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The art of dyeing textiles has a long history, as natural dyes have been used since prehistoric times. With the development of synthetic dyes in the 19th century, the focus shifted from natural to synthetic dyes due to their superior properties. Recently, however, interest in natural dyes has increased again due to environmental and health concerns. Among industrial dyes, heterocyclic dyes, especially azo dyes, are of great importance due to their color brilliance and fastness. This review examines the synthesis, application, and analysis of azo dyes, especially heterocyclic dyes. It deals with monoazo, diazo, and polyazo dyes and highlights their structures, synthesis methods, and fastness properties. In addition, the ecological impact of azo dyes and practical solutions for their synthesis and application are discussed. [ABSTRACT FROM AUTHOR]

Wood extractives have proven strong anti-oxidative properties which may be used to mitigate surface deterioration caused by photolytic effects and free radical formations. An interesting challenge regarding wood extractives is understanding how they behave in terms of treating natural wood surfaces to reduce anti-oxidative processes that arise from exposure to the main environmental factors. In this study, the possible efficacy of chestnut (Castanea sativa Mill.) extractives derived from native (CH) and thermally modified wood (TMT CH), as a means of protecting against UV exposure in poplar (Populus spp.) and spruce (Picea abies Karst.) wood, was evaluated. Chestnut wood was first thermally modified at 180 °C for 3 h, and the extractives were obtained by the accelerated solvent extraction technique (ASE) and subsequently used to treat wood surfaces. Samples were immersed in extractive solutions and exposed to artificial UV-weathering exposure, then contact angle and colour stability were monitored during the process. An FTIR analysis of the photo-degradation process of poplar and spruce surfaces was also executed. Extractives of TMT chestnut changed the total colour variation in both poplar and spruce wood. A much darker colour compared to the extractives of native wood was observed and an increase in ∆E* from 9.75 to 30.76 and 6.24 to 22.97 in poplar and spruce was calculated. The stability of the colour depended both on the surface wood and the type of extractive. The initial contact angle remained almost unchanged in the poplar wood surface and only slightly increased in spruce regardless of whether they were treated with extractives from native or TMT chestnut wood. A strong reduction in contact angle after the accelerated UV exposure test was observed, especially in spruce treated with CH extractives. FTIR analysis confirmed the lower levels of chemical degradation of surfaces observed by colorimetry, where TMT CH extractives formed more stable chemical bonds than native extractives. The comparative analysis in this study clarified the complex relationships between the effects of high-temperature modification of wood and the potential protective role of TMT extractives on some wood surfaces. [ABSTRACT FROM AUTHOR]

The scent of Anacamptis species has been analyzed by using HS-SPME-GC–MS. The sample was collected in Basilicata (Southern Italy). Every species showed a different composition of the scent in the analyses we performed. 1,2,4-Trimethoxybenzene and methyl 4-mehoxybenzoate were the main components of that of Anacamptis coriophora subsp. fragrans. The scent of Anacamptis laxiflora was due to the presence of caryophyllene. Linear hydrocarbons but also decanal were components of the scent of Anacamptis pyramidalis. Eucalyptol was found in the scent of Anacamptis papilonacea. Finally, β-sesquiphellandrene was the main component of the scent of Anacamptis morio. [ABSTRACT FROM AUTHOR]

SPME analysis of the scent of Epipactis microphylla showed the presence of limonene as the main component of the scent. Other components were 2,4,4,6,6,8,8-heptamethyl-1-nonene, pentadecane, and heptadecane. The scent of Epipactis palustris was characterized by pentadecane, 2,4,4,6,6,8,8-heptamethyl-1-nonene, and heptadecane. The scent of Neottia nidus avis showed the presence of kaur-16-ene as the main component of the scent. Other components were heinecosane, tetradecane, pentadecane, hexadecane, heptadecane, and 5,9,13-trimethyl-4,8,12-tetradecanal. The scent of Neottia ovata is due to pentadecane, hexadecane, and heptadecane. The scent of Limodorum abortivum showed the presence of 2,4,4,6,6,8,8-heptamethyl-1-nonene, pentadecane, hexadecane, heptadecane, and 2-(dodecyloxy)-ethanol. [ABSTRACT FROM AUTHOR]

