Structures of the Staphylococcus aureus ribosome inhibited by fusidic acid and fusidic acid cyclopentane.

The antibiotic fusidic acid (FA) is used to treat Staphylococcus aureus infections. It inhibits protein synthesis by binding to elongation factor G (EF-G) and preventing its release from the ribosome after translocation. While FA, due to permeability issues, is only effective against gram-positive bacteria, the available structures of FA-inhibited complexes are from gram-negative model organisms. To fill this knowledge gap, we solved cryo-EM structures of the S. aureus ribosome in complex with mRNA, tRNA, EF-G and FA to 2.5 Å resolution and the corresponding complex structures with the recently developed FA derivative FA-cyclopentane (FA-CP) to 2.0 Å resolution. With both FA variants, the majority of the ribosomal particles are observed in chimeric state and only a minor population in post-translocational state. As expected, FA binds in a pocket between domains I, II and III of EF-G and the sarcin-ricin loop of 23S rRNA. FA-CP binds in an identical position, but its cyclopentane moiety provides additional contacts to EF-G and 23S rRNA, suggesting that its improved resistance profile towards mutations in EF-G is due to higher-affinity binding. These high-resolution structures reveal new details about the S. aureus ribosome, including confirmation of many rRNA modifications, and provide an optimal starting point for future structure-based drug discovery on an important clinical drug target.

Sodium fusidate loaded apatitic calcium phosphates: Adsorption behavior, release kinetics, antibacterial efficacy, and cytotoxicity assessment.

The present work reports the adsorption, release, antibacterial properties, and in vitro cytotoxicity of sodium fusidate (SF) associated with a carbonated calcium phosphate bone cement. The adsorption study of SF on cement powder compared to stoichiometric hydroxyapatite and nanocrystalline carbonated apatite was investigated to understand the interaction between this antibiotic and the calcium phosphate phases involved in the cement formulation and setting reaction. The adsorption data revealed a fast kinetic process. However, the evolution of the amount of adsorbed SF was well described by a Freundlich-type isotherm characterized by a low adsorption capacity of the materials toward the SF molecule. The in vitro release results indicated a prolonged and controlled SF release for up to 34 days. The SF amounts eluted daily were at a therapeutic level (0.5-2 mg/L) and close to the antibiotic minimum inhibitory concentration (0.1-0.9 mg/L). Furthermore, the release data fitting and modeling suggested that the drug release occurred mainly by a diffusion mechanism. The antibacterial activity showed the effectiveness of SF released from the formulated cements against Staphylococcus aureus. Furthermore, the biological in vitro study demonstrated that the tested cements didn't show any cytotoxicity towards human peripheral blood mononuclear cells and did not significantly induce inflammation markers like IL-8.

Dual Drug-Loaded Coaxial Nanofiber Dressings for the Treatment of Diabetic Foot Ulcer.

Introduction: Diabetes mellitus is frequently associated with foot ulcers, which pose significant health risks and complications. Impaired wound healing in diabetic patients is attributed to multiple factors, including hyperglycemia, neuropathy, chronic inflammation, oxidative damage, and decreased vascularization. Rationale: To address these challenges, this project aims to develop bioactive, fast-dissolving nanofiber dressings composed of polyvinylpyrrolidone loaded with a combination of an antibiotic (moxifloxacin or fusidic acid) and anti-inflammatory drug (pirfenidone) using electrospinning technique to prevent the bacterial growth, reduce inflammation, and expedite wound healing in diabetic wounds. Results: The fabricated drug-loaded fibers exhibited diameters of 443 ± 67 nm for moxifloxacin/pirfenidone nanofibers and 488 ± 92 nm for fusidic acid/pirfenidone nanofibers. The encapsulation efficiency, drug loading and drug release studies for the moxifloxacin/pirfenidone nanofibers were found to be 70 ± 3% and 20 ± 1 µg/mg, respectively, for moxifloxacin, and 96 ± 6% and 28 ± 2 µg/mg, respectively, for pirfenidone, with a complete release of both drugs within 24 hours, whereas the fusidic acid/pirfenidone nanofibers were found to be 95 ± 6% and 28 ± 2 µg/mg, respectively, for fusidic acid and 102 ± 5% and 30 ± 2 µg/mg, respectively, for pirfenidone, with a release rate of 66% for fusidic acid and 80%, for pirfenidone after 24 hours. The efficacy of the prepared nanofiber formulations in accelerating wound healing was evaluated using an induced diabetic rat model. All tested formulations showed an earlier complete closure of the wound compared to the controls, which was also supported by the histopathological assessment. Notably, the combination of fusidic acid and pirfenidone nanofibers demonstrated wound healing acceleration on day 8, earlier than all tested groups. Conclusion: These findings highlight the potential of the drug-loaded nanofibrous system as a promising medicated wound dressing for diabetic foot applications.

