Bioactive constituents from the leaves of Clinacanthus nutans Lindau

Three chlorophyll derivatives (phaeophytins) were isolated from the chloroform extract of Clinacanthus nutans Lindau leaves by means of chromatographic techniques and bioactivity-guided fractionation to give three pure compounds. Structure elucidation of the isolated compounds was carried out on the basis of spectral analyses. Three of these were known compounds with structures related to chlorophyll a and chlorophyll b namely 13²-hydroxy-(13²-R)-phaeophytin b, 13²-hydroxy-(13²-S)-phaeophytin a and 13²-hydroxy-(13²-R)-phaeophytin a. These compounds, which have not previously been reported in this plant, were shown to have anti-herpes simplex activity. They exhibited anti-HSV-1F activity at subtoxic concentrations. Their inhibitory activity affected the virus before viral entry to the host cells. This effect might be virucidal or interference with viral adsorption or penetration.     

Specific oxygen, ammonia, and nitrate uptake rates of a biological nutrient removal process treating elevated salinity wastewater

Anaerobic/anoxic/aerobic systems inoculated without and with NaCl acclimated cultures, i.e., Models A and B, respectively, were fed with a synthetic wastewater at various salinity levels. After achieving a steady state, the systems were shocked with 70 g/l NaCl for four consecutive days before returning to pre-shock conditions. At the steady-state, the specific oxygen uptake rates (SOURs) increased with an increase of sodium chloride concentration (from 5.40 to 9.72 mg O₂/g mixed liquor suspended solids (MLSS)-h at 0–30 g/l NaCl for Model A and from 6.84 to 17.64 mg O₂/g MLSS-h at 5–30 g/l NaCl for Model B). In contrast, the specific ammonia uptake rate (SAUR) and specific nitrate uptake rate (SNUR) decreased with increasing chloride concentration (from 4.76 to 2.14 mg NH₃–N/g MLSS-h and 2.50 to 1.22 NO3–N/g MLSS-h, for Model A, and from 3.84 to 2.71 mg NH₃–N/g MLSS-hr and 2.54 to 1.82 mg NO₃–N/g MLSS-hr, for Model B). During the shocked period, the SOUR in most scenarios increased whereas the SAUR and SNUR tended to decrease. The impact of the chloride shock on nitrifiers was more obvious than on denitrifiers; however, after a certain recovery period, the activities of both nitrifiers and denitrifiers in terms of SAUR and SNUR were approximately the same as those prior to shock.