have been identified in numerous natural product biosynthetic pathways, the mechanisms for multiple halogenations and site-selectivity remain largely unclear. In this study, we biochemically characterized FasV, a flavin-dependent halogenase (FDH) that catalyzes five successive chlorinations in the biosynthesis of the naphthacene-containing aromatic polyketide naphthacemycin.

Prenylated indole diketopiperazine alkaloids as phosphatase inhibitors from the marine-derived fungus Talaromyces purpureogenus.

Six previously undescribed prenylated indole diketopiperazine alkaloids, talaromyines A-F (1-6), were isolated from the marine-derived fungus Talaromyces purpureogenus SCSIO 41517. Their structures including absolute configurations were elucidated on the basis of comprehensive spectroscopic data including NMR, HR-ESI-MS, and electronic circular dichroism calculations, together with chemical analysis of hydrolysates. Compounds 1-5 represent the first example of spirocyclic indole diketopiperazines biosynthesized from the condensation of L-tryptophan and L-alanine.

Microascones, Decahydrofluorene-Class Alkaloids from the Marine-Derived Fungus sp. SCSIO 41821.

Eight new decahydrofluorene-class alkaloids, microascones A and B ( and ), 2,3-epoxyphomapyrrolidone C (), 14,16-epiascomylactam B (), 24-hydroxyphomapyrrolidone A (), and microascones C-E (-), along with five known analogs (-) were isolated from the marine-derived fungus sp. SCSIO 41821. Compounds and have an unprecedented complex macrocyclic alkaloid skeleton with a 6/5/6/5/6/5/13 polycyclic system.

Angucyclinones with IDO and TDO inhibitory activities isolated from the actinomycetes Umezawaea beigongshangensis.

Four previously undescribed angucyclinones umezawaones A-D (1-4) were isolated from the liquid cultures of Umezawaea beigongshangensis. Their structures were determined by spectroscopic analyses, single crystal X-ray diffraction, quantum chemical C NMR and electronic circular dichroism calculations. All compounds displayed strong inhibitory activities against indoleamine 2,3-dioxygenase and tryptophan-2,3-dioxygenase in enzymatic assay, especially compound 2.

Carotane sesquiterpenoids A-G from the desert endophytic fungus sp. HM 166.

Seven undescribed carotane sesquiterpenoids named fusanoids A-G (1-7), along with one known analog (8) and two known sesterterpenes (9 and 10), were isolated from the fermentation broth of the desert endophytic fungi sp. HM166. The structures of the compounds, including their absolute configurations, were determined by spectroscopic data, single-crystal X-ray diffraction analysis, and ECD calculations.

Sesquiterpene lactone dimers from the fruit of Carpesium abrotanoides L.

Seven undescribed sesquiterpene lactone dimers (SLDs) (carpeabrodilactones A-G), one known SLD, and six known sesquiterpenes were isolated from the fruit of Carpesium abrotanoides L. Carpeabrodilactone A was a dimeric carabrane featuring a rare C-13-C-13' linkage. Carpeabrodilactones B and C are the first two SLDs to be described possessing a carabranolide unit and a guaianolide unit connected by an O-ether linkage.

Pyrrospirones K-Q, Decahydrofluorene-Class Alkaloids from the Marine-Derived Fungus sp. SCSIO 41512.

Seven new decahydrofluorene-class alkaloids, pyrrospirones K-Q (-), together with six known analogues (-) were isolated from the marine-derived fungal strain sp. SCSIO 41512. Their structures were determined by extensive spectroscopic analysis, and their absolute configurations were established by single-crystal X-ray diffraction analysis and quantum chemical calculations of electronic circular dichroism spectra.

Structure-based discovery of a specific SHP2 inhibitor with enhanced blood-brain barrier penetration from PubChem database.

The thiophene [2,3-d]pyrimidine structure-like small molecules were discovered from structure-based virtual screening of 1 billion compounds. Base on enzyme activity assay results, a SHP2-specific molecule inhibitor Comp#2 with IC of 1.174 μM, 85-fold more selective for SHP2 than the highly related SHP1 (IC > 100 μM).

Isoquinoline Alkaloids as Protein Tyrosine Phosphatase Inhibitors from a Deep-Sea-Derived Fungus .

Puniceusines A-N (-), 14 new isoquinoline alkaloids, were isolated from the extracts of a deep-sea-derived fungus, SCSIO z021. Their structures were elucidated by spectroscopic analyses. The absolute configuration of was determined by ECD calculations, and the structures of and were further confirmed by a single-crystal X-ray diffraction analysis.

