Aspulvinone O is a fungal metabolite that has been found in P. variotti and has antioxidant and anticancer activities.1,2 It scavenges 2,2-diphenyl-1-picrylhydrazyl radicals in a cell-free assay (IC50 = 11.6 μM).1 Aspulvinone O inhibits aspartate transaminase 1 (GOT1; Kd = 3.32 μM) and is cytotoxic to PANC-1, AsPC-1, and SW1990 pancreatic cancer cells (IC50s = 20.54-26.8 μM).2 It reduces the oxygen consumption rate (OCR) and induces apoptosis in SW1990 cells. Aspulvinone O (2.5 and 5 mg kg) reduces tumor growth in an SW1990 mouse xenograft model. |1. Zhang, P., Li, X.-M., Wang, J.-N., et al. New butenolide derivatives from the marine-derived fungus Paecilomyces variotii with DPPH radical scavenging activity. Phytochem. Lett. 11, 85-88 (2015).|2. Sun, W., Luan, S., Qi, C., et al. Aspulvinone O, a natural inhibitor of GOT1 suppresses pancreatic ductal adenocarcinoma cells growth by interfering glutamine metabolism. Cell Commun. Signal. 17(1), 111 (2019).
Paclitaxel octadecanedioate is a prodrug form of paclitaxel that is comprised of paclitaxel conjugated to 1,18-octadecanedioic acid.1 Unlike paclitaxel, it does not promote tubulin polymerization in vitro when used at a concentration of 10 μM. A 5:1 mixture of paclitaxel octadecanedioate:human serum albumin (HSA) is cytotoxic to HT-1080, PANC-1, and HT-29 cells (IC50s = 12, 2.48, and 8.62 nM, respectively). This mixture reduces tumor growth and increases survival in an HT-1080 mouse xenograft model in a dose-dependent manner. |1. Callmann, C.E., Leguyader, C.L.M., Burton, S.T., et al. Antitumor activity of 1,18-octadecanedioic acid-paclitaxel complexed with human serum albumin. J. Am. Chem. Soc. 141(30), 11765-11769 (2019).
PRLX-93936 is an analog of erastin that has antitumor activity. It inhibits the hypoxia-inducible factor 1 (HIF-1) signaling pathway under hypoxic conditions (IC50 = 0.09 μM in a cell-based reporter assay). PRLX-93936 (1 μM) also inhibits hypoxia-induced increases in HIF-1α expression in ME-180 cervical cancer cells. It inhibits the growth of HT-1080 fibrosarcoma, OVCAR-5 ovarian cancer, BJELR tumorigenic primary fibroblast, and PANC-1pancreatic cancer cells with IC50 values of less than 100 nM. PRLX-93936 inhibits tumor growth in PANC-1 and HT-1080 xenograft models when administered at a dose of 50 mg/kg and induces tumor regression when administered at a dose of 100 mg/kg.