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Withania somnifera (Solanaceae), commonly known as “ashwagandha”, is an ayurvedic medicinal plant that has been used for promoting good health and longevity. As part of our ongoing natural product research for the discovery of bioactive phytochemicals with novel structures, we conducted a phytochemical analysis of W. somnifera root, commonly used as an herbal medicine part. The phytochemical investigation aided by liquid chromatography-mass spectrometry (LC/MS)-based analysis led to the isolation of four withanolide glycosides (1–4), including one new compound, withanoside XII (1), from the methanol (MeOH) extract of W. somnifera root. The structure of the new compound was determined by nuclear magnetic resonance (NMR) spectroscopic data, high-resolution (HR) electrospray ionization (ESI) mass spectroscopy (MS), and electronic circular dichroism (ECD) data as well as enzymatic hydrolysis followed by LC/MS analysis. In addition, enzymatic hydrolysis of 1 afforded an aglycone (1a) of 1, which was identified as a new compound, withanoside XIIa (1a), by the interpretation of NMR spectroscopic data, HR-ESIMS, and ECD data. To the best of our knowledge, the structure of compound 2 (withagenin A diglucoside) was previously proposed by HRMS and MS/MS spectral data, without NMR experiment, and the physical and spectroscopic data of withagenin A diglucoside (2) are reported in this study for the first time. All the isolated compounds were evaluated for their anti-Helicobacter pylori, anti-oxidant, and anti-inflammatory activities. In the anti-Helicobacter pylori activity assay, compound 2 showed weak anti-H. pylori activity with 7.8% inhibition. All the isolated compounds showed significant ABTS radical scavenging activity. However, all isolates failed to show inhibitory activity against nitric oxide (NO) production in lipopolysaccharide-stimulated RAW 264.7 macrophage cells. This study demonstrated the experimental support that the W. somnifera root is rich in withanolides, and it can be a valuable natural resource for bioactive withanolides.

Withania somnifera (Solanaceae), well-known as ‘Indian ginseng’ or ‘Ashwagandha’, is a medicinal plant that is used in Ayurvedic practice to promote good health and longevity. As part of an ongoing investigation for bioactive natural products with novel structures, we performed a phytochemical examination of the roots of W. somnifera employed with liquid chromatography–mass spectrometry (LC/MS)-based analysis. The chemical analysis of the methanol extract of W. somnifera roots using repeated column chromatography and high-performance liquid chromatography under the guidance of an LC/MS-based analysis resulted in a new withanolide, withasomniferol D (1). The structure of the newly isolated compound was elucidated by spectroscopic methods, including one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR) and high-resolution (HR) electrospray ionization (ESI) mass spectroscopy, and its absolute configuration was established by electronic circular dichroism (ECD) calculations. The anti-adipogenic activities of withasomniferol D (1) were evaluated using 3T3-L1 preadipocytes with Oil Red O staining and quantitative real-time polymerase chain reaction (qPCR). We found that withasomniferol D (1) inhibited adipogenesis and suppressed the enlargement of lipid droplets compared to the control. Additionally, the mRNA expression levels of adipocyte markers Fabp4 and Adipsin decreased noticeably following treatment with 25 μM of withasomniferol D (1). Taken together, these findings provide experimental evidence that withasomniferol D (1), isolated from W. somnifera, exhibits anti-adipogenic activity, supporting the potential application of this compound in the treatment of obesity and related metabolic diseases.

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The global incidence of breast cancer has increased. However, there are many impediments to the development of safe and effective anticancer drugs. The aim of the present study was to evaluate the effect of aviculin isolated from Lespedeza cuneata (Dum. Cours.) G. Don. (Fabaceae) on MCF-7 human breast cancer cells and determine the underlying mechanism. Using the bioassay-guided isolation by water soluble tetrazolium salt (WST-1)-based Ez-Cytox assay, nine compounds (four lignan glycosides (1–4), three flavonoid glycosides (5–7), and two phenolic compounds (8 and 9)) were isolated from the ethyl acetate (EA) fraction of the L. cuneata methanolic extract. Of these, aviculin (2), a lignan glycoside, was the only compound that reduced metabolic activity on MCF-7 cells below 50% (IC50: 75.47 ± 2.23 μM). The underlying mechanism was analyzed using the annexin V Alexa Fluor 488 binding assay and Western blotting. Aviculin (2) was found to induce apoptotic cell death through the intrinsic apoptosis pathway, as indicated by the increased expression of initiator caspase-9, executioner caspase-7, and poly (ADP-ribose) polymerase (PARP). Aviculin (2)-induced apoptotic cell death was accompanied by an increase in the Bax/Bcl-2 ratio. These findings demonstrated that aviculin (2) could induce breast cancer cell apoptosis through the intrinsic apoptosis pathway, and it can therefore be considered an excellent candidate for herbal treatment of breast cancer.

