New chromonocoumarin (=6H, 7H‐[1]Benzopyrano[4,3‐b][1]benzopyran‐6,7‐dione) derivatives from Polygala fruticosa BERG

Abstract

Three chromonocoumarins ( =6H, 7H‐[1]benzopyrano[4,3‐b][1]benzopyran‐6,7‐diones) 1–3 have been isolated from the leaves and the root bark of polygala fruticosa BERG. (syn. Polygala oppositifolia L.; Polygalaceae). The structure of frutinone A (1) was established by X‐ray diffraction analysis. The structures of the previously undescribed compounds frutinone B (2) and C (3) were deduced by spectroscopic methods (EI‐MS, UV, IR, 1H‐and 13C‐NMR, including NOE and COSY) in comparison with 1. Chromonocoumarins 1–3 are the first representatives of a new type of naturally occurring compounds. Frutinone A shows strong fungicidal activity against Cladosporium cucumerinum.

Polyphenolic Glycosides and Oligosaccharide Multiesters from the Roots of Polygala dalmaisiana

“…Compound 1b was identified as frutinone B by comparison of spectral data with reported data. 4 The sugar sequence and the glycosidic site were decided by ROE and HMBC. In the ROE difference spectra of 1, when the proton signals at δ 5.45 due to H-1 of Glc and δ 5.24 due to H-1 of Rha were irradiated, ROEs were observed at δ 7.66 due to H-3′ and δ 3.68 due to H-2 of Glc, respectively.…”

“…No previous investigation has been reported on the oligosaccharide esters of P. dalmaisiana. We now report on an investigation of the roots of P. dalmaisiana, which led to isolation of four new compounds (1)(2)(3)(4), 16 new oligosaccharide esters (5, 7-21), and a known oligosaccharide ester, reiniose G (6) (Chart 1). Known compounds were identified by comparison of their spectral data with reported data.…”

Construction of trisubstituted chromone skeletons carrying electron-withdrawing groups via PhIO-mediated dehydrogenation and its application to the synthesis of frutinone A

“…One practical application of the obtained chromone derivatives was their conversion to chromone-derived natural products. Frutinone A, isolated from the leaves and root bark of Polygala fruticosa, shows various biological activities, including antibacterial, antioxidant, and potent cytochrome P450 1A2 inhibition (CYP1A2, IC 50 = 5.3 nM) properties [90][91][92]. Treating the obtained chromene-3-carboxylate 2l with LiOH [93] led to the formation of the chromene-3-carboxylic acid G. Heating compound G overnight in the presence of AgNO 3 and K 2 S 2 O 8 afforded frutinone A in an isolated yield of 45% (Scheme 5).…”

Coumarins

“…The reaction probably occurs by a free-radical mechanism involving a photo-initiated oneelectron redox process. Coumarin methyltransferases isolated from Ailanthus altissima methylate aesculetin to scopoletin (285) and isoscopoletin (286) but not scopoletin to scoparone (287).ls9 Tissue cultures of Tanacetum parthenium, T. vulgare, and Artemisia vulgaris produced significant amounts of scopoletin and isofraxidin (358) (see Section 12) under a wide variety of conditions. The two coumarins predominant in culture were either absent from or were very minor components of the parent plants.lgo Umbelliferone and scopoletin were induced in the stems of Platanus acerifolia seedlings in response to inoculation with Ceratocystis Jimbriata f. sp.…”