Effects of 2-aryl-1-cyano-1,2,3,4-tetrohydroisoquinolines on apoptosis induction mechanism in NB4 and MKN-45 cells

The Antiproliferative and Apoptosis-Inducing Effects of the Red Macroalgae Gelidium latifolium Extract against Melanoma Cells

The red macroalga Gelidium latifolium is widely distributed in the coastal areas of Indonesia. However, current knowledge on its potential biological activities is still limited. In this study, we investigated the potential bioactive compounds in Gelidium latifolium ethanol extract (GLE), and its cytotoxic effects against the murine B16-F10 melanoma cell line. GLE shows high total phenolic content (107.06 ± 17.42 mg GAE/g) and total flavonoid content (151.77 ± 3.45 mg QE/g), which potentially contribute to its potential antioxidant activity (DPPH = 650.42 ± 2.01 µg/mL; ABTS = 557.01 ± 1.94 µg/mL). ESI-HR-TOF-MS analysis revealed large absorption in the [M-H]^- of 327.2339 m/z, corresponding to the monoisotopic molecular mass of brassicolene. The presence of this compound potentially contributes to GLE's cytotoxic activity (IC₅₀ = 84.29 ± 1.93 µg/mL). Furthermore, GLE significantly increased the number of apoptotic cells (66.83 ± 3.06%) compared to controls (18.83 ± 3.76%). Apoptosis was also confirmed by changes in the expression levels of apoptosis-related genes (i.e., p53, Bax, Bak, and Bcl2). Downregulated expression of Bcl2 indicates an intrinsic apoptotic pathway. Current results suggest that components of Gelidium latifolium should be further investigated as possible sources of novel antitumor drugs.

Simple Analogues of Quaternary Benzo[c]phenanthridine Alkaloids: Discovery of a Novel Antifungal 2-Phenylphthalazin-2-ium Scaffold with Excellent Potency against Phytopathogenic Fungi

Inspired by sanguinarine and chelerythrine, a novel antifungal 2-phenylphthalazin-2-ium scaffold as a simple analogue was designed. Most of the 30 compounds showed excellent inhibition activity against almost all eight phytopathogenic fungi, far superior to sanguinarine and chelerythrine. A third of the compounds were more active than azoxystrobin in most cases. Compounds 26 and 27 showed the highest total activity against all the fungi with EC₅₀ means of ca. 4.6 μg/mL. Fusarium solani showed the highest susceptibility with an EC₅₀ mean of 3.62 μg/mL to 19 compounds. A concentration of 25.0 μg/mL 27 can fully control the Colletotrichum gloeosporioides infection in apples over 9 days. Electron microscopic observations showed that 27 was able to damage the structures of the hypha and cell membrane. The structure-activity relationship showed that the presence of electron-withdrawing groups on the C-ring increases the activity against most of the fungi. Thus, 2-phenylphthalazin-2-ium compounds represent promising leads for the development of novel fungicides.