title: Xanthine oxidase/tyrosinase inhibiting, antioxidant, and antifungal oxindole alkaloids from Isatis costata.
abstract: Phytochemical investigations on the ethyl acetate soluble fraction of the whole plant of Isatis costata Linn. (Brassicaseae) led to the isolation of the oxindole alkaloids costinones A (1), B (2), isatinones A (3), B (4), indirubin (5), and trisindoline (6). Compounds 1-6 displayed significant to moderate inhibition against xanthine oxidase enzyme with IC50 values ranging from 90.3+/-0.06 to 179.6+/-0.04 microM, whereas the standard inhibitor of xanthine oxidase (allopurinol) had an IC(50) value of 7.4+/-0.07 microM. Compounds 1 (IC50 7.21+/-0.05 microM), 2 (IC50 9.40+/-0.03 microM), 3 (IC50 11.51+/-0.07 microM), 4 (IC50 12.53+/-0.06 microM), 5 (IC50 14.29+/-0.09 microM), and 6 (IC50 17.34+/-0.04 microM) exhibited pronounced activities when compared with the standard tyrosinase inhibitor L-mimosine (IC50 3.70+/-0.03 microM), along with DPPH radical scavenging activity with IC50 226, 270, 300, 320, 401, and 431 microM, respectively. The crude extract and compounds 1, 2, 5, and 6 showed significant antifungal activity against Trichophyton schoen leinii, Aspergillus niger, Candida albicans, Trichophyton simii, and Macrophomina phaseolina.
authors.affiliation: Department of Chemistry, Kohat University of Science and Technology, Kohat, N.W.F.P., Pakistan. drijaz_chem@yahoo.com
authors.forename: Ijaz
authors.initials: I
authors.lastname: Ahmad
authors.forename: Fozia
authors.initials: F
authors.lastname: Ijaz
authors.forename: Itrat
authors.initials: I
authors.lastname: Fatima
authors.forename: Nisar
authors.initials: N
authors.lastname: Ahmad
authors.forename: Shilin
authors.initials: S
authors.lastname: Chen
authors.forename: Nighat
authors.initials: N
authors.lastname: Afza
authors.forename: Abdul
authors.initials: A
authors.lastname: Malik
mesh_terms: D000493:Allopurinol / Q000008:administration & dosage / Q000494:pharmacology; D000935:Antifungal Agents / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology; D000975:Antioxidants / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology; D005658:Fungi / Q000187:drug effects; D026121:Indole Alkaloids / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D020128:Inhibitory Concentration 50; D031219:Isatis / Q000737:chemistry*; D008898:Mimosine / Q000008:administration & dosage / Q000494:pharmacology; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology*; D014969:Xanthine Oxidase / Q000037:antagonists & inhibitors
chemical_list: D000935:Antifungal Agents; D000975:Antioxidants; D004791:Enzyme Inhibitors; D026121:Indole Alkaloids; D010936:Plant Extracts; D008898:Mimosine; D000493:Allopurinol; D014442:Monophenol Monooxygenase; D014969:Xanthine Oxidase