title: New screw lactam and two new carbohydrate derivatives from the methanol extract of rice bran.
abstract: A new screw lactam and two new carbohydrate derivatives, oryzalactam (1), oryzasaccharide A (2), and oryzasaccharide B (3), have been isolated from the methanol extract of rice bran together with four other known compounds, including momilactone A (4), butyl β-d-xylopyranose (5), ethyl β-d-xylopyranose (6), and methyl β-d-xylopyranose (7). The structures of these compounds were determined using a combination of spectroscopic methods and chemical analysis. This work represents the first recorded example of the isolation of compounds 1, 2, 3, 5, 6, and 7 from rice bran. The antioxidant experiments revealed that compound 1 possessed strong ABTS(+) (ABTS = 2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonic acid)) and DPPH (DPPH = diphenyl(2,4,6-trinitrophenyl) iminoazanium) radical scavenging with IC50 values of 33.38 ± 1.58 and 40.20 ± 1.34 μM, respectively. Antimicrobial assays revealed that compound 4 showed high levels of selectivity toward Escherichia coli with a minimal inhibitory concentration value of 5 μM.
authors.affiliation: Key Laboratory of Food Processing and Quality Control, College of Food Science and Technology, Nanjing Agricultural University , Nanjing 210095, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Jia
authors.initials: J
authors.lastname: Guo
authors.forename: Junnan
authors.initials: J
authors.lastname: Zhang
authors.forename: Tianxing
authors.initials: T
authors.lastname: Liu
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Xin
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D002241:Carbohydrates / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects; D007769:Lactams / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D015394:Molecular Structure; D012275:Oryza / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D000975:Antioxidants; D002241:Carbohydrates; D007769:Lactams; D010936:Plant Extracts
keywords: antioxidant and antimicrobial activities; oligosaccharide derivatives; rice bran; screw lactam; structural identification