Colouring Matters of Australian Plants. VIII. Naphthalene Derivatives from Dianella Species

Abstract

The roots of Dianella laevis contain a crystalline glycoside, dianellin, and the corresponding aglycone, dianellidin. Only dianellin has been isolated from D. caerulea. Dianellidin is identified as 1,8-dihydroxy-3-methyl-2-acetonaphthone and the glycoside has the sugars, glucose and rhamnose, attached at the 8-position. Dianellin is readily converted into plumbagin and is a possible natural precursor of this and other naphthoquinones found in plants. There is some evidence for the occurrence of traces of this type of compound in Dianella roots.

Naphthalene Aglycones and Glycosides from the Australian Medicinal Plant,Dianella callicarpa

“…The CH 2 Cl 2 extract was subjected to diol flash chromatography and subsequent fractions were analysed by normal phase HPLC. Fractions four, seven and eight were combined and subjected to semipreparative normal phase HPLC (35% EtOAc/n-hexane), which afforded the semi-pure naphthaquinone dimer, dianellinone (3). Comparison of the extracted UV profile and maxima (λ max at 254 and 429 nm) obtained from the HPLC PDA data (35% EtOAc/n-hexane), were consistent with literature values reported for 3 [4].…”

“…The n-hexane extract was subjected to flash silica gel chromatography generating fourteen fractions, which were subsequently analysed by normal phase HPLC. The 40 % CH 2 Cl 2 /n-hexane fraction afforded semi-pure dianellidin (2), the primary naphthalene precursor and aglycone for com-pounds 1 and 10 [3]. The ESI-MS displayed an m/z = 215 [M -H] − , consistent with a molecular formula of C 13 H 12 O 3 and 8 DBE.…”

“…The genus Dianella is commonly known as the "swamp flax-lily" and is predominately endemic to Victoria, with possible occurrences of the species also reported from the southwest regions of South Australia [1]. One of the earliest reports on the chemistry of Dianella species was the isolation of dianellin (1) obtained from the alcoholic extracts of the roots of D. caerulea, as well as the corresponding aglycone derivative dianellidin (2) (also known as musizin and nepodin [2]), obtained from the roots of D. laevis [3]. Subsequent studies have included the chemical investigation of the roots of both D. revoluta and Stypandra grandis, which have afforded dianellinone (3) and stypandrone (4), respectively [4].…”

“…One of the earliest reports on the chemistry of Dianella species was the isolation of dianellin (1) obtained from the alcoholic extracts of the roots of D. caerulea, as well as the corresponding aglycone derivative dianellidin (2) (also known as musizin and nepodin [2]), obtained from the roots of D. laevis [3]. Subsequent studies have included the chemical investigation of the roots of both D. revoluta and Stypandra grandis, which have afforded dianellinone (3) and stypandrone (4), respectively [4]. In terms of biological activity, stypandrone (4) has been shown to cause methaemoglobinemia in poisoned animals, thereby reducing the oxygen-carrying capacity of blood as well as promoting the conversion of haemoglobin to methaemoglobin in vitro, which con-tributes to the death of affected animals [5].…”

Kenyaloside, a Novel O,O,O-Triglycosylated Naphthalene Derivative from the Exudate of Kenyan Aloe Species

“…The existence of an Ar-CO-CH 3 (δ H 1.95, δ C 30.84, 206.70) and of an Ar-glycosyloxymethyl group in 2-and 3-positions, respectively, could be established on the basis of the NOE association between H-4 and Ar-CH 2 -O-protons and of the correlation observed in the HMBC spectrum between the glycosyloxymethyl protons and the aromatic carbon linked to the acetyl group (C-2). Such an assumption was in agreement with the strong similarity in the UV and IR spectra of 1 with those of dianellidin dimethyl ether (3) [6]. In addition, it can be noted that the carbon skeleton and the oxygenation pattern of the kenyaloside aglycone (1, where R 1 = R 2 = R 3 = H) are both consistent with biogenetic considerations suggesting the cyclization of a decarboxylated polyketide (heptaketide) chain as the key step in the formation of the naphthalene nucleus [7].…”