Expanding the Chemical Diversity of Grisechelins via Heterologous Expression.

Thiazole scaffold-based small molecules exhibit a range of biological activities and play important roles in drug discovery. Based on bioinformatics analysis, a putative biosynthetic gene cluster (BGC) for thiazole-containing compounds was identified from Streptomyces sp. SCSIO 40020. Heterologous expression of this BGC led to the production of eight new thiazole-containing compounds, grisechelins E, F, and I-N (1, 2, 5-10), and two quinoline derivatives, grisechelins G and H (3 and 4). The structures of 1-10, including their absolute configurations, were elucidated by HRESIMS, NMR spectroscopic data, ECD calculations, and single-crystal X-ray diffraction analysis. Grisechelin F (2) is a unique derivative, distinguished by the presence of a salicylic acid moiety. The biosynthetic pathway for 2 was proposed based on bioinformatics analysis and in vivo gene knockout experiments. Grisechelin E (1) displayed moderate antimycobacterial activity against Mycobacterium tuberculosis H37Ra (MIC of 8 µg mL-1).

Application of Subpatellar Venous Catheter Thrombolysis in Early Acute Lower Extremity Deep Vein Thrombosis.

Objective: To compare the effectiveness and safety of intravenous thrombolysis via the subpatellar vein versus the conventional popliteal vein approach in patients with early acute deep venous thrombosis (DVT) of the lower extremities. Methods: This study included 160 early-stage acute lower extremity DVT patients at our hospital from January 2020 to October 2023, randomly assigned to two groups using sealed envelopes. The control group underwent catheter-directed thrombolysis via the popliteal vein, while the study group received thrombolysis via the subpatellar vein. Surgical parameters, limb circumferences, blood parameters, vein patency, and adverse reactions were evaluated. Results: The study group had longer surgery and X-ray times, as well as a lower urokinase dose compared to the control group (P < .05), with no significant difference in thrombolysis time (P > .05). Thigh and calf circumferences and edema rates didn't significantly change before and after thrombolysis in both groups (P > .05). Hematological parameters, including PT, INR, APTT, FIB, TT, and D-D levels, remained similar between the two groups before and after thrombolysis (P > .05). However, after thrombolysis, both groups showed increased PT, INR, APTT, and TT levels and decreased FIB and D-D levels compared to before thrombolysis (P < .05). Porter scores showed no significant differences between the two groups before thrombolysis (P > .05), but after thrombolysis, both groups had reduced Porter scores, with the study group showing a more pronounced decrease (P < .05). Additionally, the study group had a higher vein patency rate and GCQ score than the control group (P < .05). Adverse reactions occurred at a similar rate in both groups (P > .05). Conclusion: Subpatellar vein catheter-directed thrombolysis offers a safe and more effective alternative to traditional popliteal vein approaches for early acute DVT of the lower extremities, improving outcomes such as vein patency and reducing the need for urokinase.

A new secondary metabolite from the marine-derived fungus Phomopsis lithocarpus FS508.

Based on the One Strain-Many Compounds (OSMAC) strategy, the secondary metabolites of Phomopsis lithocarpus FS508 were investigated. As a result, a new secondary metabolite, 4-methoxy-3-[4-(acetyloxy)-3-methyl-2-butenyl]benzoic acid (1) as well as eleven known compounds were isolated from the fermentation product of the strain FS508. Their structures were determined by NMR, IR, UV, and MS spectroscopic data analyses. All the isolated compounds were evaluated for cytotoxic and anti-inflammatory activities. Among them, compounds 3 and 9 displayed potent cytotoxicity against HepG-2 cell line, and compounds 2, 3 and 12 showed significant anti-inflammatory activities.

The biochemical basis of mitochondrial dysfunction in Zellweger Spectrum Disorder.

