Table of Contents

Abstract: The radical-scavenging activities of the synthetic antioxidants 2-allyl-4-X-phenol (X=NO₂, Cl, Br, OCH₃, COCH₃, CH₃, t-(CH₃)₃, C₆H₅) and 2,4-dimethoxyphenol, and the natural antioxidants eugenol and isoeugenol, were investigated using differential scanning calorimetry (DSC) by measuring their anti-1,1-diphenyl-2-picrylhydrazyl (DPPH) radical activity and the induction period for polymerization of methyl methacrylate (MMA) initiated by thermal decomposition of 2,2'-azobisisobutyronitrile (AIBN) and benzoyl peroxide (BPO). 2-Allyl-4-methoxyphenol and 2,4-dimethoxy-phenol scavenged not only oxygen-centered radicals (PhCOO^.) derived from BPO, but also carbon-centered radicals (R^.) derived from the AIBN and DPPH radical much more efficiently, in comparison with eugenol and isoeugenol. 2-Allyl-4-methoxyphenol may be useful for its lower prooxidative activity.

Abstract: The antibacterial activity against Staphylococcus aureus of long-chain fatty alcohols was investigated, with a focus on normal alcohols. The antibacterial activity varied with the length of the aliphatic carbon chain and not with the water/octanol partition coefficient. 1-Nonanol, 1-decanol and 1-undecanol had bactericidal activity and membrane-damaging activity. 1-Dodecanol and 1-tridecanol had the highest antibacterial activity among the long-chain fatty alcohols tested, but had no membrane-damaging activity. Consequently, it appears that not only the antibacterial activity but also the mode of action of long-chain fatty alcohols might be determined by the length of the aliphatic carbon chain.

Abstract: Exhaustive hydro-distillation of the bark, heartwood and fruits of Cryptocarya massoy (Lauraceae) afforded pale yellow-coloured oils in 0.7, 1.2 and 1.0 % yields, respectively. Detailed chemical evaluation of these distillates using GC/MS revealed the major components in the bark and the heartwood oils to be the C-10 (5,6-dihydro-6-pentyl-2H-pyran-2-one) and C-12 (5,6-dihydro-6-heptyl-2H-pyran-2-one) massoia lactones, while the major fruit oil constituent was benzyl benzoate (68.3 %). The heartwood also contained trace amounts of the C-14 (5,6-dihydro-6-nonyl-2H-pyran-2-one) massoia lactone (1.4 %) and the saturated C-10 derivative d-decalactone (2.5 %).

Abstract: Two new oxindole alkaloids isatinone A (1) and B (2) have been isolated from Isatis costata, along with the known trisindoline. Their structures have been assigned on the basis of spectroscopic techniques and chemical studies. Both new compounds showed significant antifungal activity.

Abstract: New α-aminophosphonates were synthesized by the Kabachnik-Fields reactionof 3,4,5-trimethoxybenzaldehyde (TMB) with p- or m-bromoaniline and a dialkylphosphite under solvent-free conditions. TMB was prepared from gallic acid via a fourstep synthetic sequence involving etherification, esterification, hydrazidation andpotassium ferricyanide oxidation. The structures of all synthesized compounds wereconfirmed by elemental analysis, IR, ¹H-, ¹³C- and ³¹P-NMR spectral data. Compound 7gwas also characterized by X-ray crystallography. A half-leaf method was used todetermine the in vivo curative efficacy of the eight title products against tobacco mosaicvirus (TMV). It was found that compounds 7g and 7h possess good in vivo curativeeffects against TMV.

Abstract: 2,3-Dihydro-3-[(S)-1-phenethyl]quinazolinone and some new 2-substitutedderivatives bearing isopropyl, o-nitrophenyl and p-nitrophenyl groups were prepared in40-90% yield by amidation of isatoic anhydride with (S)-phenylethylamine, followed bycondensation with triethyl orthoformate, isopropylaldehyde, o-nitro- and p-nitro-benzaldehyde, respectively. The two 2-subtituted dihydroquinazolinones obtained eitherby using isopropylaldehyde, o-nitro- or p-nitrobenzaldehyde, were separated and purifiedbefore their NMR spectra in CDCl₃ solutions were recorded. The detection of the lowenergy conformation of O=C-N-phenethyl segment in solution allowed the correlation ofthe NMR data with the configuration of newly stereogenic carbon C-2; thus, onediastereomer was labeled SS while the other was RS. Configurations determined by theNMR method were corroborated by X-ray diffraction analysis. X-ray structures of eachdiastereomeric series showed characteristic conformational types: a propeller-like for theSS and a hairpin for the RS series. Interatomic distances of the hairpin conformationsuggest the existence of intramolecular face-to-face interactions between two aromaticrings.

Abstract: A short and high yielding route for thepreparation of the title compound, starting from commercially available1,5-dihydroxynaphthalene, is described. The key step in the sequence is the airoxidation of a bis(trimethylsilyloxy)diene precursor.