Metabolic profiling for the discovery of two rare fusidane-type heterodimers from the fungal endophyte Acremonium pilosum F47.

In our process of studying fusidane-type antibiotics, metabolomics-guided chemical investigation on the endophytic Acremonium pilosum F47 led to the isolation of two unique heterodimers, acremonidiols B and C (1 and 2) consisting of a fusidane-type triterpenoid motif and a steroid unit. Four biosynthetically related known natural products including fusidic acid (FA, 3), as well as ergosterol derivatives (4-6) were also obtained. Their structures were determined by the analyses of ESI-HRMS and NMR data. Compounds 1 and 2, as hybrid molecules comprising the fusidane triterpenoid and steroid, are rare in nature. Compared with the clinically used antibiotic FA (3), new compounds 1 and 2 showed no obvious antibiotic activity, indicating the importance of free C-21 carboxyl group for antibacterial activity.

Access to New Cytotoxic Triterpene and Steroidal Acid-TEMPO Conjugates by Ugi Multicomponent-Reactions.

Multicomponent reactions, especially the Ugi-four component reaction (U-4CR), provide powerful protocols to efficiently access compounds having potent biological and pharmacological effects. Thus, a diverse library of betulinic acid (BA), fusidic acid (FA), cholic acid (CA) conjugates with TEMPO (nitroxide) have been prepared using this approach, which also makes them applicable in electron paramagnetic resonance (EPR) spectroscopy. Moreover, convertible amide modified spin-labelled fusidic acid derivatives were selected for post-Ugi modification utilizing a wide range of reaction conditions which kept the paramagnetic center intact. The nitroxide labelled betulinic acid analogue 6 possesses cytotoxic effects towards two investigated cell lines: prostate cancer PC3 (IC50 7.4 ± 0.7 µM) and colon cancer HT29 (IC50 9.0 ± 0.4 µM). Notably, spin-labelled fusidic acid derivative 8 acts strongly against these two cancer cell lines (PC3: IC50 6.0 ± 1.1 µM; HT29: IC50 7.4 ± 0.6 µM). Additionally, another fusidic acid analogue 9 was also found to be active towards HT29 with IC50 7.0 ± 0.3 µM (CV). Studies on the mode of action revealed that compound 8 increased the level of caspase-3 significantly which clearly indicates induction of apoptosis by activation of the caspase pathway. Furthermore, the exclusive mitochondria targeting of compound 18 was successfully achieved, since mitochondria are the major source of ROS generation.

New Helvolic Acid Derivatives with Antibacterial Activities from Sarocladium oryzae DX-THL3, an Endophytic Fungus from Dongxiang Wild Rice (Oryza rufipogon Griff.).

Three new helvolic acid derivatives (named sarocladilactone A (1), sarocladilactone B (2) and sarocladic acid A (3a)), together with five known compounds (6,16-diacetoxy-25-hy- droxy-3,7-dioxy-29-nordammara-1,17(20)-dien-21-oic acid (3b), helvolic acid (4), helvolinic acid (5), 6-desacetoxy-helvolic acid (6) and 1,2-dihydrohelvolic acid (7)), were isolated from the endophytic fungus DX-THL3, obtained from the leaf of Dongxiang wild rice (Oryza rufipogon Griff.). The structures of the new compounds were elucidated via HR-MS, extensive 1D and 2D NMR analysis and comparison with reported data. Compounds 1, 2, 4, 5, 6 and 7 exhibited potent antibacterial activities. In particular, sarocladilactone B (2), helvolinic acid (5) and 6-desacetoxy-helvolic acid (6) exhibited strongly Staphylococcus aureus inhibitory activity with minimum inhibitory concentration (MIC) values of 4, 1 and 4 µg/mL, respectively. The structure-activity relationship (SAR) of these compounds was primarily summarized.

High-Resolution DNA Dual-Rulers Reveal a New Intermediate State in Ribosomal Frameshifting.

