The Effect of Strain on the Aromatic Character of Infinitene

Infinitene was synthesized in a previous study in 2021, and the molecule showed high strain energy. It was not clear how the strain affected the aromatic character of the molecule. To discuss this problem, the aromatic properties of dodecacene, [12]circulene, and infinitene have been studied. The structures of these compounds have been optimized at the DFT/B3LYP/6-311G + (d,p) level of theory, and the energy of the π orbitals has been used to determine the D’ index of the aromaticity. D′ for dodecacene, [12]circulene, and infinitene were 1.45, 1.45, and 1.50, respectively, showing that infinitene is an aromatic compound but with a lower aromatic character, which is in agreement with the observed strain

Effect of heat treatment on wood chemical composition, extraction yield and quality of the extractives of some wood species by the use of molybdenum catalysts

The effect of heat treatment and the presence of some molybdenum catalysts on the amount of extractives in Populus nigra, Larix decidua, Paulownia tomentosa, Castanea sativa and Quercus frainetto wood were studied. There are an increase in the amount of lignin and extractives and a decrease in the amount of holocellulose following thermo-treatment, in the treatment temperature range. Autoclave treatment of wood with water in the presence of some molybdenum catalysts can increase the amount of extracts, but it reduces solubility. Soxhlet extraction of wood with ethanol/toluene mixture in the presence of H3PMo12O40 increases the amount of extractives and their solubility in chloroform, while in the presence of MoO3 only the solubility of extractives increases. GC–MS analysis of insoluble fraction showed the presence of myo-inositol and some simple carbohydrates, mainly ribose, xylose and glucose. GC–MS analysis of soluble fraction showed the presence of long-chain acids and fatty acid esters of 10–20 carbon atoms, mainly decanoic acid, hexadecanoic acid and octadecanoic acid, which can be a source of fatty acids for biodiesel production

Changes in the structure of the skin of kiwifruit in relation to water loss

Fruit water loss and calcium inflow decrease in kiwifruit (Actinidia deliciosa ‘Hayward’) after the first few weeks of growth, but the relationship between fruit transpiration and the structure of the skin is not clear. Changes in skin structure during fruit development were studied using cryo-scanning electron microscopy and the concentrations and types of waxes present in the skin were measured. Young fruit were covered in turgid unicellular and multicellular hairs, which grew on an amorphous and continuous layer of wax platelets. However, 5 weeks after fruit set, the hairs began to collapse and the wax layer began to crack.The epidermal cells dehydrated and suberised to form a periderm like layer.The degeneration of the hairs and the wax layer continued as the fruit matured. Fruit surface area increased from 6.9 cm2 at 4 weeks after fruit set, to 98.2 cm2 at 20 weeks after fruit set (i.e., at harvest), while the total wax content increased from 0.33 to 2.40 mg per fruit.Total wax density peaked at 91 μg cm–2 5 weeks after fruit set, then decreased to 24 μg cm–2 at harvest.Alkyl alkanoates were the main waxes [approx. 70% (w/w)] in young fruit, while hydrocarbons and alkyl alkanoates (approx. 50% each) were the main waxes in mature fruit. The decline in fruit water loss in kiwifruit was consistent with degeneration of the hairs on the skin, the evolution of the suberised outer layers, and the death of outer cells associated with wax biosynthesis

Novel Tetrahydropyridazines by Unusual Aza-Diels-Alder Reaction of Electron-poor 1,2-Diaza-1,3-dienes with Electron-poor Alkenes under Solvent Free Conditions

none51,2-Diaza-1,3-dienes bearing electron withdrawing groups react with electron-poor alkenes by means of an uncommon aza-Diels-Alder reaction furnishing novel tetrahydropyridazines with high regio- and stereoselectivity. Conducing these cycloadditions in solvent free conditions under thermal conditions the reaction times are significantly reduced, the yields are improved and the stereoselectivity remained unchanged.openO.A. ATTANASI; L. BIANCHI; M. D'AURIA; F. MANTELLINI; R. RACIOPPIAttanasi, ORAZIO ANTONIO; Bianchi, Luca; M., D'Auria; Mantellini, Fabio; R., Raciopp

The Scent of Himantoglossum Species Found in Basilicata (Southern Italy)

The SPME (Solid Phase Microextraction) analysis of the scent of H. hircinum showed the presence of elemicin in the presence of a relevant amount of eugenol. The scent of the sample of H. adriaticum collected in Abruzzo showed the presence 4-amino-5-(4-morpholinylmethyl)-2-oxazolidinone, β-ocimene, decyl decanoate, and 9-tricosene as main components. The sample of H. adriaticum collected at Marsico Nuovo has an aroma where the main component was pentadecyl hexanoate, 9-tricosene, methyleugenol, tetradecane, pentadecane, and elemicin. The samples of H. adriaticum collected at Viggianello showed some similarities in the scent: the main components were 9-tricosene and methyleugenol

Fragrance components of <i>Platanthera bifolia</i> subsp. <i>osca</i>

<p>SPME-GC-MS analysis of the scent of <i>Platanthera bifolia</i> subsp. <i>osca</i> collected during the night showed as main components lilac alcohols B, C and D and lilac aldehydes A, B and C. Other significant chemical components were linalool and caryophyllene. Some differences were found in comparison with previously reported analyses of the scent of <i>P. bifolia</i> and <i>Platanthera chlorantha</i>. The most important difference found was in the composition of the ester fraction.</p

Chemical and biological evaluation of essential oil from Saussurea costus (Falc.) Lipsch. from Garhwal Himalaya collected at different harvesting periods

The purpose of this study is the determination of chemical composition and antioxidant activity of essential oils (EOs) from Saussurea costus (Falc.) Lipsch. Roots have been collected on December of the first plant year (IY) and in April, August and December of the third plant year (I, 6B, D7). A GC analysis was carried out for achieving this purpose. Subsequently, total polyphenol content (TPC) and antioxidant activity measured by DPPH, FRAP and BCB assays were evaluated. Three different statistical methods: Relative Antioxidant Capacity Index (RACI), Pearsonâ\u80\u99s correlation coefficient (r) and PCA, were used to compare results obtained and underline EO relationships. From the results obtained, it was possible to observe how the collection period of the EO, in particular both the month and the year of collection, influences the metabolite profile