Application of high-speed countercurrent chromatography for the isolation of sulforaphane from broccoli seed meal
- Authors: Liang, Hao , Li, Chunfang , Yuan, Qipeng , Vriesekoop, Frank
- Date: 2008
- Type: Text , Journal article
- Relation: Journal of Agricultural and Food Chemistry Vol. 56, no. 17 (2008), p. 7746-7749
- Full Text: false
- Description: In order to produce large amounts of pure sulforaphane for research purposes, a novel method using high-speed countercurrent chromatography (HSCCC) was developed. Without any initial cleanup steps, sultoraphane was successfully purified from the ethyl acetate extract of the broccoli seed meal by HSCCC. The separation was performed with two-phase solvent systems: n-hexane/ethyl acetate/ methanol/water (1:5:1:5, v/v/v/v). From 850 mg of the ethyl acetate extract, 186 mg of sultoraphane was isolated with the solvent system. The purified compound was over 97% purity as determined by HPLC analysis, and the chemical structure was confirmed by MS and 1H and 13C NMR. © 2008 American Chemical Society.
Effects of cyclodextrins on the antimicrobial activity of plant-derived essential oil compounds
- Authors: Liang, Hao , Yuan, Qipeng , Vriesekoop, Frank , Lv, Fei
- Date: 2012
- Type: Text , Journal article
- Relation: Food Chemistry Vol. 135, no. 3 (2012), p. 1020-1027
- Full Text: false
- Reviewed:
- Description: Essential oils (EOs) from plants are considered to be a safer alternative when compared to synthetic antimicrobial food additives. However, a major drawback of many EOs is their hydrophobic nature, which makes them insoluble in water based media and matrices. Although cyclodextrins (CDs) can increase the solubility of EO compounds, the effects of CDs on the antimicrobial activity of EOs have not been reported. In this paper, four different EO compounds (carvacrol, eugenol, linalool and 2-pentanoylfuran) were chosen to study the influence of CDs on the solubility and antimicrobial activity on bacteria and yeast. The greatest enhancement with regards to solubility of the four test compounds was achieved by hydroxypropyl-β-CD. In most instances, not only were the minimal antimicrobial concentrations of EO compounds decreased, but the interactivity of two combined EO compounds could be strengthened by the co-addition of CDs. Furthermore, the combination of carvacrol with hydroxypropyl-β-CD caused a marked change in the major membrane lipid composition of all microorganisms investigated; while scanning electron microscopy revealed that cellular integrity was significantly affected by 2× MIC, ultimately resulting in cell lysis. © 2012 Elsevier Ltd. All rights reserved.
Separation and purification of sulforaphane from broccoli seeds by solid phase extraction and preparative high-performance liquid chromatography
- Authors: Liang, Hao , Li, Chunfang , Yuan, Qipeng , Vriesekoop, Frank
- Date: 2007
- Type: Text , Journal article
- Relation: Journal of Agricultural and Food Chemistry Vol. 55, no. 20 (2007), p. 8047-8053
- Full Text: false
- Reviewed:
- Description: A novel, rapid, and economical method to isolate and purify natural sulforaphane from broccoli seeds is described. The procedure involves solvent extraction of autolyzed seed meal, followed by separation by solid phase extraction (SPE) and purification by preparative high-performance liquid chromatography (HPLC). The SPE method provides higher yield of sulforaphane from crude extracts compared to conventional liquid-liquid extraction. High purity and recovery of sulforaphane product can be obtained by preparative HPLC with a C18 column and 30% methanol in water as the mobile phase. The purified compound was characterized by MS and 1H and 13C NMR. The techniques described here are useful tools in the preparative-scale isolation of sulforaphane in a fast, cost-effective, and waste-conscious manner. © 2007 American Chemical Society.
- Description: C1
- Description: 2003004835
Thiamin analysis in red wine by fluorescence reverse phase-HPLC
- Authors: Liddicoat, Callum , Hucker, Barry , Liang, Hao , Vriesekoop, Frank
- Date: 2015
- Type: Text , Journal article
- Relation: Food Chemistry Vol. 177, no. (2015), p. 325-329
- Full Text: false
- Reviewed:
- Description: The derivatization of thiamin vitamers to their respective thiochrome by ferricyanide to facilitate fluorescence detection following separation by HPLC provides a powerful analytical tool. However the polyphenolic compounds in red wine readily interact with ferricyanide, reducing the effectiveness of ferricyanide oxidation in the derivatization of thiamin. We describe a method to facilitate the removal of polyphenolic compounds that interfere with the ferricyanide derivatization of thiamin. Polyvinylpolypyrrolidone afforded the total removal of phenolic compounds from red wines and allowed a spike recovery of thiamin vitamers (101% for thiamin; 104% for TMP; and 100% for TDP) in a wide range of red wines. This research found that Merlot styles of red wine contained the highest concentration of total thiamin (29.01 ng/mL) while Pinot Noir wines contained the lowest total concentration (8.27 ng/mL).