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Seven phenolic compounds, <b>1</b> - <b>7</b>, including a new organic acid gallate, mucic acid 1-ethyl 6-methyl ester 2-<i>O</i>-gallate (<b>7</b>), were isolated from the MeOH extract of the fruits of <i>Phyllanthus emblica</i> L. (Euphorbiaceae). The structures were elucidated on the basis of extensive spectroscopic analysis and comparison with literature data. Upon evaluated for their antioxidant abilities by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), and ferric reducing antioxidant power (FRAP) assays. The inhibitory activities against melanogenesis in B16 melanoma cells induced by <i>α</i>-MSH, as well as cytotoxic activities against four human cancer cell lines were also evaluated. All phenolic compounds, <b>1</b> - <b>7</b>, exhibited potent antioxidant abilities (DPPH:<i> IC</i><sub>50</sub> 5.6 - 12.9 μm; ABTS: 0.87 - 8.43 μm <i>Trolox</i>/μm; FRAP: 1.01 - 5.79 μm Fe<sup>2+</sup>/μm, respectively). Besides, <b>5</b> - <b>7</b>, also exhibited moderate inhibitory activities against melanogenesis (80.7 - 86.8% melanin content), even with no or low toxicity to the cells (93.5 - 101.6% cell viability) at a high concentration of 100 μm. Compounds <b>1</b> - <b>3</b> exhibited cytotoxic activity against one or more cell lines (<i>IC</i><sub>50</sub> 13.9 - 68.4%), and compound <b>1</b> with high tumor selectivity for A549 (<i>SI</i> 3.2).
Meconopsis horridula Hook.f. Thoms has been used as a traditional Tibetan medicine to clear away heat, relieve pain, and mobilize static blood. In this study, a reliable method based on high-performance liquid chromatography with diode array detection and electrospray ionization quadrupole time-of-flight tandem mass spectrometry was established for the identification of components in this herb. A total of 40 compounds (including 17 flavonoids, 15 alkaloids, and eight phenylpropanoids) were identified or tentatively identified. Among them, 17 components were identified in the herb for the first time. Compound 39 appears to be a novel compound, which is confirmed as 3-(kaempferol-8-yl)-2,3-epoxyflavanone by NMR spectroscopy and mass spectrometry. Moreover, seven major constituents were simultaneously quantified by the developed high-performance liquid chromatography with tandem triple-quadrupole mass spectrometry method. The quantitative method was validated and quality parameters were established. The study provides a comprehensive approach for understanding this herbal medicine.