Antimicrobial Chalcones from the Seeds of Persicaria lapathifolia

Abstract

Bioassay-guided sequential extraction of the seeds of Persicaria lapathifolia followed by chromatographic separations resulted in the identification of three chalcones; flavokawain B (1), pinostrobin chalcone (2) and pashanone (3). The structures of the isolated compounds were established based on NMR and MS spectroscopic data. Disk diffusion method was employed to evaluate the antibacterial and antifungal activities of the isolated compounds against two bacterial and four fungal strains. The chloroform extract and the compounds demonstrated significant antibacterial activities. Compound 2 showed the highest activity against Staphylococccus aureus bacterial strain and Trichoderma spp fungal strain. Its antifungal activity (22 mm) against Trichoderma spp is even greater than that of the reference drug, clotrimazole (20 mm).

Anthraquinones from the Roots of Kniphofia insignis and Evaluation of Their Antimicrobial Activities

“…us, the structure of compound (2) was found to be 4,7′-bichrysophanol, trivial name asphodeline (2). As reported so far, it is the common metabolite from the genus Kniphofia including K. albescens, K. linearifolia, K. ensifolia, K. evansii, K. northiae, K. foliosa, K. tysonii, and K. isoetifolia [4,13].…”

“…Deshielded H-4′ (δ H 7.66) and H-5′ (δ H 8.03) (ring A'B'C′) in contrast to H-4 (δ H 6.63) and H-5 (δ H 6.80) (ring ABC) indicates the second moiety has a carbonyl group located at C-10'. erefore, compound 3 was characterized and identified as 10-hydroxy-10-(chrysophanol-7′-yl)chrysophanol anthrone, which was previously reported from other Kniphofia species such as K. isoetifolia [4], K. ensifolia [14,15], K. foliosa, and K. thomsonis [10].…”

“…About seven species of Kniphofia occur in Ethiopia, of which five including K. foliosa, K. hildebrandtii, K. isoetifolia, K. insignis, and K. schimperi are endemic [1,2], and the genus is widely known for its ornamental value due to their colorful flowers and used in traditional medicine [3]. Its roots are used to treat abdominal cramps, wound healing, women infertility, gonorrhea, hepatitis B, ring worm, chest pain, snake bite, and shoulder pains [1,[3][4][5][6]. e family Asphodelaceae is a rich source of mainly anthraquinones, monomeric and dimeric anthraquinones, anthrones, dimeric phenylanthraquinones, [5] and naphthoquinone [4].…”

“…Its roots are used to treat abdominal cramps, wound healing, women infertility, gonorrhea, hepatitis B, ring worm, chest pain, snake bite, and shoulder pains [1,[3][4][5][6]. e family Asphodelaceae is a rich source of mainly anthraquinones, monomeric and dimeric anthraquinones, anthrones, dimeric phenylanthraquinones, [5] and naphthoquinone [4]. It is so far only known from the Shewa and Arsi Zone.…”

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“…Two chalcones, sappanchalcone and 3-deoxysappanchalcone were isolated from the ethanolic extract obtained from Haematoxylum campechianum L. 68 Two chalcone derivatives isolated from Finger root with nutraceutical potentials 69 . Flavokawain B, pinostrobin and pashanone chalcones were isolated from seeds of Persicaria lapathifolia 70 . Importance of Chalcones: An interesting feature of chalcones pharmacophore is that they serve as starting materials for the synthesis of five and sixmembered heterocyclic compounds such as Pyrimidines, Pyrazolines, Flavones, Flavonols, Flavonones, Aurones and Benzoylcoumarones as well as certain compounds like Deoxybenzoins and Hydantoins which are of some therapeutic application 71 .…”