Correction: Biosynthesis, biological activities, and structure-activity relationships of decalin-containing tetramic acid derivatives isolated from fungi.

Correction for 'Biosynthesis, biological activities, and structure-activity relationships of decalin-containing tetramic acid derivatives isolated from fungi' by Hyun Woo Kim et al., Nat. Prod. Rep., 2024, https://doi.org/10.1039/d4np00013g.

Development of a novel testis-on-a-chip that demonstrates reciprocal crosstalk between Sertoli and Leydig cells in testicular tissue.

The reciprocal crosstalk between testicular Sertoli and Leydig cells plays a vital role in supporting germ cell development and maintaining testicular characteristics and spermatogenesis. Conventional 2D and the recent 3D assay systems fail to accurately replicate the dynamic interactions between these essential endocrine cells. Furthermore, most in vitro testicular tissue models lack the ability to capture the complex multicellular nature of the testis. To address these limitations, we developed a 3D multicellular testis-on-a-chip platform that effectively demonstrates the reciprocal crosstalk between Sertoli cells and the adjacent Leydig cells while incorporating various human testicular tissue constituent cells and various natural polymers infused with blood coagulation factors. Additionally, we identified SERPINB2 as a biomarker of male reproductive toxicity that is activated in both Sertoli and Leydig cells upon exposure to various toxicants. Leveraging this finding, we designed a fluorescent reporter-conjugated toxic biomarker detection system that enables both an intuitive and quantitative assessment of material toxicity by measuring the converted fluorescence intensity. By integrating this fluorescent reporter system into the Sertoli and Leydig cells within our 3D multicellular chip platform, we successfully developed a testis-on-chip model that can be utilized to evaluate the male reproductive toxicity of potential drug candidates. This innovative approach holds promise for advancing toxicity screening and reproductive research.

The Modulation of Respiratory Epithelial Cell Differentiation by the Thickness of an Electrospun Poly-ε-Carprolactone Mesh Mimicking the Basement Membrane.

The topology of the basement membrane (BM) affects cell physiology and pathology, and BM thickening is associated with various chronic lung diseases. In addition, the topology of commercially available poly (ethylene terephthalate) (PET) membranes, which are used in preclinical in vitro models, differs from that of the human BM, which has a fibrous and elastic structure. In this study, we verified the effect of BM thickness on the differentiation of normal human bronchial epithelial (NHBE) cells. To evaluate whether the thickness of poly-ε-carprolactone (PCL) mesh affects the differentiation of NHBE cells, cells were grown on thin- (6-layer) and thick-layer (80-layer) meshes consisting of electrospun PCL nanofibers using an air-liquid interface (ALI) cell culture system. It was found that the NHBE cells formed a normal pseudostratified epithelium composed of ciliated, goblet, and basal cells on the thin-layer PCL mesh; however, goblet cell hyperplasia was observed on the thick-layer PCL mesh. Differentiated NHBE cells cultured on the thick-layer PCL mesh also demonstrated increased epithelial-mesenchymal transition (EMT) compared to those cultured on the thin-layer PCL mesh. In addition, expression of Sox9, nuclear factor (NF)-κB, and oxidative stress-related markers, which are also associated with goblet cell hyperplasia, was increased in the differentiated NHBE cells cultured on the thick-layer PCL mesh. Thus, the use of thick electrospun PCL mesh led to NHBE cells differentiating into hyperplastic goblet cells via EMT and the oxidative stress-related signaling pathway. Therefore, the topology of the BM, for example, thickness, may affect the differentiation direction of human bronchial epithelial cells.

Nanostructured Molecular Packing of Polymer Films Formed on Water Surfaces.