Design, synthesis, biological evaluation and molecular dynamics simulation studies of imidazolidine-2,4-dione derivatives as novel PTP1B inhibitors.

Protein tyrosine phosphatase 1B (PTP1B) is a member of the phosphotyrosine phosphatase family and plays an important role in the signal transduction of diabetes. Inhibition of PTP1B activity can increase insulin sensitivity and reduce blood sugar levels. Therefore, it is urgent to find compounds with novel structures that can inhibit PTP1B.

Talaromyoxaones A and B: Unusual Oxaphenalenone Spirolactones as Phosphatase Inhibitors from the Marine-Derived Fungus SCSIO 41517.

(+)- and (-)-talaromyoxaones A and B ( and , respectively), two new oxaphenalenone derivatives with a hemiacetal frame and an unprecedented spirolactone frame of a 2',3,4'-spiro[isobenzofuran-1,3'-pyran]-3-one unit that show biosynthetic enantiodivergence, and two new oxaphenalenone analogues (±)-11-apopyrenulin () and (+)- or (-)-abeopyrenulin () were isolated from the marine-derived fungus SCSIO 41517. Their structures were elucidated by spectroscopic analysis, single-crystal X-ray diffraction, and quantum chemical calculations of ECD spectra. Compounds and showed selective inhibitory activity against phosphatases SHP1, SHP2, and MEG2 with IC values of 1.

Inducing secondary metabolite production of Aspergillus sydowii through microbial co-culture with Bacillus subtilis.

Background: The co-culture strategy which mimics natural ecology by constructing an artificial microbial community is a useful tool to activate the biosynthetic gene clusters to generate new metabolites. However, the conventional method to study the co-culture is to isolate and purify compounds separated by HPLC, which is inefficient and time-consuming. Furthermore, the overall changes in the metabolite profile cannot be well characterized.

Exploring the dynamic mechanism of allosteric drug SHP099 inhibiting SHP2.

The E69K mutation is one of the most frequent protein tyrosine phosphatase-2 (SHP2) mutations in leukemia, and it can cause the increase in the protein activity. Recent studies have shown that the E69K mutation was fairly sensitive to the allosteric inhibitor of SHP2 (SHP099). However, the molecular mechanism of the allosteric drug SHP099 inhibiting SHP2 remains unclear.

Mycotoxins as inhibitors of protein tyrosine phosphatases from the deep-sea-derived fungus Aspergillus puniceus SCSIO z021.

Nine new xanthone-type and anthraquinone-type mycotoxins including austocystins J-N (1-5), 7-chloro versicolorin A (6), 3'-hydroxy-8-O-methyl versicolorin B (7), 8-O-methyl versiconol (8) and 2',3'-dihydroxy versiconol (9), together with 17 known analogues (10-26) were isolated from an extract of the deep-sea-derived fungus Aspergillus puniceus SCSIO z021. Their structures were elucidated by detailed analysis of spectroscopic data, and their absolute configurations were further determined by quantum chemical calculations of ECD spectra or comparison of the experimental ECD spectra. Eleven hydrogenated austocystins were synthesized from 1-2, 10-15 and 17 by catalytic hydrogenation for bioactivities evaluation.

Exploring the mechanism of the potent allosteric inhibitor compound2 on SHP2 and SHP2 by molecular dynamics study.

Abnormal activation of Ras/MAPK signaling pathway could trigger excessive cell division. Src-homology 2 (SH2) domain-containing protein tyrosine phosphatase (SHP2) could promote Ras/MAPK activation by integrating growth factor signals. Thus, SHP2 inhibitors had become a hot topic in the treatment of cancer.

Scaffold-based selective SHP2 inhibitors design using core hopping, molecular docking, biological evaluation and molecular simulation.

PTPN11 (coding the gene of SHP2), a classic non-receptor protein tyrosine phosphatase, is implicated in multiple cell signaling pathway. Abnormal activation of SHP2 has been shown to contribute to a variety of human diseases, including Juvenile myelomonocytic leukemia (JMML), Noonan syndrome and tumors. Thus, the SHP2 inhibitors have important therapeutic value.

Penicimeroterpenoids A-C, Meroterpenoids with Rearrangement Skeletons from the Marine-Derived Fungus sp. SCSIO 41512.

