PapA3 Is an Acyltransferase Required for Polyacyltrehalose Biosynthesis in Mycobacterium tuberculosis
摘要:
Mycobacterium tuberculosis possesses an unusual cell wall that is replete with virulence-enhancing lipids. One cell wall molecule unique to pathogenic M. tuberculosis is polyacyltrehalose (PAT), a pentaacylated, trehalose-based glycolipid. Little is known about the biosynthesis of PAT, although its biosynthetic gene cluster has been identified and found to resemble that of the better studied M. tuberculosis cell wall component sulfolipid-1. In this study, we sought to elucidate the function of papA3, a gene from the PAT locus encoding a putative acyltransferase. To determine whether PapA3 participates in PAT assembly, we expressed the protein heterologously and evaluated its acyltransferase activity in vitro. The purified enzyme catalyzed the sequential esterification of trehalose with two palmitoyl groups, generating a diacylated product similar to the 2,3-diacyltrehalose glycolipids of M. tuberculosis. Notably, PapA3 was selective for trehalose; no activity was observed with other structurally related disaccharides. Disruption of the papA3 gene from M. tuberculosis resulted in the loss of PAT from bacterial lipid extracts. Complementation of the mutant strain restored PAT production, demonstrating that PapA3 is essential for the biosynthesis of this glycolipid in vivo. Furthermore, we determined that the PAT biosynthetic machinery has no cross-talk with that for sulfolipid-1 despite their related structures.
A W/O/W emulsion composition having high emulsion stability, which can be prepared extremely easily and for which the production efficiency of the W/O/W emulsion product is favorable, and a method of producing such a W/O/W emulsion composition. The W/O/W emulsion composition of the present invention includes 0.001 to 60% by mass of a component (A) described below and 0.001 to 10% by mass of a component (B) described below; wherein, a mass ratio between the component (A) and the component (B) is within a range from 1:0.01 to 1:1.4. Component (A): a sugar fatty acid ester composition obtained by esterifying a sugar and a fatty acid of 8 to 28 carbon atoms, in which a hydroxyl value of said sugar fatty acid ester composition is within a range from 20 to 220. Component (B): a nonionic surfactant having an HLB value of not less than 7.
SURFACTANT, AND EMULSION COSMETIC AND LIPOSOME EACH CONTAINING THE SAME
申请人:Ikemoto, Takeshi
公开号:EP0729781A1
公开(公告)日:1996-09-04
A surfactant containing at least one trehalose-6-fatty acid ester represented by general formula (I) (wherein R represents C8-C22 (un)saturated acyl which may be substituted by OH, etc.) and excellent in surface activity and safety; an emulsion cosmetic containing the surfactant and a water-soluble polymer, excellent in prolonged storage stability and organoleptic characteristics, and reduced in skin stimulation, and having a beautiful appearance with a fine texture; and a liposome having a membrane wall comprising the trehalose ester and being excellent in physical and chemical stabilities such as prolonged preservability.
一种表面活性剂,至少含有一种由通式(I)代表的曲哈糖-6-脂肪酸酯(其中 R 代表 C8-C22(非)饱和酰基,可被 OH 等取代),具有优异的表面活性和安全性;一种乳液化妆品,含有表面活性剂和水溶性聚合物,具有优异的长期储存稳定性和感官特性,减少对皮肤的刺激。),具有优异的表面活性和安全性;一种含有该表面活性剂和水溶性聚合物的乳液化妆品,具有优异的长期贮存稳定性和感官特性,减少了对皮肤的刺激,外观漂亮,质地细腻;以及一种脂质体,其膜壁含有该曲卤糖酯,具有优异的物理和化学稳定性,如长期保存性。
Surfactant, and an emulsion-type cosmetic composition and a liposome containing said surfactant
申请人:——
公开号:US20040022819A1
公开(公告)日:2004-02-05
The invention provides a surfactant comprising at least one trehalose-6-fatty acid ester selected from those represented by the following formula:
1
wherein R represents a saturated or unsaturated acyl group having 8-22 carbon atoms, and may have a hydroxyl group or other substituents, and an emulsion-type cosmetic composition comprising said surfactant and a water-soluble polymer. The surfactant of the invention has excellent surface activity and safety. Also, the emulsion-type cosmetic composition has excellent long-term storage stability and sensory properties, has no irritation to skin, and gives beautiful appearance with fine surface texture. Further, the invention is a liposome having a membrane wall composed of trehalose fatty acid ester. Said liposome has excellent chemical and physical stabilities such as long-term storage stability.
本发明提供了一种表面活性剂,该表面活性剂包含至少一种三卤糖-6-脂肪酸酯,该酯选自下式所代表的那些酯:
1
其中 R 代表具有 8-22 个碳原子的饱和或不饱和酰基,并可带有羟基或其他取代基,以及包含所述表面活性剂和水溶性聚合物的乳液型化妆品组合物。本发明的表面活性剂具有优异的表面活性和安全性。此外,本发明的乳液型化妆品组合物具有优异的长期储存稳定性和感官特性,对皮肤无刺激,外观漂亮,表面质地细腻。此外,本发明是一种脂质体,其膜壁由曲卤糖脂肪酸酯构成。所述脂质体具有优异的化学和物理稳定性,如长期储存稳定性。
Use of sugar esters in cosmetic and/or pharmaceutical preparations
申请人:Pauly Gilles
公开号:US20050220726A1
公开(公告)日:2005-10-06
Methods for treating the skin and/or hair comprising: (a) providing a composition comprising a sugar ester; and (b) contacting a substrate selected from the group consisting of skin and hair with the composition are described.