Synthesis and biological activity of thiophene bioisosteres of natural styryl lactone goniofufurone and related compounds.

Ten new thiophene derivatives related to goniofufurone have been obtained by multistep synthesis starting from d-glucose. The critical step of the synthesis was the Grignard reaction of 2-thienyl magnesium bromide with a protected dialdose, yielding the C-5 epimeric thiophene derivatives 9 and 10. The mixture was oxidized to the 5-keto derivative 11, which after deprotection was converted to the corresponding keto-lactone 14.

Design, synthesis, and biological evaluation of thiazole bioisosteres of goniofufurone through in vitro antiproliferative activity and in vivo toxicity.

The synthesis of several new goniofufurone bioisosteres was achieved in which the phenyl residue was replaced by a thiazole ring. The key steps of the synthesis included the initial condensation of cyanohydrin benzoates with cysteine ethyl ester hydrochloride, followed by the subsequent reaction of resulting C-4' epimeric thiazolines with DBU, to introduce 5-deoxy functionality and to elaborate the thiazole ring in one step. Synthesized compounds showed potent growth inhibitory effects against selected human tumour cell lines, especially bioisostere 4, which in the culture of MCF-7 cells displayed the highest activity (IC = 0.

Structure based design, synthesis and in vitro antitumour activity of tiazofurin stereoisomers with nitrogen functions at the C-2' or C-3' positions.

Three novel tiazofurin analogues having d-arabino stereochemistry and nitrogen functionalities at the C-2' position (5-7) have been designed and synthesized in multistep sequences, starting from d-glucose. The known d-xylo stereoisomer of 1 (compound 2) along with two new analogues bearing nitrogen functions at the C-3' (3 and 4) has also been synthesized from the same sugar precursor. The synthetic sequence consisted of the following three stages: (i) the multistep synthesis of suitably protected pentofuranosyl cyanides, (ii) the construction of ethyl thiazole-4-carboxylate part by cyclocondensation of thus obtained glycofuranosyl cyanides with l-cysteine ethyl ester followed by dehydrogenation, and (iii) the final transformation of the ethyl thiazole-4-carboxylates into the target tiazofurin analogues using the esters ammonolysis.

Design, synthesis and in vitro antitumour activity of new goniofufurone and 7-epi-goniofufurone mimics with halogen or azido groups at the C-7 position.

A series of new antitumour lactones containing the [3.3.0] bicyclic furano-lactone core and the halogen or azido group at the C-7 position have been designed, synthesized, and evaluated for their in vitro antitumour activity against a panel of human tumour cell lines.

Conformationally constrained goniofufurone mimics as inhibitors of tumour cells growth: Design, synthesis and SAR study.

Synthesis of conformationally restricted (+)-goniofufurone (1) and 7-epi-(+)-goniofufurone (2) analogues, with embedded O-isopropylidene, O-methylidene or cyclic carbonate functions is disclosed starting from d-glucose. A number of potential bioisosteres of 1 and 2 bearing both 5,7-O-methylidene and 4-substituted cinnamoyloxy functions at the C-7 position have also been synthesized. In vitro cytotoxicity of target molecules against a number of human tumour cell lines were recorded and compared with those observed for the parent molecules 1 and 2.

Heteroannelated and 7-deoxygenated goniofufurone mimics with antitumour activity: design, synthesis and preliminary SAR studies.

Cytotoxic (+)-goniofufurone mimic such as benzoxepane 2 was preferentially formed after the treatment of 7-O-benzoyl-5-O-benzyl (+)-goniofufurone derivative 6 with titanium(IV) fluoride. However, the corresponding 7-epimer 5 (derivative of 7-epi-goniofufurone) under the similar reaction conditions gave mainly 7-deoxy derivative 7 as a result of an unexpected 1,5-hydride shift. Extension of this methodology to the enantiomer ent-6 provided cytotoxic (-)-goniofufurone mimics ent-2 and ent-7.