Farouk Ameer

Synthesis of Methoxy‐2‐hydroxy‐1,4‐naphthoquinones and Reaction of One Isomer with Aldehydes Under Basic Conditions

Abstract Two protocols for the synthesis of methoxy‐2‐hydroxy‐1,4‐naphthoquinones were investigated in order to evaluate their behavior towards aldehydes under amine‐basic conditions. Both the nature of the quinone and aliphatic aldehyde contribute to the viability of this condensation as well as further transformations.

THE DDQ MEDIATED CYCLIZATION PRODUCTS OF SOME 2-HYDROXY-3-(1′-ALKENYL)-1,4-NAPHTHOQUINONES

ABSTRACT The DDQ mediated cyclisation products derived from 2-hydroxy-3-(1′-alkenyl)-1,4-napthoquinones viz. 17 were found to be temperature dependent. At 60°C the naphthofuranquinone 19 was the predominant isomer whereas at 8°C, the naphthopyranquinone 18 was exclusively formed.

CONDENSATION PRODUCTS BETWEEN CAPROALDEHYDE AND 2-HYDROXY-1,4-NAPHTHOQUINONE

Reaction between caproaldehyde 2 and 2-hydroxy-1,4-naphthoquinone 1 under both acidic and basic conditions resulted in the formation of useful compounds including the desired 2-hydroxy-3(1′-hexenyl)-1,4-naphthoquinone 3. The varied results on the reaction conditions and factors affecting the reaction are discussed.

New polyhydroxylated sterols from Palythoa tuberculosa and their apoptotic activity in cancer cells

The chemical study on the total extract of the zoanthid Palythoa tuberculosa, collected from the Red Sea, resulted in the isolation of seven polyhydroxylated sterols (1-7), six of which, palysterols A-F (2-7), are new. Their chemical structures were elucidated on the basis of extensive analysis of their 1-, 2D NMR and MS spectroscopic data. This is the first chemical investigation on the species collected from Red Sea. We studied the cytotoxic effects of the total extract and some of the new polyhydroxylated sterols in three human cancer cell lines (MCF-7, HeLa, and HT-29) and one non-cancerous human cell line (KMST-6). Palysterol F (7), in particular, was able to selectively induce high levels of apoptosis (>75%) in breast adenocarcinoma (MCF-7) cells but not HeLa, HT-29 and KMST-6 cells.

THE SYNTHESIS OF NEW BRONCHODILATOR PRODRUGS

Abstract Prodrug 14 has been synthesized to investigate its lung accumulating property while prodrugs 19, 20 and 22 incorporating structural features of 14 have been prepared for evaluation as bronchodilatory agents.

Corrigendum to “New polyhydroxylated sterols from Palythoa tuberculosa and their apoptotic activity in cancer cells” [Steroids 101 (2015) 110–115]

Department of Chemistry, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa Department of Biotechnology, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa National Institute of Oceanography and Fisheries, Attaka P.O. Box 182, Suez, Egypt d Zoology Department, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031, South Africa Centro de Química Orgánica ‘‘Lora-Tamayo” (CSIC), C/Juan de la Cierva 3, 28006 Madrid, Spain

Synthesis of 2-acetyl-4-hydroxynaphtho [2,3-b]pyran-5,10-dione and the 4-deoxy analogue as models for comparative biological evaluations

Abstract Two deoxy analogues of the known antibiotic, erythrostominone, have been synthesised for comparative evaluations. It was found that both the 2‐acetyl and the 4‐hydroxy substituents in the pyran ring are vital for improved biological activity.