BiochemicalSystema~'csand Ecology,Vol. 21, No. 5, pp. 645-646, 1993. Printed in Great Britain. 0305-1978/93 $6.00+ 0.00 © 1993PergamonPressLtd. Flavonoid Variation with the Plant Age in Zizyphus mistol Leaves JUAN P. PELOTTO* and MARIA A. DEL PERO MARTINEZ Centro de Estudios Farmacol6gicos y Botanicos (CEFYBO), Consejo Nacional de Investigaciones Cientificas y T~cnicas (CONICET), Serrano 665, Buenos Aires, 1414, Argentina Key Word Index--Zizyphus mistol; Rhamnaceae; intraspecific flavonoid variation; quercetin glycosides; isorhamnetin glycosides; acylated glycosides. Subject and Source Zizyphus mistol Griseb. (Rhamnaceae) is a deciduous spiny tree characteristic of Chaco forests of Central and Northern Argentina and Paraguay. Young and mature leaves of 10 saplings and 10 adults were collected in the Reserva Natural de Copo, Santiago del Estero, Argentina (25°55'S, 62°05'W), at the beginning and the end of the wet season, respectively. Material was authenticated by Dr Pastor Arenas, curator of the CEFYBO Herbarium (BACP). Previous Work Reports from other Zizyphus species are available (leaves: Souleles and Shammas, 1988; Nawwar eta/., 1984; bark: Tripathy et al., 1988; seeds: Woo et al., 1979, 1980) but Z. mistol has not yet been studied. Present Study Methanolic extracts were two-dimensionally chromatographed on paper (BAW/15% Acetic Acid). Compounds were identified by standard methods, UV-VIS spectroscopy and TLC comparison with authentic samples (Budzianowksi, 1991).1" Within each plant age group (n = 10) and for both leaf age groups results obtained were very consistent (Table 1). Variation in aglycones and glycosylation pattern was evident between plant age groups. By direct comparison, isorhamnetin glycosides were present in large amounts in young and mature leaves of saplings, whilst they were abundant in adults, especially in mature leaves. Young leaves of adults were richer in quercetin glycosides than mature ones and showed more complex structures including acylated glycosides. The latter were based on glycosides already present in the profiles of adults and saplings. On the other hand, old leaves of saplings revealed the same pattern observed in young leaves, containing mostly quercetin glycosides. Acylation, xylosides and arabinosides were restricted to saplings and young leaves of adults, suggesting that together with quercetin glycosides they may be considered as "juvenile" features. Chemotaxonomic and Ecological Significance These results are of interest for future comparative chemotaxonomic studies in the genus because isorhamnetin has not yet been cited for other Zizyphus species. Differences in flavonoid pattern may reflect distinct characteristic growth conditions and/or age specific requirements. This appears to be supported by the fact that noticeable morphological differences between saplings and adults were observed in the field. Sapling showed a radial system of prostrate twigs instead of a principal axis, typical of the adult forms. In contrast to adults, saplings occur preferentially in open sites. There are diverse examples of intraspecific flavonoid variation in relation to developmental changes (for a review see Bohm, 1987). Most of them refer to changes that occur in an organ during maturation in short-lived plants. In this study little or no variation in flavonoid pattern was observed between young and old leaves of the adults and the saplings, respectively. The major differences were present between plant ages. Studies in saponin and tannin content, which are not the subject of this report, resulted in a comparable variation (Pelotto and Del Pero Martinez, unpublished data) reinforcing the idea that saplings and adults of Zizyphus mistolare two morphologically, ecologically and probably physiologically, well-defined phases of this long-lived plant. *Author to whom correspondence should be addressed. tSupplementary data supplied. (Received 14 January 1993) 645 646 NEW SOURCE REPORT TABLE 1. DISTRIBUTION OF FLAVONOID GLYCOSIDES IN LEAVES OF SAPLINGS AND ADULTS OF Z I Z Y P H U S Saplings Flavonoid glycoside YL* MISTOL Adults ML YL ML • ~ • • • [~j Quercetin (Q) Q-3-O-galactoside . Q-3- O-p-cou ma ric-(xylose-galactose) • . . . • Q-3- O-rhamnose-galactose 0-3- O-rutinoside El • ~ • Q-3- O-glucose-ara binose-a rabinoset L] • Q-3- O-glucose-rhamnose-rhamnoset QI3- O-glucose-r hamnose--galactose CJ -- • Q-3-O-(p-coumaric-vanillic)-(rhamnose-galactose) -- Q-3-O-(p-coumaric-ferulic) (rhamnose-galactose) ..- • Eli • -- ~3 Q-3-O-(p-coumaric-vanillic)-rutinoside - -- • Q-3-O-(p-coumaric-sinapic)-rutinoside -- -- [3 -= Isorhamnetin (IR) IR-3-O-glucoside -- IR 30-galactose~arabinose Lq [3 IR-3-O-rutinoside E.I -- L3 -- -E~ [~ • -- LJ -- I R - 3 - O rhamnose-galactose IR-3-O-glucose-rhamnose-galactoset -- IR~3-O-(ferulic-vanillic)-(galactose-arabinose) -- ~] • -12 • *YL: young leaves; MT: mature leaves; tSugar moieties tentatively identified; I : present in high concentrations; EJ: present in lower concentrations; - - : absent. References Bohm, B. A. (1987) The BotanicalReview53, 197; Budzianowski, J. (1991) J. Chromat. 540, 469; Nawwar, M. A. M., Ishak, M. S., Michael, H. N. and Buddrus, J. (1984) Phytochemistry 23, 2110; Souleles, Chr. and Shammas, G. (1988) Fitoterapia 59, 154; Tripathy, Y. C., Devi, S., Pandley, V. B. and Shah, A. H. (1988) Fitoterapia 59, 158; Woo, W. S., Kang, S. S., Shim, S. H., Wagner, H., Chari, V. M., Seligmann, O. and Obermeier, G. (1979) Phytochemistry18, 353; Woo, W. S,, Kang, S. S., Wagner, H., Seligmann, O. and Chari, V. M . (1980) P h y t o c h e m i s t r y 19, 2791.