In this study, we examined the nanostructured molecular packing and orientations of poly[[N,N'-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5'-(2,2'-bithiophene)] (P(NDI2OD-T2)) films formed on water for the application of nanotechnology-based organic electronic devices. First, the nanoscale molecule-substrate interaction between the polymer and water was modulated by controlling the alkyl side chain length in NDI-based copolymers. Increasing alkyl side chain lengths induced a nanomorphological transition from face-on to edge-on orientation, confirmed by molecular dynamics simulations revealing nanostructural behavior. Second, the nanoscale intermolecular interactions of P(NDI2OD-T2) were controlled by varying the volume ratio of the high-boiling-point additive solvent in the binary solvent blends. As the additive solvent ratio increased, the nanostructured molecular orientation of the P(NDI2OD-T2) films on water changed remarkably from edge-on to bimodal with more face-on crystallites, thereby affecting charge transport. Our finding provides essential insights for precise nanoscale morphological control on water substrates, enabling the formation of high-performance polymer films for organic electronic devices.

Percutaneous distal chevron osteotomy is associated with lower immediate postoperative pain and a greater range of motion than the open technique: A prospective randomized study.

PURPOSE: The results of past studies comparing percutaneous techniques with traditional open techniques for hallux valgus are controversial. Therefore, this study aimed to compare the radiologic and clinical outcomes of percutaneous and open distal chevron osteotomies. METHODS: Seventy-one patients with mild to severe hallux valgus deformity were randomized to undergo percutaneous distal chevron osteotomy (percutaneous group, n = 36) or open distal chevron osteotomy (open group, n = 35) between October 2019 and September 2020. Radiological and clinical outcomes were assessed preoperatively and postoperatively. Outcome measures included the foot and ankle outcome score, foot functional index, visual analogue scale (VAS) scores for pain, range of motion (ROM) of the first metatarsophalangeal (MTP) joint, hallux valgus angle, intermetatarsal angle, and first metatarsal shortening. Additionally, the first metatarsal declination angle was measured to evaluate sagittal malunion. RESULTS: The mean first metatarsal declination angle decreased significantly at 12 months postoperatively in both groups (p = 0.021 and p < 0.001 in the percutaneous and open groups, respectively), and the decrement was significantly greater in the open group (p = 0.033). The mean VAS score for pain on postoperative day one was 4.2 ± 1.9 and 5.3 ± 1.7 in the percutaneous and open groups, respectively (p = 0.019). The mean ROM of the first MTP joint did not change significantly after surgery, from 72.5 ± 7.5 preoperatively to 71.0 ± 9.5 at 12 months postoperatively in the percutaneous group (p = 0.215); however, it decreased significantly from 70.6 ± 7.3 preoperatively to 63.4 ± 10.4 at 12 months postoperatively in the open group (p < 0.001). There were no significant differences between the groups regarding other clinical outcomes. CONCLUSION: The percutaneous group showed a lower immediate pain level at postoperative day 1 and better ROM of the first MTP joint at 12 months postoperatively.

Biosynthesis, biological activities, and structure-activity relationships of decalin-containing tetramic acid derivatives isolated from fungi.

Covering: up to December 2023Decalin-containing tetramic acid derivatives, especially 3-decalinoyltetramic acids (3-DTAs), are commonly found as fungal secondary metabolites. Numerous biological activities of this class of compounds, such as antibiotic, antiviral, antifungal, antiplasmodial, and antiprotozoal properties, have been the subject of ongoing research. For this reason, these molecules have attracted a lot of interest from the scientific community and various efforts including semi-synthesis, co-culturing with bacteria and biosynthetic gene sequencing have been made to obtain more derivatives. In this review, 3-DTAs are classified into four major groups based on the absolute configuration of the bicyclic decalin ring. Their biosynthetic pathways, various biological activities, and structure-activity relationship are then introduced.

Effect of direct-acting antivirals on disease burden of hepatitis C virus infection in South Korea in 2007-2021: a nationwide, multicentre, retrospective cohort study.

