Targeting Pancreatic Cancer with Novel Plumbagin Derivatives: Design, Synthesis, Molecular Mechanism, In Vitro and In Vivo Evaluation

The potentiality of isoflavones from Derris robusta (DC.) Benth. against α-glucosidase

The four recently described isoflavones, derrisrobustones A-D, and eight known isoflavones extracted from Derris robusta (DC.) Benth. (Leguminosae) were identified as potential isoflavones for α-glucosidase inhibitory activity. However, the inhibitory ability of each isoflavone was quite different and the structural and dynamical properties of the isoflavones in the binding with α-glucosidase have not been studied. In this study, the molecular dynamics (MD) simulation and the molecular mechanics generalized Born surface area (MM/GBSA) methods were applied to gain insight into isoflavones bound with the α-glucosidase active site. The results found that the isoflavones with a hydroxy substituent could be stabilized in the α-glucosidase active site with low values of the binding free energy, especially derrisrobustone D and derrubone. The isoflavones, except for derrubone, were bound with α-glucosidase by means of electrostatic force effectively.

Targeting Pancreatic Cancer with Novel Nicolaioidesin C Derivatives: Molecular Mechanism, In Vitro, and In Vivo Evaluations

Pancreatic cancer, one of the deadliest cancers with the lowest 5-year survival rate, often develops resistance to gemcitabine-based chemotherapies. The hypovascular nature of pancreatic tumors forces cancer cells to adapt to nutrient-depleted tumor microenvironments. Conventional anticancer agents targeting rapidly dividing cancer cells under nutrient-rich conditions are largely ineffective against adapted pancreatic cancer cells. Thus, targeting cancer cells under nutrient starvation, termed the "antiausterity strategy", may be effective for pancreatic cancer. This study examined nicolaioidesin C (Nic-C) derivatives as antiausterity agents. Among the 32 derivatives, Nic-15 (4n) exhibited superior cytotoxicity against MIA PaCa-2 and PANC-1 pancreatic cancer cells, inhibited MIA PaCa-2 cell migration and colony formation, and modulated the PI3K/Akt/mTOR pathway, while reducing the ER stress markers induced by gemcitabine. Nic-15 was found to inhibit tumor growth and enhance the efficacy of gemcitabine in an in vivo xenograft model. Nic-15 in combination with gemcitabine may be an effective strategy for the treatment of pancreatic cancer.

Inhibition of SARS-CoV-2 Nsp9 ssDNA-Binding Activity and Cytotoxic Effects on H838, H1975, and A549 Human Non-Small Cell Lung Cancer Cells: Exploring the Potential of Nepenthes miranda Leaf Extract for Pulmonary Disease Treatment

Carnivorous pitcher plants from the genus Nepenthes are renowned for their ethnobotanical uses. This research explores the therapeutic potential of Nepenthes miranda leaf extract against nonstructural protein 9 (Nsp9) of SARS-CoV-2 and in treating human non-small cell lung carcinoma (NSCLC) cell lines. Nsp9, essential for SARS-CoV-2 RNA replication, was expressed and purified, and its interaction with ssDNA was assessed. Initial tests with myricetin and oridonin, known for targeting ssDNA-binding proteins and Nsp9, respectively, did not inhibit the ssDNA-binding activity of Nsp9. Subsequent screenings of various N. miranda extracts identified those using acetone, methanol, and ethanol as particularly effective in disrupting Nsp9's ssDNA-binding activity, as evidenced by electrophoretic mobility shift assays. Molecular docking studies highlighted stigmast-5-en-3-ol and lupenone, major components in the leaf extract of N. miranda, as potential inhibitors. The cytotoxic properties of N. miranda leaf extract were examined across NSCLC lines H1975, A549, and H838, focusing on cell survival, apoptosis, and migration. Results showed a dose-dependent cytotoxic effect in the following order: H1975 > A549 > H838 cells, indicating specificity. Enhanced anticancer effects were observed when the extract was combined with afatinib, suggesting synergistic interactions. Flow cytometry indicated that N. miranda leaf extract could induce G2 cell cycle arrest in H1975 cells, potentially inhibiting cancer cell proliferation. Gas chromatography-mass spectrometry (GC-MS) enabled the tentative identification of the 19 most abundant compounds in the leaf extract of N. miranda. These outcomes underscore the dual utility of N. miranda leaf extract in potentially managing SARS-CoV-2 infection through Nsp9 inhibition and offering anticancer benefits against lung carcinoma. These results significantly broaden the potential medical applications of N. miranda leaf extract, suggesting its use not only in traditional remedies but also as a prospective treatment for pulmonary diseases. Overall, our findings position the leaf extract of N. miranda as a promising source of natural compounds for anticancer therapeutics and antiviral therapies, warranting further investigation into its molecular mechanisms and potential clinical applications.

Structural variety and pharmacological potential of naphthylisoquinoline alkaloids

Naphthylisoquinoline alkaloids are a fascinating class of natural biaryl compounds. They show characteristic mono- and dimeric scaffolds, with chiral axes and stereogenic centers. Since the appearance of the last comprehensive overview on these secondary plant metabolites in this series in 1995, the number of discovered representatives has tremendously increased to more than 280 examples known today. Many novel-type compounds have meanwhile been discovered, among them naphthylisoquinoline-related follow-up products like e.g., the first seco-type (i.e., ring-opened) and ring-contracted analogues. As highlighted in this review, the knowledge on the broad structural chemodiversity of naphthylisoquinoline alkaloids has been decisively driven forward by extensive phytochemical studies on the metabolite pattern of Ancistrocladus abbreviatus from Coastal West Africa, which is a particularly "creative" plant. These investigations furnished a considerable number of more than 80-mostly new-natural products from this single species, with promising antiplasmodial activities and with pronounced cytotoxic effects against human leukemia, pancreatic, cervical, and breast cancer cells. Another unique feature of naphthylisoquinoline alkaloids is their unprecedented biosynthetic origin from polyketidic precursors and not, as usual for isoquinoline alkaloids, from aromatic amino acids-a striking example of biosynthetic convergence in nature. Furthermore, remarkable botanical results are presented on the natural producers of naphthylisoquinoline alkaloids, the paleotropical Dioncophyllaceae and Ancistrocladaceae lianas, including first investigations on the chemoecological role of these plant metabolites and their storage and accumulation in particular plant organs.

Unlocking the potential of 1,4-naphthoquinones: A comprehensive review of their anticancer properties

Cancer encompasses a group of pathologies with common characteristics, high incidence, and prevalence in all countries. Although there are treatments available for this disease, they are not always effective or safe, often failing to achieve the desired results. This is why it is necessary to continue the search for new therapies. One of the strategies for obtaining new antitumor drugs is the use of 1,4-naphthoquinone as a scaffold in synthetic or natural products with antitumor activity. This review focuses on compiling studies related to the antitumor activity of 1,4-naphthoquinone and its natural and synthetic derivatives over the last 10 years. The work describes the main natural naphthoquinones with antitumor activity and classifies the synthetic naphthoquinones based on the structural modifications made to the scaffold. Additionally, the formation of metal complexes using naphthoquinones as a ligand is considered. After a thorough review, 197 synthetic compounds with potent biological activity against cancer have been classified according to their chemical structures and their mechanisms of action have been described.