N hexane

Sodium chloride, methanol, ethanol, amino acid standards, acetonitrile, phenyl isothiocyanate, gallic acid, triethylamine, n-hexane, boron trifluoride-methanol, dichloromethane, formic acid, diethyl ether, petroleum ether, sodium hydroxide, potassium hydroxide, hydrochloric acid, and perchloric acid were purchased from ANPEL Laboratory Technologies (Shanghai) Inc. Vitamin B1/B2 and vitamin E were purchased from Shanghai Yuanye Bio-Technology Co., Ltd. Folin-Ciocalteu reagent, 2,2-diphenyl-1-picrylhydrazyl (DPPH), mixed standards of fatty acids, cyanidin 3-O-glucoside, anthranone, 1,2,3-trihydroxybenzene, benzoyl-dl-arginine p-nitroanilide hydrochloride, dimethyl sulfoxide, sulfosalicylic acid, trypsin, and phytic acid were purchased from Sigma-Aldrich Chemical Co. (St. Louis, MO, USA). The purity of chemicals used for High-Performance Liquid Chromatography (HPLC) and Gas Chromatography Mass Spectroscopy (GCMS) complied with the requirement of relevant procedures. All other chemicals were of analytical grade.

Eight different organs of pecan, including kernel (without testa), testa, shell, shuck, leaf, branch, bark, and flower (male inflorescence), were collected in October 2018 (except the flower were in May 2019) at the scientific orchards of the Institute of Botany, Jiangsu Province and Chinese Academy of Sciences. Samples were collected from healthy adult trees of cultivar “Pawnee.” Six biological replicates were prepared for each organ, and each biological replicate contained samples from three trees. After transported back to the laboratory, the testa was peeled manually from the surface of kernels and was stored at −70°C, so as samples of other parts. Before use, all samples were powdered and homogenized in liquid nitrogen with mortars and pestles.
Menthol, acetic acid, n‐hexane, acetonitrile (HPLC grade), and formic acid were purchased from ANPEL Laboratory Technologies. Standard reference compounds, including (+)‐catechin, ellagic acid, and quercetin, were purchased from Nanjing Spring & Autumn Biological CO., Ltd.

PBDE standard mixtures (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, BDE-154, BDE-183, BDE-209) and BDE-77, BDE-118, BDE-128, BDE-205, ¹³C-BDE-209 were purchased from Cambridge Isotope Laboratories Inc. (Tewksbury, MA, USA), these standards all have a concentration of 50 μg/mL. The OASIS HLB SPE cartridge (500 mg/mL) was acquired from Waters Corporation (Milford, MA, USA). N-Hexane, dichloromethane, acetone, anhydrous sodium sulfate (Na₂SO₄), concentrated sulfuric acid (H₂SO₄), and sodium hydroxide (NaOH) were obtained from Anpel Laboratory Technologies (Shanghai) Inc. (Shanghai, China). Diatomaceous earth and quartz sand were purchased from BUCHI Labortechnik AG (Flawil, Switzerland). Water and silica gel were obtained from Millipore Corporation (Burlington, MA, USA). Aluminum oxide was purchased from Sigma Aldrich (St. Louis, MO, USA).