Background: It is unclear whether direct-acting antivirals (DAAs) treatment improves the disease burden in hepatitis C virus (HCV) infection. This study aimed to investigate the effect of DAA treatment on the reduction of disease burden in patients with HCV infection using individual participant data. Methods: This nationwide multicentre retrospective cohort study recruited patients with HCV infection from 29 tertiary institutions in South Korea. The data collection was done from medical records in each institution. The study included the untreated patients and the DAAs-treated patients and excluded those with a history of interferon-based treatments. Disease burden was the primary outcome, as represented by disability-adjusted life years (DALYs). Improvement in fibrosis after DAA treatment was assessed using APRI, FIB-4 index, and liver stiffness (LS) as assessed by transient elastography. Clinical outcomes were hepatocellular carcinoma (HCC), decompensation, and mortality. Findings: Between January 1, 2007, and February 17, 2022, data from 11,725 patients with HCV infection, 8464 (72%) of whom were treated with DAAs, were analysed. DAA treatment significantly improved APRI- (median 0.64 [interquartile range (IQR), 0.35-1.31]-0.33 [0.23-0.52], p < 0.0001), FIB-4- (median 2.42 [IQR, 1.48-4.40]-1.93 [1.31-2.97], p < 0.0001), and liver LS-based fibrosis (median 7.4 [IQR, 5.3-12.3]-6.2 [4.6-10.2] kPa, p < 0.0001). During the median follow-up period of 27.5 months (IQR, 10.6-52.4), 469 patients died (4.0%), 586 (5.0%) developed HCC, and 580 (4.9%) developed decompensation. The APRI-based DALY estimate was significantly lower in the DAA group than in the untreated group (median 4.55 vs. 5.14 years, p < 0.0001), as was the FIB-4-based DALY estimate (median 5.43 [IQR, 3.00-6.44] vs. 5.79 [3.85-8.07] years, p < 0.0001). The differences between the untreated and DAA groups were greatest in patients aged 40-60 years. In multivariable analyses, the DAA group had a significantly reduced risk of HCC, decompensation, and mortality compared with the untreated group (hazard ratios: 0.41 [95% confidence interval (CI), 0.34-0.48], 0.31 [95% CI, 0.30-0.38], and 0.22 [95% CI, 0.17-0.27], respectively; p < 0.0001). Interpretation: Our findings suggest that DAA treatment is associated with the improvement of liver-related outcomes and a reduction of liver fibrosis-based disease burden in patients with HCV infection. However, further studies using liver biopsy are needed to clarify the effect of DAA treatment on the reduction in the exact fibrosis-based disease burden beyond noninvasive tests. Funding: The Korea Disease Control and Prevention Agency.

Clinical outcomes of transarterial chemoembolization in Child-Turcotte Pugh class A patients with a single small (≤3 cm) hepatocellular carcinoma.

BACKGROUND AND AIM: Transarterial chemoembolization (TACE) is one of the standard modalities used to treat unresectable hepatocellular carcinoma (HCC), but the effectiveness of TACE for treating patients with a solitary small (≤3 cm) HCC and well-preserved liver function has not been definitively established. This study aimed to determine the therapeutic impact of TACE in patients with these characteristics. METHODS: This multicenter (four university hospitals) retrospective cohort study analyzed the medical records of 250 patients with a solitary small (≤3 cm) HCC and Child-Turcotte-Pugh (CTP) class A liver function diagnosed over 10 years. Posttreatment outcomes, including overall survival (OS), recurrence-free survival (RFS), and adverse events, were assessed following TACE therapy. RESULTS: One hundred and thirty-eight of the 250 patients (55.2%) treated with TACE achieved complete remission (CR). Overall median OS was 77.7 months, and median OS was significantly longer in the CR group than in the non-CR group (89.1 vs. 58.8 months, P = 0.001). Median RFS was 19.1 months in the CR group. Subgroup analysis identified hypertension, an elevated serum albumin level, and achieving CR as significant positive predictors of OS, whereas diabetes, hepatitis c virus infection, and tumor size (>2 cm) were poor prognostic factors of OS. CONCLUSIONS: The study demonstrates the effectiveness of TACE as a viable alternative for treating solitary small (≤3 cm) HCC in CTP class A patients.

Age-Related Decrease in Pellino-1 Expression Contributes to Osteoclast-Mediated Bone Loss.

