Four new meroterpenoids, austalides V−X (1−3) and a farnesylated phthalide derivative (4), were isolated from the culture of the marine fungus Penicillium rudallense, together with eight known meroterpenoids derivatives (5−12). Their structures, including absolute configurations, were determined by spectroscopic methods. All of the isolated compounds were evaluated for their inhibitory activities on the receptor activator of nuclear factor κB ligand (RANKL)-induced osteoclast differentiation. Compounds 1, 2, 5−7, and 10 exhibited potent osteoclast differentiation inhibitory activity with ED 50 values of 1.9−2.8 μM.

Pancreatic cancer, which has an extremely poor prognosis, is one of the most fatal human cancers. Chemotherapy is the main palliative treatment for advanced cancer patients and also plays an indispensable role in postoperative treatments for surgical patients. Therefore, there is an urgent need to develop more innovative anticancer drugs to fight against this fatal disease.Here, we investigate the potential of benzophenone derivatives, obtained from a marine-derived strain of the fungus Pestalotiopsis neglecta, as antiproliferative lead compounds for the treatment of pancreatic cancer. The compounds, seven new (1−7) and two known (8 and 9) halogenated benzophenone derivatives, were obtained by bioactivityguided fractionation from the cultures of Pestalotiopsis neglecta. The structures were defined by spectroscopic methods including X-ray crystallographic analysis. Using the commonly used pancreatic cancer cell line PANC-1, 2 and 4 were found to suppress cell proliferation and induce apoptosis in the low micromolar range of 7.6 and 7.2 μM, respectively. Mechanistically, benzophenone derivatives not only inhibit MEK activity in the cytoplasm but also suppress ERK activity in the cytoplasm and nucleus. An in silico study suggests that benzophenone derivatives could potentially inhibit MEK activity by binding to the allosteric pocket in MEK. Benzophenones could serve as new lead compounds for the treatment of pancreatic cancer.

The pandemic caused by severe acute respiratory Coronavirus-2 (SARS-CoV-2) has been ongoing for over two years, and treatment for COVID-19, other than monoclonal antibodies, is urgently required. Accordingly, we have investigated the inhibitors of SARS-CoV-2 protein targets by high-throughput virtual screening using a marine natural products database. Considering the calculated molecular properties and availability of the compounds, (+)-usnic acid was selected as a suitable hit. In the in vitro antiviral assay of (+)-usnic acid by the immunofluorescence method, IC50 was 7.99 μM, which is similar to that of remdesivir used as a positive control. The generalized Born and surface area continuum solvation (MM/GBSA) method was performed to find the potent target of (+)-usnic acid, and the Mpro protein showed the most prominent value, −52.05 kcal/mol, among other SARS-CoV-2 protein targets. Thereafter, RMSD and protein–ligand interactions were profiled using molecular dynamics (MD) simulations. Sodium usnate (NaU) improved in vitro assay results with an IC50 of 5.33 μM and a selectivity index (SI) of 9.38. Additionally, when (+)-usnic acid was assayed against SARS-CoV-2 variants, it showed enhanced efficacy toward beta variants with an IC50 of 2.92 μM and SI of 11.1. We report the in vitro anti-SARS-CoV-2 efficacy of (+)-usnic acid in this study and propose that it has the potential to be developed as a COVID-19 treatment if its in vivo efficacy has been confirmed.

The expression of multiple proteins and high-throughput vector assembly system are highly relevant in the field of plant genetic engineering and synthetic biology. Deployment of the self-cleaving 2A peptide that mediates polycistronic gene expression has been an effective strategy for multigene expression, as it minimizes issues in coordinated transgene regulation and trait staking in plants. However, efficient vector assembly systems optimized for 2A peptide-mediated polycistronic expression are currently unavailable. Furthermore, it is unclear whether protein expression levels are influenced by the transgene position in the polycistronic expression cassette. In this article, we present Golden Gate cloning-compatible modular systems allowing rapid and flexible construction of polycistronic expression vectors applicable for plants. The genetic modules comprised 2A peptides (T2A and P2A)-linked tricistron expression cassette and its acceptor backbones, named pGO-DV1 and pGO-DV2. While both acceptor backbones were binary T-DNA vectors, pGO-DV2 was specially designed to function as a DNA replicon enhancing gene expression levels. Using the Golden Gate cloning, a set of six tricistronic vectors was constructed, whereby three transgenes encoding fluorescent proteins (mCherry, eYFP, and eGFP) were combinatorially placed along the expression cassette in each of the binary vectors. Transient expression of the construct in tobacco leaves revealed that the expression levels of three fluorescent proteins were comparable each other regardless of the gene positions in the tricistronic expression cassette. pGO-DV2-based constructs were able to increase protein expression level by up to 71%, as compared to pGO-DV1-based constructs.

The aim of this study was to isolate and identify chemical components with osteoclast differentiation inhibitory activity from Ulmus macrocarpa Hance bark. Spectroscopic analyses, including nuclear magnetic resonance (NMR) and electronic circular dichroism (ECD), resulted in the unequivocal elucidation of active compounds such as (2S)-naringenin-6-C-β-d-glucopyranoside (1), (2R)-naringenin-6-C-β-d-glucopyranoside (2), (2R,3S)-catechin-7-O-β-d-xylopyranoside (3), (2R,3S)-catechin-7-O-β-d-apiofuranoside (6), (2R,3R)-taxifolin-6-C-β-d-glucopyranoside (7), and (2S,3S)-taxifolin-6-C-β-d-glucopyranoside (8). Mechanistically, the compounds may exhibit osteoclast differentiation inhibitory activity via the downregulation of NFATc1, a master regulator involved in osteoclast formation. This is the first report of their inhibitory activities on the receptor activator of nuclear factor κB ligand (RANKL)-induced osteoclast differentiation in murine bone marrow-derived macrophages. These findings provide further scientific evidence for the rational application of the genus Ulmus for the amelioration or treatment of osteopenic diseases.