Cytotoxic alkaloids from the fruit pods of Macleaya microcarpa.

19 compounds, including seven previously undescribed alkaloids ((-)-macleayin K (1), (+)-macleayin K (2), macleayin M (3), macleayin N (4), macleayin L (5), macleayin O (6), oxohydrastinine A (7), one new natural product (8), and 11 known compounds, were isolated from the fruit pods of Macleaya microcarpa. Their structures were defined based on NMR, HRESIMS, and electronic circular dichroism (ECD) data. A network pharmacology approach combined with molecular docking and in vitro validation was performed to determine the bioactivity, key targets of the 19 compounds against breast cancer (BC) and cervical cancer (CC). EGFR and PIK3CA could become potential therapeutic targets based a network pharmacology. Moreover, molecular docking suggested that the 19 compounds combined well with EGFR and PIK3CA, respectively. Their cytotoxicity of selected compounds was tested against the MCF-7 and HeLa cells, and the preliminary structure-activity relationship is discussed. Compounds 1 (IC50: 6.00 µM) and 2 (IC50: 6.82 µM) exhibited strong inhibitory activity against the HeLa cells and are worthy of further study.

Stilbenes with potent cytotoxicity from the seedcases of Paeonia suffruticosa Andrews.

Stilbenes (based on the 1,2-diphenylethylene skeleton) are a class of plant polyphenols with rich structural and bioactive diversity. Twenty-six stilbenes, including five undescribed compounds (7,8-dioxy-4,3',5'-trihydroxystilbene, trans-13'-methoxygnetin H, suffruticosol E, paestibenetrimerols A and B), were isolated from the seedcases of Paeonia suffruticosa Andrews. Their structures were elucidated by spectroscopic analyses and comparison with previously reported data. The absolute configurations of trans-13'-methoxygnetin H, suffruticosol E, paestibenetrimerols A and B were assigned from their respective electronic circular dichroism (ECD) spectra. Additionally, the structures of known compounds suffruticosols A, B and rockiol B were revised and the absolute configurations of them, and along with (+)-davidiol A, were also further determined by ECD. The isolated compounds, trans-gnetin H, cis-gnetin H and suffruticosol E, were found to have potent cytotoxicity against the DU-145 and MDA-MB-231 cell lines with IC50 values of 4.89-8.61 µM. The preliminary antitumor structure-activity relationship of these stilbenes is discussed as well.

Cephalotaxine-type and homoerythrina-type alkaloids with antiproliferative effects from Cephalotaxus fortunei.

Twenty-two cephalotaxine-type and ten homoerythrina-type alkaloids, including seven previously undescribed ones, were isolated from the twigs and leaves and the seed kernels of Cephalotaxus fortunei. Their structures were established by spectroscopic analysis, single crystal X-ray diffraction, and ECD calculation methods. Cephalofortunine A ß-N-oxide (1) is the first nitrogen-oxidized homoerythrina-type alkaloid. The isolated compounds were evaluated for their in vitro antiproliferative effects against two human leukemia cell lines (THP-1 and K562). All compounds showed different levels of antiproliferation in THP-1 and K562 cells with GI50 values of 0.24-29.55 µM. Hainanensine (31) was the most active against two cancer cell lines with GI50 values of 0.24 ± 0.07, and 0.29 ± 0.01 µM, respectively.

Anti-tumor alkaloids from Peganum harmala.

Six alkaloids peharmalines F-K, along with 14 known ones, were isolated from the aerial part of Peganum harmala L.. The structures of the isolated compounds were determined based on their HR-ESI-MS data, extensive NMR spectroscopic analyses, and ECD calculations. 3-(4-Hydroxyphenyl)quinoline exhibited potent antiproliferative activity against the HepG-2 cell lines with an IC50 value of 3.05 µM. Norharmane displayed a moderate inhibition against A549 and HepG-2 cells with IC50 values of 16.45 µM and 17.27 µM, respectively.

Absolute Configurations of 14,15-Hydroxylated Prenylxanthones from a Marine-Derived Aspergillus sp. Fungus by Chiroptical Methods.

Determination of the absolute configrations for natural products is one of the most important and challenging tasks, especially when the molecules display high conformational flexibility. In this paper, eight new prenylxanthones, aspergixanthones A-H (1-8), and one known analogue (9), were isolated from the marine-derived fungus Aspergillus sp. ZA-01. The absolute configurations of C-14 and C-15 in 1-8 were difficult to be assigned due to the high conformational flexibility of the chains. To solve this problem, the experimental ECD, ORD, and VCD spectra of 1 were combined for analysis with the corresponding theoretical predictions for its different diastereomers. This study suggested that a concerted application of more than one chiroptical methods could be used as a preferable approach for the stereochemical characterizations of flexible molecules. Compounds 1-9 were evaluated for their cytotoxic and antibacterial activities. Among them, 6 showed cytotoxicity against the A-549 cell line with the IC50 value of 1.1 µM, and 7 exhibited antibacterial activity against Micrococcus lysodeikticus with the MIC value of 0.78 µg/mL.