Ribosomal frameshifting is an important pathway used by many viruses for protein synthesis that involves mRNA translocation of various numbers of nucleotides. Resolving the mRNA positions with subnucleotide precision will provide critical mechanistic information that is difficult to obtain with current techniques. We report a method of high-resolution DNA rulers with subnucleotide precision and the discovery of new frameshifting intermediate states on mRNA containing a GA7 G motif. Two intermediate states were observed with the aid of fusidic acid, one at the "0" reading frame and the other near the "-1" reading frame, in contrast to the "-2" and "-1" frameshifting products found in the absence of the antibiotic. We termed the new near-"-1" intermediate the Post(-1*) state because it was shifted by approximately half a nucleotide compared to the normal "-1" reading frame at the 5'-end. This indicates a ribosome conformation that is different from the conventional model of three reading frames. Our work reveals uniquely precise mRNA motions and subtle conformational changes that will complement structural and fluorescence studies.

Cheminformatics-Based Identification of Potential Novel Anti-SARS-CoV-2 Natural Compounds of African Origin.

The coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome virus 2 (SARS-CoV-2) has impacted negatively on public health and socioeconomic status, globally. Although, there are currently no specific drugs approved, several existing drugs are being repurposed, but their successful outcomes are not guaranteed. Therefore, the search for novel therapeutics remains a priority. We screened for inhibitors of the SARS-CoV-2 main protease and the receptor-binding domain of the spike protein from an integrated library of African natural products, compounds generated from machine learning studies and antiviral drugs using AutoDock Vina. The binding mechanisms between the compounds and the proteins were characterized using LigPlot+ and molecular dynamics simulations techniques. The biological activities of the hit compounds were also predicted using a Bayesian-based approach. Six potential bioactive molecules NANPDB2245, NANPDB2403, fusidic acid, ZINC000095486008, ZINC0000556656943 and ZINC001645993538 were identified, all of which had plausible binding mechanisms with both viral receptors. Molecular dynamics simulations, including molecular mechanics Poisson-Boltzmann surface area (MM/PBSA) computations revealed stable protein-ligand complexes with all the compounds having acceptable free binding energies <-15 kJ/mol with each receptor. NANPDB2245, NANPDB2403 and ZINC000095486008 were predicted as antivirals; ZINC000095486008 as a membrane permeability inhibitor; NANPDB2403 as a cell adhesion inhibitor and RNA-directed RNA polymerase inhibitor; and NANPDB2245 as a membrane integrity antagonist. Therefore, they have the potential to inhibit viral entry and replication. These drug-like molecules were predicted to possess attractive pharmacological profiles with negligible toxicity. Novel critical residues identified for both targets could aid in a better understanding of the binding mechanisms and design of fragment-based de novo inhibitors. The compounds are proposed as worthy of further in vitro assaying and as scaffolds for the development of novel SARS-CoV-2 therapeutic molecules.

Antimicrobial activity of fusidic acid inclusion complexes.

OBJECTIVES: To synthesize and characterize the inclusion complexes of fusidic acid with ß - cyclodextrin, followed by the evaluation of their antimicrobial activity against pure strain (Staphylococcus aureus ATCC 25,923) and isolated Staphylococcus from clinical cases. METHODS: The desired compounds were synthesized using molar ratio of fusidic acid: ß-cyclodextrin of 1:1. Synthesized compounds were analyzed by Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Thermal Analysis, and the results confirmed the formation of inclusion compounds by fusidic acid with ß-cyclodextrin. RESULTS: Physical-chemical characterization confirmed the preparation of desired inclusion compounds, and the antimicrobial test confirmed that all compounds obtained have antimicrobial activity. Antimicrobial activity of freeze-drying complex againstS. aureus is similar with pure fusidic acid activity, being better than the cefoxitin one. Similar behavior was observed against methicillin-resistant S. aureus and S. epidermidis. CONCLUSIONS: In the present work, three different inclusion complexes of fusidic acid were prepared using three different preparation methods. All inclusion complexes obtained presented good antimicrobial activity against differentS. aureus strains. Antimicrobial activity of these new prepared compounds was observed to be better than that of cefoxitin.

Structure-activity relationship analyses of fusidic acid derivatives highlight crucial role of the C-21 carboxylic acid moiety to its anti-mycobacterial activity.

