Five new compounds (1-5), including two secolignans, two tetrahydrofuran lignans, and one highly methoxylated dihydronaphthalenone, were isolated from the whole plant of Peperomia pellucida. These compounds were accompanied by the known peperomins A, B, C, and E, 7,8-trans-8,8'-trans-7',8'-cis-7,7'-bis(5-methoxy-3,4-methylenedioxyphenyl)-8-acetoxymethyl-8'-hydroxymethyltetrahydrofuran, 7,8-trans-8,8'-trans-7',8'-cis-7-(5-methoxy-3,4-methylenedioxyphenyl)-7'-(4-hydroxy-3,5-dimethoxyphenyl)-8,8'-diacetoxymethyltetrahydrofuran, sesamin, and isoswertisin. New structures were elucidated mainly by NMR and MS techniques, and anticancer activities evaluated in HL-60, MCF-7, and HeLa cell lines. Compound 1 and peperomin E show growth inhibitory effects on the three cancer cell lines with IC(50) values ranging between 1.4 and 9.1 and between 1.8 and 11.1 microM, respectively. Compound 2 has a weak suppressive activity on HL-60 cells (IC(50) = 10.8 microM), while 7,8-trans-8,8'-trans-7',8'-cis-7,7'-bis(5-methoxy-3,4-methylenedioxyphenyl)-8-acetoxymethyl-8'-hydroxymethyltetrahydrofuran exhibits estrogen-like properties (EC(50) = 3.1 microM) in CV-1 cells transfected with human estrogen receptor (ERalpha).

Ischemic retinopathy and age-related macular degeneration are the leading ocular diseases that cause blindness. The etiology of these diseases is due in part to the reduction of blood flow in the retina and/or choroid. Crocin analogs isolated from Crocus sativus L. were found to significantly increase the blood flow in the retina and choroid and to facilitate retinal function recovery. Increased blood flow due to vasodilation presumably improves oxygenation and nutrient supply of retinal structures. These results indicated that crocin analogs could be used to treat ischemic retinopathy and/or age-related macular degeneration. It was noted that disaccharide analogs of crocin, such as crocin-1 and crocin-2, were less potent than monosaccharide analogs of crocin, such as crocin-3 and crocin-4, constituting an interesting structure-activity relationship.

Flavonoid represents a significant class of secondary metabolites in Pu-erh tea with benefits to human health. For a rapid and complete discovery of such compounds, we established a data mining workflow that integrates software MS-DIAL, MS-FINDER, and molecular networking analysis. As a result, 181 flavonoids were tentatively annotated including 22 first found in Puerh tea, and two of them were potentially new molecules. The dynamic alteration of these flavonoids during Pu-erh fermentation was further investigated. They all showed a trend of first increasing and then decreasing. Moreover, statistical analysis showed that the first to third pile turnings of the fermentation process had a greater impact on the changes of flavonoids. Partial metabolic pathways were proposed. This study provides a quick and automatic strategy for flavonoid profiling. The temporal dimension of flavonoids during fermentation may serve as a theoretical basis for Pu-erh tea manufacturing technology and study on substance foundation.

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Covalent modification of proteins by reactive pollutants/metabolites might trigger various toxicities resulting from the disruption of protein structures and/or functions, which is critical for understanding the mechanism of pollutants-induced toxicity. However, this mechanism has rarely been touched on due to the lack of a methodology. In this research, the protein modification of bisphenol A (BPA) in rats was characterized using a series of liquid chromatography–tandem mass spectrometry (LC–MS) approaches. BPA-modified cysteine (Cys1) was first released from proteins via enzymatic hydrolysis and identified using LC–MS. Moreover, the positive correlation between Cys1 and hepatotoxicity indicated the involvement of protein modification in BPA toxicity. Then, in vitro incubation of BPA with amino acids and protein confirmed that BPA could specifically modify cysteine residues of proteins after bioactivation and provided four additional modification patterns. Finally, 24 BPA-modified proteins were identified from the liver of BPA-exposed rats using proteomic analysis, and they were mainly enriched in oxidative stress-related pathways. The modification on superoxide dismutases, catalase, and glutathione S-transferases disrupted their enzymatic functions, leading to oxidative damage. These results revealed that the covalent protein modification is an unignorable factor for BPA hepatotoxicity. Moreover, the workflow can be applied to identify protein adducts of other emerging contaminants and possible risk.

Two new oleanane-type triterpene saponins named pedunsaponins B (2) and C (3) were isolated from the roots of Pueraria peduncularis. Their structures were determined to be 3-O-(6-O-methyl)-beta-glucuronopyranosyl-3beta,15alpha-dihydroxyolean-12-en-16-one (2), and 3-O-beta-glucopyranosyl-(1 --> 3)-beta-glucuronopyranosyl-3beta,15alpha-dihydroxyoleana-12-en-16-one (3), on the basis of spectroscopic evidence.

Branched fatty acid ester of hydroxy fatty acid (FAHFA) is a class of natural lipid with important biological functions. In this study, we first profiled natural-origin FAHFAs in different teas using the chemical labeling-assisted liquid chromatography-mass spectrometry method. Consequently, we observed rich molecular diversity of FAHFAs with multiple regioisomers in teas. Additionally, the FAHFA contents had a positive relationship with the tea fermentation degree and a negative relationship with homologous fatty acids. Moreover, the highly accumulated FAHFAs (e.g., 3-MAHMA) in some postfermented teas (e.g., Fu brick tea) were also basically interpreted with regiospecificity of FAHFAs in both teas and fungus. This study revealed that tea is a rich natural source of FAHFAs, and some abundant FAHFAs might be the functional molecules accounting for the antidiabetic function of teas.

A new lignan glycoside was isolated from the n-BuOH extract of Peperomia duclouxii C. DC., and its structure was elucidated to be 2-(4''-hydroxy-3'', 5''-dimethoxybenzyl)-3-(5'-methoxy-3', 4'-methylenedioxybenzyl)butyrolactone-4''-O-beta-D-glucopyranoside (1) by spectral methods.