Peroxisomal biogenesis disorders (PBDs) are genetic disorders of peroxisome biogenesis and metabolism that are characterized by profound developmental and neurological phenotypes. The most severe class of PBDs-Zellweger spectrum disorder (ZSD)-is caused by mutations in peroxin genes that result in both non-functional peroxisomes and mitochondrial dysfunction. It is unclear, however, how defective peroxisomes contribute to mitochondrial impairment. In order to understand the molecular basis of this inter-organellar relationship, we investigated the fate of peroxisomal mRNAs and proteins in ZSD model systems. We found that peroxins were still expressed and a subset of them accumulated on the mitochondrial membrane, which resulted in gross mitochondrial abnormalities and impaired mitochondrial metabolic function. We showed that overexpression of ATAD1, a mitochondrial quality control factor, was sufficient to rescue several aspects of mitochondrial function in human ZSD fibroblasts. Together, these data suggest that aberrant peroxisomal protein localization is necessary and sufficient for the devastating mitochondrial morphological and metabolic phenotypes in ZSDs.

Anti-Inflammatory Phomalones from the Deep-Sea-Derived Fungus Trichobotrys effuse FS522.

Four new phomalones A-D (1-4), together with five known analogues (5-9) were isolated from the deep-sea-derived fungus Trichobotrys effuse FS522. Their structures of the new compounds established by analysis of their NMR and HR-ESI-MS spectroscopic data, and the absolute configurations of 2 was determined by electronic circular dichroism (ECD) calculations. compounds 4, 6 and 8 substantially inhibited the production of nitric oxide (NO) with IC50 values of 4.64, 13.90, and 34.07 µM.

Potential Anti-Candida albicans Mechanism of Trichoderma Acid from Trichoderma spirale.

Candida albicans is the main causal pathogen of fungal infections in human beings. Although diverse anti-C. albicans drugs have been explored, the drug resistance and side effects of these drugs are intensifying. Thus, it is urgent to explore new anti-C. albicans compounds from natural products. In this study, we identified trichoderma acid (TA), a compound from Trichoderma spirale with a strong inhibitory effect on C. albicans. Transcriptomic and iTRAQ-based proteomic analyses of TA-treated C. albicans in combination with scanning electronic microscopy and reactive oxygen species (ROS) detection were performed to investigate the potential targets of TA. The most significant differentially expressed genes and proteins after TA treatment were verified through Western blot analysis. Our results revealed that mitochondrial membrane potential, endoplasmic reticulum, ribosomes in the mitochondria, and cell walls were disrupted in TA-treated C. albicans, leading to the accumulation of ROS. The impaired enzymatic activities of superoxide dismutase further contributed to the increase in ROS concentration. The high concentration of ROS led to DNA damage and cell skeleton destruction. The expression levels of Rho-related GTP-binding protein RhoE (RND3), asparagine synthetase (ASNS), glutathione S-transferase, and heat shock protein 70 were significantly up-regulated in response to apoptosis and toxin stimulation. These findings suggest that RND3, ASNS, and supereoxide dismutase 5 are the potential targets of TA, as further demonstrated through Western blot analysis. The combination of transcriptomic, proteomic, and cellular analyses would provide clues for the anti-C. albicans mechanism of TA and the defensive response mechanism of C. albicans. TA is thus recognized as a promising new anti-C. albicans leading compound that alleviates the hazard of C. albicans infection in human beings.

Saikosaponin A and Its Epimers Alleviate LPS-Induced Acute Lung Injury in Mice.

The purpose of this work was to illustrate the effect of processing with vinegar on saikosaponins of Bupleurum chinense DC. (BC) and the protective effects of saikosaponin A (SSA), saikosaponin b1 (SSb1), saikosaponin b2 (SSb2), and saikosaponin D (SSD) in lipopolysaccharide (LPS)-induced acute lung injury (ALI) mice. We comprehensively evaluated the anti-inflammatory effects and potential mechanisms of SSA, SSb1, SSb2, and SSD through an LPS-induced ALI model using intratracheal injection. The results showed that SSA, SSb1, SSb2, and SSD significantly decreased pulmonary edema; reduced the levels of IL-6, TNF-α, and IL-1ß in serum and lung tissues; alleviated pulmonary pathological damage; and decreased the levels of the IL-6, TNF-α, and IL-1ß genes and the expression of NF-κB/TLR4-related proteins. Interestingly, they were similar in structure, but SSb2 had a better anti-inflammatory effect at the same dose, according to a principal component analysis. These findings indicated that it may not have been comprehensive to only use SSA and SSD as indicators to evaluate the quality of BC, especially as the contents of SSb1 and SSb2 in vinegar-processed BC were significantly increased.

