Molecular Networking-Guided Isolation of Cyclopentapeptides from the Hydrothermal Vent Sediment Derived Fungus Aspergillus pseudoviridinutans TW58-5 and Their Anti-inflammatory Effects.

Repetitive isolation of known compounds remains a major challenge in natural-product-based drug discovery. LC-MS/MS-based molecular networking has become a highly efficient strategy for the discovery of new natural products from complex mixtures. Herein, we report a molecular networking-guided isolation procedure, which resulted in the discovery of seven new cyclopentapeptides, namely, pseudoviridinutans A-F (1-7), from the marine-derived fungus Aspergillus pseudoviridinutans TW58-5. Compounds 1-7 feature a rare amino acid moiety, O,ß-dimethyltyrosine, observed for the first time from a marine-derived fungus. The planar structures of 1-7 were elucidated by detailed analyses of IR, UV, HR ESI-Q-TOF MS, and 1D and 2D NMR spectroscopic data. Meanwhile, their absolute configurations were determined through a combination of Marfey's method and X-ray diffraction. Subsequent bioassay revealed the anti-inflammation potential of 1-7, especially 6, which inhibited the production of nitric oxide (NO), a vital inflammatory mediator, in LPS-induced murine macrophage RAW264.7 cells by regulating the expression level of NLRP3 and iNOS.

Novel citrinin derivatives from fungus Penicillium sp. TW131-64 and their antimicrobial activities.

Six new citrinin derivatives (1, 2, 4, 10, 11, and 16), along with fourteen known analogues, were acquired from Penicillium sp. TW131-64, a marine-derived fungus strain. The chemical structures of new compounds were identified through adopting various spectroscopic methods in combination with X-ray diffraction technology and comparison of the experimental electronic circular dichroism (ECD) with calculated ones. Among them, compounds 1-4 were nitrogen-containing citrinin derivatives existing in enantiomers which were resolved by chiral chromatography. A putative biosynthetic pathway for compounds 1-4 was proposed. Additionally, the antimicrobial activities of these compounds were detected by the broth microdilution assays. Citrinin derivatives 1, 2, 4 and their corresponding enantiomers (1a, 2a, 4a, 1b, 2b, and 4b) exhibited potent antimicrobial activities towards Helicobacter pylori standard strains and multidrug-resistant strains (MIC values ranging from 0.25 to 8 µg/mL), which were comparable or even better than metronidazole. Moreover, compounds 1a and 1b also showed remarkable broad antimicrobial effects towards Staphylococcus aureus, Enterococcus faecalis, methicillin-resistant Staphylococcus aureus (MRSA), Bacillus subtilis, vancomycin-resistant Enterococcus faecium (VRE), and Candida albicans. In summary, our studies demonstrated that citrinin enantiomers 1a-4a and 1b-4b, especially 1a and 1b, can be lead compounds in the research and development (R & D) of novel antimicrobial drugs. KEY POINTS: • 3 novel nitrogen-containing citrinin derivatives (1, 2, 4) were isolated. • citrinin derivatives 1-4 in enantiomers were resolved by chiral chromatography. • citrinin derivatives 1a and 1b showed broad and significant antimicrobial effects.

Nur77 Serves as a Potential Prognostic Biomarker That Correlates with Immune Infiltration and May Act as a Good Target for Prostate adenocarcinoma.

Prostate adenocarcinoma (PRAD) is the most frequent malignancy, and is the second leading cause of death due to cancer in men. Thus, new prognostic biomarkers and drug targets for PRAD are urgently needed. As we know, nuclear receptor Nur77 is important in cancer development and changes in the tumor microenvironment; whereas, the function of Nur77 in PRAD remains to be elucidated. The TCGA database was used to explore the Nur77 expression and its role in the prognosis of PRAD. It was shown that Nur77 was down regulated in PRAD, and low Nur77 expression was correlated with advanced clinical pathologic characteristics (high grade, histological type, age) and poor prognosis. Furthermore, key genes screening was examined by univariate Cox analysis and Kaplan-Meier survival. Additionally, Nur77 was closely related to immune infiltration and some anti-tumor immune functions. The differentially expressed genes (DEGs) were presented by protein-protein interaction (PPI) network analysis. Therefore, the expression level of Nur77 might help predict the survival of PRAD cases, which presents a new insight and a new target for the treatment of PRAD. In vitro experiments verified that natural product malayoside targeting Nur77 exhibited significant therapeutic effects on PRAD and largely induced cell apoptosis by up-regulating the expression of Nur77 and its mitochondrial localization. Taken together, Nur77 is a prognostic biomarker for patients with PRAD, which may refresh the profound understanding of PRAD individualized treatment.

