Linaroside — A new flavone glycoside from some species of Linaria

LINAROSIDE -A FROM SPECIES SOME NEW L. P. Smirnova, A. I. Ban'kovskii, FLAVONE OF GLYCOSIDE Linaria UDC 547.972.2 G. G . Z a p e s o c h n a y a , and K. I. Boryaev Continuing a chemical study of the total flavonoids of Linaria s e s s i l i s and L. kokanica [1], by c h r o matography on polyamide we have isolated a minor component - a light yellow m i c r o c r y s t a l l i n e substance. After d e c r y s t a l l i z a t i o n f r o m m e t h a n o l - a c e t o n e - w a t e r , it had the composition C23H24011, mp 259-262°C, [ ~ ] ~ - 6 8 . 1 ° (c 0.94; pyridine) R f 0.35 (15% CH3COOH, leningrad "M" ["slow"] paper), Xmax (methanol), 277~, 330 nm, ~'max (methanol +CH3ONa ) 290 rim, ~,max (methanol +CH3COONa ) 277, 330 rim. On acid hydrolysis, the substance f o r m e d glucose and pectolinarigenin. The NMR s p e c t r u m of the t r i m e t h y l s i l y l derivative showed the following signals: doublet at 7.72 ppm, J =9 Hz, 2H (H-2', 6'); doublet at 6.88 ppm, J = 9 Hz, 2H (H-3', 5'); singlet at 646 ppm, 1 H (I-I-8); singlet at 642 ppm, 1H (H-3); doublet at 4.96 ppm, J = 6.5 Hz, 1H (anomeric p r o t o n on glucose); multiplet at 3.4-3.9 ppm, 6H (protons of a sugar); and singlet at 3.78 ppm, 6H (2 CH30 ). The r e s u l t s of a c o m p a r i s o n of the NMR s p e c t r a , the R f values, and a mixed melting point with a sample of pectolinarigenin 7-glucoside obtained by the stepwise hydrolysis of pectolinarin showed the identity of these substances. The flavone glycoside isolated is a new natural substance having the s t r u c t u r e of 5 , 7 - d i h y d r o x y - 4 ' , 6 dimethoxyflavone 7-O-/3-D-glucopyranoside. We have proposed for it the name linaroside. Thus, f r o m toadflax we have obtained a successive chain of pectolinarogenin derivatives: the aglycone, its 7-glucoside, its 7-ramuoglucoside (pectolinarin), and acetylpectolinarin. LITERATURE I. CITED L. P. Smirnova, G. G. Zapesochnaya, A. I, Ban'kovskii, and K. I. Boryaev, Khim. P r i r o d n . Soedin., 118 (1973). All-Union S c i e n t i f i c - R e s e a r c h Institute of Medicinal Plants. T r a n s l a t e d f r o m Khimiya Prirodnykh Soedinenii, No. 2, pp. 249-250, March-April, 1974. Original article submitted F e b r u a r y 26, 1973. © 19 76 Plenum Publishing Corporation, 227 West 17th Street, New York, N. Y. 1001I. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, microfilming, recording or otherwise, without written permission o f the publisher. A copy o f this article is available from the publisher for $15.00. 259  (...truncated)