Aging-related bone loss is driven by various biological factors, such as imbalanced bone metabolism from decreased osteoblast and increased osteoclast activities. Various transcriptional and post-transcriptional factors increase osteoclast activity with aging; however, studies regarding the post-translational regulators of osteoclast activity are still limited. The ubiquitin E3 ligase Pellino-1 is a well-known post-translational regulator of inflammation. However, how Pellino-1 expression regulation affects osteoclast differentiation remains unclear. This study determined that Pellino-1 levels are reduced in bone marrow monocytes (BMMs) from 40-week-old mice compared to 4-week-old mice. Interestingly, conditional Knockout (cKO) of Pellino-1 in 6-week-old mice resulted in decreased bone mass, reduced body size, and lower weight than in Pellino-1 floxed mice; however, these differences are not observed in 20-week-old mice. The increased number of tartrate-resistant acid phosphatase (TRAP)-positive cells and serum levels of C-terminal telopeptides of type I collagen, a marker of bone resorption, in 6-week-old Pellino-1 cKO mice implied a connection between Pellino-1 and the osteoclast population. Enhanced TRAP activity and upregulation of osteoclast genes in BMMs from the cKO mice indicate that Pellino-1 deletion affects osteoclast differentiation, leading to decreased bone mass and heightened osteoclast activity. Thus, targeting Pellino-1 could be a potential gene therapy for managing and preventing osteoporosis.

Understanding the Antiplasmodial Action of Resistance-Refractory Xanthoquinodin A1.

Our previous work identified a series of 12 xanthoquinodin analogues and 2 emodin-dianthrones with broad-spectrum activities against Trichomonas vaginalis, Mycoplasma genitalium, Cryptosporidium parvum, and Plasmodium falciparum. Analyses conducted in this study revealed that the most active analogue, xanthoquinodin A1, also inhibits Toxoplasma gondii tachyzoites and the liver stage of Plasmodium berghei, with no cross-resistance to the known antimalarial targets PfACS, PfCARL, PfPI4K, or DHODH. In Plasmodium, inhibition occurs prior to multinucleation and induces parasite death following 12 h of compound exposure. This moderately fast activity has impeded resistance line generation, with xanthoquinodin A1 demonstrating an irresistible phenotype in both T. gondii and P. falciparum.

Circulating miRNA-4701-3p as a predictive biomarker of cardiovascular disease which induces angiogenesis by inhibition of TOB2.

Angiogenesis is mainly regulated by the delivery of VEGF-dependent signaling to cells. However, the angiogenesis mechanism regulated by VEGF-induced miRNA is still not understood. After VEGF treatment in HUVECs, we screened the changed miRNAs through small-RNA sequencing and found VEGF-induced miR-4701-3p. Furthermore, the GFP reporter gene was used to reveal that TOB2 expression was regulated by miR-4701-3p, and it was found that TOB2 and miR-4701-3p modulation could cause angiogenesis in an in-vitro angiogenic assay. Through the luciferase assay, it was confirmed that the activation of the angiogenic transcription factor MEF2 was regulated by the suppression and overexpression of TOB2 and miR-4701-3p. As a result, MEF2 downstream gene mRNAs that induce angiogenic function were regulated. We used the NCBI GEO datasets to reveal that the expression of TOB2 and MEF2 was significantly changed in cardiovascular disease. Finally, it was confirmed that the expression of circulating miR-4701-3p in the blood of myocardial infarction patients was remarkably increased. In patients with myocardial infarction, circulating miR-4701-3p was increased regardless of age, BMI, and sex, and showed high AUC levels in specificity and sensitivity analysis (AUROC) (AUC = 0.8451, 95 % CI 0.78-0.90). Our data showed TOB2-mediated modulation of MEF2 and its angiogenesis by VEGF-induced miR-4701-3p in vascular endothelial cells. In addition, through bioinformatics analysis using GEO data, changes in TOB2 and MEF2 were revealed in cardiovascular disease. We suggest that circulating miR-4701-3p has high potential as a biomarker for myocardial infarction.

Facilely Modified Nickel-Based Hole Transporting Layers for Organic Solar Cells with 19.12% Efficiency and Enhanced Stability.