Citrinin Monomer, Trimer, and Tetracyclic Alkaloid Derivatives from the Hydrothermal Vent-Associated Fungus Penicillium citrinum TW132-59.

Five new unusual citrinin-derived alkaloids with a tetracyclic core, citrinidines A-E (1-5), two new amide alkaloids, methyl (2S,8E)-1'-(2-methyl-3-oxodec-8-enamido) butanoate (6) and (2S,8E)-2-methyl-3-oxodec-8-enamide (7), a new unusual citrinin trimer, tricitrinol C (8), a new citrinin acetal-ketal derivative, citrininol (9), together with four known citrinin monomers (10-13), and three known citrinin dimers (14-16), were isolated from the fermentation of hydrothermal vent-associated fungus Penicillium citrinum TW132-59. Their structures were unambiguously determined by nuclear magnetic resonance (NMR), mass spectrometry, Mosher's method, 13C NMR calculation in combination with DP4+, and ECD calculations. A plausible biosynthetic pathway of all new compounds (1-9) was proposed. Citrinin trimer (8) exhibited potent cytotoxicity activity with an IC50 value of 1.34 ± 0.11 µM, and compounds 1 and 15 showed moderate cytotoxicity with IC50 values of 17.50 ± 1.43 and 9.45 ± 0.55 µM, respectively, against A549 cell line.

Synthesis of sorbicillinoid analogues with anti-inflammation activities.

Recently, we demonstrated potential anti-inflammatory effects of sorbicillinoids isolated from marine fungi. Here, we report the synthesis of a series of new sorbicillinoid analogues and assessed their anti-inflammatory activities. Our results reveal that side chain substitution with (E)-2-butenoyl, (E)-3-(4-fluorophenyl)-2-propenoyl, and (E)-3-(3,4,5-trimethoxyphenyl)-2-propenoyl significantly enhanced the inhibitory effects of the derivatives on nitric oxide (NO) production and inducible NO synthesis (iNOS) expression stimulated by lipopolysaccharides (LPS) in mouse macrophage. Further chemical derivatization shows that the monomethylresorcinol skeleton worked better than the dimethylresorcinol skeleton in inhibiting LPS-induced inflammatory response in cultured cells. Among the 29 synthesized sorbicillinoid analogues, compounds 4b and 12b exhibited the strongest anti-inflammatory activities, holding the promise of being developed into lead compounds that can be explored as potent anti-inflammation agents.

Synthesis and biological evaluation of 3ß-O-neoglycosides of caudatin and its analogues as potential anticancer agents.

In order to study the structure-activity relationship (SAR) of C21-steroidal glycosides toward human cancer cell lines and explore more potential anticancer agents, a series of 3ß-O-neoglycosides of caudatin and its analogues were synthesized. The results revealed that most of peracetylated 3ß-O-monoglycosides demonstrated moderate to significant antiproliferative activities against four human cancer cell lines (MCF-7, HCT-116, HeLa, and HepG2). Among them, 3ß-O-(2,3,4-tri-O-acetyl-ß-L-glucopyranosyl)-caudatin (2k) exhibited the highest antiproliferative activity aganist HepG2 cells with an IC50 value of 3.11 µM. Mechanical studies showed that compound 2k induced both apoptosis and cell cycle arrest at S phase in a dose dependent manner. Overall, these present findings suggested that glycosylation is a promising scaffold to improve anticancer activity for naturally occurring C21-steroidal aglycones, and compound 2k represents a potential anticancer agent deserved further investigation.

New Polyketides from a Hydrothermal Vent Sediment Fungus Trichoderma sp. JWM29-10-1 and Their Antimicrobial Effects.

