Abietane diterpenes from Abies spectabilis and their anti-pancreatic cancer activity against the MIA PaCa-2 cell line.

An ethanolic extract of the stem of Abies spectabilis exhibited strong cytotoxicity against MIA PaCa-2 human pancreatic cancer cells preferentially under nutrient-deprived conditions. Therefore, phytochemical investigation of this bioactive extract was carried out, and that led the isolation of ten compounds (1-10) including a new abietane-type diterpene (1). The structure of the new compound (1) was elucidated by combined spectroscopic techniques, including HRFABMS, NMR and quantum ECD calculation. All the isolated compounds were evaluated for their efficacy against MIA PaCa-2 human pancreatic cancer cell line by employing an anti-austerity strategy. Among the tested compounds, dehydroabietinol (5) displayed the most potent activity with a PC50 value of 6.6 µM. Dehydroabietinol (5) was also found to retard the MIA PaCa-2 cell migration under normal nutrient-rich conditions displaying its anti-metastatic potential. Investigation on the mechanism suggested that dehydroabietinol (5) is an inhibitor of the key cancer cell survival Akt/mTOR/autophagy signaling pathway.

Chemical constituents of Thai Piper ribesoides and their antiausterity activities against the PANC-1 human pancreatic cancer cell line.

A methanolic extract of Thai Piper ribesoides showed preferential cytotoxicity against PANC-1 human pancreatic cancer cells under a nutrient-deprived condition, with a PC50 value of 24 µg/mL. Phytochemical investigation of this bio-active extract led to the isolation of six compounds (1-6), including two new polyoxygenated cyclohexane derivatives, named ribesoidones A and B (1 and 2). The structural elucidation of the new compounds was achieved by a combination of HREIMS, NMR, and circular dichroism spectroscopic analyses. Isolated compounds were tested for their antiausterity activity against PANC-1 human pancreatic cancer cell line. Among these, compounds 1, 3, and 4 displayed potent preferential cytotoxic activity with PC50 values of 5.5-7.2 µM. Ribesoidone A (1) was also found to inhibit PANC-1 colony formation under normal nutrient-rich conditions.