Lapacho类似物的合成及其构效关系。2.碱性萘并[2,3 - b ]呋喃-4,9-二酮的修饰,氧化还原活化和8-羟基萘并[2,3 - b ]噻吩-4,9-二酮对人角质形成细胞过度增殖的抑制作用
摘要:
在寻找抗角质形成细胞过度增生的新型药物时,对线性带电lapacho醌naphtho [2,3 - b ] furan-4,9-dione(7)的基本结构进行了修改。几种杂环稠合萘醌的合成及其与结构和活性的关系,以及这些8-羟基萘[2,3 - b ]噻吩-4,9-二酮之一的全范围2和7取代衍生物(描述图8a)。总共71种类似物中,特别是2-thenoyl取代的26l,2-nicotinoyl取代的26m和2-oxadiazole取代的35a与抗银屑病药anthralin相比具有优势。使用HaCaT细胞作为模型评估了它们抑制角质形成细胞过度增殖的潜能,并与相对较低的对角质形成细胞的膜破坏作用相结合,这是通过从细胞质中释放出乳酸脱氢酶活性来确定的。关于作用机理,研究了在分离的酶法测定中通过一电子还原和二电子还原来还原lapacho醌的氧化还原,并在基于角质形成细胞的过度增殖测定中证实了它们产生超氧化物的潜力。
The process for removing a secondary hydroxyl group from an organic compound having at least one secondary hydroxyl group and having any amino groups protected, comprises the reaction of a reactive ester of said secondary hydroxyl group selected from the group consisting of an O-alkylthioester and an O-alkylselenoester with at least one mole of an organotin hydride, preferably tri-n-butylstannane, in an inert, aprotic solvent at a temperature of at least about 100.degree. C and under an inert atmosphere. The process is particularly useful in removing secondary alcohols in aminoglycoside antibiotics to produce deoxy derivatives thereof having antibacterial activity. Also described are novel O-sec.-alkylthiobenzoate, O-sec.-alkyl-S-methylxanthate, N-(sec.-alkoxythiocarbonyl)-imidazole esters, and di-O-alkylthiocarbonates having at least one secondary O-alkyl group, useful intermediates of the claimed process.
TMSOTf acts as Lewis acid to activate carbamoyl chlorides and generates highly electrophilic carbamoyl triflates in situ; these are active species for late‐stage aromatic carbamoylation.
The development of sustainable methods is highly desirable in synthetic organic chemistry. In this regard, we report hydroxylamine hydrochloride mediated, one-pot synthesis of 1,3-diazaheterocycles using anthranilamide or -phenylenediamine with amides transamidation under solvent free condition at 120–140 °C for 8–14 h. This method proceeds smoothly under metal- and oxidant-free conditions exhibited