Pyrone and isocoumarin derivatives from the endophytic fungus Cytospora rhizophorae.

Cytospone A (1), a pyrone and isocoumarin hetero-dimer possessing an unprecedented skeleton with a polyoxygen-hetero 6/6/6/6 tetracyclic fused ring system, and three other biosynthetic precursors cytospones B-D (2-4), along with eleven known compounds were purified from Cytospora rhizophorae A761. The deduced structure of cytospone A represents the first family of natural hetero-dimers comprising pyrone and isocoumarin moieties. A plausible biogenetic pathway involving an intriguing Knoevenagel condensation/6π electrocyclization cascade sequence as the key chemical transformation is proposed.

Neocucurbols A-H, Phomactin Diterpene Derivatives from the Marine-Derived Fungus Neocucurbitaria unguis-hominis FS685.

Neocucurbols A-D (1-4) are diterpene derivatives that possess a complex 6/6/5/5/6 polycyclic ring system with a characteristic tetrahedrofuran bridge ring skeleton. Neocucurbols E-H (5-8) are diterpenes that feature a 6/8/6 tricyclic ring system. Their structures were unambiguously determined by detailed spectroscopic analyses, X-ray diffractions studies, and ECD calculations. All compounds (1-8) were evaluated for in vitro antimicrobial and cytotoxic activities.

Two New Phenylhydrazone Derivatives from the Pearl River Estuary Sediment-Derived Streptomyces sp. SCSIO 40020.

Two new phenylhydrazone derivatives and one new alkaloid, penzonemycins A-B (1-2) and demethylmycemycin A (3), together with three known compounds including an alkaloid (4) and two sesquiterpenoids (5-6), were isolated from the Streptomyces sp. SCSIO 40020 obtained from the Pearl River Estuary sediment. Their structures and absolute configurations were assigned by 1D/2D NMR, mass spectroscopy and X-ray crystallography. Compound 1 was evaluated in four human cancer cell lines by the SRB method and displayed weak cytotoxicity in three cancer cell lines, with IC50 values that ranged from 30.44 to 61.92 µM, which were comparable to those of the positive control cisplatin. Bioinformatic analysis of the putative biosynthetic gene cluster indicated a Japp-Klingemann coupling reaction involved in the hydrazone formation of 1 and 2.

Diverse Secondary Metabolites from the Coral-Derived Fungus Aspergillus hiratsukae SCSIO 5Bn1003.

Three new metabolites, including a cyclic tetrapeptide asperhiratide (1), an ecdysteroid derivative asperhiratine (2), and a sesquiterpene lactone asperhiratone (3), were isolated and identified from the soft coral-derived fungus Aspergillus hiratsukae SCSIO 5Bn1003, together with 10 known compounds. Their structures were elucidated via spectroscopic analysis, X-ray diffraction analysis, and electronic circular dichroism calculations. In addition, the absolute configuration of 1 was determined by Marfey's technique and an analysis of the acid hydrolysates using a chiral phase HPLC column. Among all the compounds, 6 and 8 showed medium cytotoxic activities against four tumor cell lines (SF-268, HepG-2, MCF-7, and A549), with IC50 values ranging from 31.03 ± 3.04 to 50.25 ± 0.54 µM. Meanwhile, they strongly inhibited α-glucosidase activities, with IC50 values of 35.73 ± 3.94 and 22.00 ± 2.45 µM, which were close to and even stronger than the positive control acarbose (IC50 = 32.92 ± 1.03 µM). Compounds 6-8 showed significant antibacterial activities against Bacillus subtilis, with MIC values of 10.26 ± 0.76 µM, 17.00 ± 1.25 µM, and 5.30 ± 0.29 µM, respectively. Compounds 9 and 12 exhibited potent radical scavenging activities against DPPH, with IC50 values of 12.23 ± 0.78 µM and 7.38 ± 1.16 µM. In addition, asperhiratide (1) was evaluated for anti-angiogenic activities in the in vivo zebrafish model, which showed a weak inhibitory effect on intersegmental vessel (ISV) formation.

