Chlorins (dihydroporphyrins) are considered, due to their ideal photophysical properties, as attractive photosensitizers for photodynamic therapy (PDT) of cancer and other therapeutic and diagnostic applications. Chlorophyll [Formula: see text], as a naturally occurring chlorin, forms an almost unlimited renewable resource for preparation of potential biologically active chlorin photosensitizers and fluorescence markers. To achieve amphiphilic photosensitizers which might be selectively enriched in tumor cells, we addressed linkage of per se lipophilic chlorophyll derivatives with carbohydrate based hydrophilic aminopolyols.
Enantiomerically pure ring building block for naturally occurring hydroporphyrins and possibly vitamin B12 was synthesized starting from methylated Hagemann´s ester. Originally, this ester was utilized to investigate preparation of ring building blocks for vitamin B12 in Eschenmoser´s and Woodward´s syntheses. Hagemann´s ester furnished methyl 4-acetoxy-2,3-dimethylcyclohex-2-en-1-carboxylate in racemic form. Kinetic enzymatic resolution of the cyclohexene acetate led to the enantiopure hydroporphyrin building block methyl {(1S,2S,5S,3Z)-3-(2-t-butoxy-2-oxoethylidene)-1. 5-dimethyl-7-oxo-4-aza-6-oxabicyclo[3.3.0]oct-2-yl}-2-propionate. O CO 2 CH 3 CO 2 CH 3 OH N H O CO 2 CH 3 O CO 2 tBu CO 2 CH 3 OAc
Dihydroartemisinin was converted to its corresponding alkyne-functionalized esters, which were subsequently deployed as substrates for a 'click' chemistrymediated coupling with 3'-azido-3'-deoxythydimine (AZT) to furnish novel triazole-artesunate-AZT hybrid compounds. Moreover, various substituted triazole-artemisinin hybrids were synthesized based on 'click' chemistry between propargyl-substituted derivatives and artemisinin containing a 2-hydroxypropane unit. Fourteen new hybrids were thus successfully prepared and evaluated as cytotoxic agents, revealing an interesting anticancer activity of four triazole-artemisinin derivative hybrids in KB and HepG2 cancer cell lines.
In this work, the crude MeOH extract of fruits of Dipterocarpus retusus Blume (Dipterocarpaceae) growing in Vietnam was prepared and studied. Five compounds: ε-viniferin, paucifloroside, ursolic acid, quercetin, and (+)-catechin, was isolated. The structures of these compounds were elucidated by spectroscopic methods. The extracts from fruits of D. retusus Blume by metanol and its some isolated stilbene compounds were evaluated for anti-inflammatory effect activities.
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