Active compounds in Populus nigra L. wilted leaves responsible for attracting Helicoverpa armigera (Hübner) (Lep., Noctuidae) and new agaropectin formulation

Abstract:  The leaf extracts of Populus nigra were collected and identified by steam distillation, air entrainment and gas chromatographic–mass spectrometric analysis. Electroantennograms were recorded from Helicoverpa armigera adults in response to the chemicals identified. Both aromatic compounds and green-leaf volatiles elicited strong responses. Field experiments revealed that the active compounds responsible for attracting H. armigera moths are mainly short-side-chain aromatic alcohols and aldehydes. We, for the first time, used agaropectin as the controlled-release matrix of insect attractants. A five-component lure containing all the aromatics without phenolics, mixed in the proportions as found in the steam distillate of the leaves collected in August, produced the best trap catch. The results showed that the volatiles of wilted leaves of P. nigra can attract H. armigera adults by feeding attraction.     

Induction of shikonin formation by agar in Lithospermum erythrorhizon cell suspension cultures

Cultured cells of Lithospermum erythrorhizon capable of producing red naphthoquinone (shikonin) derivatives on Linsmaier-Skoog agar medium ceased s     

New insights in agar biorefinery with arylsulphatase activities

Agar is a major gelling agent used both in food and pharmaceutical applications. Traditional purification of agar is generally performed by sequential time consuming chemical and/or physical steps, leading to both poor recovery yields and low productivities. As a consequence, only 30% of the amount of agar produced is actually available under purified form to feed the world market.The current limiting factor for purification is the presence of sulphated compounds such as sulphated-agaropectin, which strongly affect the technological properties of the agar gel such as gel strength, melting and fusion temperatures and electroendosmosis.In this context, this communication aims at discussing about the development of a biorefining agar purification approach which allows overcoming the current limitations associated with traditional purification methods. More specifically, this article focuses on the potential role of arylsulphatases in agar purification processes to reduce the number of purification steps and to improve recovery yields.This review first presents the global gelling agents market before focusing on agar characteristics and production processes. Then, after a brief reminder of the sulphur metabolism, the roles, classes and properties of the different arylsulphatases are described to draw perspectives on their integration in current or new agar production processes.     

江蓠琼胶酯组分的制备及其抗病毒活性

以20.0 g江蓠琼脂粉为原料,经DEAE-纤维素柱层析制得琼胶酯0.46 g,产率为2.30%。抑菌圈法测定表明,琼胶酯样品对大肠杆菌和金黄色葡萄球菌无抗菌作用;采用半叶枯斑法测定,表明琼胶酯样品对烟草花叶病毒具明显的钝化作用,琼胶酯样品浓度0.05～2.0 mg·mL-1对烟草花叶病毒的抑制率为37.02%～81.51%,呈现出显著的浓度剂量效应。研究首次报道海洋红藻中的琼胶酯组分对植物病毒的抑制作用,对拓宽琼脂糖制备过程产生的副产物琼胶酯组分的用途有积极意义。