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All Journal HAYATI Journal of Biosciences Indonesian Journal of Chemical Analysis (IJCA)
Yahya, Mohd Fakharul Zaman Raja
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Agriculture, Biological Sciences & Forestry Chemical Engineering, Chemistry & Bioengineering Chemistry Earth & Planetary Sciences Environmental Science

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Assessment of Biological Activity, Total Phenolic Content, and Cytotoxicity of Ethyl Acetate Extracts from an Endophytic Fungus, Lasiodiplodia pseudotheobromae IBRL OS-64 Mat Jalil, Mohd Taufiq; Zakaria, Nurul Aili; Yahya, Mohd Fakharul Zaman Raja; Mohamad, Sharifah Aminah Syed; Ibrahim, Darah
HAYATI Journal of Biosciences Vol. 32 No. 2 (2025): March 2025
Publisher : Bogor Agricultural University, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.4308/hjb.32.2.445-458

Abstract

The biological activities of ethyl acetate extracts of Lasiodiplodia pseudotheobromae IBRL OS-64 were assessed in the present study. Antioxidant activity was measured using the DPPH scavenging assay, antibacterial activity via broth microdilution, and total phenolic content using the Folin-Ciocalteu method. In vivo toxicity was determined using a brine shrimp lethality assay. The fraction extract exhibited the highest antioxidant activity, with an EC50 of 441.6 µg/ml, surpassing the crude extract's. The EEELP showed a relatively low phenolic content of 13.273 µg GAE/mg extract. Regarding antibacterial activity, both crude and fraction extracts demonstrated MIC values ranging from 62.5 to 250 µg/ml against Gram-positive bacteria, while MBC values ranged from 125 to 500 µg/ml for both extracts. The MIC values for crude and fraction extracts against Gram-negative bacteria were 250-500 µg/ml, whilst the MBC values for both crude and fraction extracts were in the range of 500–2,000 µg/ml. The findings also revealed that Gram-positive bacteria were more susceptible to both extracts (crude and fraction) than Gram-negative bacteria. The crude extract exhibited a non-cytotoxic effect with an LC50 value of 2054.88 µg/ml for acute exposure and a low cytotoxic effect with an LC50 value of 199.69 µg/ml for chronic exposure. Meanwhile, the fraction extract demonstrated a non-cytotoxic effect for both acute and chronic with an LC50 value of 5744.14 µg/ml and 1035.94 µg/ml, respectively. Therefore, the present study suggests that the fraction extract could be an effective pharmaceutical agent and safe for drug development due to its low toxicity.
Synthesis of Biochar-Like Graphene Nanosheets (BLG) from Candlenut Shells with Integrated Conductive and Antibacterial Functionalities Samosir, Friscilla Romiduk; Yahya, Mohd Fakharul Zaman Raja; Siburian, Rikson
Indonesian Journal of Chemical Analysis (IJCA) Vol. 8 No. 2 (2025): Indonesian Journal of Chemical Analysis
Publisher : Universitas Islam Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20885/ijca.vol8.iss2.art7

Abstract

Graphene’s exceptional electrical, mechanical, and chemical properties have enabled breakthroughs in electronics, energy storage, and biomedicine, yet large-scale, low-cost, and sustainable production methods remain elusive. Here, we report a facile, scalable route to synthesize Biochar-Like Graphene Nanosheets (BLG) from candlenut shell biomass using activated carbon as a dual-function reducing agent and combustion inhibitor in a modified muffle furnace pyrolysis system. Structural analysis by X-ray diffraction and Fourier-transform infrared spectroscopy confirms the formation of defect-rich, low-oxygen sp² carbon networks, while scanning electron microscopy reveals wrinkled layered morphologies that promote electrolyte accessibility. Electrical measurements demonstrate a voltage-dependent conductivity, reaching 368.67 μS·cm⁻² at 1.5 V, alongside stable power density (6.72 W·kg⁻¹) and high energy density (403.2 Wh·kg⁻¹), indicative of excellent charge transport and storage capabilities. Remarkably, BLG exhibits potent antibacterial activity against Salmonella typhimurium with a 10.76 ± 0.23 mm inhibition zone and positive MIC and MBC responses, attributed to synergistic membrane disruption, reactive oxygen species generation, and electron transfer effects. This biomass-to-graphene strategy offers a sustainable, multifunctional nanomaterial platform for next-generation energy, environmental, and biomedical technologies
Co-Authors Darah Ibrahim Mat Jalil, Mohd Taufiq Mohamad, Sharifah Aminah Syed Rikson Siburian Samosir, Friscilla Romiduk Zakaria, Nurul Aili