97633-82-4Relevant academic research and scientific papers
Total synthesis of natural and unnatural lamellarins with saturated and unsaturated D-rings
Ploypradith, Poonsakdi,Petchmanee, Thaninee,Sahakitpichan, Poolsak,Litvinas, Nichole D.,Ruchirawat, Somsak
, p. 9440 - 9448 (2007/10/03)
(Chemical Equation Presented) Twenty-eight natural and unnatural lamellarins with either a saturated or an unsaturated D-ring were synthesized according to our developed synthetic route. The key step involved the Michael addition/ring closure (Mi-RC) of the benzyldihydroisoquinoline and α-nitrocinnamate derivatives, which provided the 2-carboethoxypyrrole intermediates in moderate to good yields (up to 78% yield). Subsequent hydrogenolysis/lactonization furnished lamellarins with a saturated D-ring in excellent yields (up to 93% yield). DDQ oxidation of the saturated lamellarin acetates led directly to the corresponding unsaturated analogues in 54-95% yield. In addition, only two steps in our developed strategy require column chromatography.
Topoisomerase I-mediated DNA cleavage as a guide to the development of antitumor agents derived from the marine alkaloid lamellarin D: Triester derivatives incorporating amino acid residues
Tardy, Christelle,Facompre, Michael,Laine, William,Baldeyrou, Brigitte,Garcia-Gravalos, Dolores,Francesch, Andres,Mateo, Cristina,Pastor, Alfredo,Jimenez, Jose A.,Manzanares, Ignacio,Cuevas, Carmen,Bailly, Christian
, p. 1697 - 1712 (2007/10/03)
The marine alkaloid lamellarin D (LAM-D) has been recently characterized as a potent poison of human topoisomerase I endowed with remarkable cytotoxic activities against tumor cells. We report here the first structure-activity relationship study in the LAM-D series. Two groups of triester compounds incorporating various substituents on the three phenolic OH at positions 8, 14 and 20 of 6H-[1]benzopyrano[4′,3′:4,5]pyrrolo[2,1-a]isoquinolin-6- one pentacyclic planar chromophore typical of the parent alkaloid were tested as topoisomerase I inhibitors. The non-amino compounds in group A showed no activity against topoisomerase I and were essentially non cytotoxic. In sharp contrast, compounds in group B incorporating amino acid residues strongly promoted DNA cleavage by human topoisomerase I. LAM-D derivatives tri-substituted with leucine, valine, proline, phenylalanine or alanine residues, or a related amino side chain, stabilize topoisomerase I-DNA complexes. The DNA cleavage sites detected at T↓G or C↓G dinucleotides with these molecules were identical to that of LAM-D but slightly different from those seen with camptothecin which stimulates topoisomerase I-mediated cleavage at T↓G only. In the DNA relaxation and cleavage assays, the corresponding Boc-protected compounds and the analogues of the non-planar LAM-501 derivative lacking the 5-6 double bond in the quinoline B-ring showed no effect on topoisomerase I and were considerably less cytotoxic than the corresponding cationic compounds in the LAM-D series. The presence of positive charges on the molecules enhances DNA interaction but melting temperature studies indicate that DNA binding is not correlated with topoisomerase I inhibition or cytotoxicity. Cell growth inhibition by the 41 lamellarin derivatives was evaluated with a panel of tumor cells lines. With prostate (DU-145 and LN-CaP), ovarian (IGROV and IGROV-ET resistant to ecteinascidin-743) and colon (LoVo and LoVo-Dox cells resistant to doxorubicin) cancer cells (but not with HT29 colon carcinoma cells), the most cytotoxic compounds correspond to the most potent topoisomerase I poisons. The observed correlation between cytotoxicity and topoisomerase I inhibition strongly suggests that topoisomerase I-mediated DNA cleavage assays can be used as a guide to the development of superior analogues in this series. LAM-D is the lead compound of a new promising family of antitumor agents targeting topoisomerase I and the amino acid derivatives appear to be excellent candidates for a preclinical development.
ANTITUMORAL ANALOGS OF LAMELLARINS
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Page 72, (2010/02/06)
New lamellarins are provided of the general formula III wherein X is selected from the group consisting of N, O and S; wherein R1, R2, R3, R4, R5, R6, R7, R8 and Rsub
Metabolites of the Marine Prosobranch Mollusc Lamellaria sp.
Andersen, Raymond J.,Faulkner, D. John,Cun-heng, He,Duyne, Gregory D. Van,Clardy, Jon
, p. 5492 - 5495 (2007/10/02)
The marine prosobranch mollusc, Lamellaria sp. contains four aromatic metabolites, lamellarins A-D (1-4).The structure of lamellarin A (1) was determined by an X-ray crystallographic study and the structures of lamellarins B-D (2-4) were assigned by inter
