79546-49-9Relevant academic research and scientific papers
Shornephine A: Structure, chemical stability, and P-glycoprotein inhibitory properties of a rare diketomorpholine from an Australian marine-derived Aspergillus sp.
Khalil, Zeinab G.,Huang, Xiao-Cong,Raju, Ritesh,Piggott, Andrew M.,Capon, Robert J.
, p. 8700 - 8705 (2014)
Chemical analysis of an Australian marine sediment-derived Aspergillus sp. (CMB-M081F) yielded the new diketomorpholine (DKM) shornephine A (1)together with two known and one new diketopiperazine (DKP), 15b-β-hydroxy-5-N-acetyladreemin (2), 5-N-acetyladreemin (3), and 15b-β-methoxy-5-N-acetyladreemin (4), respectively. Structure elucidation of 1.4 was achieved by detailed spectroscopic analysis, supported by chemical degradation and derivatization, and biosynthetic considerations. The DKM (1)underwent a facile (auto) acid-mediated methanolysis to yield seco-shornephine A methyl ester (1a). Our mechanistic explanation of this transformation prompted us to demonstrate that the acid-labile and solvolytically unstable DKM scaffold can be stabilized by N-alkylation. Furthermore, we demonstrate that at 20 μM shornephine A (1)is a noncytotoxic inhibitor of P-glycoprotein-mediated drug efflux in multidrug-resistant human colon cancer cells.
Preparation of optically active peralkyldiphosphines and their use, as the rhodium(I) complex, in the asymmetric catalytic hydrogenation of ketones
Tani, Kazuhide,Suwa, Kenichi,Tanigawa, Eiji,Ise, Tomokazu,Yamagata, Tsuneaki,et al.
, p. 203 - 222 (2007/10/02)
Two types of the optically active peralkyldiphosphine, 2,3-O-isopropylidene-2,3-dihydroxy-1,4-bis(dialkylphosphino)butane (Rdiop 3) and N-(N'-substituted carbamoyl)-4-dicyclohexylphosphino-2-dicyclohexylphosphinomethylpyrrolidine (R-Cycapp 8), have been p
Scope and Limitations of the TiCl4-Mediated Additions of Isocyanides to Aldehydes and Ketones with Formation of α-Hydroxycarboxylic Acid Amides
Seebach, Dieter,Adam, Geo,Gees, Thomas,Schiess, Martin,Weigand, Wolfgang
, p. 507 - 518 (2007/10/02)
The adducts obtained from TiCl4 and achiral (8-12) or chiral, nonracemic (13-22) isocyanides are combined with aldehydes (aromatic or aliphatic) and ketones (acetone, cyclohexanone, acetophenone) to give, after aqueous workup, α-hydroxyamides (27-55) .The transformation is compatible with a variety of functional groups (aromatic and heterocyclic rings, amino, ether, ester, and amido groups, halides, and phosphonate substituents).The yields range from 14 to over 95percent (with the lower values in the case of more highly functionalised isocyanides).No diastereoselectivity is observed with chiral isocyanides.If the R groups of the isocyanide (R-NC) form a rather stable cation (t-alkyl or benzylic), cyanohydrins may result from the reaction, rather than the N-substituted α-hydroxyamides (see Scheme 2).
ASYMMETRIC HYDROGENATION OF N-(α-KETOACYL)-α-AMINO ESTERS
Tani, Kazuhide,Tanigawa, Eiji,Tatsuno, Yoshitaka,Otsuka, Sei
, p. 737 - 738 (2007/10/02)
Asymmetric hydrogenation of N-(α-ketoacyl)-α-amino esters with Cydiop-rhodium(I) complex catalysts produced optically active N-(α-hydroxyacyl)-α-amino esters in high optical yields, which may be useful as building blocks of depsipeptides.Almost no influen
SYNTHESIS OF CHIRAL OLIGOPEPTIDES BY MEANS OF CATALYTIC ASYMMETRIC HYDROGENATION OF DEHYDROPEPTIDES
Ojima, Iwao,Yoda, Noriko,Yatabe, Momoko,Tanaka, Toshiyuki,Kogure, Tetsuo
, p. 1255 - 1268 (2007/10/02)
Asymmetric hydrogenation of Ac-ΔTyr(Ac)-(S)-Ala-Gly-OMe (6), Ac-ΔTyr(Ac)-(R)-Ala-Gly-(S)-Phe-OMe (7), Ac-ΔPhe-NH-CH(R)-CH2-OCH2Ph (10), HCO-ΔPhe-(S)-Leu-OMe (16), X-AA-ΔPhe-AA'-OMe ( 5: X=tBOC, CBZ, CF3CO; AA, AA'= α-amino acid ), and t
SYNTHESIS OF CHIRAL DEPSIPEPTIDE BUILDING BLOCK BY THE ASYMMETRIC REDUCTION OF N-(α-KETOACYL)-α-AMINO ESTERS
Ojima, Iwao,Tanaka, Toshiyuki,Kogure, Tetsuo
, p. 823 - 826 (2007/10/02)
Asymmetric reduction of N-(α-ketoacyl)-α-amino esters was performed by using homogeneous hydrosilylation and hydrogenation catalyzed by rhodium(I) complexes.The asymmetric hydrosilylation achieved good to high stereoselectivities giving the corresponding