Hole transporting layers (HTLs), strategically positioned between electrode and light absorber, play a pivotal role in shaping charge extraction and transport in organic solar cells (OSCs). However, the commonly used poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) HTL, with its hygroscopic and acidic nature, undermines the operational durability of OSC devices. Herein, an environmentally friendly approach is developed utilizing nickel acetate tetrahydrate (NiAc·4H2O) and [2-(9H-carbazol-9-yl)ethyl] phosphonic acid (2PACz) as the NiAc·4H2O/2PACz HTL, aiming at overcoming the limitations posed by the conventional PEDOT:PSS one. Encouragingly, a remarkable power conversion efficiency (PCE) of 19.12% is obtained for the OSCs employing NiAc·4H2O/2PACz as the HTL, surpassing that of devices with the PEDOT:PSS HTL (17.59%), which is ranked among the highest ones of OSCs. This improvement is attributed to the appropriate work function, enhanced hole mobility, facilitated exciton dissociation efficiency, and lower recombination loss of NiAc·4H2O/2PACz-based devices. Furthermore, the NiAc·4H2O/2PACz-based OSCs exhibit superior operational stability compared to their PEDOT:PSS-based counterparts. Of significant note, the NiAc·4H2O/2PACz HTL demonstrates a broad generality, boosting the PCE of the PM6:PY-IT and PM6:Y6-based OSCs from 16.47% and 16.79% (with PEDOT:PSS-based analogs as HTLs) to 17.36% and 17.57%, respectively. These findings underscore the substantial potential of the NiAc·4H2O/2PACz HTL in advancing OSCs, offering improved performance and stability, thereby opening avenue for highly efficient and reliable solar energy harvesting technologies.

Yeast-derived particulate beta-glucan induced angiogenesis via regulating PI3K/Src and ERK1/2 signaling pathway.

The importance of ß-glucan from S. cerevisiae in angiogenesis has not been well studied. We investigated whether ß-glucan induces angiogenesis through PI3K/Src and ERK1/2 signaling pathway in HUVECs. We identified that ß-glucan induced phosphorylation of PI3K, Src, Akt, eNOS, and ERK1/2. Subsequently, we found that this phosphorylation increased the viability of HUVECs. We also observed that stimulation of ß-glucan promoted the activity of MEF2 and MEF2-dependent pro-angiogenic genes, including EGR2, EGR3, KLF2, and KLF4. Additionally, the role of ß-glucan in angiogenesis was confirmed using in vitro and ex vivo experiments including cell migration, capillary-like tube formation and mouse aorta ring assays. To determine the effect of ß-glucan on the PI3K/Akt/eNOS and ERK1/2 signaling pathway, PI3K inhibitor wortmannin and ERK1/2 inhibitor SCH772984 were used. Through the Matrigel plug assay, we confirmed that ß-glucan significantly increased angiogenesis in vivo. Taken together, our study demonstrates that ß-glucan promotes angiogenesis via through PI3K and ERK1/2 signaling pathway.

Reduced Risk of Hepatocellular Carcinoma in Patients with Chronic Hepatitis B Receiving Long-Term Besifovir Therapy.

No information is available regarding the influence of besifovir (BSV), a new nucleotide analogue, on the occurrence of hepatocellular carcinoma (HCC) in patients with chronic hepatitis B (CHB). This study evaluated the reduced risk of HCC in patients undergoing BSV treatment. A total of 188 patients with CHB were treated with BSV for up to 8 years. We prospectively assessed the incidence of HCC compared with the risk from prediction models. During the follow-up, 5 patients developed HCC: 1 of 139 patients with non-cirrhotic CHB, and 4 of 49 patients with liver cirrhosis. We compared the HCC incidence in non-cirrhotic and cirrhotic patients with the predicted number derived from the REACH-B (risk estimation for HCC in CHB) model and GAG-HCC (guide with age, gender, HBV DNA, core promotor mutation, and cirrhosis) model, respectively. The standardized incidence ratio (SIR) was 0.128 (p = 0.039) at 7 years in non-cirrhotic CHB patients, and the SIR was 0.371 (p = 0.047) at 7.5 years in cirrhotic patients, suggesting a significantly decreased HCC incidence in both groups. HCC prediction was available for BSV-treated patients using existing models. In conclusion, BSV decreased the risk of HCC in patients with CHB, and prediction models were applicable. Clinical trial registry website and trial number: ClinicalTrials.gov no: NCT01937806.

