1.A new sesquiterpene lactone and other constituents of Moquiniastrum polymorphum subsp. floccosum (Asteraceae).
Strapasson LB, Rúdiger AL, Burrow RA, Barison A, Stefanello ME. Nat Prod Commun. 2014 Nov;9(11):1541-3.
A new guaianolide, 1S, 3S, 5R, 6S, 7S, 11R-l-hydroxy-11α,13-dihydrozaluzanin C (1), was isolated from Moquiniastrum polymorphum subsp. floccosum trunk bark, together with fifteen known compounds, which were identified as 11α,13-dihydroglucozaluzanin C (2), 8α-hydroxy-11α,13-dihydrozaluzanin C (3), zaluzanin C (4), gochnatiolide B (5), ethyl caffeate (6), methyl chlorogenate (7), ethyl chlorogenate (8), methyl 3,5-dicaffeoyl quinate (9), ethyl 3,5-dicaffeoyl quinate (10), methyl 4,5-dicaffeoyl quinate (11), ethyl 4,5-dicaffeoyl quinate (12), ethyl 3,4-dicaffeoyl quinate (13), 3,5-dicaffeoyl quinic acid (14), 4,5-dicaffeoyl quinic acid (15), and 3,4-dicaffeoyl quinic acid (16). With the exception of 5, all known compounds are being reported for the first time in M. polymorphum.
2.Identification and characterization of five new classes of chlorogenic acids in burdock (Arctium lappa L.) roots by liquid chromatography/tandem mass spectrometry.
Jaiswal R1, Kuhnert N. Food Funct. 2011 Jan;2(1):63-71. doi: 10.1039/c0fo00125b. Epub 2010 Dec 6.
Burdock (Arcticum lappa L.) roots are used in folk medicine and also as a vegetable in Asian countries especially Japan, Korea, and Thailand. We have used LC-MS(n) (n = 2-4) to detect and characterize in burdock roots 15 quantitatively minor fumaric, succinic, and malic acid-containing chlorogenic acids, 11 of them not previously reported in nature. These comprise 3-succinoyl-4,5-dicaffeoyl or 1-succinoyl-3,4-dicaffeoylquinic acid, 1,5-dicaffeoyl-3-succinoylquinic acid, 1,5-dicaffeoyl-4-succinoylquinic acid, and 3,4-dicaffeoyl-5-succinoylquinic acid (M(r) 616); 1,3-dicaffeoyl-5-fumaroylquinic acid and 1,5-dicaffeoyl-4-fumaroylquinic acid (M(r) 614); 1,5-dicaffeoyl-3-maloylquinic acid, 1,4-dicaffeoyl-3-maloylquinic acid, and 1,5-dicaffeoyl-4-maloylquinic acid (M(r) 632); 1,3,5-tricaffeoyl-4-succinoylquinic acid (M(r) 778); 1,5-dicaffeoyl-3,4-disuccinoylquinic acid (M(r) 716); 1,5-dicaffeoyl-3-fumaroyl-4-succinoylquinic acid and 1-fumaroyl-3,5-dicaffeoyl-4-succinoylquinic acid (M(r) 714); dicaffeoyl-dimaloylquinic acid (M(r) 748); and 1,5-dicaffeoyl-3-succinoyl-4-dimaloylquinic acid (M(r) 732).
3.Hierarchical scheme for liquid chromatography/multi-stage spectrometric identification of 3,4,5-triacyl chlorogenic acids in green Robusta coffee beans.
Jaiswal R1, Kuhnert N. Rapid Commun Mass Spectrom. 2010 Aug 15;24(15):2283-94. doi: 10.1002/rcm.4639.
Liquid chromatography/multi-stage spectrometry (LC/MS(n)) (n = 2-4) has been used to detect and characterize in green Robusta coffee beans eight quantitatively minor triacyl chlorogenic acids with seven of them not previously reported in nature. These comprise 3,4,5-tricaffeoylquinic acid (Mr 678); 3,5-dicaffeoyl-4-feruloylquinic acid, 3-feruloyl-4,5-dicaffeoylquinic acid and 3,4-dicaffeoyl-5-feruloylquinic acid (Mr 692); 3-caffeoyl-4,5-diferuloylquinic acid and 3,4-diferuloyl-5-caffeoylquinic acid (Mr 706); and 3,4-dicaffeoyl-5-sinapoylquinic acid and 3-sinapoyl-4,5-dicaffeoylquinic acid (Mr 722). Structures have been assigned on the basis of LC/MS(n) patterns of fragmentation. A new hierarchical key for the identification of triacyl quinic acids is presented, based on previously established rules of fragmentation. Fifty-two chlorogenic acids have now been characterized in green Robusta coffee beans. In this study five samples of green Robusta coffee beans and fifteen samples of Arabica coffee beans were analyzed with triacyl chlorogenic acids only found in Robusta coffee bean extracts.
4.Antioxidant and DNA-protective activities of chlorogenic acid isomers.
Xu JG1, Hu QP, Liu Y. J Agric Food Chem. 2012 Nov 21;60(46):11625-30. doi: 10.1021/jf303771s. Epub 2012 Nov 13.
Chlorogenic acid is a well-known antioxidant and has more isomers according to the difference in binding location and number of caffeic on quinic acid. In this study, we investigated and compared the profiles of antioxidant and DNA-protective activities of chlorogenic acid isomers including three caffeoylquinic acid isomers (3-O-caffeoylquinic acid, 3-CQA; 4-O-caffeoylquinic acid, 4-CQA; and 5-O- caffeoylquinic acid, 5-CQA) and three dicaffeoylquinic acid isomers (3,5-dicaffeoyl-quinic acid, ICAA; 3,4-dicaffeoylquinic acid, ICAB; and 4,5-dicaffeoyl-quinic acid, ICAC). The results showed that each of chlorogenic acid isomers studied exhibited antioxidant activities and DNA damage protective effects to various extents. On the whole, dicaffeoylquinic acids possessed better antioxidant activities, mostly because they have more hydroxyl groups than caffeoylquinic acids. Three caffeoylquinic acid isomers showed quite similar antioxidant activities, indicating that the position of esterification on the quinic moiety of caffeoylquinic acid had no effect on its antioxidant activities.