Identification of volatile compounds contained in the therapeutic essential oils from Pogostemon cablin, Melaleuca leucadendra, and Mentha piperita and their purified fractions.

Pogostemon cablin, Melaleuca leucadendra, and Mentha piperita are three aromatic plants that have been reported to produce a high yield of volatile components with medicinal and therapeutic properties. This present study aimed to perform qualitative and semi-quantitative analysis on the volatile components present in the aforementioned aromatic plants. Essential oils from P. cablin and M. leucadendra were obtained from community-based enterprises in Aceh Province, Indonesia. The essential oils were further purified using vacuum rotary evaporator. In addition, we also investigated the essential oils from M. piperita based on the priorly optimized parameters. The volatile components contained in the essential oils were identified using gas chromatography-mass spectrometry (GC-MS) analysis. The qualitative data were derived from the MS data based on the fragmented components separated by the GC and compared with the database. The abundance of each volatile component was determined based on the area percentage of the chromatographic peak. In P. cablin oil, the relative abundance of α-guaiene and seychellene was higher in heavy fraction (17.11 and 10.29, respectively), while patchouli alcohol in light fraction (69.92%). Eucalyptol was found higher in the light fraction of M. leucadendra oil (MO) than that in the heavy fraction (78.87% vs. 17.34%, respectively). As for the M. piperita oil, menthone was found as the predominant component with relative abundance of 21.6%. Essential oils extracted from P. cablin, M. leucadendra, and M. piperita consist of volatile components with medicinal and therapeutic potentials, in which their compositions are affected by the purification process.

Recent Advances in Nanocellulose Aerogels for Efficient Heavy Metal and Dye Removal.

Water pollution is a significant environmental issue that has emerged because of industrial and economic growth. Human activities such as industrial, agricultural, and technological practices have increased the levels of pollutants in the environment, causing harm to both the environment and public health. Dyes and heavy metals are major contributors to water pollution. Organic dyes are a major concern because of their stability in water and their potential to absorb sunlight, increasing the temperature and disrupting the ecological balance. The presence of heavy metals in the production of textile dyes adds to the toxicity of the wastewater. Heavy metals are a global issue that can harm both human health and the environment and are mainly caused by urbanization and industrialization. To address this issue, researchers have focused on developing effective water treatment procedures, including adsorption, precipitation, and filtration. Among these methods, adsorption is a simple, efficient, and cheap method for removing organic dyes from water. Aerogels have shown potential as a promising adsorbent material because of their low density, high porosity, high surface area, low thermal and electrical conductivity, and ability to respond to external stimuli. Biomaterials such as cellulose, starch, chitosan, chitin, carrageenan, and graphene have been extensively studied for the production of sustainable aerogels for water treatment. Cellulose, which is abundant in nature, has received significant attention in recent years. This review highlights the potential of cellulose-based aerogels as a sustainable and efficient material for removing dyes and heavy metals from water during the treatment process.

Characterization of Bioactive Compounds from Patchouli Extracted via Supercritical Carbon Dioxide (SC-CO2) Extraction.

Patchouli extracts and oils extracted from Pogostemon cablin are essential raw material for the perfume and cosmetics industries, in addition to being used as a natural additive for food flavoring. Steam distillation is a standard method used for plant extraction. However, this method causes thermal degradation of some essential components of the oil. In this study, patchouli was extracted with supercritical carbon dioxide (SC-CO2) under different conditions of pressure (10-30 MPa) and temperature (40-80 °C). The chemical components of the crude extracted oil and the functional group were characterized using gas chromatography-mass spectrometry (GC-MS) and Fourier Transform Infrared Spectroscopy (FT-IR). The extraction with supercritical carbon dioxide was shown to provide a higher yield (12.41%) at a pressure of 20 MPa and a temperature of 80 °C. Patchouli alcohol, Azulene, δ-Guaiene, and Seychellene are the main bioactive compounds that GC-MS results have identified. FTIR spectra showed alcohol, aldehyde, and aromatic ring bond stretching peaks. Extraction of patchouli with supercritical carbon dioxide provided a higher yield and a better quality of the crude patchouli oil.

Synthesis and Characterization of Novel Patchouli Essential Oil Loaded Starch-Based Hydrogel.

