Calcined Biowaste Durian Peel as a Heterogeneous Catalyst for Room-Temperature Biodiesel Production Using a Homogenizer Device

Calcined biowaste durian peel (BDP) contains 86% potassium element as the main compound and has successfully catalyzed the transesterification of palm oil to biodiesel at room temperature. The effect of catalyst weight, molar ratio of palm oil to methanol, reaction time, and rotational speed of the homogenizer device was investigated on biodiesel conversion and yield. The highest biodiesel conversion of 97.4 ± 0.3% was achieved using the following reaction conditions: a catalyst weight of 5 wt %, a molar ratio of palm oil to methanol of 1:15, a reaction time of 10 min, and a rotational speed of 6000 rpm. Unfortunately, calcined BDP could not hold its catalytic activity in the reusability study. The biodiesel conversion was decreased in the second cycle due to the decrease of both catalyst weight and concentration of potassium ions after the first cycle. However, the calcined BDP paired with a homogenizer device could produce biodiesel in a short reaction time and at room temperature.

Characterization of red algae (Gracilaria verrucosa) on potential application for topical treatment of oral mucosa wounds in Rattus norvegicus

Wound healing in the mouth has its challenges due to masticatory movements and the presence of bacteria that can inhibit its process. The aim of this study was to analyze the contents of red algae (Gracilaria verrucosa) from Indonesia, and its potential as a wound-healing agent for oral wounds using animal model. Red algae content was determined by phytochemical tests and gas chromatography-mass spectroscopy (GC-MS). The wound was made by making an incision on the gingival mucosa of Rattus norvegicus and the parameters assessed were bleeding time, number of fibroblast cells, and time of wound closure. Three doses of G. verrucosa gel were used (2.5%, 5%, and 10%) and the gels were applied twice a day, at 6:00 and 18:00. Application was carried out topically by applying 0.1 ml of gel to the incision wound using a 1 mL syringe. Our phytochemical test indicated that the G. verrucosa contained alkaloids, steroids, flavonoids, and phenols. The dominant contains of the G. verrucosa were glycerol (36.81%), hexadecenoic acid (20.74%), and cholesterol (7.4%). The hemostasis test showed that the 2.5% G. verrucosa extract gel had the shortest bleeding time, 33.98±2.66 seconds. On the seventh day of the initial proliferation phase, the number of fibroblasts was not significantly different among groups. On day 14, the number of fibroblasts was only significantly different between 10% G. verrucosa and untreated group (p=0.007). On day 28, however, both 5% and 10% G. verrucosa were significantly higher compared to untreated group, both had p=0.010. Daily clinical examination showed that animals that were given 2.5% and 5% of G. verrucosa extract gel experienced wound closure on day 10. Animals treated with 10% of extract gel, all wounds healed on day 9. This study suggested that G. verrucosa extract could accelerate wound closure and wound healing.

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.

COVID-19 pandemic sheds a new research spotlight on antiviral potential of essential oils - A bibliometric study

Background

Essential oils are thought as potential therapies in managing coronavirus disease 2019 (COVID-19). Many researchers have put their efforts to tackle the pandemic by exploring antiviral candidates which consequently changes the research landscape. Herein, we aimed to assess the effect of COVID-19 pandemic toward the landscape of essential oil research.

Methods

This study employed bibliometric analysis based on the metadata of published literature indexed in the Scopus database. The search was performed on December 15^th, 2022 by using keyword 'essential oil' and its synonyms. We grouped the data based on publication year; pre-COVID-19 (2014-2019) and during COVID-19 (2020-2024, some studies have been published earlier). Further, we separated the COVID-19-focused research from COVID-19 (2020-2024) by introducing a new keyword 'COVID-19' during the search. All metadata were processed using VoSviewer and Biblioshiny for network visualization analysis. Selections of frequently occurring keywords, clusters of keyword co-occurrence, and the list of most impactful papers were performed by two independent reviewers.

Results

Metadata from a total of 35,262 publications were included for bibliometric analysis, comprised of three groups of datasets namely pre-COVID-19 (n = 18,670), COVID-19 (n = 16,592), and COVID-19-focused (n = 281). Five research topics clusters were found from pre-COVID-19 dataset, eight - from COVID-19 dataset, and nine - from COVID-19-focused dataset. COVID-19 cluster containing the keyword 'antiviral' emerged in the COVID-19 dataset, whereas none of the previous research topic clusters contained the keyword 'antiviral'. Antiviral, angiotensin-converting enzyme 2 (ACE2) inhibitory, and anti-inflammation activities were among the top occurring keywords in studies covering both essential oil and COVID-19. Studies on essential oil used for managing COVID-19 were most reported by authors from the United States (documents = 37, citations = 405), Australia (documents = 16, citations = 115) and Italy (documents = 23, citations = 366).

Conclusion

A significant increase was found during COVID-19 pandemic for publications covering essential oil themes, but only a small portion was occupied by COVID-19 research. The COVID-19 pandemic does not alter the ongoing progress of essential oil research but rather offers a new spotlight on the antiviral potential of essential oils. Hence, the COVID-19 pandemic has provided an opportunity to investigate deeper the antiviral potential of essential oils.

