Synthesis and protective effects of bis{4-[N,N-di-(carboxymethyl)amino]phenoxy}alkane derivatives on UVA-induced production of MMP-1 in human skin fibroblasts.

UV-induced matrix metalloproteinase (MMP) production is considered a cause of skin aging. In this study, a number of novel bis{4-[N,N-di-(carboxymethyl)amino]phenoxy}alkane derivatives were synthesized and evaluated as UVA-protective agents. These compounds significantly protected human dermal fibroblast (HDF) cells from UVA-induced cytotoxicity and inhibited MMP-1 activation and expression with potency comparable to desferoxamine (DFO). Promoter activity assay indicated that they inhibited MMP-1 expression at the transcriptional level. Further studies revealed that the mechanism of these compounds may include blockage of the UVA-induced activation of the p38/mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK) pathways. Together, these results suggest that further development of these compounds may be of interest.

Synthesis and biological evaluation of sulfur-containing cinnamate and salicylate derivatives.

UV irradiation induced formation of reactive oxygen radical species and matrix metalloproteinases (MMPs) are thought to be involved in photo-damage to the skin. MMP-1 is the major collagenolytic enzyme responsible for collagen destruction in skin tissue. To develop new anti-photoaging agents, a series of 2,2'-dithiocinnamate derivatives and 2,2'-dithio or 2-thiobenzoate derivatives were designed and synthesized. The biological activities of the synthesized compounds were assayed for ABTS [2,2'-azinobis-(3-ethyl-benzo-thiazoline-6-sulfonic acid)] radical scavenging activity, MMP-1 inhibitory activity, and cytotoxicity to human dermal fibroblast cells. Compounds with potential of resistance to UV irradiation were identified. These compounds are expected to be useful for preventing photo-damage to the skin.

Synthesis and HIV-1 integrase inhibition of novel bis- or tetra-coumarin analogues.

Present studies were undertaken on the preparation of synthetic analogues of bis- or tetra-coumarins and their activity against HIV-1 integrase (HIV-1 IN). Among these coumarin analogues, compounds 14, 16 and 18 were found to be potent molecules against HIV-1 IN at IC50 values of 0.96, 0.58, and 0.49 microM, respectively. The results provided a tool for guiding the further design of more potent antiviral agents and for predicting the affinity of related compounds.

HIV-1 integrase inhibition of biscoumarin analogues.

Nineteen biscoumarins bearing free and modified hydroxyl substituents at benzoyloxyphenyl linker have been synthesized by multiple step synthesis. Among these biscoumarins, thirteen were found to be active molecules against HIV-1 integrase (HIV-1 IN). The structure-activity relationship of the nineteen compounds on HIV IN may be useful for the design of potent therapeutic agents.

Synthesis of selenium-containing polyphenolic acid esters and evaluation of their effects on antioxidation and 5-lipoxygenase inhibition.

Six novel selenium-containing polyphenolic acid esters were synthesized and evaluated as antioxidants and 5-lipoxygenase inhibitors. Synthesis of the title compounds involved the Mitsunobu reaction of polyphenolic acids with 2-phenylselenoethanol. Compounds and were found to be very effective antioxidants and 5-lipoxygenase inhibitors with activity comparable to or better than caffeic acid (3,4-dihydroxycinnamic acid) phenethyl ester (CAPE).

Evaluation of polyphenolic acid esters as potential antioxidants.

Six polyphenolic acid esters were synthesized and their antioxidative properties were evaluated in three model systems [2,2'-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay, 2,2'-azobis(2-amidinopropane)dihydrochloride (AAPH)-induced lipid peroxidation system, and the dye-bleaching assay of peroxynitrite radical]. Among these compounds, we found that compounds 4 [3,4-dihydroxy-benzoic acid-(2-phenoxyethyl ester)], and 5 [3,4-dihydroxy-cinnamic acid-(2-phenoxyethyl ester)] provided comparable activity to caffeic acid phenethyl ester (CAPE) in the DPPH model. Compound 3 [2,5-dihydroxy-benzoic acid-(2-phenoxyethyl ester)], was found to be more active than CAPE in the AAPH system, it also displayed about 2-fold greater activity than CAPE in the peroxynitrite radical model. These results suggest that these phenolic acid ester derivatives, with their potent anti-oxidant activities, may have useful applications as antioxidants.

Synthesis and biological evaluation of ebselen and its acyclic derivatives.

Five ebselen and three acyclic ebselen derivatives were synthesized. These compounds were screened for their glutathione peroxidase (GSH Px)-like activity and scavenging activity against 1,1-diphenyl-2-pycryl-hydrazyl (DPPH) and peroxynitrite radical. All tested compounds displayed similar significant GSH Px-like activity, which are slightly higher than that of ebselen. The peroxynitrite scavenging activity showed that the acyclic allylseleno 4c was five times more potent than ebselen.

Synthesis and biological activity of sulfur-containing aryl-aldehyde Schiff bases.

A series of chemically modified aryl-aldehyde Schiff bases has been synthesized and tested for their antioxidant activity and radiation protection. We observed that disulfide-containing aryl-aldehyde Schiff base 6c exhibited potent free radical scavenging, antioxidation, and radioprotection activities.

Chemical modification of coumarin dimer and HIV-1 integrase inhibitory activity.

A systematic series of chemically modified coumarin dimmers has been synthesized and tested for their inhibitory activity against HIV-1 integrase. We observed that modified coumarin dimmers containing hydrophobic moiety on the linker display potent inhibitory activities.

A new synthetic route towards the mono-O-protected anti-conformationally constrained pyrimidine acyclic nucleoside.

Novel synthetic approach to mono-O-protected anti-conformationally constrained pyrimidine acyclic nucleoside was attained from the coupling of lithiated 2,4-dimethoxy-6-methylpyrimidine with 1-benzyloxy-3-(tert-butyldiphenylsilyloxy)propan-2-one, followed by the sequential reactions of methylthiomethylation, cyclization, hydroxylation, and dealkylation.