The synthesis of both enantiomers of lactobacillic acid and mycolic acid analogues
作者:Geoffrey D. Coxon、Stefan Knobl、Evan Roberts、Mark S. Baird、Juma R. Al Dulayymi、Gurdyal S. Besra、Patrick J. Brennan、David E. Minnikin
DOI:10.1016/s0040-4039(99)01378-7
日期:1999.9
cis-cyclopropane-1, 2-dimethanol by enzymatic desymmetrisation. The syntheses of (11S 12R)-lactobacillic acid (2) and (1R, 2S) 1-(3′-methoxycarbonylpropyl)-2-octadecylcyclopropane (26) and related analogues (27 and 28) have also been achieved.
(11 R,12 S)-乳酸核糖酸(1)已经通过不对称环丙烷化由D-甘露糖醇或通过酶促不对称化从顺式-环丙烷-1、2-二甲醇制备。还已经合成了(11 S 12 R)-乳酸杆菌酸(2)和(1 R,2 S)1-(3'-甲氧基羰基丙基)-2-十八烷基环丙烷(26)及其相关类似物(27和28)。 。
Isolation, Synthesis, and Biological Activity of Chlorinated Alkylresorcinols from <i>Dictyostelium</i> Cellular Slime Molds
Eight chlorinated alkylresorcinols, monochasiol A–H (1–8), were isolated from the fruiting bodies of Dictyostelium monochasioides. Compounds 1–8 were synthesized to confirm their structures and to obtain sufficient material for performing biological tests. Monochasiol A (1) selectively inhibited the concanavalin A-induced interleukin-2 production in Jurkat cells, a human T lymphocyte cell line. Monochasiols
introducing a tolyl or phenyl ligand at the apical position, respectively, via the S(E)Ar mechanism, and they were found to be efficient catalysts for cis-selective asymmetric cyclopropanation. The scope of the cyclopropanation was wide, and the reactions of not only conjugated mono-, di-, and trisubstituted olefins but also nonconjugated terminal olefins proceeded with high enantio- and cis-selectivity
Metabolic Isolation, Stereochemical Determination, and Total Synthesis of Predominant Native Cholesteryl Phosphatidyl-α-glucoside from Carcinogenic <i>Helicobacter pylori</i>
cholesteryl 6-O-phosphatidyl α-glucoside (CPG) from Helicobacter pylori via an integrated biological and chemical strategy. The strategy employed (i) the metabolic isolation of a CPG analogue and (ii) the enzymatic degradation of the analogue to obtain the native lactobacillic acid for the stereochemical determination. The absolute stereochemistry of the acid was found to be 11R and 12S. Using the new
Total Synthesis of an Immunogenic Trehalose Phospholipid from <i>Salmonella</i> Typhi and Elucidation of Its <i>sn</i>-Regiochemistry by Mass Spectrometry
作者:Vivek K. Mishra、Jeffrey Buter、Molly S. Blevins、Martin D. Witte、Ildiko Van Rhijn、D. Branch Moody、Jennifer S. Brodbelt、Adriaan J. Minnaard
DOI:10.1021/acs.orglett.9b01725
日期:2019.7.5
Diphosphatidyltrehalose (diPT) is an immunogenic glycolipid, recently isolated from Salmonella Typhi. Despite rigorous structure elucidation, the sn-position of the acyl chains on the glycerol backbone had not been unequivocally established. A stereoselective synthesis of diPT and its regioisomer is reported herein. Using a hybrid MS3 approach combining collisional dissociation and ultraviolet photodissociation mass spectrometry for analysis of the regioisomers and natural diPT, the regiochemistry of the acyl chains of this abundant immunostimulatory glycolipid was established.