Selective Preparation of 2,3-Epoxypropanamide and Its Facile Conversion to 2,3-Dihydroxypropanamide with Acidic Resins

Abstract

In the equimolar reaction of acrylonitrile with hydrogen peroxide to 2,3-epoxypropanamide (glycidamide), the selectivity and the yield of the epoxide were improved by adding aq. NaOH solution continuously at a constant rate. The conventional literature procedure, by controlled pH from 7.0 to 7.5, resulted in an unfavorable decomposition of hydrogen peroxide. 2,3-Epoxypropanamide could be easily converted to 2,3-dihydroxypropanamide (glyceramide) by a catalytic amount of commercially available acidic resins.

Antityrosinase and Antioxidant Effects of ent-Kaurane Diterpenes from Leaves of Broussonetia papyrifera

“…The extract was subjected to silica gel column chromatography (CC) and eluted with a gradient solvent system of CH 2 Cl 2 /MeOH (100−0%). Compounds were eluted in the following order: taraxerol acetate ( 9 , 96 mg), 1 (63 mg), 3 (47 mg), glyceric acid methyl ester ( 10 , 6 mg), apigenin ( 4 , 18 mg), broussonetone B ( 2 , 13 mg), amentoflavone ( 8 , 10 mg), apigenin-7- O -glucuronide methyl ester ( 6 , 12 mg), vitexin ( 5 , 55 mg), and apigenin-7- O -β-glucopyranoside ( 7 , 16 mg) . Compounds 1 − 3 were further purified by CC with hexane/acetone (3:2−1:1) and crystallized from MeOH.…”

“…The extract was subjected to silica gel column chromatography (CC) and eluted with a gradient solvent system of CH 2Cl2/MeOH (100-0%). Compounds were eluted in the following order: taraxerol acetate (9, 96 mg), 12 1 (63 mg), 3 (47 mg), glyceric acid methyl ester (10, 6 mg), 13 apigenin (4, 18 mg), 7 broussonetone B (2, 13 mg), amentoflavone (8, 10 mg), 11 apigenin-7-O-glucuronide methyl ester (6, 12 mg), 19 Mushroom Tyrosinase Inhibition Assay. Compounds 1-5 and kojic acid were dissolved in DMSO or methanol and diluted to various concentrations using potassium phosphate buffer (pH 6.8).…”

“…Since the flavonoids isolated from Broussonetia papyrifera L. (Moraceae) have been demonstrated to be effective mushroom tyrosinase inhibitors and the methanolic extract of ground leaves of this plant displayed a greater mushroom tyrosinase inhibitory effect than kojic acid (IC 50 104.2 μg/mL vs >500 μg/mL after 2 h) together with DPPH free radical scavenging activity (IC 50 = 40.72 μg/mL) in our preliminary screening, isolation of the active principles proceeded. Three new ent -kaurane diterpenes ( 1 − 3 ), apigenin ( 4 ), vitexin ( 5 ), apigenin-7- O -glucuronide methyl ester ( 6 ), apigenin-7- O -glucoside ( 7 ), amentoflavone ( 8 ), taraxerol acetate, and glyceric acid methyl ester were isolated and identified using NMR and other spectroscopic methods. The ent -kauranes 1 − 3 are the first diterpenoids isolated from B .…”

“…1706 (CdO) cm -1 ; 1 H NMR (500 MHz, acetone-d6) see Table1;13 C NMR (125 MHz, acetone-d6) see Table 1; ESIMS (+) m/z 359 [M + Na] + ; HRFABMS (+) m/z 337.2390 [M + H] + (calcd for C20H33O4, 337.2379). CdO) cm -1 ; 1 H NMR (500 MHz, CDCl3) see Table 1; 13 C NMR (125 MHz, CDCl3) see Table 1; EIMS m/z 377 [M + H] + (4), 361 [M -Me] + (100), 301 (64), 283 (77), 273 (22), 255 (22); HRFABMS m/z 377.2691 [M + H] + (calcd for C23H37O4, 377.2692).…”

Determination of N7‐glycidamide guanine adducts in human blood DNA following exposure to dietary acrylamide using liquid chromatography/tandem mass spectrometry

“…Glycidamide was prepared by reaction of acrylonitrile with hydrogen peroxide. 28 The crude glycidamide preparation, with an estimated 20-fold molar excess, was reacted with 2 0 -deoxyguanosine in water or [ 15 N 5 ]-2 0 -deoxyguanosine dissolved in 50 mM phosphate buffer, pH 7.0, at 60 C for 4 h. 19 The resultant products were subjected to high-performance liquid chromatographic (HPLC) purification and confirmation of the identity of N7-GA-Gua was confirmed by nuclear magnetic resonance (NMR) spectroscopy (Figure S1, supporting information), MS and UV spectrometry, and [ 15 N 5 ]N7-GA-Gua was characterised by MS and recording UV scan spectra ranging between 240 and 320 nm. The concentration of the standards was calculated using the extinction coefficient (7.1 mM À1 cm À1 ) by determining the UV absorbance at 285 nm.…”