Fusidic acid (FA) is a potent congener of the fusidane triterpenoid class of antibiotics. Structure-activity relationship (SAR) studies suggest the chemical structure of FA is optimal for its antibacterial activity. SAR studies from our group within the context of a drug repositioning approach in tuberculosis (TB) suggest that, as with its antibacterial activity, the C-21 carboxylic acid group is indispensable for its anti-mycobacterial activity. Further studies have led to the identification of 16-deacetoxy-16ß-ethoxyfusidic acid (58), an analog which exhibited comparable activity to FA with an in vitro MIC99 value of 0.8 µM. Preliminary SAR studies around the FA scaffold suggested that the hydrophobic side chain at C-20, like the C-11 OH group, was required for activity. The C-3 OH group, however, can be functionalized to obtain more potent compounds.

Drug repurposing: Fusidic acid as a potential inhibitor of M. tuberculosis FtsZ polymerization - Insight from DFT calculations, molecular docking and molecular dynamics simulations.

Filamentous Temperature Sensitive Mutant Z (FtsZ), an important cell division protein in bacteria, has been validated as a potential target for antibiotics development. Citric acid has been found to inhibit the polymerization of Mycobacterium tuberculosis (MTB) FtsZ and several other drugs have been predicted as potential inhibitors through a gene ontology-based drug repurposing approach. An in-depth study on four of the predicted drugs; Fusidic acid (FusA), l-tryptophan, Carbamic acid, and 2-(3-guanidinophenyl)-3-mercaptopropanoic acid, as potential inhibitors of MTB-FtsZ polymerization was conducted using Citric acid as reference compound. The applied in silico methods involve DFT calculations, molecular docking and molecular dynamics simulations. DFT approach was applied to evaluate selectivity and stability properties of the predicted drugs. Calculated parameters including non-linear optical properties, charge distribution and electrostatic potential analyses enabled selectivity prediction of these potential drugs. DFT-based descriptors revealed FusA as the most potent compound, even more reactive than the referenced compound, Citric acid, which is also supported from the molecular docking study. Parameters including MM/PBSA binding free energies, RMSD, RMSF, RoG and hydrogen bond analysis also support FusA as the best potential MTB-FtsZ polymerization inhibitor, that forms a stable complex with the protein and impose greatest level of rigidity to the protein.

Synthesis, antifungal activity and potential mechanism of fusidic acid derivatives possessing amino-terminal groups.

Aim: Fusidic acid (FA) is a narrow-spectrum bacteriostatic antibiotic. We inadvertently discovered that a FA derivative modified by an amino-terminal group at the 3-OH position, namely 2, inhibited the growth of Cryptococcus neoformans. Methods & results: Multiscale molecular modeling approaches were used to analyze the binding modes of 2 with eEF2. FA derivatives modified at the 3-OH position were designed based on in silico models; seven derivatives possessing different amino-terminal groups were synthesized and tested in vitro for antifungal activity against C. neoformans. Conclusion: Compound 7 had the strongest minimum inhibitory concentration. Two protonated nitrogen atoms of 7 interacted with a negative electrostatic pocket of eEF2 likely explain the superiority of 7-2.

Linear Copolymers Based on Choline Ionic Liquid Carrying Anti-Tuberculosis Drugs: Influence of Anion Type on Physicochemical Properties and Drug Release.

In this study, drug nanocarriers were designed using linear copolymers with different contents of cholinium-based ionic liquid units, i.e., [2-(methacryloyloxy)ethyl]trimethylammonium chloride (TMAMA/Cl: 25, 50, and 75 mol%). The amphiphilicity of the copolymers was evaluated on the basis of their critical micelle concentration (CMC = 0.055-0.079 mg/mL), and their hydrophilicities were determined by water contact angles (WCA = 17°-46°). The chloride anions in the polymer chain were involved in ionic exchange reactions to introduce pharmaceutical anions, i.e., p-aminosalicylate (PAS-), clavulanate (CLV-), piperacillin (PIP-), and fusidate (FUS-), which are established antibacterial agents for treating lung and respiratory diseases. The exchange reaction efficiency decreased in the following order: CLV- > PAS- > PIP- >> FUS-. The hydrophilicity of the ionic drug conjugates was slightly reduced, as indicated by the increased WCA values. The major fraction of particles with sizes ~20 nm was detected in systems with at least 50% TMAMA carrying PAS or PIP. The influence of the drug character and carrier structure was also observed in the kinetic profiles of the release processes driven by the exchange with phosphate anions (0.5-6.4 µg/mL). The obtained polymer-drug ionic conjugates (especially that with PAS) are promising carriers with potential medical applications.

