title: [Structural analyses of barbaloin-related compounds in aloe drinks].
abstract: Four kinds of barbaloin (BA)-related compounds (A, B, C, D) in aloe drinks were isolated by using preparative HPLC. LC/MS analyses of these compounds showed the identical quasimolecular ion peak at m/z 833 [M-H]-. The chemical structures were mainly determined by NMR, including 1H-1H two-dimensional correlation spectroscopy (COSY), nuclear Overhauser and exchange spectroscopy (NOESY), heteronuclear multiple quantum coherence (HMQC), and heteronuclear multiple-bond connectivity (HMBC) experiments. They were identified as BA-related compounds A (10R, 10"S), B (10S, 10"S), C (10S, 10"R), and D (10R, 10"R) coupled through a C-10 to C-7' linkage, and newly found in nature. These results suggested that BA is converted to dimers during storage of aloe drinks.
authors.affiliation: Tokyo Metropolitan Research Laboratory of Public Health: 3-24-1, Hyakunin-cho, Shinjuku-ku, Tokyo 169-0073, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Shindo
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Ushiyama
authors.forename: Kimiko
authors.initials: K
authors.lastname: Kan
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Uehara
authors.forename: Kazuo
authors.initials: K
authors.lastname: Yasuda
authors.forename: Ichiro
authors.initials: I
authors.lastname: Takano
authors.forename: Kazuo
authors.initials: K
authors.lastname: Saito
mesh_terms: D000504:Aloe; D000873:Anthracenes / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D005504:Food Analysis; D009682:Magnetic Resonance Spectroscopy
chemical_list: D000873:Anthracenes; C045601:barbaloin