Antioxidant and antiproliferative activities of n-hexane extract and its fractions from Blumea balsamifera L. leaves

Blumea balsamifera is a plant species that has been popularly used to treat a broad spectrum of diseases. In efforts of tackling the increasing threat of cancers, B. balsamifera has been studied for its anticancer potentials. Hence, through this research, we aimed to evaluate the antioxidant and antiproliferative activities of n-hexane extract from B. balsamifera L. leaves along with its fractionation products. After the n-hexane extract has been obtained, the sample was column chromatographed using gradient elution with n-hexane:ethyl acetate solvent. All the isolation protocols produced 1 n-hexane extract and 10 different fractions (fractions 1-10). Antioxidant and antiproliferative effects of the samples were assessed based on 2,2-diphenyl-1-picrylhydrazyl and brine shrimp lethality test assay, respectively. None of the samples have a strong antioxidant level because all samples yielded IC₅₀ of more than 100 ppm - the best of them was fraction 8 with IC₅₀ = 113.716 ppm. On contrary, most of the samples were observed to have a potent antiproliferative effect, especially fraction 8 with LC₅₀ = 2.00 ppm. Taken altogether, fraction 8 from the n-hexane extract of B. balsamifera L. leaves is the most potential candidate for proliferative disease therapy, where further studies confirming the results are required.

In-Vitro Screenings for Biological and Antioxidant Activities of Water Extract from Theobroma cacao L. Pod Husk: Potential Utilization in Foods

Increasing production of cocoa (Theobroma cacao L.) leads to a higher environmental burden due to its solid waste generation. Cocoa pod husk, one of the major solid wastes of cocoa production, contains rich bioactive compounds unveiling its valorization potential. With that in mind, our research aimed to explore the biological and antioxidant activities of aqueous extracts from cocoa pod husks. In this present work, cocoa pod husk was extracted using water and subsequentially partitioned using n-hexane, ethyl acetate, and methanol. The antimicrobial investigation revealed that the ethyl acetate solubles were active against the Staphylococcus aureus, Escherichia coli, and Candida albicans, where at a 20% w/v concentration, the inhibition diameters were 6.62 ± 0.10, 6.52 ± 0.02, and 11.72 ± 0.36 mm, respectively. The extracts were found non-toxic proven by brine shrimp lethality tests against Artemia salina with LC50 scores ranging from 74.1 to 19,054.6 μg/mL. The total phenolic content and total flavonoid content were obtained in the range of 47.44 to 570.44 mg/g GAE and 1.96 to 4.34 mg/g QE, respectively. Antioxidant activities of the obtained extracts were revealed by 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) assay with EC50 reached as low as 9.61 μg/mL by the ethyl acetate soluble. Phytochemical screening based on gas chromatography-mass spectroscopy analysis on the sample with the highest antioxidant activities revealed the dominant presence of three phytosterols, namely gamma-sitosterol, stigmasterol, and campesterol.

Synthesis of Polyurethane Membranes Derived from Red Seaweed Biomass for Ammonia Filtration

The development of membrane technology is rapidly increasing due to its numerous advantages, including its ease of use, chemical resistant properties, reduced energy consumption, and limited need for chemical additives. Polyurethane membranes (PUM) are a particular type of membrane filter, synthesized using natural organic materials containing hydroxy (-OH) groups, which can be used for water filtration, e.g., ammonia removal. Red seaweed (Rhodophyta) has specific molecules which could be used for PUM. This study aimed to ascertain PUM synthesis from red seaweed biomass (PUM-RSB) by using toluene diisocyanate via the phase inversion method. Red seaweed biomass with a particle size of 777.3 nm was used as starting material containing abundant hydroxy groups visible in the FTIR spectrum. The PUM-RSB produced was elastic, dry, and sturdy. Thermal analysis of the membrane showed that the initial high degradation temperature was 290.71 °C, while the residue from the thermogravimetric analysis (TGA) analysis was 4.88%. The PUM-RSB section indicates the presence of cavities on the inside. The mechanical properties of the PUM-RSB have a stress value of 53.43 MPa and a nominal strain of 2.85%. In order to optimize the PUM-RSB synthesis, a Box–Behnken design of Response Surface Methodology was conducted and showed the value of RSB 0.176 g, TDI 3.000 g, and glycerin 0.200 g, resulting from the theoretical and experimental rejection factor, i.e., 31.3% and 23.9%, respectively.

Lignan compound isolated from n-Hexane extract myristica fragrans Houtt root as antioxidant and antitumor activities against MCF-7 cell lines data

Nutmeg plant (Myristica fragrans Houtt) is known as one of traditional medicine. The nutmeg root has a strong potential in antioxidant and anticancer agents among other nutmeg plant parts. The n-hexane root extract has been carried out by thin-layer chromatography and obtained 8 fractions (labeled as Myristica fragrans Houtt Root: MFHR 1 − 8). Specifically, the MFHR 4 has been purified for several times to obtain a yellow-brown color. Furthermore, lignan compound 6′-methyl-(7‑hydroxy-8-methylbut-9-en)-3,2′-dimethoxybiphenyl-4,5-diol) was identified with chemical formula of C₂₀H₂₄O₅ and analyzed using UV–vis spectroscopy, fourier-transform infrared spectroscopy (FTIR), 1D/2D nuclear magnetic resonance (NMR), and liquid chromatography–mass spectrometry (LC-MS). Based on MTT assay, MFHR demonstrated moderate anticancer activity against MCF-7 cell lines of 51.95 µM, meanwhile, DPPH activity confirmed the strong antioxidant activity with IC50 value of 12.67 ppm.