THE CHEMICAL COMPOSITION OF SEDUM RUPESTRE L. SSP. RUPESTRE EPICUTICULAR WAXES: HORTICULTURAL VERSUS THE NATURAL PLANT HABITAT

Abstract

The aim of this study was to mutually compare the chemical compositions of epicuticular waxes of two different Sedum rupestre ssp. rupestre plant material samples. These were collected during the post fructification vegetative stage from the wild-growing (NH) and cultivated populations (HH). Epicuticular waxes (isolated in the form of hexane washings of leaves and stems) were analyzed using GC-MS, GC-FID and 1D- (¹H, ¹³C) and 2D-NMR analyses. The epicuticular wax of both samples consisted of only two alkanes and one triterpene: hentriacontane (2.9 and 4.7% in NH and HH samples, respectively), tritriacontane (31.8 and 41.3% in NH and HH samples, respectively) and germanicyl formate (61.1 and 50.5% in NH and HH samples, respectively). Based on the obtained results, it seems that the type of habitat (natural or horticultural) does not affect the qualitative but only the quantitative composition of S. rupestre ssp. rupestre epicuticular waxes.

HEMIJSKI SASTAV EPIKUTIKULARNOG VOSKA BILJNE VRSTE SEDUM RUPESTRE L. SSP. RUPESTRE: HORTIKULTURNO I PRIRODNO STANIŠTE

Cilj istraživanja je bio određivanje i upoređivanje hemijskog sastava epikutikularnih voskova dva uzorka vrste S.rupestre ssp. rupestre u vegetativnoj fazi nakon plodonošenja sa različitih lokaliteta i različitih uslova staništa (prirodni, NH, i hortikulturni uslovi, HH). GC-MS, GC-FID i 1D- (¹H i ¹³C) i 2D-NMR analize su korišćene radi identifikacije i kvantifikacije sastojaka epikutikularnih voskova izolovanih u obliku heksanskih ispiraka listova i stabla. Oba uzorka su sadržala hentriakontan (NH 2,9% i HH 3,4 %), tritriakontan (NH 31,8% i HH 41,3%) i triterpen germanicil-formijat (NH 61,1% i HH 50,5%). Upoređivanjem dobijenih rezultata opaža se da uslovi staništa ne utiču na kvalitativni sastav, ali da postoji razlika u kvantitativnom sastavu epikutikularnih voskova biljne vrste S.rupestre ssp. rupestre.

HIGHLIGHTS

• A comparative analysis of cuticular waxes composition of two Sedum rupestre ssp. rupestre samples was achieved.
• The major components of both samples (natural habitat, NH and horticulture, HH) were: hentriacontane (C₃₁), tritriacontane (C₃₃) and germanicyl formate (GM).
• The germanicyl formate structure was determined from the analysis of MS, ¹H and ¹³C NMR spectra.
• Both samples were quite similar in qualitative composition, NH and HH: C₃₁ (2.9% and 4.72%), C₃₃ (31.76% and 41.32%) and GM (61.09% and 50.54%).
• There was a discrepancy in the percentage representation of the main components.