Marine fungi-derived secondary metabolites are still an important source for the discovery of potential antimicrobial agents. Here, five new polyketides (1, 2, and 6-8) and seven known compounds (3-5 and 9-12) were obtained from the culture of the marine-derived fungus Trichoderma sp. JWM29-10-1. Their structures were identified by extensive spectrographic data analyses, including 1D and 2D NMR, UV, IR, and HR-ESI-MS. Further, the absolute configurations of new compounds were determined by circular dichroism (CD) spectrum and alkali-hydrolysis in combination with the in situ dimolybdenum CD method. Subsequently, the antimicrobial effects of these isolated compounds were assessed by examining the minimal inhibition concentration (MIC) with the broth microdilution assay. Compounds 1 and 2 exhibited potent antimicrobial activity against Helicobacter pylori, including multidrug-resistant strains, with MIC range values of 2-8 µg/mL. Moreover, compound 1 showed significant inhibitory effects on the growth of Gram-positive pathogens, including methicillin-resistant Staphylococcus aureus (MRSA), Enterococcus faecalis, and vancomycin-resistant Enterococcus faecium, which greatly threaten human health. This study demonstrates that chromone derivatives 1-2, especially for 1, could be potential lead compounds for the development of new antimicrobial agents and provides insight for future medicinal chemistry research.

Two New Prenylated Glycine Derivatives from the Marine-Derived Fungus Fusarium sp. TW56-10.

Two new prenylated glycine derivatives N-({4-[(3-methylbut-2-en-1-yl)oxy]phenyl}acetyl)glycine (1) and methyl N-({4-[(3-methylbut-2-en-1-yl)oxy]phenyl}acetyl)glycinate (2), along with nine known compounds (3-11) were purified from the marine-derived fungus Fusarium sp. TW56-10. Their chemical structures were determined by spectroscopic evidence, including extensive nuclear magnetic resonance (NMR), high-resolution electrospray ionization mass spectroscopy (HR-ESI-MS) data, infrared radiation (IR) and Ultraviolet spectra (UV). Compound 4 (8-O-methylfusarubin) exhibited cytotoxic activity with IC50 value of 11.45 µM for A549 cells.

Weakly Supervised Segmentation of COVID19 Infection with Scribble Annotation on CT Images.

Segmentation of infections from CT scans is important for accurate diagnosis and follow-up in tackling the COVID-19. Although the convolutional neural network has great potential to automate the segmentation task, most existing deep learning-based infection segmentation methods require fully annotated ground-truth labels for training, which is time-consuming and labor-intensive. This paper proposed a novel weakly supervised segmentation method for COVID-19 infections in CT slices, which only requires scribble supervision and is enhanced with the uncertainty-aware self-ensembling and transformation-consistent techniques. Specifically, to deal with the difficulty caused by the shortage of supervision, an uncertainty-aware mean teacher is incorporated into the scribble-based segmentation method, encouraging the segmentation predictions to be consistent under different perturbations for an input image. This mean teacher model can guide the student model to be trained using information in images without requiring manual annotations. On the other hand, considering the output of the mean teacher contains both correct and unreliable predictions, equally treating each prediction in the teacher model may degrade the performance of the student network. To alleviate this problem, the pixel level uncertainty measure on the predictions of the teacher model is calculated, and then the student model is only guided by reliable predictions from the teacher model. To further regularize the network, a transformation-consistent strategy is also incorporated, which requires the prediction to follow the same transformation if a transform is performed on an input image of the network. The proposed method has been evaluated on two public datasets and one local dataset. The experimental results demonstrate that the proposed method is more effective than other weakly supervised methods and achieves similar performance as those fully supervised.

Benzannulated 5,5-spiroketal sesquiterpenes from the roots of Angelica Pubescens.

Two new tetrahydrobenzannulated 5,5-spiroketal sesquiterpenes (1 and 2) and three novel benzannulated 5,5-spiroketal sesquiterpenes (3-5) namely angepubesins A-E, together with a new heliannane-type benzannulated sesquiterpene namely angepubesin F (6) and two known monoterpenes (7 and 8), were isolated from the roots of Angelica Pubescens. Their structures were identified by various spectroscopic analyses (NMR, MS, UV, IR), in combination with 13C NMR calculation as well as MAE, CMAE, DP4 + and MAEΔΔδ values analyses. The absolute configurations of 1-6 were determined by modified Mosher's method, ECD calculation and single-crystal X-ray diffraction (Cu Kα). Furthermore, the inhibitory activities of these isolated compounds against nitric oxide (NO) production induced by lipopolysaccharide (LPS) in RAW264.7 macrophage cells were evaluated. The results showed that compounds 2-4, 6 and 7, especially 6, displayed markedly inhibitory effects on NO production in a concentration-dependent manner. Mechanical study revealed that compound 6 could significantly inhibit the expression of nitric oxide synthase (iNOS) protein at a concentration of 10 µM. In addition, compound 6 suppressed the activation of JAK-STAT and NF-κB pathways.