Chevalones H-M: Six New α-Pyrone Meroterpenoids from the Gorgonian Coral-Derived Fungus Aspergillus hiratsukae SCSIO 7S2001.

Six new α-pyrone meroterpenoid chevalones H-M (1-6), together with six known compounds (7-12), were isolated from the gorgonian coral-derived fungus Aspergillus hiratsukae SCSIO 7S2001 collected from Mischief Reef in the South China Sea. Their structures, including absolute configurations, were elucidated on the basis of spectroscopic analysis and X-ray diffraction data. Compounds 1-5 and 7 showed different degrees of antibacterial activity with MIC values of 6.25-100 µg/mL. Compound 8 exhibited potent cytotoxicity against SF-268, MCF-7, and A549 cell lines with IC50 values of 12.75, 9.29, and 20.11 µM, respectively.

Structurally Diverse Polycyclic Salicylaldehyde Derivative Enantiomers from a Marine-Derived Fungus Eurotium sp. SCSIO F452.

To enlarge the chemical diversity of Eurotium sp. SCSIO F452, a talented marine-derived fungus, we further investigated its chemical constituents from a large-scale fermentation with modified culture. Four pairs of new salicylaldehyde derivative enantiomers, euroticins F-I (1-4), as well as a known one eurotirumin (5) were isolated and characterized. Compound 1 features an unprecedented constructed 6/6/6/5 tetracyclic structures, while 2 and 3 represent two new types of 6/6/5 scaffolds. Their structures were established by comprehensive spectroscopic analyses, X-ray diffraction, 13C NMR, and electronic circular dichroism calculations. Selected compounds showed significant inhibitory activity against α-glucosidase and moderate cytotoxic activities against SF-268, MCF-7, HepG2, and A549 cell lines.

Euroticins A and B, Two Pairs of Highly Constructed Salicylaldehyde Derivative Enantiomers from a Marine-Derived Fungus Eurotium sp. SCSIO F452.

Two pairs of salicylaldehyde derivative enantiomers, euroticins A and B (1 and 2), were isolated from a marine-derived fungus Eurotium sp. SCSIO F452. Compound 1 possesses a highly constructed 6/6/6/5/7 pentacyclic structure featuring an unprecedented 2,11-dioxatricyclo[5.3.1.04,8]undecane core. Compound 2 represents the first example of 6/6/6/6 tetracyclic salicylaldehyde derivative. Their structures were established by spectroscopic analyses, X-ray diffraction, and electronic circular dichroism (ECD) and 13C NMR calculations. Compounds (+)-2 and (-)-2 exhibited remarkable antioxidative activities.

Structural elucidation, total synthesis, and cytotoxic activity of effphenol A.

A highly substituted phenol derivative, effphenol A (1), was isolated from the deep-sea-derived fungus Trichobotrys effuse FS524. Its complete structural assignment was established through a combination of spectroscopic analysis together with single-crystal X-ray diffraction experiments and further unequivocally confirmed by a biomimetic total synthesis. Structurally, effphenol A possesses a poly-substituted 6-5/6/6 tetracyclic ring system, which represents the first case of such a skeleton found in nature. Furthermore, the cytotoxic activity of effphenol A (1) toward four human cancer cell lines was assayed.

Photeroids A and B, unique phenol-sesquiterpene meroterpenoids from the deep-sea-derived fungus Phomopsis tersa.

Photeroids A (1) and B (2), two structurally fascinating meroterpenoids, were isolated from the deep-sea-derived fungus Phomopsis tersa FS441. Their structures were sufficiently established by a comprehensive interpretation of the spectroscopic data, NMR spectra, and ECD calculation. Photeroids A and B represented the first phenolic sesquiterpene meroterpenoids featuring a highly fused 6/6/6/6 tetracyclic ring system derived through a rarely-occurring hetero-Diels-Alder reaction via an orthoquinone methide intermediate. Additionally, they were also evaluated for their cytotoxic activities against four human cancer cells, wherein compounds 1 and 2 exhibited moderate cytotoxic activities.

