Showing papers on "Karanjin published in 2004"

Potential use of karanjin (3-methoxy furano-2′,3′,7,8-flavone) as a nitrification inhibitor in different soil types

Abstract: Karanjin, a furanoflavonoid (3-methoxy furano – 2 ′ , 3 ′ , 7, 8-flavone), is obtained from the seeds of karanja tree (Pongamia glabra Vent.), which is reported to have nitrification inhibitory properties but has been tested in few soil types. Efficiency of karanjin as a nitrification inhibitor in seven different soils of India was tested in a laboratory incubation study. The soils (800 g) were adjusted to field capacity moisture content, fertilized with urea and urea combined with karanjin at a rate of 20% of applied urea-N (100 mg kg − 1 soil) and incubated at 35°C for a period of 7 weeks, during which urea [CO(NH2)2], ammonium (NH4 + ), nitrite (NO2 − ) and nitrate (NO3 − ) content in the soils was measured periodically and nitrification inhibition at different stages was calculated. Urea hydrolysis was almost complete within 72 h of application in all the soils and was not affected by karanjin. Karanjin had conserved ammonium in all the soils at all stages and nitrate formation was effectively mini...

Methane consumption from ambient atmosphere by a Typic Ustochrept soil as influenced by urea and two nitrification inhibitors

Abstract: The effect of urea and urea mixed with different doses of two nitrification inhibitors, dicyandiamide (DCD) and karanjin [a furanoflavonoid, extracted from seeds of the karanja (Pongamia glabra Vent.) tree], on methane (CH4) consumption was examined in a Typic Ustochrept (alluvial inceptisol) soil, collected from a field under rice-wheat rotation. The soil, fertilized with urea (100 mg N kg-1 soil) and urea combined with different doses of the two inhibitors, DCD and karanjin (each added at 5%, 10%, 15%, 20% and 25% of applied N), was incubated at 25°C, at field capacity moisture content for 35 days. The methane consumption rate ranged between 0.2 and 1.7 µg CH4 kg-1 soil day-1 with little temporal variation (CV =10–31%). It was significantly higher in the control (no fertilizer-N) than other treatments except for a few cases, while total CH4 consumption in the incubation period was significantly higher in the control than other treatments. Methane consumption rate was found to be negatively and positively correlated with soil NH4+ and NO2- + NO3- content, respectively. Mean CH4 consumption rate, as well as total CH4 consumption, was lower on the addition of karanjin due to slower nitrification and higher conservation of NH4+ released from applied urea. Addition of urea led to a 17% reduction of total CH4 consumption while urea combined with karanjin and DCD had 50–64% and 19–34% reduction, respectively. Karanjin was a more effective nitrification inhibitor than DCD during the incubation period.

Study on flavonoids from stem bark of Pongamia pinnata

Abstract: Seven flavonoids, pongaflavone (1), karanjin (2), pongapin (3), pongachromene (4), 3,7-Dimethoxy-3', 4'-methylenedioxyflavone (5), millettocalyxin C( 6), 3,3',4', 7-tetramethoxyflavone (7), were isolated from 50% EtOH syrup of the bark of Pongamia pinnata and structureal elucidated on the base of spectral data. Compound 6 was isolated for first time from the plant of the genus Pongamia.