Three novel andrastin-type meroterpenoids, penicimeroterpenoids A-C (-), possessing two unprecedented skeletons consisting of fused 6/5/6/6/7 and 6/5/6/6/4 polycyclic systems, were obtained from the marine-derived fungus sp. SCSIO 41512. Their structures were determined by spectroscopic methods, and the absolute configurations were further determined by single-crystal X-ray diffraction analysis for and quantum chemical calculations of ECD spectra for and , respectively.

Molecular mechanism of microRNA-21 promoting Schwann cell proliferation and axon regeneration during injured nerve repair.

At present, the functional recovery after nerve injury is not satisfactory in clinical practice. The aim of this study was to explore the molecular mechanism of miR-21 promoting Schwann cells (SC) proliferation and axon regeneration after peripheral nerve injury, providing a theoretical basis for injured nerve repair. Nerve injury models were constructed to determine the expression of miR-21 in the injured nerve by Quantitative Real-Time PCR (qRT-PCR).

Design potential selective inhibitors for human leukocyte common antigen-related (PTP-LAR) with fragment replace approach.

The overexpression of PTP-LAR could cause the insulin resistance, so PTP-LAR might be a promising target for treating diabetes. In this study, we applied the computer modeling methods with fragment replace approach to screen the fragment database by targeting PTP domain and site B with the aim to discover potent and selective PTP-LAR inhibitors. A series of novel 4-thiazolidone derivatives were gained.

Identification of novel inhibitor of protein tyrosine phosphatases delta: structure-based pharmacophore modeling, virtual screening, flexible docking, molecular dynamics simulation, and post-molecular dynamics analysis.

Owing to their unique functions in regulating the synapse activity of protein tyrosine phosphatases delta (PTPδ) that has drawn special attention for developing drugs to autism spectrum disorders (ASDs). In this study, the PTPδ pharmacophore was first established by the structure-based pharmacophore method. Subsequently, 10 compounds contented Lipinski's rule of five was acquired by the virtual screening of the PTPδ pharmacophore against ZINC and PubChem databases.

Identification of potential leukocyte antigen-related protein (PTP-LAR) inhibitors through 3D QSAR pharmacophore-based virtual screening and molecular dynamics simulation.

Owing to its negative regulatory role in insulin signaling, protein tyrosine phosphatase of leukocyte antigen-related protein (PTP-LAR) was widely thought as a potential drug target for diabetes. Now, it was urgent to search for potential LAR inhibitors targeting diabetes. Initially, the pharmacophore models of LAR inhibitors were established with the application of the HypoGen module.

Exploring the effect of aplidin on low molecular weight protein tyrosine phosphatase by molecular docking and molecular dynamic simulation study.

The low molecular weight protein tyrosine phosphatase (LMW-PTP) could regulate many signaling pathways, and it had drawn attention as a potential target for cancer. As previous report has indicated that the aplidin could inhibit the LMW-PTP, and thus, the relevant cancer caused by the abnormal regulation of the LMW-PTP could be remission. However, the molecular mechanism of inhibition of the LMW-PTP by the aplidin had not been fully understood.

Design, synthesis, biological evaluation and molecular dynamics studies of 4-thiazolinone derivatives as protein tyrosine phosphatase 1B (PTP1B) inhibitors.

Protein tyrosine phosphatase 1B (PTP1B) is a key negative regulator of insulin signaling pathway, and more and more studies have shown that it is a potential target for the treatment of type 2 diabetes mellitus (T2DM). In this study, 17 new 4-thiazolinone derivatives were designed and synthesized as novel PTP1B inhibitors, and ADMET prediction confirmed that these compounds were to be drug-like. enzyme activity experiments were performed on these compounds, and it was found that a plurality of compounds had good inhibitory activity and high selectivity against PTP1B protein.

Exploring the cause of the inhibitor 4AX attaching to binding site disrupting protein tyrosine phosphatase 4A1 trimerization by molecular dynamic simulation.

Ectopic overexpression of protein tyrosine phosphatase of liver regeneration-1 (PTP4A1, also called PRL-1) markedly enhanced hepatocellular carcinoma (HCC) cells migration and invasion. The PTP4A1 trimerization played a vital role in mediating cell proliferation and motility. Biochemical and structural studies have proved that the compound 4AX, a well-known inhibitor for PRL1, directly binds to the PTP4A1 trimer interface and obstructs trimer formation of PTP4A1.

Crystal structure of diethyl 3,3'-[(2-fluoro-phen-yl)methyl-idene]bis-(1-indole-2-carboxyl-ate).

In the title compound, CHFNO, the mean planes of the two indole ring systems (r.m.s.