In recent years, long periods of drought and heat waves have become increasingly frequent, causing forest dieback phenomena that make stands more sensitive to biotic stressors. How trees may respond to extreme climatic events and which metabolites are involved under stress conditions is still not clear. In this study, using Solid Phase Micro-Extraction (SPME)-GC/MS, we analysed how dieback (D) and non-dieback (ND) Hungarian oak trees from the San Paolo Albanese site respond to these climatic dynamics, focusing on volatile organic compounds (VOCs). For each group of trees, three wood samples were taken, and each was divided into four sub-samples with five growth rings and subjected to SPME and increase in basal area (BAI) analysis of the last 20 years. Dieback trees had a lower number of leaves, and this condition may translate into less photosynthesis, less organic matter production, and lower reserves of carbohydrates being available for growth. Indeed, D trees showed lower radial increases and a lower content of aldehydes, terpenes, and fatty acids than ND trees, indicating a better health of ND trees compared to D trees. Meanwhile, D trees showed a reduction in terpenes, such as α-pinene, γ-eudesmol, and cyperene (with significant insecticidal activity), a reduction in aromatic aldehydes, such as furfural and 5-methylfurfural, and an increase in silanols (with antimicrobial function). Considering the different compounds' contents between D and ND trees, our study could be useful for detecting bio-indicators to identify an early warning signal of dieback phenomena. [ABSTRACT FROM AUTHOR]

Several methods have been used to determine the volatile organic compounds emitted by Ophrys orchids. The use of different methods results in incomparable data. Solid-phase microextraction (SPME) has not been used extensively on Ophrys orchids. The main components found in the SPME analysis of the scent in Ophrys orchids were as follows: O. apifera: benzyl benzoate and α-copaene; O. crabronifera subsp. biscutella: pentadecane, heptadecane, and nonadecane; O. bertolonii subsp. bertolonii: pentadecane and heptadecane; O. passionis subsp. garganica: i-propyl palmitate and heptadecane; O. holosericea subsp. apulica: α-copaene, pentadecane, and heptadecane; O. lacaitae: α-copaene, pentadecane, and heptadecane; O. bombyliflora: cyclosativene, pentadecane, and ethyl dodecanoate; O. insectifera: 8-heptadecene and pentadecane; O. lutea: heptadecane and docosane; O. tenthredinifera subsp. neglecta: α-copaene, caryophyllene, and i-propyl palmitate. [ABSTRACT FROM AUTHOR]

The main component of the essential oil of Santolina etrusca is viridiflorol (23.98–42.23%). a compound not found in the essential oil of Santolina camaecyparissus. The main component found in this study is the same found in the essential oil obtained from plants collected in Tuscany and Umbria. However, there are important differences in the other components of the essential oil, where we found the presence of eucalyptol (2.98–9.73%) and germacrene D (2.39–19.59%). Finally, seasonal variation of the essential oil composition induces a reduction of sesquiterpenes amounts with the corresponding increase of the monoterpenes during spring and summer. [ABSTRACT FROM AUTHOR]

SPME-GCMS analysis of vesicles of Sanguinea cultivar showed the presence of limonene (45.63%), sabinene (22.65%), and bicyclogermacrene (10.80%). The analysis of the peel showed that the main components were limonene (48.24%), sabinene (37.15%), and α-pinene (4.26%). In Pink Ice cultivar the main components of the vesicles were sabinene (31.68%), limonene (20.71%), and bicyclogermacrene (14.18%). Peel analysis showed the presence of limonene (37.68%), sabinene (33.33%), and α-pinene (5.55%). In Faustrime limonene (51.54%), γ-terpinene (10.01%), α-bergamotene (7.48%), β-bisabolene (7.07%), and a-phellandrene (5.68%) were detected. In peel analysis limonene (27.84%), α-pinene (9.41%), γ-terpinene (10.00%), and citronellal (10.51%) were found. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The aim of this work is to prepare the nanocomposites TiO2/x%Curcumin (with x = 3, 5 and, 10) by wet impregnation method. Subsequently, these nanocomposites materials were successfully used for the photocatalytic degradation of a model dye, methylene blue (MB). The results obtained show good photocatalytic activity of said materials. An elimination conversion of 63% (which can be considered as the optimal value in this study) is obtained after 160 min at room temperature for an MB concentration of 10 mg/L for the TiO2/5%curcumin nanocomposite sample. This is due to the effect of adsorption, which is an important parameter controlling the degradation phenomenon. Indeed, the added curcumin causes an increase in the pH of the medium, which causes better adsorption of MB on the surface of the TiO2/5%curcumin nanocomposite material. Then, the TiO2/5%Curcumin nanocomposite material (the best in photocatalysis) was characterized by various analysis techniques: structural and optical, including Fourier Transform Infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Ultraviolet–Visible spectroscopy (UV–Vis.) and scanning electron microscopy (SEM). The results of the FT-IR analysis indicate a good homogeneity between TiO2 and Curcumin. Due to the reduced value of the gap energy (2.93 eV) of the TiO2/5%Curcumin nanocomposite material, determined from optical measurements, this nanocomposite material exhibits good semiconductor behavior. SEM analysis reveal that the average particle size of TiO2–anatase remains unchanged when adding curcumin. [ABSTRACT FROM AUTHOR]