Tetramic acid-motif natural products from a marine fungus Tolypocladium cylindrosporum FB06 and their anti-Parkinson activities.

Tetramic acid-containing natural products are attracting significantly increasing attention from biologists and chemists due to their intriguing structures and biological activities. In the present study, two new tetramic acid alkaloids tolypyridone I (1) and tolypyridone J (2), together with five known ones (3-7), were isolated from cultures of a marine fungus Tolypocladium cylindrosporum FB06 isolate obtained from a marine sediment in Beaufort sea of North Alaska. Their structures were elucidated using 1D, 2D NMR, and HRESIMS. Their configurations were established on the basis of 1H coupling constants, ROESY correlations and DP4 calculations. Compound 2 was isolated as mixtures of rotational isomers with C-3 to C-7 axis between 4-hydroxy-2-pyridone and 1-ethyl-3,5-dimethylcyclohexane, hindering rotation. In our unbiased screening to discover neuroprotective compounds in an in vitro Parkinson's disease (PD) model, SH-SY5Y dopaminergic cells were treated with isolated compounds followed by treatment with 1-methyl-4-phenylpyridinium (MPP+), a parkinsonian neurotoxin. Among tested compounds, F-14329 (7) significantly protected cells from MPP+-induced cytotoxicity. MPP+-mediated cell death is known to be related to the regulation of Bcl-2 family proteins, specifically the down-regulation of anti-apoptotic Bcl-2 and the up-regulation of pro-apoptotic Bax levels. Treatment with 2 mmol/L of MPP+ for 24 h significantly reduced Bcl-2 levels compared to control treated with vehicle. However, treatment with F-14329 (7) attenuated such reduction. This study demonstrates that tetramic acid-motif compounds could be potential lead compounds for treating PD. Supplementary Information: The online version contains supplementary material available at 10.1007/s42995-023-00198-7.

D-Pinitol mitigates post-traumatic stress disorder-like behaviors induced by single prolonged stress in mice through mineralocorticoid receptor antagonism.

Post-traumatic stress disorder (PTSD) is a mental illness that can occur in individuals who have experienced trauma. Current treatments for PTSD, typically serotonin reuptake inhibitors, have limited effectiveness for patients and often cause serious adverse effects. Therefore, a novel class of treatment with better pharmacological profile is necessary. D-Pinitol has been reported to be effective for depression and anxiety disorders, but there are no reports associated with PTSD. In the present study, we investigated the effects of D-pinitol in a mouse model of PTSD induced by a single prolonged stress (SPS) protocol. We examined the therapeutic effects of D-pinitol on emotional and cognitive impairments in the SPS mouse model. We also investigated the effects of D-pinitol on fear memory formation. Mineralocorticoid receptor transactivation assay, Western blot, and quantitative PCR were employed to investigate how D-pinitol exerts its pharmacological activities. D-Pinitol ameliorated PTSD-like behaviors in a SPS mouse model. D-Pinitol also normalized the increased mRNA expression levels and protein levels of the mineralocorticoid receptor in the amygdala. A mineralocorticoid receptor agonist reversed the effects of D-pinitol on fear extinction and recall, and the antagonistic property of D-pinitol against the mineralocorticoid receptor was confirmed in vitro. Our findings suggest that D-pinitol could serve as a potential therapeutic agent for PTSD due to its antagonistic effect on the mineralocorticoid receptor.

Recent progress and prospects of dimer and multimer acceptors for efficient and stable polymer solar cells.