Biosynthetic Study of Cephalosporin P1 Reveals a Multifunctional P450 Enzyme and a Site-Selective Acetyltransferase.

Fusidane-type antibiotics are a group of triterpenoid antibiotics. They include helvolic acid, fusidic acid, and cephalosporin P1, 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. Here, we report two separate gene clusters for cephalosporin P1 biosynthesis. One consists of the six conserved genes, and the other contains three genes encoding a P450 enzyme (CepB4), an acetyltransferase (CepD2), and a short-chain dehydrogenase/reductase (CepC2). Introduction of these three genes into Aspergillus oryzae, which harbors the six conserved genes, produced cephalosporin P1. Stepwise introduction revealed that CepB4 not only catalyzes stereoselective dual oxidation of C6 and C7, but also monooxygenation of C6 or C7. This led to the generation of five new analogues. Using monohydroxylated products as substrates, we demonstrated that CepD2 specifically acetylates C6-OH, although both C6-OH and C7-OH acetylated analogues have been identified in nature.

Discovery and synthesis of 3- and 21-substituted fusidic acid derivatives as reversal agents of P-glycoprotein-mediated multidrug resistance.

In this study, we synthesized 23 fusidic acid (FA) derivatives and screened them for tumor drug resistance reversal activity and cytotoxicity toward the KBV (multidrug-resistant oral epidermoid carcinoma) cell line based on MTT assay. Tumor resistance reversal activity of fusidic acid (FA) derivatives was discovered for the first time. Our results showed that compound 1 enhanced the cytotoxicity of paclitaxel toward the drug-resistant KBV cells at a concentration of 5 µM. And compound 1 sensitized KBV cells toward paclitaxel in arresting cells in the G2/M phase and inducing cell apoptosis. Further researches showed that compound 1 inhibited the drug efflux activity of P-glycoprotein (P-gp) by increasing the ATPase activity of P-gp without affecting its expression. The structure-activity relationships (SARs) of the FA derivatives were also preliminarily investigated. Our findings indicate that compound 1 is a promising lead compound for designing FA derivatives with improved tumor drug resistance reversal activity in the future.

Semisynthetic Antimycobacterial C-3 Silicate and C-3/C-21 Ester Derivatives of Fusidic Acid: Pharmacological Evaluation and Stability Studies in Liver Microsomes, Rat Plasma, and Mycobacterium tuberculosis culture.

Fusidic acid (FA), a natural product fusidane triterpene-based antibiotic with unique structural features, is active in vitro against Mycobacterium tuberculosis, the causative agent of tuberculosis (TB). While possessing good pharmacokinetics in man, FA is rapidly metabolized in rodents, thus complicating proof-of-concept studies in this model. Toward the repositioning of FA as an anti-TB agent, we herein describe the synthesis, activity, and metabolism of FA and semisynthesized ester derivatives in rat liver microsomes, rat plasma, and mycobacterial cell culture. FA and derivative molecules with a free C-3 OH underwent species-specific metabolism to the corresponding 3-OH epimer, 3-epifusidic acid (3-epiFA). FA was also metabolized in rat plasma to form FA lactone. These additional routes of metabolism may contribute to the more rapid clearance of FA observed in rodents. C-3 alkyl and aryl esters functioned as classic prodrugs of FA, being hydrolyzed to FA in microsomes, plasma, and Mycobacterium tuberculosis culture. In contrast, C-3 silicate esters and C-21 esters were inert to hydrolysis and so did not act as prodrugs. The antimycobacterial activity of the C-3 silicate esters was comparable to that of FA, and these compounds were stable in microsomes and plasma, identifying them as potential candidates for evaluation in a rodent model of tuberculosis.

Modulation and Visualization of EF-G Power Stroke During Ribosomal Translocation.

During ribosome translocation, the elongation factor EF-G undergoes large conformational change while maintaining its contact with the moving tRNA. We previously measured a power stroke accompanying EF-G catalysis, which was consistent with structural studies. However, the role of power stroke in translocation fidelity remains unclear. Here, we report quantitative measurements of the power strokes of structurally modified EF-Gs by using two different techniques and reveal the correlation between power stroke and translocation efficiency and fidelity. We discovered that the reduced power stroke only lowered the percentage of translocation but did not introduce translocation error. The established force -structure-function correlation for EF-G indicates that power stroke drives ribosomal translocation, but the mRNA reading frame is probably maintained by ribosome itself. Furthermore, the microscope detection method reported here can be simply implemented for other biochemical applications.