Starch hydrogels are highly available, biocompatible and biodegradable materials that have promising applications in medical and pharmaceutical industries. However, their applications are very limited due to their poor mechanical properties and fragility. Here, we investigated, for the first time, conventional corn and waxy corn starch-based hydrogels for loading patchouli essential oil. The essential oil extracted by supercritical carbon dioxide with a yield reached 8.37 ± 1.2 wt.% (wet sample) at 80 °C temperature and 10 MPa pressure. Patchouli essential oil exhibited a 23 to 28 mm zone of inhibition against gram-positive and gram-negative bacteria. Waxy starch hydrogels had better properties in term of viscosity, water evaporation stability and the delivery of essential oil than conventional starch hydrogels. The viscosity and spreadability of a 6% waxy starch sample were 15,016 ± 59 cP and 4.02 ± 0.34 g·cm/s, respectively, compared with those of conventional starch hydrogel (13,008 ± 29 cP and 4.59 ± 0.88 g·cm/s). Waxy starch-based hydrogels also provided slower in vitro biodegradation behavior and sustained release of essential oil compared with conventional starch hydrogels. All the samples were biocompatible and non-cytotoxic to fibroblast cells; the addition of patchouli essential oil enhances the proliferation of the cells. The enhanced viscosity, good antibacterial and improved biocompatibility results of prepared hydrogels confirm their suitability for wound healing applications.

A comparative study of spinel structured Mn3O4, Co3O4 and Fe3O4 nanoparticles in catalytic oxidation of phenolic contaminants in aqueous solutions.

Spinel structured Mn3O4, Co3O4 and Fe3O4 nanoparticles were prepared, characterized, and tested in degradation of aqueous phenol in the presence of peroxymonosulfate. It was found that Mn3O4 and Co3O4 nanoparticles are highly effective in heterogeneous activation of peroxymonosulfate to produce sulfate radicals for phenol degradation. The activity shows an order of Mn3O4>Co3O4>Fe3O4. Mn3O4 could fast and completely remove phenol in about 20 min, at the conditions of 25 ppm phenol, 0.4 g/L catalyst, 2 g/L oxone®, and 25 °C. A pseudo first order model would fit to phenol degradation kinetics and activation energies on Mn3O4 and Co3O4 were obtained as 38.5 and 66.2 kJ/mol, respectively. In addition, Mn3O4 exhibited excellent catalytic stability in several runs, demonstrating that Mn3O4 is a promising catalyst alternative to toxic Co3O4 for water treatment.

Different crystallographic one-dimensional MnO2 nanomaterials and their superior performance in catalytic phenol degradation.

Three one-dimensional MnO2 nanoparticles with different crystallographic phases, α-, ß-, and γ-MnO2, were synthesized, characterized, and tested in heterogeneous activation of Oxone for phenol degradation in aqueous solution. The α-, ß-, and γ-MnO2 nanostructured materials presented in morphologies of nanowires, nanorods, and nanofibers, respectively. They showed varying activities in activation of Oxone to generate sulfate radicals for phenol degradation depending on surface area and crystalline structure. α-MnO2 nanowires exhibited the highest activity and could degrade phenol in 60 min at phenol concentrations ranging in 25-100 mg/L. It was found that phenol degradation on α-MnO2 followed first order kinetics with an activation energy of 21.9 kJ/mol. The operational parameters, such as MnO2 and Oxone loading, phenol concentration and temperature, were found to influence phenol degradation efficiency. It was also found that α-MnO2 exhibited high stability in recycled tests without losing activity, demonstrating itself to be a superior heterogeneous catalyst to the toxic Co3O4 and Co(2+).

Heterogeneous activation of peroxymonosulphate by supported ruthenium catalysts for phenol degradation in water.

Activated carbon (AC) and Zeolite Socony Mobil-5 (ZSM5) supported ruthenium oxide catalysts were prepared and tested to degrade aqueous phenol in the presence of peroxymonosulphate. The physicochemical properties of ruthenium oxide based catalysts were characterised by several techniques such as XRD (X-ray diffraction), SEM-EDS (scanning electron microscopy-energy dispersive X-ray spectroscopy), and N(2) adsorption. It was found that RuO(2)/AC was highly effective in heterogeneous activation of peroxymonosulphate to produce sulphate radicals, presenting higher reaction rate in phenol degradation compared with RuO(2)/ZSM-5. Degradation efficiency of phenol could be achieved at 100% of phenol decomposition and 60% of total organic carbon (TOC) removal in 1h at the conditions of 50ppm phenol, 0.2g catalyst, 1g Oxone(®) in 500mL solution at 25°C using the two catalysts. It was also found that phenol degradation was strongly influenced by catalyst loading, phenol concentration, Oxone(®) concentration and temperature. Kinetic studies proved that a pseudo first order kinetics would fit to phenol decomposition and the activation energies for RuO(2)/AC and RuO(2)/ZSM5 were obtained to be 61.4 and 42.2kJ/mol, respectively.