Chemistry of wood
Maryam Ahmadi; Seyed Majid Zabihzadeh; Noureddin Nazarnezhad; Ghasem Asadpour; Pourya Biparva
Abstract
Background and objectives: Plant extracts contain antioxidant compounds, which have garnered increasing attention in various scientific and industrial fields due to their significance. Among the most important groups of compounds present in plant extracts are phenolic compounds. These compounds not only ...
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Background and objectives: Plant extracts contain antioxidant compounds, which have garnered increasing attention in various scientific and industrial fields due to their significance. Among the most important groups of compounds present in plant extracts are phenolic compounds. These compounds not only possess antioxidant properties but also have diverse applications in various industries. Numerous plants have been investigated for the extraction of bioactive compounds. Chinaberry (Melia azedarach), a woody species, is known to contain antioxidant substances. In this study, the extracts from heartwood and sapwood of chinaberry were obtained, and the extracted compounds were identified. Additionally, the antioxidant properties of these compounds were evaluated. This research provides valuable insights into the potential applications of antioxidant compounds derived from chinaberry in different industries.Methodology: First, the heartwood and sapwood of Melia azedarach (chinaberry) were separated and ground using a laboratory mill. Particles of size 60 mesh were isolated using a laboratory sieve. Prior to extraction, the wood flour underwent pre-extraction with hexane. Three different extraction methods were employed: Soxhlet, immersion, and ultrasonic. In all methods, 10 grams of wood flour were used as the raw material. In the Soxhlet method, the raw material was placed in a thimble and then the thimble contain wood flour transferred to a flask containing 250 mL of ethanol. The Soxhlet system was set up, and after the first siphoning, the samples were heated for 6 hours to complete the extraction process. In the immersion method, the samples were stirred with 250 mL of ethanol at 40°C for 24 hours using a magnetic stirrer. In the ultrasonic method, the wood flour was combined with 100 mL of ethanol in a beaker. The resulting mixture was treated at 40°C for a total of 6 minutes, divided into two 3-minute intervals, using ultrasonic waves at a frequency of 20 kHz and an amplitude of 50%. The compounds present in the extracts obtained from all three methods were identified using GC-MS analysis. The total phenolic and flavonoid content of the extracts was quantified. Additionally, the antioxidant activity of the extracts was evaluated using the DPPH method.Results: The analysis of extractable content before pre-extraction with hexane revealed that the heartwood contained a higher number of extractable materials compared to the sapwood. Following extraction using three different methods, a re-assessment of extractable content indicated that the highest amount was obtained from the sapwood using the Soxhlet method. GC-MS analysis of extracts derived from the heartwood and sapwood of Melia azedarach showed that methoxyphenol was the predominant phenolic compound identified in both wood types when extracted using the Soxhlet method. In the immersion method, beta-sitosterol was the most abundant compound in the heartwood, while methylphenol dominated in the sapwood. For the ultrasonic method, imidazolidinedione was the most abundant compound in the heartwood, and beta-sitosterol prevailed in the sapwood. The highest phenolic compound content was observed in the sapwood extract obtained using the Soxhlet method, measuring 0.45865 µg gallic acid per mg of extract. The maximum flavonoid content was also recorded in the sapwood extract from the Soxhlet method, with 0.493172 mg quercetin per gram of dry weight. Antioxidant activity assessment demonstrated that the extract obtained from the heartwood using the immersion method exhibited the highest antioxidant activity.Conclusion: This study aimed to investigate the extraction of heartwood and sapwood from Melia azedarach and evaluate the impact of three different extraction methods- soxhlet, immersion, and ultrasonic- on the yield of the extracted materials. Additionally, the antioxidant properties of the extracts obtained through these methods were assessed. The results revealed that phenolic compounds constituted the majority of the extracted materials in both heartwood and sapwood extracts of this species. The soxhlet method demonstrated the highest efficiency in extracting phenolic and flavonoid compounds from the sapwood, while the immersion method exhibited the highest antioxidant activity in the extracts obtained from the heartwood. These findings underscore the influence of the extraction method on the quantity and type of compounds extracted as well as their antioxidant properties. This study provides valuable insights into the potential utilization of antioxidant compounds in industrial and pharmaceutical applications.