High-throughput multiplex assays with mouse macrophages on pillar plate platforms.

It is challenging to rapidly identify immune responses that reflect the state and capability of immune cells due to complex heterogeneity of immune cells and their plasticity to pathogens and modulating molecules. Thus, high-throughput and easy-to-use cell culture and analysis platforms are highly desired for characterizing complex immune responses and elucidating their underlying mechanisms as well. In response to this need, we have developed a micropillar chip and a 384-pillar plate, printed mouse macrophage, RAW 264.7 cell line in alginate on the pillar plate platforms, and established multiplex cell-based assays to rapidly measure cell viability, expression of cell surface markers, and secretion of cytokines upon stimulation with model compound, lipopolysaccharide (LPS), as well as synthetic N-glycan polymers that mimic native glycoconjugates and could bind to lectin receptors on RAW 264.7 cells. Interestingly, changes in RAW 264.7 cell viability, expression levels of cell surface makers, and release of cytokines measured from the pillar plate platforms in the presence and absence of LPS were well correlated with those obtained from their counterpart, the 96-well plate with 2D-cultured macrophages. With this approach, we identified that α2,3-linked N-sialyllactose polymer has significant macrophage modulation activity among the N-glycan polymers tested. Therefore, we successfully demonstrated that our pillar plate platforms with 3D-cultured macrophages can streamline immune cell imaging and analysis in high throughput in response to compound stimulation. We envision that the pillar plate platforms could potentially be used for rapid characterization of immune cell responses and for screening immune cell-modulating molecules.

New Drimane Sesquiterpenes and Polyketides from Marine-Derived Fungus Penicillium sp. TW58-16 and Their Anti-Inflammatory and α-Glucosidase Inhibitory Effects.

Marine fungi-derived natural products represent an excellent reservoir for the discovery of novel lead compounds with biological activities. Here, we report the identification of two new drimane sesquiterpenes (1 and 2) and six new polyketides (3-8), together with 10 known compounds (9-18), from a marine-derived fungus Penicillium sp. TW58-16. The planar structures of these compounds were elucidated by extensive 1D and 2D NMR, which was supported by HR-ESI-MS data. The absolute configurations of these compounds were determined by experimental and calculated electronic circular dichroism (ECD), and their optical rotations compared with those reported. Evaluation of the anti-inflammatory activity of compounds 1-18 revealed that compound 5 significantly inhibited the release of nitric oxide (NO) induced by lipopolysaccharide (LPS) in RAW264.7 cells, correlating with the inhibition of expression of inducible nitric oxide synthase (iNOS). In addition, we revealed that compounds 1, 3-6, 14, 16, and 18 showed strong α-glucosidase inhibitory effects with inhibition rates of 35.4%, 73.2%, 55.6%, 74.4%, 32.0%, 36.9%, 88.0%, and 91.1%, respectively, which were comparable with or even better than that of the positive control, acarbose. Together, our results illustrate the potential of discovering new marine-based therapeutic agents against inflammation and diabetes mellitus.

Isolation and Characterization of Anti-Inflammatory Sorbicillinoids from the Mangrove-Derived Fungus Penicillium sp. DM815.

Marine derived fungus has gained increasing ground in the discovery of novel lead compounds with potent biological activities including anti-inflammation. Here, we first report the characterization of one new sorbicillinoid (1) and fourteen known compounds (2-15) from the ethyl acetate (AcOEt) extract of a cultured mangrove derived fungus Penicillium sp. DM815 by UV, IR, HR ESI-Q-TOF MS, and NMR spectra. We then evaluated the anti-inflammatory effects of eleven sorbicillinoids (1-11) using cultured macrophage RAW264.7 cells. The results show that compound 9, and to a lesser degree compound 5, significantly inhibited the Gram-negative bacteria lipopolysaccharide (LPS)-induced upregulation of the inducible nitric oxide synthase (iNOS). Consistently, compounds 5 and 9 significantly reduced the level of nitric oxide (NO), the product of iNOS, induced by LPS. We further show that these two compounds dose-dependently inhibited LPS-triggered iNOS expression and NO production, but had no effect on proliferation of RAW264.7 cells in the presence of LPS. In conclusion, our study identifies novel and known sorbicillinoids as potent anti-inflammatory agents, holding the promise of developing novel anti-inflammation treatment in the future.

