Isookanin

J Agric Food Chem. 2015 Jan 14;63(1):200-7.

New phenolic compounds from Coreopsis tinctoria Nutt. and their antioxidant and angiotensin i-converting enzyme inhibitory activities.[Pubmed: 25516207 ]

Three new phenolic compounds, coretinphenol (1), coretincone (2), and coretinphencone (3), were isolated from the buds of Coreopsis tinctoria Nutt., together with nine known compounds, including butein (4), okanin (5), isoliquiritigenin (6), maritimetin (7), taxifolin (8), Isookanin (9), marein (10), sachalinoside B (11), and 2-phenylethyl-β-d-glucoside (12).
METHODS AND RESULTS:
The chemical structures of these compounds were elucidated by extensive spectroscopic analysis and on the basis of their chemical reactivity. This work represents the first recorded example of the isolation of compounds 1–3, 6, 7, 9, 11, and 12 from C. tinctoria. Compounds 5–9 showed strong diphenyl(2,4,6-trinitrophenyl)iminoazanium (DPPH) radical-scavenging activity, with IC50 values of 3.35 ± 0.45, 9.6 ± 2.32, 4.12 ± 0.21, 6.2 ± 0.43, and 7.9 ± 0.53 μM, respectively. Compounds 2 and 8 exhibited angiotensin I-converting enzyme inhibitory activity, with IC50 values of 228 ± 4.47 and 145.67 ± 3.45 μM, respectively.
CONCLUSIONS:
The activities of phenolic compounds isolated from C. tinctoria support the medicinal use of this plant in the prevention of cardiovascular diseases.

Molecules . 2020 Jun 5;25(11):2631.

Subacute Oral Administration of Clinacanthus nutans Ethanolic Leaf Extract Induced Liver and Kidney Toxicities in ICR Mice[Pubmed: 32517000]

Abstract This study investigated the leaves of Clinacanthus nutans for its bioactive compounds and acute and subacute toxicity effects of C. nutans ethanolic leaf extract (CELE) on blood, liver and kidneys of ICR mice. A total of 10 8-week-old female mice were divided into groups A (control) and B (2000 mg/kg) for the acute toxicity study. A single dose of 2000 mg/kg was administered to group B through oral gavage and mice were monitored for 14 days. In the subacute toxicity study, mice were divided into five groups: A (control), B (125 mg/kg), C (250 mg/kg), D (500 mg/kg) and E (1000 mg/kg). The extract was administered daily for 28 days via oral gavage. The mice were sacrificed, and samples were collected for analyses. Myricetin, orientin, isoorientin, vitexin, isovitexin, Isookanin, apigenin and ferulic acid were identified in the extract. Twenty-eight days of continuous oral administration revealed significant increases (p < 0.05) in creatinine, ALT and moderate hepatic and renal necrosis in groups D and E. The study concluded that the lethal dose (LD50) of CELE in mice is greater than 2000 mg/kg and that repeated oral administrations of CELE for 28 days induced hepatic and renal toxicities at 1000 mg/kg in female ICR mice. Keywords: Clinacanthus nutans; ICR mice; acute toxicity; biochemical parameters; histopathology; Isookanin; myricetin; orientin; subacute toxicity; vitexin.

Fitoterapia. 2012 Oct;83(7):1169-75.

Phenolics from Bidens bipinnata and their amylase inhibitory properties.[Pubmed: 22814126 ]

METHODS AND RESULTS:
A new chlorinated flavonoid, 3, 6, 8-trichloro-5, 7, 3', 4'-tetrahydroxyflavone (1), a new biscoumaric acid derivative, 4-O-(2″, 3″-O-diacetyl-6″-O-p-coumaroyl-β-D-glucopyranosyl)-p-coumaric acid (2), and 8, 3', 4'-trihydroxyflavone-7-O-β-D-glucopyranoside (3) together with twenty-four known compounds (4-27) were isolated from the whole plant of Bidens bipinnata. All chemical structures were established on the basis of UV-, MS- and NMR (¹H, ¹³C, ¹H-¹H COSY, HMQC and HMBC) spectroscopic data. Some of the isolated compounds were tested for the inhibition of α-amylase.
CONCLUSIONS:
The result showed that Isookanin (6) was a potent inhibitor of α-amylase (IC₅₀=0.447 mg/ml).