High power conversion efficiency (PCE) and long-term stability are essential prerequisites for the commercialization of polymer solar cells (PSCs). Small-molecule acceptors (SMAs) are core materials that have led to recent, rapid increases in the PCEs of the PSCs. However, a critical limitation of the resulting PSCs is their poor long-term stability. Blend morphology degradation from rapid diffusion of SMAs with low glass transition temperatures (Tgs) is considered the main cause of the poor long-term stability of the PSCs. The recent emergence of oligomerized SMAs (OSMAs), composed of two or more repeating SMA units (i.e., dimerized and trimerized SMAs), has shown great promise in overcoming these challenges. This innovation in material design has enabled OSMA-based PSCs to reach impressive PCEs near 19% and exceptional long-term stability. In this review, we summarize the evolution of OSMAs, including their research background and recent progress in molecular design. In particular, we discuss the mechanisms for high PCE and stability of OSMA-based PSCs and suggest useful design guidelines for high-performance OSMAs. Furthermore, we reflect on the existing hurdles and future directions for OSMA materials towards achieving commercially viable PSCs with high PCEs and operational stabilities.

Identification of fungal natural products with potent inhibition in Toxoplasma gondii.

In an effort to identify novel compounds with potent inhibition against Toxoplasma gondii, a phenotypic screen was performed utilizing a library of 683 pure compounds derived primarily from terrestrial and marine fungi. An initial screen with a fixed concentration of 5 µM yielded 91 hits with inhibition comparable to an equal concentration of artemisinin. These compounds were then triaged based on known biological and chemical concerns and liabilities. From these, 49 prioritized compounds were tested in a dose response format with T. gondii and human foreskin fibroblasts (HFFs) for cytotoxicity. Ten compounds were identified with an IC50 less than 150 nM and a selectivity index (SI) greater than 100. An additional eight compounds demonstrated submicromolar IC50 and SI values equal to or greater than 35. While the majority of these scaffolds have been previously implicated against apicomplexan parasites, their activities in T. gondii were largely unknown. Herein, we report the T. gondii activity of these compounds with chemotypes including xanthoquinodins, peptaibols, heptelidic acid analogs, and fumagillin analogs, with multiple compounds demonstrating exceptional potency in T. gondii and limited toxicity to HFFs at the highest concentrations tested. IMPORTANCE: Current therapeutics for treating toxoplasmosis remain insufficient, demonstrating high cytotoxicity, poor bioavailability, limited efficacy, and drug resistance. Additional research is needed to develop novel compounds with high efficacy and low cytotoxicity. The success of artemisinin and other natural products in treating malaria highlights the potential of natural products as anti-protozoan therapeutics. However, the exploration of natural products in T. gondii drug discovery has been less comprehensive, leaving untapped potential. By leveraging the resources available for the malaria drug discovery campaign, we conducted a phenotypic screen utilizing a set of natural products previously screened against Plasmodium falciparum. Our study revealed 18 compounds with high potency and low cytotoxicity in T. gondii, including four novel scaffolds with no previously reported activity in T. gondii. These new scaffolds may serve as starting points for the development of toxoplasmosis therapeutics but could also serve as tool compounds for target identification studies using chemogenomic approach.

The residue of salinomycin in the muscles of olive flounder (Paralichthys olivaceus) and black rockfish (Sebastes Schlegeli) after oral administration analyzed by LC-Tandem-MS.

BACKGROUND: Salinomycin, an antibiotic, have potential as a veterinary drug for fish due to its anti-parasitic activity against several fish parasites. Thus the residual levels of salinomycin in muscles of two significant aquaculture species in Korea, olive flounder and black rockfish, were analyzed using HPLC-MS-MS. RESULTS: The proper method to analyze the residual salinomycin in fish muscles using LC-MS-MS was settled and the method was validated according to CODEX guidelines. The residues in three distinct groups for two fish species were analyzed using the matrix match calibration curves at points of five different times following oral administration. After oral administration, salinomycin rapidly breaks down in both olive flounder and black rockfish. After 7th days, the average residue in all groups of two fish spp. decreased below limit of quantitation (LOQ). CONCLUSION: Due to low residue levels in fish muscles, salinomycin may therefore be a treatment that is safe for both fish and humans. This result could contribute to establishment of MRL (minimal residual limit) for approval of salinomycin for use in aquaculture.