Coumarins of Angelica pachycarpa Fruits

Abstract

Key Word Index: A n g e l i c a p a c h y c a r p a ; Umbelliferae; C o u m a r i n s ; Linear F u r o c o u m a r i n s ; Vanillin.Byakangelicin, byakangelicol, heraclenol, isoscopoletin, oxypeucedanin, oxypeucedanin hydrate, marmesin, scoparone, scopoletin, ulopterol, umbelliferone, umbelliprenin and vanillin were identified in fruits of A. paabycarpa. This is the second report of isoscopoletin in Umtielliferae. The co-occurrence of these coumatins is discussed.Previously we reported the occurrence of byakangelicin, oxypeucedanin hydrate, umbelliferone, marmesin and ostruthol in the aerial parts of Angelica pachycarpaLGE. [I]. In continuing with our studies on this umbellifer endemic to NW Spain, we now report the identification of several coumarins in its fruits.Byakangelicin, oxypeucedanin hydrate, marmesin, umbelliferone, scopoletin and isoscopoletin were characterized in both the phenolic ether-extract and the aqueous residue. Scoparone, ulopterol and heraclenol were identified in the former and vanillin in the later extract.From the neutral fraction substantial amounts of umbelliprenin were isolated but the remaining constituents were such a complex mixture that' the syrupy concentrate was fractionally distilled a t 70-80' and 100-110' under vacuum for 1 hr. The distilates were chromatbgraphed by TLC on silica gel in chloroform-methanol (9:1), b y . P C in IAW or TLC in ethyl acetatecyclohexane (35:65). Umbelliferone, byakangelicin and oxypeucedanin hydrate were again present, and other prominent compounds were byakangelicol and oxypeucedanin.From a biochemical standpoint, A. pachycarpa shows a metabolism mainly focussed to synthesize isopentenyl-diol deriyatives, as the final step in the biosynthesis of linear furocoumarins. . In contrast to other Angelica species, this plant lacks the ability to synthesize angular furocoumarins; actually, traces of columbianetin were detected (Rubido, unpublished results) but presumably owing to an enzyme deficiency its conversion to angelicin does not occur. Our results support the hypothesis of a less well-developed "angular" enzyme system in most plants [2].Concerning isos~o~oletin, this is only the second report of this uncommon coumarin in the Umbelliferae, as it was reported previously in Bupleurum fruticescens [3]. Mps are uncorr. UV, IR and PMR spectra were run in MeOH, KBr and CDCI, at 80 Hz, respectively. Fruits (185 g, d.w.), collected in Muros (Corufia) in July 1973, were homogenized, extracted and fractionated with 5010 NaHCO, by the same method as had been used for the aerial parts [I]. The initial aqueous residue was successively paper chromatographed with toluene-acetic acidwater (4:1:5, upper layer, TAW), by TLC in silica gel with benzene-ethyl acetateacetic acid (50:5:2) and then again PC with TAW, water or isopropanol-ammonia-water (1 0: 1 :I, IAW). Bands.fluorescing Downloaded by: University of Victoria. Copyrighted material.

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“…Ipomoea mauritiana Jacq. are β-sitosterol 8 , βsitosterol-3-O-β-D-glucoside, Umbelliferone, Taraxerol acetate, scopoletin and scoparnone 9 etc.…”