Journal of Chromatography A, 1082 (2005) 51–59 On-line identification of sugarcane (Saccharum officinarum L.) methoxyflavones by liquid chromatography–UV detection using post-column derivatization and liquid chromatography–mass spectrometry Renata Colombo a , Janete H. Yariwake a,∗ , Emerson F. Queiroz b , Karine Ndjoko b , Kurt Hostettmann b a Instituto de Qu´ ımica de S˜ ao Carlos, Universidade de S˜ ao Paulo, Caixa Postal 780, 13560-970 S˜ ao Carlos, SP, Brazil b Laboratoire de Pharmacognosie et Phytochimie, ´ Ecole de Pharmacie Gen` eve-Lausanne, Universit´ e de Genev` e, Quai Ernest Ansermet 30, 1211 Gen` eve 4, Gen` eve, Switzerland Available online 10 February 2005 Abstract Sugarcane (Saccharumofficinarum L., Gramineae) bagasse and leaves were investigated for their flavonoid content and transgenic sugarcane (“Bowman-Birk” and “Kunitz”) was compared with non-modified (“control”) plants. Analyses were carried out by high-performance liquid chromatography coupled to diode array UV detection (LC/UV), also using post-column addition of shift reagents, and tandem MS (atmospheric pressure chemical ionization–MS/MS and collision-induced dissociation–MS). On-line UV and MS data demonstrated the presence of methoxyflavone glycosides and aglycones in a total of seven compounds. Three naturally occurring flavones glycosides and two unusual erythro- and threo-diastereoisomeric flavolignan 7-O-glucosides were identified together with their aglycones. © 2005 Elsevier B.V. All rights reserved. Keywords: Saccharum officinarum; LC/UV; LC/MS; Flavonoids; Transgenic plants 1. Introduction Flavonoids are polyphenols which occur in higher plants, including medicinal and edible plants (vegetables, fruits, etc.) and also in some foods and beverages such as tea, red wine and juices. In recent years, an increasing number of publica- tions have reported on the chemistry of flavonoids especially due to their biological properties (antibacterial, antiviral, anti-inflammatory, anti-allergic, anti-thrombotic, vasodila- tory, anti-mutagenic and neoplastic) and their ability in the diet to protect against or inhibit the development of cancer [1,2]. The recent progress in LC-hyphenated techniques such as high-performance liquid chromatography–UV–photodiode ∗ Corresponding author. Tel.: +55 16 3373 9447; fax: +55 16 3373 9982. E-mail address: janete@iqsc.usp.br (J.H. Yariwake). array detection (LC/UV-DAD) and LC–mass spectrometry (LC/MS) has led to instrumental developments and different modes of operations of such techniques, providing powerful analytical tools for the efficient detection and rapid charac- terization of natural products in complex biological matrices such as plant extracts. Furthermore, LC-hyphenated tech- niques are playing increasingly important roles in support of phytochemical investigations, such as targeting the isola- tion of new active compounds, for the dereplication of known plant constituents and for metabolite profiling studies [3,4]. Sugarcane (Saccharum officinarum L.) is one of the most important crops in Brazil and the flavonoid content is un- der investigation because these compounds may justify the potential utilization of sugarcane derivatives as nutraceuti- cal foods. Products such as the sugarcane juice and syrup, besides some sweets produced from sugarcane juice, are tra- ditionally consumed by the populations of several tropical 0021-9673/$ – see front matter © 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.chroma.2005.01.083