A microwave-assisted stereoselective synthesis of polyandrocarpamines A and B

Abstract

A stereoselective synthesis of the marine natural products, polyandrocarpamines A and B, has been achieved using a high-yielding one-step aldol condensation reaction under microwave conditions. The structures of both synthetic compounds were confirmed following 1D and 2D NMR, UV, IR and MS spectral analysis, and by comparison with literature data. Both synthetic natural products were assigned Z geometry about their exocyclic double bond on the basis of 13 C/ 1 H long-range coupling constants, which were measured using a gHSQMBC experiment. Polyandrocarpamines A and B were evaluated for their cytotoxicity towards the tumour cell lines, MCF-7 (breast), H460 (lung) and SF268 (central nervous system). Polyandrocarpamine A displayed selective cytotoxicity towards the SF268 cell line with a GI 50 value of 65 µM.

Marine natural products

“…793 Botryllazine B (Botryllus leachi) 794 and analogues are mixed-type inhibitors of recombinant human aldose reductase. 797 The structures of eudistomins Y 1 -Y 6 (Eudistoma sp.) 797 The structures of eudistomins Y 1 -Y 6 (Eudistoma sp.)…”

Benzylidene 2-Aminoimidazolones Derivatives: Synthesis and <i>in Vitro</i> Evaluation of Anti-tumor Carcinoma Activity

“…The intermediate 4 was reacted with other commercially available material 4-hydroxybenzaldehyde 5a or vanillin 5b to form 6a or 6b by condensation according to the literature. 6,8) Compounds 6a, b was oxidized by tert-butylhydroperoxide (TBHP) to obtain the important intermediate 7a, b. Then corresponding amine, alkane amines or alcohol amines were introduced onto the sulfonic group of compounds 7a, b to obtain the targeted compounds 1a-k, 2a-k.…”

“…1) Resourceful novel and structurally diverse metabolites from marine organisms, in particular those coming from sponges, have proved to display a wide variety of biological activities including antihistamine activity, 2) antiinflammation, 3) neuroprotective activity, 4,5) antitumor, 6) antioxidant, 7) etc. For example (see Fig.…”

“…6,9,10) Many recent reports and reviews have also highlighted that Polyandrocarpamines A exhibit potent antitumor activity. 6,11,12) Phorbatopsins A which was isolated from the Mediterranean marine sponge Phorbas topsent exhibited antioxidant activity. 7) Interestingly, these marine natural products share a common skeletal structure that is 2-aminoimidazolone core.…”

Microwaves in the Synthesis of Natural Products

“…These simple alkaloids were first isolated and synthesized in 2002, and although sufficient quantities were generated by total synthesis, no biological activity has been reported so far. Davis et al[45] reported an MWassisted synthesis of polyandrocarpamine A (201) and B (202). They started from the HCl salt of glycocyamidine (203), which was condensed with aldehyde 204 in an NaOAc-AcOH slurry under MW irradiation at 160 • C for 30 min to yield the polyandrocarpamines A (201) (56%) and B (202) (80%) in high yields (Scheme 19.43).…”