Bioactive compounds from <Emphasis Type="Italic">Smilax excelsa</Emphasis> L.

Phytochemical investigation of EtOAc extract of Smilax excelsa has led to isolation and structure elucidation of five compounds. The structures of these compounds are established by different spectroscopic techniques including 1D and 2D-NMR, HRMS and ECD spectroscopy. The compounds were: solanesol (1), violasterol A (2), trans-resveratrol (3), 5-O-caffeoylshikimic acid (4) and 6-O-caffeoyl-β-d-fructofuranosyl-(2-1)-α-d-glucopyranoside (5). The configuration of compound 2 was established by electronic circular dichroism (ECD) spectroscopy. Meanwhile the cytotoxicity and antibacterial activity of the compounds were evaluated by MTT and MIC assays. Compounds 1 and 2 showed promising inhibition on MCF-7 cell line with IC₅₀ of 161.6 and 190.0 µM, respectively. Also compounds 2 and 3 illustrated activity against Staphylococcus aureus with MIC values of 142.5 and 136.9 µM, respectively.     

Crystal structure and density functional theory study on structural properties and energies of a isonicotinohydrazide compound

An X-ray and a theoretical study of the structure of the isoniazid derivative N'-(4-dimethylaminobenzylidene)-isonicotinohydrazide monohydrate (1) are reported. In this work, we will report a combined experimental and theoretical study on the molecular structure, vibrational spectra and energies of N'-(4-dimethylaminobenzylidene)-isonicotinohydrazide monohydrate. The calculated parameters are in good agreement with the corresponding X-ray diffraction values. The FTIR spectrum in the range of 400-4000 cm-1 of N'-(4-dimethylaminobenzylidene)-isonicotinohydrazide monohydrate has been recorded. The molecular geometry and vibrational frequencies and energies in the ground state are calculated by using the DFT (B3LYP, PBE1PBE) methods with 6-311G** basis sets. The calculated HOMO and LUMO energies also confirm that charge transfer occurs within the molecule. The geometries and normal modes of vibrations obtained from B3LYP/PBE1PBE/6-311G** calculations are in good agreement with the experimentally observed data.     

Poly(1,4-butyl-bis-vinylpyridinium) borohydride as a new stable and efficient reducing agent in organic synthesis

The unstable sodium borohydride is stabilized on modified poly(4-vinylpyridinium), and it is used as an efficient and regenerable polymer-supported borohydride reagent for the reduction of a variety of carbonyl compounds, such as aldehydes, ketones, α,β-unsaturated carbonyl compounds, α-diketones and acyloins, in good to excellent yields.     

4-Imidazol-1-yl-butane-1-sulfonic acid ionic liquid: Synthesis,structural analysis,physical properties and catalytic application as dual solvent-catalyst

Abstract

4-Imidazol-1-yl-butane-1-sulfonic acid (ImBu-SO₃H) has been successfully synthetized and fully characterized by FT-IR and high-resolution NMR spectroscopy (¹H, ¹³C). The “plausible” alternative structures of ImBu-SO₃H were discussed on the basis of its NMR data. The ionic liquid showed interesting dual solvent-catalyst property, which was studied experimentally for the acetylation of a variety of functionalized alcohols, phenols, thiols, amines and α-tocopherol (α-CTP) as the most active form of vitamin E with acetic anhydride and which provided good yields within a short reaction time. ImBu-SO₃H was successfully recycled by product extraction with an average recovered yield of 82% for 5 subsequent runs. The catalytic activity of the recycled ImBu-SO₃H showed almost no loss even after five consecutive runs.     

Essential oil composition and antioxidant activity of different extracts of Nepeta betonicifolia C.A. Meyer and Nepeta saccharata Bunge

Aerial parts essential oil of Nepeta betonicifolia and N. saccharata were obtained by hydrodistillation and analysed by GC-FID and GC-MS. Thirty-three and eighteen components represented 97.9% and 98.2% of the total oils identified, respectively. Main compounds of the oil of N. betonicifolia were 4aα,7β,7aα-nepetalactone (42.0%), germacrene D (6.0%), triplal (5.2%), 1-nor-bourbonanone (4.0%) and 1,8-cineole (3.2%). The principal constituents of the essential oil of N. saccharata were found to be 4aβ,7α,7aβ-nepetalactone (66.9%), germacrene D (12.9%), sabinene (6.5%) and trans-caryophyllene (3.3%). The radical scavenging capacity (RSC) of methanol extracts and chloroform, butanol and water subfractions of aerial parts of N. betonicifolia and N. saccharata were evaluated by using DPPH, FRAP and ABTS assays. TPC of each extract was measured using Folin-Ciocalteau. The antioxidant activity of the butanolic subfractions of both plants was higher than other extracts examined.     

Poly(4-vinylpyridine) catalyzed chemoselective O-TMS protection of alcohols and phenols and N-Boc protection of amines

Poly(4-vinylpyridine) (PVP) acts as an efficient and reusable catalyst for the selective and efficient trimethylsilylation of alcohols and phenols with hexamethyldisilazane (HMDS) and N-tert-butoxycarbonylation of amines with (Boc)₂O. All reactions were performed under mild conditions in good to high yields.