Hepatocellular carcinoma (HCC) is the fastest-growing tumor capable of spreading to other organs via blood vessels formed by endothelial cells. Apoptosis and angiogenesis-targeting therapies are attractive for cancer treatment. In this study, we aimed to study the in vitro cytotoxicity of Withania somnifera against human HCC (HepG2) cells, identify potential antitumoral withanolide glycosides from the active fraction, and elucidate cytotoxic molecular mechanisms of identified bioactive compounds. W. somnifera (Solanaceae), well-known as ‘ashwagandha’, is an Ayurvedic medicinal plant used to promote health and longevity, and the MeOH extract of W. somnifera root exhibited cytotoxicity against HepG2 cells during initial screening. Bioactivity-guided fractionation of the MeOH extract and subsequent phytochemical investigation of the active n-BuOH-soluble fraction resulted in the isolation of five withanolide glycosides (1–5), including one new metabolite, withanoside XIII (1), aided by liquid chromatography–mass spectrometry-based analysis. The new compound structure was determined by 1D and 2D nuclear magnetic resonance spectroscopy, high-resolution electrospray ionization mass spectroscopy, electronic circular dichroism, and enzymatic hydrolysis. In addition, withanoside XIIIa (1a) was identified as the new aglycone (1a) of 1. Isolated withanolide glycosides 1–5 and 1a were cytotoxic toward HepG2 cells; withagenin A diglucoside (WAD) (3) exhibited the most potent cytotoxicity against HepG2 cells, with cell viability less than 50% at 100 μM. WAD cytotoxicity was mediated by both extrinsic and intrinsic apoptosis pathways. Treatment with WAD increased protein expression levels of cleaved caspase-8, cleaved caspase-9, cleaved caspase-3, Bcl-2-associated X protein (Bax), and cleaved poly(ADP-ribose) polymerase (cleaved PARP) but decreased expression levels of B-cell lymphoma 2 (Bcl-2). Moreover, WAD inhibited tubular structure formation in human umbilical vein endothelial cells (HUVECs) by inhibiting the protein expression of vascular endothelial growth factor receptor 2 and its downstream pathways, including extracellular signal-regulated kinase (ERK), phosphoinositide 3-kinase (PI3K), Akt, and mammalian target of rapamycin (mTOR). These effects were also enhanced by co-treatment with ERK and PI3K inhibitors. Overall, these results indicate that WAD (3) induced HepG2 apoptosis and inhibited HUVEC tube formation, suggesting its potential application in treating liver cancers.

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Carthamus tinctorius L. (Compositae; safflower or Hong Hua) has been used in Korean traditional medicine for maintaining the homeostasis of body circulation. Phytochemical investigation was performed on the florets of C. tinctorius by liquid chromatography–mass spectrometry (LC/MS), which afforded two dihydrophaseic acid glucosides (1 and 2). Isolated compounds were structurally confirmed using a combination of spectroscopic methods including 1D and 2D nuclear magnetic resonance and high-resolution electrospray ionization mass spectroscopy. Their absolute configurations were established by quantum chemical electronic circular dichroism calculations and enzymatic hydrolysis. The anti-adipogenesis activity of the isolated compounds was evaluated using 3T3-L1 preadipocytes. Treatment with the dihydrophaseic acid glucoside (1) during adipocyte differentiation prevented the accumulation of lipid droplets and reduced the expression of adipogenic genes, Fabp4 and Adipsin. However, compound 2 did not affect adipogenesis. Our study yielded a dihydrophaseic acid glucoside derived from C. tinctorius, which has potential advantages for treating obesity.