The anatomy and essential oil composition of the different organs of Pimpinella tragium and P. saxifraga (Apiaceae)

Abstract

This work was aimed at investigating the anatomy and composition of the essential oils from different organs of two Pimpinella species, P. tragium and P. saxifraga, originating from the central part of the Balkan Peninsula. The results of the analysis of the anatomy of the different organs of P. tragium and P. saxifraga showed that they were very similar in terms of the structure of the roots, stems and petioles. The roots showed a secondary structure and the stems had a primary structure with closed collateral vascular bundles. The petioles were cordatum, ribbed with an adaxial groove, and sparsely covered with short unior bicellular non-glandular trichomes with a pointed top (both species) or with long uniseriate, multicellular, non-glandular trichomes (P. saxifraga). Differences were observed in the anatomy of the leaves and in the indumentum of the fruits. The leaves of P. tragium were isobilateral, while those of P. saxifraga were dorsiventral. The P. tragium fruits were pubescent, covered with numerous, multicellular, uniseriate, straight or curved, gradually acuminate non-glandular trichomes, whereas the fruits of P. saxifraga were glabrous. These differences are of ecological and taxonomic significance. Secretory canals were observed in all the investigated organs of both species. The essential oils, isolated by hydrodistillation from the aerial parts with inflorescences, the roots from the flowering and fruiting period, and the fruits of both species, were analysed by GC-FID/MS. Although P. tragium and P. saxifraga essential oils showed certain differences in qualitative and quantitative patterns, all the oils were characterised by the presence of pseudoisoeugenol type phenylpropanoid epoxy-pseudoisoeugenyl-2-methylbutyrate, as well as by that of trinorsesquiterpenes pregeijerene, geijerene and trinoranastreptene. In addition, azulenes were present in all the root essential oils, whereas in the majority of the oils from the fruits and flowering aerial parts the common compound was the sesquiterpene β-bisabolene. The occurrence of phenylpropanoids of pseudoisoeugenol type and geijerenes is important from the chemotaxonomic point of view and confirms them as chemical markers of the Pimpinella species analysed so far.

Cilj ovog istraživanja bio je analiza anatomske građe i hemijskog sastava etarskih ulja različitih organa dve vrste roda Pimpinella, P. tragium i P. saxifraga, poreklom iz centralnog dela Balkanskog poluostrva. Na osnovu rezultata analize unutrašnje građe različitih organa P. tragium i P. saxifraga može se zaključiti da postoje velike sličnosti u građi korena, stabla i lisne drške. Koren obe vrste bio je sekundarne građe, stablo primarne građe sa zatvorenim kolateralnim sprovodnim snopićima, a lisne drške srcolike, rebraste sa adaksijalnim žlebom, sporadično prekrivene kratkim jednoćelijskim ili dvoćelijskim, na vrhu zašiljenim nežlezdanim trihomama (obe vrste) ili dugim uniserijatnim, višećelijskim nežlezdanim trihomama (P. saxifraga). Uočene su razlike u anatomiji listova i in- dumentumu plodova ove dve vrste. Listovi P. tragium bili su izobilateralni, a P. saxifraga dorziventralni. Plodovi P. tragium bili su maljavi, prekriveni brojnim, višećelijskim, uniserijatnim, uspravnim ili zakrivljenim, postepeno zašiljenim nežlezdanim trihomama, dok su plodovi P. saxifraga bili goli. Ove razlike u anatomskoj građi su od ekološkog i taksonomskog značaja. U svim organima obe ispitivane vrste uočeno je prisustvo sekretornih kanala. Etarska ulja su izolovana postupkom destilacije vodenom parom iz različitih organa obe vrste, nadzemnog dela sa cvastima, korena prikupljenog u fazi cvetanja i u fazi plodonošenja i ploda i analizirana GC-FID/ MS metodom. Iako su ispitivana etarska ulja P. tragium i P. saxifraga bila donekle različitog kvalitativnog i kvantitativnog sastava, za sva etarska ulja bilo je karakteristično prisustvo fenilpropanoida pseudizoeugenol tipa epoksi-pseudoizoeugenil-2-metilbutirata, kao i trinorseskviterpena pregeijerena, geijerena i trinoranastreptena. Pored toga, u svim etarskim uljima dobijenim iz korena bili su prisutni azuleni, a u većini etarskih ulja plodova i nadzemnih delova u cvetu karakterističan sastojak bio je sekviterpen β-bisabolen. Prisustvo fenilpropanoida pseudoizoeugenol tipa i trinorsekviterpena tipa geijerena značajno je sa hemotaksonomskog aspekta i pot- vrđuje njihovu ulogu hemijskih markera do sada ispitivanih Pimpinella vrsta.