25328-01-2Relevant academic research and scientific papers
Structure-cytotoxicity relationships of some helenanolide-type sesquiterpene lactones
Beekman, Aaeron C.,Woerdenbag, Herman J.,Van Uden, Wim,Pras, Niesko,Konings, Antonius W. T.,Wikstroem, Hakan V.,Schmidt, Thomas J.
, p. 252 - 257 (1997)
This study deals with the cytotoxicity of helenanolide-type (10α- methylpseudoguaianolide) sesquiterpene lactones. We determined the influence of substitution patterns on the toxicity of 21 helenanolides to a cloned Ehrlich ascites tumor cell line, EN2. Within a series of helenalin esters, the acetate (2) and isobutyrate (3) were more toxic than helenalin itself (1). Esters with larger acyl groups (tiglate 4 and isovalerate 5) exhibited a decreased toxicity compared with the parent alcohol (1). Similar relationships were observed between the 6,8-diastereomer of helenalin, mexicanin I (6) and its acetate (7) and isovalerate (8). In contrast, cytotoxicity within a series of 11α,13-dihydrohelenalin esters (9-12) was shown to be directly related to the size and lipophilicity of the ester side chain, dihydrohelenalin (9) being the least toxic compound in this group. Investigation of several 2,3-dihydrohelenalin derivatives (13-21) with 2α- hydroxy-4-oxo- and 2α,4α-dihydroxy- or -O-acyl-substituted cyclopentane rings (arnifolins and chamissonolides, respectively), for which no pharmacological data have been reported so far, revealed further interesting influences of the substitution pattern on cytotoxicity. The results may be interpreted in terms of lipophilicity and steric effects on the accessibility of the reactive sites considered responsible for biological activity.
STRUCTURE-ACTIVITY RELATIONSHIPS OF PSEUDOGUAIANOLIDES ISOLATED FROM GAILLARDIA PULCHELLA AND THEIR DERIVATIVES
Harimaya, Kenzo,Inayama, Seiichi
, p. 993 - 1008 (2007/10/02)
Three new pseudoguaianolides, 4-epipulchellin (1), 4-epineopulchellin (2) and pulchelloid D (3), were isolated from Gaillardia pulchella together with other eleven pseudoguaianolides and three guaianolides.Fifteen natural sesquiterpene lactones and their thirty one derivatives were tested for cytotoxic activity against KB cell line.Among them, twenty seven compounds were shown to be active (ED50 4 μg/ml).The structure-activity relationships of these sesquiterpene lactones are discussed.
ISOLATION AND STRUCTURE OF NEW PSEUDOGUAIANOLIDES,4-EPIPULCHELLIN AND 4-EPINEOPULCHELLIN FROM GAILLARDIA PULCHELLA
Harimaya, Kenzo,Hori, Hitoshi,Ohkura, Tamiko,Kawamata, Takeshi,Gao, Ji-Fu,Inayama, Seiichi
, p. 83 - 88 (2007/10/02)
The structure of 4-epipulchellin (1a) and 4-epineopulchellin (1b), new pseudoguaianolide sesquiterpene lactones isolated from Gaillarda pulchella, was determined on the basis of spectroscopic data and chemical transformations from pulchellin (2a) and neopulchellin (2b) into 1a and 1b, respectively.