Two New Spiro-Heterocyclic γ-Lactams from A Marine-Derived Aspergillus fumigatus Strain CUGBMF170049.

Two new spiro-heterocyclic γ-lactam derivatives, cephalimysins M (1) and N (2), were isolated from the fermentation cultures of the marine-derived fungus Aspergillus fumigatus CUGBMF17018. Two known analogues, pseurotin A (3) and FD-838 (4), as well as four previously reported helvolic acid derivatives, 16-O-propionyl-16-O-deacetylhelvolic acid (5), 6-O-propionyl-6-O-deacetylhelvolic acid (6), helvolic acid (7), and 1,2-dihydrohelvolic acid (8) were also identified. One-dimensional (1D), two-dimensional (2D) NMR, HRMS, and circular dichroism spectral analysis characterized the structures of the isolated compounds.

Stability kinetics of fusidic acid: Development and validation of stability indicating analytical method by employing Analytical Quality by Design approach in medicinal product(s).

A simple, rapid, accurate, reproducible and sensitive reverse phase HPLC method for the estimation of fusidic acid (FA) by means of Analytical Quality by Design (AQbD) was the aim of the present study. Initially, the vital pre-requisites for AQbD like analytical method target profile and critical analytical attributes (CAAs) like theoretical plates, tailing factor and percent assay were defined. An octadecyl silyl silica C18 column with a packing size of 5 µm was employed and the detection was performed at 235 nm using UV-detector. The separation was performed with isocratic elution employing mixture of methanol: acetonitrile (5: 95, v/v) and an aqueous phase with pH of 2.8 containing 0.1% orthophosphoric acid in the ratio of 60: 40 (v/v). Ishikawa fish-bone diagram provided the basis of the variation in CAAs with various inputs. Taguchi Design was selected as the initial screening design to select critical method parameters (CMPs) affecting method development and Central Composite Design (CCD) was further applied for systematic optimization of chromatographic method by evaluating CAAs. Crucial parameters viz. limit of detection, limit of quantification, specificity, linearity and sensitivity were employed to validate the method in accordance with the ICH guidelines. Stress degradation studies were performed and the developed method was able to successfully differentiate the degraded products from the parent drug, that too in a topical gel. In conclusion, the findings of the present study validated the utility of AQbD in the systematic design of a liquid chromatographic method with fine sensitivity for FA estimation in medicinal products.

Helvolic Acid Derivatives with Antibacterial Activities against Streptococcus agalactiae from the Marine-Derived Fungus Aspergillus fumigatus HNMF0047.

Streptococcus agalactiae is a hazardous pathogen that can cause great harm to humans and fish. In the present study, the known fungal metabolite helvolic acid (10), seven new helvolic acid derivatives named 16- O-deacetylhelvolic acid 21,16-lactone (2), 6- O-propionyl-6,16- O-dideacetylhelvolic acid 21,16-lactone (3), 1,2-dihydro-6,16- O-dideacetylhelvolic acid 21,16-lactone (4), 1,2-dihydro-16- O-deacetylhelvolic acid 21,16-lactone (5), 16- O-propionyl-16- O-deacetylhelvolic acid (6), 6- O-propionyl-6- O-deacetylhelvolic acid (7), and 24- epi-6ß,16ß-diacetoxy-25-hydroxy-3,7-dioxo-29-nordammara-1,17(20)-diene-21,24-lactone (9), and two known ones (1 and 8) were isolated from the marine-derived fungus Aspergillus fumigatus HNMF0047 obtained from an unidentified sponge from Wenchang Beach, Hainan Province, China. The structures and the absolute configurations of the new compounds were unambiguously elucidated by spectroscopic data and electronic circular dichroism (ECD) spectroscopic analyses along with quantum ECD calculations. In addition, the spectroscopic data of compound 1 are reported here for the first time, the configuration of C-24 of known compound 8 was revised based on comparison of its ROESY data with its C-24 epimer 9, and the absolute configuration of 8 was also determined for the first time. Compounds 6, 7, and 10 showed stronger antibacterial activity than a tobramycin control against S. agalactiae with MIC values of 16, 2, and 8 µg/mL, respectively.