The main problem of the use of N fertilizer in paddy soil Vertisols is the low efficiency. Ureahumic acid applications at certain dosage are believed to increase rice growth and production. This study was aimed to examine the effect of urea and urea-humic acid to the amount and form of N-available, N uptake, plant growth, and the production of rice. Five dosage levels of urea-humic acid were applied for rice on Vertisols. Results of the research showed that the urea-humic acid fertilizer could increase the content of N-NH4 + soil at 28 days and N-NO3 -soil at 42 days. The urea-humic acid could improve plant height, number of tillers, and total dry weight. The highest rice production is achieved by 100% humic acid-urea, especially on parameters of dry weight effectively harvested and effectively milled, with 5.56 tons and 4.61 tons per hectare respectively. Correlation between soil N-NO3 -level with soil N-NH4 + level was significant at p = 0.05 (r = 0.871). Efficiency of urea-humic acid fertilizer at 100% recommended dosage (200 kg urea-humic acid) to the dry weight of effectively harvested crop with dry weight of effectively milled crop was 22% compared to the recommended urea fertilizer (200 kg ha -1 ).
The flavonoids derived from Eugenia polyantha leaves were characterized by rapid and low cost approach. The aim of this research is to characterize secondary metabolite profile of flavonoids in the n-butanol fraction of E. polyantha using thin layer chromatography and ultraviolet-visible spectrophotometry. The n-butanol fraction was separated by using silica gel 60 GF 254 as the stationary phase; chloroform: ethanol: glacial acetic acid (9.4: 0.5: 0.1) as the mobile phase; and visualized by using UV light 366 nm. Five isolates were obtained from the separation, but there were only three isolates (R f 0.26; 0.44; 0.77) respectively identified as flavonoid compounds. The characterization of the isolates by UV-Vis spectrophotometry showing that the ranges of λ max were 250-280 nm (band II) and 310-360 nm (band I), which indicate the existence of flavone compounds. Further characterization of the three isolate using the AlCl 3 5%/HCl 6 M solution showed that the λ max shifted from band I to the higher wavelength (bathochromic). The λ max shift indicated the existences of ketone at C-4, hydroxyl group at C-5, and orthodihydroxyl at ring B. According to the maximum wavelength, the result of the characterization showed that the flavonoid compounds of the n-butanol were 5,3',4'-trihydroxyflavone-3-C-glycoside or 5,4',5'-trihydroxyflavone-3-C-glycoside; 5,6,3',4'-tetrahydroxyflavone or 5,6,4',5'-tetrahydroxyflavone; and 5,3',4'-trihydroxyflavone or 5,4',5'-trihydroxyflavone.
A new havanensin-type limonoid, 16β-hydroxydysobinin (1), along with four known limonoids (2–5), have been isolated from the seeds of Chisocheton macrophyllus. The chemical structure of the new compound was determined by referencing spectroscopic data, and by comparison to those related spectra previously reported. Each compound was evaluated for their cytotoxic effects against Michigan Cancer Foundation-7 (MCF-7) breast cancer cells and display no significant activity.
Three previously unreported quinolinone alkaloids: melicodenines J-L (1-3) and six known compounds (4-9), were isolated from the leaves of Melicope denhamii (Seem) T.G. Hartley. The structures of three quinolinone alkaloids were identified based on HRESIMS and NMR spectra. Compounds 1-9 were assayed in three cancer cells (MCF-7, HeLa, and P-388). Compounds 1 and 5 showed high cytotoxic activity against HeLa cells with IC 50 values of 1.8 and 0.8 mM, respectively.
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