Antimycobacterial and antioxidant flavones fromLimnophila geoffrayi

Abstract

The chloroform extract of the aerial part of Limnophila geoffrayi showed antimycobacterial and antioxidant activities. Bioassay-guided fractionation has led to the isolation of the flavones nevadensin (5,7-dihydroxy-6,8,4'-trimethoxyflavone, 1) and isothymusin (6,7-dimethoxy-5,8,4'-trihydroxyflavone, 2). Both compounds 1 and 2 exhibited inhibition activity against Mycobacterium tuberculosis, with equal MIC value of 200 microg/mL. Only compound 2 exhibited antioxidant activity against the radical scavenging ability of DPPH, with the IC50 value of 7.7 microg/mL. The crude hexane, chloroform and methanol extracts as well as the pure compounds 1 and 2 did not exhibit mutagenic activity in the Bacillus subtilis recassay.

Plants: A Source for New Antimycobacterial Drugs

“…prop-2-en-1-one (30 µg/mL) [45] cordiachrome C (1.5 µg/mL) [52] aromatic alkene, and pyrrolidine amide (25 µg/mL) [69] 5,4′-dihydroxy-3,7,8,3′-tetramethoxy flavones (> 50 µg/mL) (25 µg/mL) [28] palmarumycin JC2 (6.25 µg/mL) [39] Isobavachalcone (18 µg/mL) [45] globiferin (6.2 µg/mL) [52] tetrahydroxy squalene (10 µg/mL) [70] 5,4′-dihydroxy-3,7,8-trimethoxyflavone (> 50 µg/mL) (25-50 µg/mL) [28] α-tocopheryl quinone (25 µg/mL) [40] scopoletin (42 µg/mL) [45] diol derivative of labdane (250 µg/mL) [53] trans,trans-1,7,diphenylhepta-4,6-dien-3-one (> 128 µg/mL) [71] nevadensin and isothymusin (200 µg/mL) [29] 2′,5′′-dimethoxysesamin (63 µg/mL) [47] dioxime derivative of labdane and labdane (500 µg/mL) [53] xanthones (10 µg/mL) [72] pisonivanone (12.5 µg/mL) [32] ethoxycubebin (62.4 µM) [49] caniojane (25 µg/mL) [54] continued phytol derivatives (15.6-50 µg/mL) [64] phytol (100 µg/mL) [64] zylamine (2) inhibited both the sensitive and MDR strains of M. tuberculosis at minimum inhibitory concentrations (MIC) of 50 and 200 µg/mL, respectively [8]. Justicia adhatoda L., Acanthaceae, is known as vasaka in the Indian system of medicine.…”

“…Dorstenia barteri Bureau., Moraceae, a small herb from most regions of tropical South America, contains active phytochemicals against bacteria and fungi. The dichloromethane : methanol (1 : 1) extract of it contains isobachalcone (26), kanzanol C (27), 4-hydroxylonchocarpin (28), stipulin (29), and amentoflavone (30). When comparing compounds from 27 to 30, isobachalcone was more active against M. smegmatis and M. tuberculosis [19].…”

“…Limnophila geoffrayi Bon., Scrophulariaceae, a common ingredient in northeastern Thailand curry, is an antipyretic, expectorant, and a lactogogue. The antimycobacterial compounds nevadensin (45) and isothymusin (46) were reported from the chloroform extract of the above plant through bioassay-guided fractionation and the compounds were safe to use as evidenced from a mutagenic assay [29]. Pelargonium reniforme Spreng., Geraniaceae, of Africa is being used in the treatment of various ear, nose, and throat infections, and the main constituent of the tuberculosis remedy in the extract is known as "Umckaloabo".…”

Chemical Constituents of Aerial Parts and Roots of <i>Pycnanthemum flexuosum</i>

“…(16), acteoside (23), leucosceptoside A (24), martynoside (25), plantainoside (26), darendoside B (28), eritrichin (31), dihydrosyringin (32), benzyl-O-β-Dglucopyranoside (34), chlorogenic acid (36), and caffeic acid (37) were identified as compounds isolated from other Lamiaceae plants previously. 1) Genkwanin (5), 3) cirsilineol (7), 4) isothymusin (8), 5) 9) neoponcirin (22), 11) artselaeroside A (27), 12) 2″,3″-di-O-acetyl martynoside (29), 13) stachysoside B (30), 14) albizinin (33), 15) (+)-pinoresinol 4-O-β-D-glucopyranoside (35), 16) syringic acid (38), 17) vanillic acid (39), 18) and methyl syringate 4-O-β-D-glucopyranoside (40) 19) were identified by comparing their spectroscopic data with those in the literature.…”

Synthesis, Characterization and Antimicrobial Study of Some New Cyclohexenone Derivatives

“…These compounds are precursors of flavonoids and isoflavonoids which are abundant in plants. Various biological activities are associated with chalcones, such as anticancer (Modzelewska et al, 2006), antitumor (Kumar et al, 2003), antioxidant (Suksamrarn et al, 2003) and antimalarial (Ferrer et al, 2009). In addition of being used in pharmaceutical industries, chalcones also find wide applications in dyes (Asiri, 2003) and cosmetic compositions (Forestier et al, 1989).…”