Tuliposides H-J and Bioactive Components from the Bulb of Amana edulis

Three new tuliposides H-J (1-3) and 11 known compounds were obtained from the methanolic extracts of the bulbs of Amana edulis for the first time. Their structures were elucidated by NMR, MS, and IR spectroscopic data, optical rotation, and Mosher's method. The melanogenesis properties of all the isolates were evaluated in B16 melanoma cells. Consequently, tributyl citrate (9) had anti-melanogenesis activity but was cytotoxic toward B16. (+)-Pyroglutamic acid (4), (+)-butyl 5-oxopyrrolidine-2-carboxylate (6), (-)-3-hydroxy-2-methylbutyrolactone (10), and 5-(hydroxymethyl)furfural (12) had increased melanin productions and tyrosinase activities. Those active components could be further studied as the candidates against melanoma and vitiligo for skin diseases or whitening/hypopigmentation for hair.

Automated summary

Three new tuliposides and 11 known compounds were isolated from the bulbs of Amana edulis for the first time, and their structures were elucidated using various spectroscopic methods. Evaluation in B16 melanoma cells showed certain compounds affecting melanin production and tyrosinase activities, suggesting potential candidates for treating skin diseases.