Nuciferine (batch number 141113, purity > 98%) and Rhodamine 6G(Rh6G, batch number 160713, purity > 95%) were purchasedfrom Weikeqi Biotechnology Co., Ltd. (Sichuan, China). Quercetin(batch number H-009-170,426, purity > 98%), rutin (batch numberL-001-160,520, purity > 98%) and kaempferol (batch numberS-014-160,708, purity > 98%) were bought from Chengdu HerbpurifyCo., Ltd. (Sichuan, China).

Nuciferine (chemical structure is presented in Fig. S1A?), with a purity of more than 98%, was purchased from Weikeqi Biological Technology Co. Ltd (Chengdu, China), and its structure was identified by 1H-NMR (Fig. S1B?) and 13C-NMR (Fig. S1C?) spectroscopy.

Five standard compounds, including rutin, quercetin, kaempferol, caffeic acid, and luteolin 7-glucoside, were purchased from the China National Institutes for Food and Drug Control. Six standard compounds, including isoquercitrin, isorhamnetin, catechin, epicatechin, nuciferine, and chlorogenic acid, were purchased from Sichuan Weikeqi Biological Technology Co., Ltd. (Sichuan, China). The purity of all the regents was HPLC ≥ 98%.

Nuciferine (C19H21NO2; molecular weight, 295.38 Da; purity ≥ 98%) was purchased from Sichuan Weikeqi Biological Technology Co., Ltd. (Sichuan, China). HFD (17.7% sucrose, 17.7% fructose, 19.4% protein, and 40% fat) was obtained from Beijing Huafukang Bioscience Co., Ltd. (Beijing, China).

NF (98.0%, Fig. 1) was purchased from Weikeqi Biological TechnologyCo. Ltd. (Chengdu, Sichuan province, China).N-Nornuciferine(N-NF, 97.8%) and 2-hydroxy-1-methoxyaporphine (HMA, 98.3%)were isolated from lotus leaves