57371-42-3

A series of eugenol derivatives (2-14) were synthesized and evaluated for their antibacterial activity against five bacterial test strains; three Gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus and Staphylococcus epidermidis) and two Gram-negative bacteria (Escherichia coli and Salmonella typhimurium) using well-diffusion method. Among the compounds tested, compounds 2-4 displayed susceptible activity toward S. epidermidis with 16-18 mm whereas compounds 12 exhibited susceptible inhibition towards S. aureus only with inhibition diameter of 16 mm, respectively. Other compounds possessed varied antibacterial activities classified as intermediate or resistance indicating that eugenol derivatives have narrow spectrum activity and specifically to Gram-positive bacteria.

The first report for the synthesis of tyrosyl-DNA phosphodiesterase I inhibitors 3,4-dimethoxyphenol-1-β-d-(6′-O-galloyl)glucopyranoside 3 and 3-(4-hydroxy-3-methoxyphenyl)propane-1,2-diol 2-β-d-(6′-O-galloyl) glucopyranoside 5 has been accomplished starting from readily available d-glucose as a starting material. An efficient and general approach has been reported for the synthesis of compounds 3 and 5 with an overall yield of 26% and 27%, respectively.

-

We described the efficient preparation of (E)-(2-arylvinyl)boronates from allylbenzene derivatives on the basis of an isomerization/cross-metathesis sequence catalyzed by a modified Hoveyda-Grubbs catalyst. The implementation of the experimental procedure was simple and compatible with a large variety of substrates. This methodology provides a new chemical transformation not described to date. Allyl-substituted aromatics can thus be converted into diversely functionalized compounds, such as (E)-stilbene derivatives or (E)-vinyl azides, in only two steps. Copyright

We have recently demonstrated that hydroxychavicol is a major constituent and the most active biophenolic of Piper betel leaves with significant antiproliferative activity in the micro molar range. Herein we present the design, synthesis and evaluation of fifteen novel hydroxychavicol analogs with varying antiproliferative activities in cancer cell lines from two representative tissue types, namely, the prostate and cervix that show very encouraging results compared to the parent compounds. Our long range goal is to develop a structure-activity guided relationship to gain mechanistic insights into novel molecular targets of this class of bioactive molecules for rational drug development. Cytotoxicity-guided experimentation on these novel analogs yielded the following structural factors as the key activity regulators: 1) unlike the hydroxyl substituent at position-4, the position-3 hydroxyl is vital for enhanced activity 2) acetoxyl groups are dispensable for activity as corroborated earlier by others 3) allylic double bonds at 2′C-3′C serve to positively influence antiproliferative activity 4) long saturated side chains at 1′-position negatively regulate antiproliferative activity and 5) maneuvering position-4 with a benzyl group positively impacted the biological activity profile. Most amphiphilic compounds showed moderate to good therapeutic potential as expected on the basis of medicinal chemistry principles. Intriguingly, the most active compound with ten-fold higher activity than the parent molecule was realized by sheer serendipity to employ a silica gel based rearrangement that was further explored using nuclear magnetic resonance spectroscopy and density functional theory calculations. This is the first report to describe strategies for optimal synthesis of a novel series of 15 analogs based upon hydroxychavicol, a simple phytochemical of immense anticancer potential.

Synthesis of 6-gingerol and its congeners 7- and 9-gingerols has been achieved from eugenol by a new scalable and eco-friendly protocol. The key steps are functionalization of eugenol to the nitro compound and its reaction under optimized condition with terminal alkenes to afford intermediate isoxazolines. The latter on catalytic hydrogenation in presence of Raney nickel afford corresponding gingerols in good yields.

Exchange of the lipophilc part of ortho-substituted cinnamic acid lead structures with different small molecule fluorophoric moieties via a dimethylene spacer resulted in hEP3R ligands with affinities in the nanomolar concentration range. Synthesized compounds emit fluorescence in the blue, green, and red range of light and have been tested concerning their potential as a pharmacological tool. hEP3Rs were visualized by confocal laser scanning microscopy on HT-29 cells, on murine kidney tissues, and on human brain tissues and functionally were characterized as antagonists on human platelets. Inhibition of PGE2 and collagen-induced platelet aggregation was measured after preincubation with novel hEP3R ligands. The pyryllium-labeled ligand 8 has been shown as one of the most promising structures, displaying a useful fluorescence and highly affine hEP3R antagonists.

We have synthesized a series of novel isoxazolines via 1,3-dipolar cycloaddition of in situ generated nitrile oxide from 2,4-dimethoxy benzaldoxime and naphthaldehyde oxime with 4-allyl-2-methoxyphenol derivatives. The synthesized compounds were evaluated for anti-stress activity in acute stress (AS) induced peripheral changes. Adult male Sprague-Dawley rats, subjected to AS, cause a significant increase in gastric ulceration, adrenal gland weight, plasma glucose, corticosterone levels, and creatine kinase activity. Compounds 3d, 3g, 5b, 5c, 5d, and 5g displayed most promising anti-stress effect by reverting these peripheral stress parameters at a dose of 40 mg/kg p.o.

A high yielding route to the (-)-platensimycin core is communicated. This entailed the discovery of Bi(OTf)3 to catalyze a Friedel-Crafts cyclization of a free lactol, supplemented by LiClO4 to suppress the Lewis basicity of the sulfonate group. After TBAF-promoted cyclodearomatization, a diastereoselective conjugate reduction of a dienone was achieved by adopting amine-based organocatalytic rationales to reverse the inherent steric control of the substrate.

(Chemical Equation Presented) The first total synthesis of (-)-plicatic acid has been achieved by a concise and enantioselective route. In this synthesis, a conceptually new strategy featuring an asymmetric epoxidation-intramolecular epoxy-ring-opening Friedel-Crafts reaction sequence was developed for the stereoselective construction of the 2,7′- cyclolignane skeleton bearing contiguous quaternary-quaternary-tertiary stereocenters. The implementation of this strategy was enabled by the development of a modified protocol for the Seebach epoxidation with TADOOH, which affords an unprecedented, highly enantioselective and diastereoselective epoxidation with a range of α-carbonyl-β-substituted acrylates 3.

A counterattack protocol for differential acetylative cleavage of phenylmethyl ether has been developed. The phenylmethyl moiety is liberated as benzyl bromide that is isolated and reused providing advantages in terms of waste minimization/utilization and atom economy. The applicability of this methodology has been extended for solid phase organic reactions with the feasibility of reuse of the solid support.

A series of novel ortho-substituted cinnamic acids have been synthesized, and their binding activity and selectivity on the four prostaglandin E 2 receptors evaluated. Many of them are very potent and selective EP3 antagonists (Ki 3-10 nM), while compound 9 is a very good and selective EP2 agonist (Ki 8 nM). The biological profile of the EP2 agonist 9 in vivo and the metabolic profile of selected EP3 antagonists are also reported.