Callyspongiolide Is a Potent Inhibitor of the Vacuolar ATPase.

Callyspongiolide is a marine-derived macrolide that kills cells in a caspase-independent manner. NCI COMPARE analysis of human tumor cell line toxicity data for synthetic callyspongiolide indicated that its pattern of cytotoxicity correlated with that seen for concanamycin A, an inhibitor of the vacuolar-type H+-ATPase (V-ATPase). Using yeast as a model system, we report that treatment with synthetic callyspongiolide phenocopied a loss of V-ATPase activity including (1) inability to grow on a nonfermentable carbon source, (2) rescue of cell growth via supplementation with Fe2+, (3) pH-sensitive growth, and (4) a vacuolar acidification defect visualized using the fluorescent dye quinacrine. Crucially, in an in vitro assay, callyspongiolide was found to dose-dependently inhibit yeast V-ATPase (IC50 = 10 nM). Together, these data identify callyspongiolide as a new and highly potent V-ATPase inhibitor. Notably, callyspongiolide is the first V-ATPase inhibitor known to be expelled by Pdr5p.

Bioactive Metabolites from the Deep-Sea-Derived Fungus Diaporthe longicolla FS429.

The chemical investigation of a methanol extract of the deep-sea-derived fungus Diaporthe longicolla FS429 led to the isolation of two novel diterpenoids longidiacids A and B (1 and 2), two new polyketides (3 and 4), two new cytochalasin analogues longichalasins A and B (6 and 8) and three known analogues 5, 7, 9. Their structures were elucidated through comprehensive spectroscopic analysis, while the absolute configurations were established by the comparison of the experimental and quantum chemical calculated ECD spectra. The structure of compound 7 was confirmed through X-ray diffraction for the first time. In the bioassays compound 8 exhibited antiproliferative effects against SF-268, with an IC50 value of 16.44 µM. Moreover, compounds 1 and 8 were detected to inhibit 35.4% and 53.5% of enzyme activity of Mycobacterium tuberculosis protein tyrosine phosphatase B (MptpB) at a concentration of 50 µM.

Highly Substituted Phenol Derivatives with Nitric Oxide Inhibitory Activities from the Deep-Sea-Derived Fungus Trichobotrys effuse FS524.

Chemical investigation on EtOAc extract of the deep-sea-derived fungus Trichobotrys effuse FS524 resulted in the isolation of six new highly substituted phenol derivatives trieffusols A-F (1-6), along with ten known relative analogues (7-16). Their structures with absolute configurations were extensively characterized on the basis of spectroscopic data analyses, single-crystal X-ray diffraction experiments, and electronic circular dichroism (ECD) calculations. Structurally, trieffusols A and B shared an unprecedented ploy-substituted 9-phenyl-hexahydroxanthone skeleton with an intriguing 6-6/6/6 tetracyclic fused ring system, which were often encountered as significant moieties in the pharmaceutical drugs but rarely discovered in natural products. In the screening towards their anti-inflammatory activities of 1-6, trieffusols C and D exhibited moderate inhibitory activities against nitric oxide (NO) production in LPS-induced RAW 264.7 macrophages with IC50 values ranging from 51.9 to 55.9 µM.

Rhizophols A and B, antioxidant and axially chiral benzophenones from the endophytic fungus Cytospora rhizophorae.

Two novel polyketones, rhizophols A-B (1-2), were isolated from the endophytic fungus Cytospora rhizophorae A761. They shared unprecedented poly-substituted benzophenone skeletons featuring an epoxy isopentyl unit and a propionyl moiety. Their structures were evidenced by extensive spectroscopic analyses, X-ray diffraction, and quantum energy calculation. Moreover, compound 1 was proved to be a promising lead compound for novel antioxidant drugs.