Petroleum ether

The 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,4,6-Tris(2-pyridyl)-s-triazine (TPTZ), 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH), fluorescein sodium, acetylthiocholine iodide, vitamin C (Vc), and 2,6-di-tert-butyl-4-methylphenol (BHT) were obtained from Aladdin Biotechnology (analytical grade, China). Other analytical grade chemicals, including methanol, petroleum ether, ethyl acetate, and n-butanol were purchased from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China).
Chromatographic acetonitrile was purchased from Merck (Darmstadt, Germany). α-glucosidase (from saccharomyces cerevisiae), xanthine oxidase (XO), acetylcholinesterase (AChE), acarbose, galantamine (GALM), allopurinol, 4-methylumbelliferyl-β-D glucuronide (4-MUG), 5,5′-dithiobis (2-nitrobenzoic acid) (DTNB), and acetylthiocholine iodide (ATCI) were purchased from Sigma-Aldrich (St. Louis, MO, USA).

Standards of rutin, gallic acid, hyperoside, kaempferol-3-O-glucoside, quercetin-3-O-hexoside, luteolin-7-O-glucoside, 3-caffeoylquinic acid (3-CQA), 3,4-dicaffeoylquinic acid (3,4-diCQA), 3,5-dicaffeoylquinic acid (3,5-diCQA), 4,5-dicaffeoylquinic acid (4,5-diCQA), and 3,4,5-tricaffeoylquinic acid were purchased from Yuanye Biotechnology Co., Ltd. (Shanghai, China). Folin–Ciocalteu reagent, 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and 2,4,6-tris (2-pyridyl)-s-triazine (TPTZ) were purchased from Sigma–Aldrich (Shanghai, China). HPLC-grade mEthanol was purchased from Merck (Darmstadt, Germany). All other analytical-grade chemicals and reagents used in the study: Ethanol, petroleum ether, ethyl acetate, acetone, ether, chloroform, n-butanol, mEthanol, formic acid, phenol, sulfuric acid, sodium nitrite (NaNO₂), aluminum nitrate (Al(NO₃)₃·9H₂O), sodium hydroxide (NaOH), sodium carbonate, 3,5-dinitrosalicylic acid (DNS), and ferric chloride were purchased from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China).

The HPLC grade methanol, acetonitrile, and water (Optima™ LC/MS grade) were purchased from Fisher Chemical, United States of America. Formic acid (HPLC grade) was purchased from CNW, Germany. 2-propanol (HPLC grade) was purchased from Merck (Darmstadt, Germany). MTBE (HPLC grade) was purchased from Adamas-beta. Ammonium acetate (HPLC grade) was purchased from Sigma-Aldrich (St. Louis, MO, United States). Petroleum ether, dichloromethane, ethyl acetate, n-butanol (analytical grade) were purchased from Sinopharm Chemical Reagent Co., Ltd (Shanghai, China). Ultrapure water was prepared using a Milli-Q water purification system (Millipore Corp. Billerica, MA, United States). Analytical grade ethanol and methanol were purchased from Beijing Chemical Works (Beijing, China).

Chemicals obtained commercially were used as received. Nuclear magnetic resonance (NMR) spectra were recorded on a Bruker DPX-400 spectrometer (Bruker Co., Billerica, MA, USA) using residue of the deuterated solvent or tetramethylsilane (TMS) as the internal standard (Cambridge Isotope Lab. Inc., Tewksbury, MA, USA). For copies of ¹H and ¹³C-NMR spectra of the products, please see Supplementary Materials. All products were isolated by flash chromatography using petroleum ether (Sinopharm Chemical Reagent Co. Ltd., Shanghai, China) (60–90 °C)/ethyl acetate (Sinopharm Chemical Reagent Co. Ltd., Shanghai, China) as eluents. Triethylborane (1 M in THF), tributylborane, 9-BBN (1 M in THF) and BH₃ (1 M in THF) were purchased from J&K chemicals (Beijing, China). Amides [3 (link)], PEPPSI catalyst [30 (link)], 1,3-bis(2,6-diisopropylphenyl)imidazolium chloride (IPr-HCl) [32 (link)], palladacycle (IPr) [33 (link)], and tri(n-octyl)borane [36 (link)] were prepared according to the procedures reported previously. Solvents, methyl tert-butyl ether (MTBE), tetrahydrofuran (THF), and dioxane were dried over sodium while acetonitrile was distilled over CaH₂ prior to use.

Black maca was purchased from a farm in Yunnan Province of New Era Health Industry (Group) Co., Ltd. Phosphate‐buffered saline (PBS), Hank's balanced salt solution (HBSS), bovine serum, Dulbecco's modified Eagle's medium (DMEM), and glucose‐free DMEM were purchased from Gibco Life Technologies; oleic acid (OA), palmitic acid (PA), 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH, 90%), dimethyl sulfoxide (DMSO), 3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5‐diphenylterazolium bromide (MTT), oil red O staining agent, trypsin, rutin standard, and macaamide standard were purchased from Sigma; fatty acid‐free bovine serum albumin (BSA) was provided by WAKO; RIPA lysate and TG, glucose assay and glycogen assay kits were procured from Nanjing Jiancheng Bioengineering Institute; and ethanol, petroleum ether, ethyl acetate, and n‐butanol were purchased from Sinopharm Chemical Reagent Co., Ltd. All other chemicals and solvents, all of which were of analytical grade, were obtained from China.