Progressive global perception and local polishing network for lung infection segmentation of COVID-19 CT images.

In this paper, a progressive global perception and local polishing (PCPLP) network is proposed to automatically segment the COVID-19-caused pneumonia infections in computed tomography (CT) images. The proposed PCPLP follows an encoder-decoder architecture. Particularly, the encoder is implemented as a computationally efficient fully convolutional network (FCN). In this study, a multi-scale multi-level feature recursive aggregation (mmFRA) network is used to integrate multi-scale features (viz. global guidance features and local refinement features) with multi-level features (viz. high-level semantic features, middle-level comprehensive features, and low-level detailed features). Because of this innovative aggregation of features, an edge-preserving segmentation map can be produced in a boundary-aware multiple supervision (BMS) way. Furthermore, both global perception and local perception are devised. On the one hand, a global perception module (GPM) providing a holistic estimation of potential lung infection regions is employed to capture more complementary coarse-structure information from different pyramid levels by enlarging the receptive fields without substantially increasing the computational burden. On the other hand, a local polishing module (LPM), which provides a fine prediction of the segmentation regions, is applied to explicitly heighten the fine-detail information and reduce the dilution effect of boundary knowledge. Comprehensive experimental evaluations demonstrate the effectiveness of the proposed PCPLP in boosting the learning ability to identify the lung infected regions with clear contours accurately. Our model is superior remarkably to the state-of-the-art segmentation models both quantitatively and qualitatively on a real CT dataset of COVID-19.

Lung segmentation and automatic detection of COVID-19 using radiomic features from chest CT images.

This paper aims to develop an automatic method to segment pulmonary parenchyma in chest CT images and analyze texture features from the segmented pulmonary parenchyma regions to assist radiologists in COVID-19 diagnosis. A new segmentation method, which integrates a three-dimensional (3D) V-Net with a shape deformation module implemented using a spatial transform network (STN), was proposed to segment pulmonary parenchyma in chest CT images. The 3D V-Net was adopted to perform an end-to-end lung extraction while the deformation module was utilized to refine the V-Net output according to the prior shape knowledge. The proposed segmentation method was validated against the manual annotation generated by experienced operators. The radiomic features measured from our segmentation results were further analyzed by sophisticated statistical models with high interpretability to discover significant independent features and detect COVID-19 infection. Experimental results demonstrated that compared with the manual annotation, the proposed segmentation method achieved a Dice similarity coefficient of 0.9796, a sensitivity of 0.9840, a specificity of 0.9954, and a mean surface distance error of 0.0318 mm. Furthermore, our COVID-19 classification model achieved an area under curve (AUC) of 0.9470, a sensitivity of 0.9670, and a specificity of 0.9270 when discriminating lung infection with COVID-19 from community-acquired pneumonia and healthy controls using statistically significant radiomic features. The significant features measured from our segmentation results agreed well with those from the manual annotation. Our approach has great promise for clinical use in facilitating automatic diagnosis of COVID-19 infection on chest CT images.

An evolvable adversarial network with gradient penalty for COVID-19 infection segmentation.

COVID-19 infection segmentation has essential applications in determining the severity of a COVID-19 patient and can provide a necessary basis for doctors to adopt a treatment scheme. However, in clinical applications, infection segmentation is performed by human beings, which is time-consuming and generally introduces bias. In this paper, we developed a novel evolvable adversarial framework for COVID-19 infection segmentation. Three generator networks compose an evolutionary population to accommodate the current discriminator, i.e., generator networks evolved with different mutations instead of the single adversarial objective to provide sufficient gradient feedback. Compared with the existing work that enforces a Lipschitz constraint by weight clipping, which may lead to gradient exploding or vanishing, the proposed model also incorporates the gradient penalty into the network, penalizing the discriminator's gradient norm input. Experiments on several COVID-19 CT scan datasets verified that the proposed method achieved superior effectiveness and stability for COVID-19 infection segmentation.

microRNA-199a counteracts glucocorticoid inhibition of bone marrow mesenchymal stem cell osteogenic differentiation through regulation of Klotho expression in vitro.

