Qingqing Wang,Wei Zhang,Fangping Zhong,Wenchao Yang,Xiuhai Gan
Photosynthesis system Ⅱ (PS Ⅱ) inhibitors can block electron transport and disrupt plant photosynthesis and are used as herbicides. In order to develop new and effective PS II inhibitors, the lead structure lawsone was first found with remarkable herbicidal activity based on a virtual screening strategy, and its derivatives were designed and synthesized. The results of herbicidal activity evaluation showed that most of the compounds could achieve more than 80 % inhibitory effect on roots and stems of Portulaca oleracea at a dose of 100 μg/mL. Meanwhile, compound 4d showed more than 90 % inhibition on the stem of P. oleracea and on the root of Echinochloa crusgalli, which were superior to lawsone (64.9 and 67.6 %) and atrazine (63.6 and 65.9 %), respectively. Interestingly, 4d exhibited 100 % post-emergence herbicidal activity to Amaranthus retroflexus and Abutilon theophrasti at a dosage of 300 g a.i./ha, which was similar to atrazine but superior to lawsone. In addition, compound 4d can affect the efficiency of the photochemical process and strong bind PS II D1 protein. It revealed that compound 4d can be used as a promising PS II D1 inhibitor. This study provides a promising lead compound for developing new PS II inhibitors.
Henna ( Lawsonia inermis ) plant biomass is a popular source of natural dye lawsone used all over the world. In this study, the effect of temperature on fermentative production of short-chain fatty acids (SCFA) from raw henna biomass was investigated. The results indicated that mesophilic fermentation (35 °C) upgraded the SCFA production as compared with those under normal (25 °C) and thermophilic (25 °C) conditions, increasing by up to 2.2-fold and 1.5-fold, respectively. Acetic acid was the main SCFA component, accounting for 50 ~ 70% of the total SCFA, and followed by n -butyric acid and propionic acid. The enzymatic activities of α-glucosidase in thermophilic series were lower than those in mesophilic series, resulting in a less carbohydrate consumption and SCFA production. Soluble lawsone was positively correlated with fermentation temperature; and the average concentration (87.0 mg/L) in mesophilic series was appropriate to serve as a redox mediator to improve the acidification process for SCFA production. Future work to systematically scrutinize the confounding factors affecting the fermentation process of henna biomass was required.
Graphical abstract
Yang Li,Cai Tianming,Ding Dahu,Cai Tianjin,Jiang Canlan,Li Hua,Yang Qian,Chen Liwei
2-hydroxy-1,4 naphthoquinone (lawsone) is widely used and induces environmental pollutions during its production and application. In the present study, a lawsone-degrading bacterium strain, LH-3 was successfully isolated from the activated sludge. Based on the 16S rRNA gene analysis, the strain LH-3 phylogenetically belonged to the Pseudomonas taiwanensis . It could degrade 200 mg L −1 lawsone completely in 9 h with an inoculum quantity of 1% (v/v). The effects of environmental conditions on the degradation process and the degradation pathway were systematically investigated. LH-3 could maintain its high degradation efficiency under high salt condition. The identified intermediates of salicylic acid, 2-hydroxy-4-oxo-chroman-2-carboxylic acid, and catechol elucidated the potential degradation pathway. Furthermore, the immobilized LH-3 strain cells prepared with alginate gel and biochar performed excellent stability in nine successive degradation runs. It could sucessfully survive in laboratory scale sequencing batch reactor and become to be the dominant species. This study clearly revealed that LH-3 could serve as an attractive candidate for the microbial remediation of lawsone-containing wastewater.
危险品化学品经营许可证（带存储）