Stereochemistry and NMR Data Assignment of Cyclopeptide Alkaloids from Zizyphus Oxyphylla

Abstract

The structures of (3 S,7 R,13 S)-6-[2-(dimethylamino)-3-phenylpropanoyl]-19-methoxy-2-oxa-6,9,15-triazatetracyclo[16.3.1.03,7. 09,13]docosa-1-(22),16,18,20-tetraene-8,14-dione (1), nummularin-C (2) and nummularin-R (3) have been previously determined mainly based on mass spectrometric data. Stereochemistry and complete 1H and 13C NMR spectroscopic data assignments of these compounds are now described. Compounds 1 and 2 are reported for the first time from

Isolation and Structure Elucidation by LC-DAD-MS and LC-DAD-SPE-NMR of Cyclopeptide Alkaloids from the Roots of Ziziphus oxyphylla and Evaluation of Their Antiplasmodial Activity

“…The NMR data of compound 1 were in agreement with previously reported assignments for nummularine-R. 16 1 H and 13 C NMR chemical shift assignments for 1 are listed in Tables 1 and 2, respectively. This cyclopeptide alkaloid has been previously isolated from Z. oxyphylla and was found to be present in both batches.…”

“…Whereas for the first batch a general liquid−liquid partition and fractionation scheme was followed, a more alkaloid-specific fractionation procedure was used for the second batch in order to increase the number of alkaloids detected. The isolation of single compounds was The NMR data of compound 1 were in agreement with previously reported assignments for nummularine-R. 16 1 H and 13 C NMR chemical shift assignments for 1 are listed in Tables 1 and 2, respectively. This cyclopeptide alkaloid has been previously isolated from Z. oxyphylla and was found to be present in both batches.…”

New 14-Membered Cyclopeptide Alkaloids from Zizyphus oxyphylla Edgew

“…This process yielded two new cyclopeptide alkaloids ( 3 , 4 , 5 ) and from the dichloromethane fraction of root, two cyclopeptide alkaloids ( 1 and 2 ) were isolated as white amorphous powders ( Figure 1 ). Structures of the known compounds ( 1 – 3 ) were elucidated by comparing their analytical data with literature values [ 6 , 8 – 11 ].…”

Absolute configuration of (2S)-4-(4-hydroxyphenyl)butan-2-ol

“…For the biological activity and medicinal uses of Taxus. wallichiana Zucc, see: Ahmed (1997); Baquar (1995); Kaul (1997); Nisar et al (2008a,b;2010); Prasain et al (2001); Wani et al (1971). Hydrogen-bond geometry (Å , ).…”

“…The genus Taxus belonging to the family Taxaceae is well known for its anticancer agents, namely taxol and dosetaxel (Wani et al, 1971;Prasain et al, 2001;Nisar et al, 2008a,b;2010). Taxus.…”