Abstract: Simultaneous application of UV light and ultrasonic irradiation to a reaction mixture containing 1-iodocyclohexene is reported. The irradiation of 1-iodocyclohexene in methanol was carried out with or without addition of zinc. The effect of ultrasound or mechanical stirring on this solid-liquid system was also compared. The irradiation of 1-iodocyclohexene in methanol in the presence of zinc increases the yield of the nucleophilic trapping product, compared with the yield after irradiation in the absence of zinc. The photodegradation of 1-iodocyclohexene was slightly accelerated after addition of zinc. A rapid formation of radical product was accompanied by substantial decrease of 1-iodocyclohexene after application of ultrasound and irradiation without the zinc. The ultrasound significantly affects the photobehaviour of this reaction, predominantly its radical route. The joint application of ultrasound and zinc contributes positively to the production of radical and ionic products. The sonochemical stirring is more effective than mechanical stirring.

Abstract: A route for the preparation of 2,5-disubstituted octahydroquinolin-4-ones, synthetic precursors of the decahydroquinoline-type toxins, is presented. The key steps are an asymmetric epoxidation and an intramolecular hetero Diels-Alder reaction between an activated diene and an imine. The presence of an allylic stereogenic center induces some selectivity and thus only two cycloadducts are obtained in 70:30 ratio and good yield.

Abstract: The complete characterization of two compounds obtained from the acetoneextract of Populus tremula knotwood has been was achieved using LC-DAD-MS,MS/MS, IR and NMR. The new compounds were unequivocally identified as a mixtureof the ester isomers of the (E) and (Z) p-coumarate of 1-O-rutinose. The isomers showedthe capacity to inhibit lipid peroxidation induced by tert-butylhydroperoxide and to trapperoxyl radicals, as determined by a chemiluminescence method. These new phenyldisaccharides also showed a significant ORAC (oxygen radical absorbance capacity)value, i.e. 11.7 μM TE (Trolox Equivalents).

Abstract: Based on the molecular modeling analysis against Y181CHIV-1 RT, dipyridodiazepinone derivatives containing an unsubstituted lactamnitrogen and 2-chloro-8-arylthiomethyl were synthesized via an efficientroute. Some of them were evaluated for their antiviral activity against HIV-1RT subtype E and were found to exhibit virustatic activity comparable to some clinically usedtherapeutic agents.

Abstract: The one-pot reaction of aromatic aldehydes, ethylenediamine and Oxone® (2KHSO₅·KHSO₄·K₂SO₄) in pure water was found to unexpectedly afford aldoximes in excellent yields.

Abstract: The asymmetric rhodium-catalysed 1,4-addition of alkenylzirconium reagents to 2-cyclohexenone can be useful in the synthesis of 3-alkenyl-2-methylcyclohexanones, provided that formaldehyde is used in trapping the intermediate zirconium enolates. In this manner a four-step sequence leading to the two epimeric 3-hexenyl-2-methylcyclohexanones in enantiomeric form was developed.

Abstract: A series of eight new azomethine derivatives were synthesized by reacting 2-formylphenoxyacetic acid with aromatic amines. The chemical structures of these compounds were confirmed by means of ¹H-NMR, ¹³C-NMR, MS and elemental analysis. The compounds were assayed by the disc diffusion method for antibacterial against Staphylococcus aureus and Escherichia coli. Among the compounds tested, 2a, 2b, 2e, 2g and 2h exhibited good antibacterial activity, almost equal to that of Ciprofloxacin used as standard.

Abstract: Synthesis of 3,1,5-benzoxadiazepines from the condensation of o-phenylenediamine (o-PDA) and acyl chlorides in the presence of a catalytic amount of various heteropolyacids (HPAs) is reported.

Abstract: One new and six known flavone glycosides were isolated from the MeOH extract of Melilotus neapolitana Ten. The new compound, identified as 7-O-β-D-gluco-pyranosyloxy-4',5-dihydroxy-3-[O-α-L-rhamnopyranosyl-(1→6)-3-O-β-D-glucopyrano-syloxy]flavone (1) by 1D and 2D NMR techniques and mass spectra, was isolated along with kaempferol-3-O-rutinoside (2), kaempferol-3-O-glucoside (3), rutin (4), quercetin-3-O-glucoside (5), isorhamnetin-3-O-rutinoside (6), and isorhamnetin-3-O-glucoside (7). The antioxidant and radical scavenging activities of these compounds and the whole crude methanol extract were evaluated. The organic extract can inhibit MDA marker’s synthesis by 57%. All the metabolites displayed good reducing power, with the kaempferol (2,3) and isorhamnetin derivatives (6,7) being less active than the corresponding quercetin derivatives 4,5.

Abstract: art of our research program concentrates on the discovery of new bioactivecompounds prepared either by total synthesis or molecular transformation of compoundswith bioactivity profiles. In this work we have focused our interest on chemicaltransformations of the Diels-Alder adduct tricyclo[6.2.1.0^2,7]undeca-4,9-dien-3,6-dione inorder to obtain cage-like compounds and derivatives, followed by an evaluation of theirbiological activity.