Four limonoids, 1 - 4, five alkaloids, 5 - 9, and four phenolic compounds, 10 - 13, were isolated from a MeOH extract of the bark of Phellodendron amurense (Rutaceae). Among these, compound 13 was new, and its structure was established as rel-(1R,2R,3R)-5-hydroxy-3-(4-hydroxy-3-methoxyphenyl)-6-methoxy-1-(methoxycarbonylmethyl)indane-2-carboxylic acid methyl ester (γ-di(methyl ferulate)) based on the spectrometric analysis. Upon evaluation of compounds 1 - 13 against the melanogenesis in the B16 melanoma cells induced with α-melanocyte-stimulating hormone (α-MSH), four compounds, limonin (1), noroxyhydrastinine (6), haplopine (7), and 4-methoxy-1-methylquinolin-2(1H)-one (8), exhibited potent melanogenesis-inhibitory activities with almost no toxicity to the cells. Western blot analysis revealed that compound 6 inhibited melanogenesis, at least in part, by inhibiting the expression of protein levels of tyrosinase, TRP-1, and TRP-2 in α-MSH-stimulated B16 melanoma cells. In addition, when compounds 1 - 13 were evaluated for their cytotoxic activities against leukemia (HL60), lung (A549), duodenum (AZ521), and breast (SK-BR-3) cancer cell lines, five compounds, berberine (5), 8, canthin-6-one (9), α-di-(methyl ferulate) (12), and 13, exhibited cytotoxicities against one or more cancer cell lines with IC values in the range of 2.6 - 90.0 μm. In particular, compound 5 exhibited strong cytotoxicity against AZ521 (IC 2.6 μm) which was superior to that of the reference cisplatin (IC 9.5 μm).
Nine cyclic diarylheptanoids, 1-9, including two new compounds, i.e., 9-oxoacerogenin A (8) and 9-O-β-D-glucopyranosylacerogenin K (9), along with three acyclic diarylheptanoids, 10-12, and four phenolic compounds, 13-16, were isolated from a MeOH extract of the bark of Acer nikoense (Aceraceae). Acid hydrolysis of 9 yielded acerogenin K (17) and D-glucose. Two of the cyclic diarylheptanoids, acerogenin A (1) and (R)-acerogenin B (5), were converted to their ether and ester derivatives, 18-24 and 27-33, respectively, and to the dehydrated derivatives, 25, 26, 34, and 35. Upon evaluation of compounds 1-16 and 18-35 for their inhibitory activities against melanogenesis in B16 melanoma cells, induced with α-melanocyte-stimulating hormone (α-MSH), eight natural glycosides, i.e., six diarylheptanoid glycosides, 2-4, 6, 9, and 12, and two phenolic glycosides, 15 and 16, exhibited inhibitory activities with 24-61% reduction of melanin content at 100 μM concentration with no or almost no toxicity to the cells (88-106% of cell viability at 100 μM). In addition, when compounds 1-16 and 18-35 were evaluated for cytotoxic activity against human cancer cell lines, two natural acyclic diarylheptanoids, 10 and 11, ten ether and ester derivatives, 18-22 and 27-31, and two dehydrated derivatives, 34 and 35, exhibited potent cytotoxicities against HL60 human leukemia cell line (IC(50) 8.1-19.3 μM), and five compounds, 10, 11, 20, 29, and 30, against CRL1579 human melanoma cell line (IC(50) 10.1-18.4 μM).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.