~ Pergamon PIh S0031-9422(96)00727-3 Phytochemistry, Vol. 45, No. 1, pp. 201-202, 1997 Copyright © 1997 Elsevier Science Ltd Printed in Great Britain. All rights reserved 0031-9422/97 $17.00+0.00 QUERCETAGETIN 6-O-fl-D-GLUCOPYRANOSIDE FROM TAGETES MANDONII MARIO D'AGOSTINO,FRANCESCO DE SIMONE,* SONIAPIACENTE,*COSIMOPIZZA* and FELICESENATORE'~ Dipartimento di Chimica delle Sostanze Naturali, Universit~i degli Studi di Napoli "Federico II", via D. Montesano 49, 80131 Napoli, Italy; *Centro Interdipartimentale di Chimica, Biologia e Tecnologia Farmaceutiche (C.I.C.B.T.F.), Universit~i degli Studi di Salerno, Piazza V. Emanuele 9, Penta di Fisciano, Salerno, Italy (Received8 July 1996) Key Word Index--Tagetes mandonii; Compositae; flavonol glycosides; quercetagetin 6- glycoside; IH and 13C NMR. Abstraet--A new natural glycoside, quercetagetin 6-O-fl-D-glucopyranoside, has been isolated from the meth- anol extract of the aerial parts of Tagetes mandonii and identified on the basis of ~H and 13C NMR and UV spectral data. © 1997 Elsevier Science Ltd. All rights reserved INTRODUC~ON Continuing our studies on the Tayetes genus (Com- positae) [1], we have undertaken an investigation of the aerial parts of Tayetes mandonii Sch. Bip., a her- baceous plant widespread in the Peruvian Sierra where it is used for the treatment of gastrointestinal diseases and for its antidiarrhoic properties [2]. The present paper deals with the isolation of fla- vonol compounds, identified by NMR and UV spec- tral data as quercetagetin 6-glucoside (1), quercetin 3- glucoside (2), quercetin 3-rhamnoside (3), myricetin 3-glucoside (4) and rhamnetin (5). While the 7-0- glucoside [3-5] and the 3-O-glucoside [6] of quer- cetagetin are already known, 1 is a new natural product. OH H O ~ O ~ OH OH 0 1 R = [$-D-Glucopyranosyl 6 R=H RESULTS ANDDISCUSSION The JH NMR spectrum of 1 showed the pattern of a quercetagetin O-glucoside. Thus, the signal located at 6 6.92 (IH, s) was ascribable to H-8, the only one proton of the ring A, while the 3H ABX system at 6 6.91 (d, J = 8.5 Hz), 7.77 (d, J = 2 Hz) and 7.68 (dd, J = 2 and 8.5 Hz) was consistent with the signals of a 3',4'-disubstituted ring B of a flavonol [7]. Further features were signals corresponding to the anomeric proton (6 5.10, d, J = 7.5 Hz) and to H2-6 (6 3.68, dd, J = 5 and 12 Hz; 6 3.88, dd, J = 3.5 and 12 Hz;) of a fl-D-glucopyranosyl unit. The identity of the sugar was confirmed by ~3C NMR (Table 1) [8]. In the 13C NMR spectrum the C-6, C-5 and C-7 ~'Author to whom correspondence should be addressed. signals of 1, compared with the corresponding peaks for a sample of quercetagetin (6) obtained by acidic hydrolysis of 1 (Table 1) showed an upfield shift of 3.6 ppm and downfield shifts of 2.2 and 3.0 ppm, respectively. This, together with the presence of the peak at 6 137.0, characteristic of a free 3-hydroxyl [9], indicated that the glycosylation site was C-6. This hypothesis was further confirmed by UV batho- chromic shifts of band I by adding powdered sodium acetate (7-hydroxyl free) and band III by adding alu- minium chloride (5-hydroxyl free) (see Experimental) [io]. On the basis of these data 1 was identified as quer- cetagetin 6-O-fl-o-glucopyranoside. The identification of known compounds quercetin 3-O-fl-D-glu- copyranoside (2), quercetin 3-O-fl-D-rhamnoside (3), myricetin 3-O-fl-D-glucopyranoside (4) and rhamnetin (5) was based on comparison with literature data [1, 8-9l. 201