Liquid chromatography with mass spectrometry and NMR spectroscopy based discovery of cytotoxic principles from Daphne tangutica Maxim

Isolation and characterisation of secondary metabolites from Trifolium vesiculosum Savi and their antiproliferative activities

One unreported flavonol namely morin-7-O-methyl ether (1) along with seven known compounds were isolated from the aerial parts of Trifolium vesiculosum Savi which were elucidated by using extensive spectroscopic methods such as 1D and 2D NMR and HR-MS. According to the cell viability assay (MTS) on the purified compounds (1-8), quercetin-3-O-(6''-trans-p-coumaroyl)-β-galactoside (4) revealed remarkable antiproliferative activity most particularly against breast cancer cells (IC50  = 2.90 ± 0.25 µM in HCC1937 and 7.98 ± 0.57 µM in MCF7) while moderate inhibitory activity (IC50  = 17.96 ± 0.51-51.70 ± 2.69 µM) on prostate, colorectal and liver cancer cell viability was observed. Further mechanistic examinations (Annexin V/PI staining, DNA content and detection of reactive oxygen species analyses) showed that compound 4 significantly induced apoptosis, enhanced mitochondrial reactive oxygen species (ROS) accumulation, and caused cell cycle arrest in cancer cells by increasing accumulation of cells at G0/G1 and/or G2/M phases of the cell cycle.

Guide isolation of guaiane-type sesquiterpenoids from Daphne tangutica maxim. And their anti-inflammatory activities

Using liquid chromatography with tandem mass spectrometry guided molecular networking, 12 undescribed guaiane-type sesquiterpenoids, namely tanguticatins A-L, 19 known analogs and a previously undescribed triterpene (tanguticatin M) were obtained from Daphne tangutica Maxim and characterized. Their planar structures and configurations were elucidated and unequivocally assigned by detailed spectroscopic analyses, electronic circular dichroism spectral calculations and single single-crustal X-ray diffraction analysis. All the isolated compounds were evaluated for lipopolysaccharide-induced nitric oxide production in murine microglial BV2 cells. Tanguticatin E and K exhibited more potent inhibitory effects than minocycline (positive control).

Target isolation of cytotoxic diterpenoid esters and orthoesters from Daphne tangutica maxim based on molecular networking

Guiding by LC-MS/MS analysis and the GNPS Molecular Networking, five undescribed daphnane diterpenoids, tanguticanines A-E, and eleven known analogues were discovered from the whole plants of Daphne tangutica Maxim. Their structures and absolute configurations were determined via extensive NMR spectroscopic analysis, ECD calculations, and X-ray diffraction crystallography. Tanguticanine E (5) exhibited promising cytotoxicity against the HepG2 cell line with an IC₅₀ value of 9.93 ± 0.10 μM. Further flow cytometry experiment was performed to detect cell apoptosis, and the results indicated that cytotoxic diterpenoids (tanguticanines B, D and E, altadaphnan C, gniditrin, hirsein A and simplexin) exert their effects through induction of apoptosis.

Implementation of design of experiments for optimization of forced degradation conditions and development of a stability-indicating high-performance liquid chromatography method for sepiwhite

Sepiwhite is a novel anti-pigmenting agent that is derived from fatty acid and phenylalanine and used for hyperpigmentation induced by light exposure or inflammation. In this study, a simple and validated high-performance liquid chromatography method for the quantitation of sepiwhite was developed. Optimized forced degradation of sepiwhite at thermal, acid/base, photolysis, oxidative, and heavy metal ions conditions were evaluated and the effect of each of them on production of specific 10%-30% degradants was studied by the approach of design of experiments. Sepiwhite accelerated study was conducted and toxicity of sepiwhite at each condition was tested. An optimized high-performance liquid chromatography method was validated by a face-centered central composition design. Ten different degradants were identified from sepiwhite and degradation behavior under different conditions was studied. Sepiwhite and its degradant products show no cytotoxicity. This optimized high-performance liquid chromatography method can be applied for quality control assay and sepiwhite degradation behavior may be considered in the manufacturing of sepiwhite products.

Effects of an ethyl acetate extract of Daphne altaica stem bark on the cell cycle, apoptosis and expression of PPARγ in Eca‑109 human esophageal carcinoma cells

Daphne altaica Pall. (D. altaica; Thymelaeaceae) has long been used in traditional Kazakh medicine for the treatment of cancer and respiratory diseases. Previous studies have demonstrated the in vitro anticancer effects of D. altaica extract and its constituents in certain cancer cell lines; however, the underlying molecular mechanisms are not completely understooD. The present study aimed to investigate the molecular mechanisms underlying the activity of an ethyl acetate extract of D. altaica (Da‑Ea) by assessing its effects on cell morphology, cell apoptosis, cell cycle progression and the expression levels of peroxisome proliferator‑activated receptor γ (PPARγ) in Eca‑109 cells. Cell morphology was observed under a phase contrast microscope. Cell apoptosis and cell cycle progression were assessed by flow cytometry following Annexin V/propidium iodide (PI) double staining and PI single staining, respectively. The mRNA and protein expression levels of PPARγ were determined by reverse transcription‑quantitative PCR and western blotting, respectively. Compared with the control group, the percentage of apoptotic cells, cell cycle arrest at S phase and apoptotic morphological cell characteristics were increased in Da‑Ea‑treated Eca‑109 cells. Furthermore, Da‑Ea treatment upregulated the mRNA and protein expression levels of PPARγ compared with the control cells. High‑performance liquid chromatography with diode‑array detection indicated that daphnetin‑7‑O‑β‑D‑glucoside, daphnetin, demethyldaphnoretin‑7‑O‑β‑D‑glucopyranoside and genkwanol A were the main constituents of Da‑Ea. Collectively, the results suggested that Da‑Ea displayed antiproliferative activities in Eca‑109 cells by inducing apoptosis and S phase cell cycle arrest, as well as upregulating PPARγ expression levels.