Osteogenic differentiation (OD) of bone marrow mesenchymal stem cells (BMSCs) is critically important for mitigation of osteoporosis. Glucocorticoids (GCs) are extensively used for treating chronic inflammation, although long-term exposure to GCs is capable of triggering osteoporosis. microRNAs (miRNAs) have been reported to play a critical role in bone diseases. In the present study, we treated BMSCs with dexamethasone (DEX) during OD to stimulate GC-mediated osteoporosis. Microarray and quantitative polymerase chain reaction (Q-PCR) assays demonstrated that miR-199a was upregulated during OD of BMSCs, while DEX treatment caused a significant reduction in miR-199a. Alkaline phosphatase (ALP) activity, Alizarin red (AR) staining, and Q-PCR were applied to assess the role of miRNA-199a overexpression in DEX-triggered OD inhibition. miR-199a was able to rescue OD and ALP activity, which were inhibited by DEX. Additionally, we observed that ALP, BMP2, COL1A1, and Runx2 were increased after transfection of miRNA-199a mimics. Furthermore, we confirmed that miRNA-199a facilitates OD of BMSCs through direct inhibition of Klotho protein and messenger RNA expression affecting the downstream fibroblast growth factor receptor 1/extracellular-signal-regulated kinase and Janus kinase 1/signal transducer and activator of transcription 1 pathways. This study indicates that miR-199a plays a critical role in preventing GC-mediated osteoblast differentiation and may function as a promising miRNA biomarker for osteoporosis.

Author Correction: Delivery of acetylthevetin B, an antitumor cardiac glycoside, using polymeric micelles for enhanced therapeutic efficacy against lung cancer cells.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

New pyrones and their analogs from the marine mangrove-derived Aspergillus sp. DM94 with antibacterial activity against Helicobacter pylori.

Marine fungi are well known for their ability to produce a multitude of natural products and have been proved to be a particularly rich source of drug leads. Here, 20 pyrones and their analogs (1-20), including two new compounds (1 and 6), were obtained from a marine-derived fungus strain of Aspergillus sp. DM94. Their structures were determined by analyses of UV, IR, HR-ESI-MS, and NMR data. The ability to inhibit Helicobacter pylori in vitro was assessed for these isolated compounds. Results showed that the bis-naphtho-γ-pyrones exhibited potent antibacterial activity against both the standard and multidrug-resistant H. pylori strains. Structure-activity relationship (SAR) analysis suggested that the bis-naphtho[2,3-b]pyrones showed better anti-H. pylori activity than a hybrid of naphtho[2,3-b]pyrone and naphtho[1,2-b]pyrone. In addition, the free hydroxyl group of the C-8 position in the lower unit is vital for its anti-H. pylori activity. Importantly, compound 18 showed a synergistic effect in combination with amoxicillin, clarithromycin, or metronidazole, suggesting its potential use to overcome antibiotic resistance of H. pylori. This study shed light on the discovery of new anti-H. pylori agents. KEY POINTS: • New pyrones discovered from a marine-derived fungus Aspergillus sp. DM94. • Bis-naphtho-γ-pyrones showed potent anti-H. pylori activity. • The anti-H. pylori SAR analysis of bis-naphtho-γ-pyrones was discussed. • Bis-naphtho-γ-pyrone 18 showed synergistic effect with clinical antibiotics.

New Ophiobolins from the Deep-Sea Derived Fungus Aspergillus sp. WHU0154 and Their Anti-Inflammatory Effects.

Deep-sea fungi have become a new arsenal for the discovery of leading compounds. Here five new ophiobolins 1-5, together with six known analogues 6-11, obtained from a deep-sea derived fungus WHU0154. Their structures were determined by analyses of IR, HR-ESI-MS, and NMR spectra, along with experimental and calculated electronic circular dichroism (ECD) analysis. Pharmacological studies showed that compounds 4 and 6 exhibited obvious inhibitory effects on nitric oxide (NO) production induced by lipopolysaccharide (LPS) in murine macrophage RAW264.7 cells. Mechanical study revealed that compound 6 could inhibit the inducible nitric oxide synthase (iNOS) level in LPS-stimulated RAW264.7 cells. In addition, compounds 6, 9, and 10 could significantly inhibit the expression of cyclooxygenase 2 (COX 2) in LPS-induced RAW264.7 cells. Preliminary structure-activity relationship (SAR) analyses revealed that the aldehyde group at C-21 and the α, ß-unsaturated ketone functionality at A ring in ophiobolins were vital for their anti-inflammatory effects. Together, the results demonstrated that ophiobolins, especially for compound 6, exhibited strong anti-inflammatory effects and shed light on the discovery of ophiobolins as new anti-inflammatory agents.