Dikhi Firmansyah
Department Of Chemistry, Faculty Of Mathematics And Natural Sciences, Institut Teknologi Bandung, Bandung 40132, West Java, Indonesia

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Antioxidant Activity of Fungus Comb Extracts Isolated from Indo-Malayan Termite Macrotermes gilvus Hagen (Isoptera: Termitidae) Yanti Rachmayanti; Dikhi Firmansyah; Reza Ro'isatul Umma; Decsa Medika Hertanto; I Ketut Sudiana; Djoko Santoso; Dodi Nandika; Lina Karlinasari; Arinana Arinana; Irmanida Batubara; Lucia Dhiantika Witasari
Indonesian Journal of Chemistry Vol 22, No 6 (2022)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.77227

Abstract

Indonesian termites are one of the wealthiest biological resources considering their very high species diversity (300 species) and extensive geographical distribution in the Indonesian mainland. However, its potential as a source of bioactive compounds has not been fully explored. One of the endemic termite sub-families of Indonesian, Macrotermitinae (Isoptera: Termitidae), has a food source in the form of fungal nodules that grow and spread in a particular structure in the termite nest that is shaped like a mammalian brain called a fungus comb, which likely serves as a source of bioactive compounds. This study aims to analyze the potential of fungus comb from an Indonesian Macrotermitinae sub-family species as a source of antioxidants. Antioxidant activity was tested on four different extracts of fungus comb (EFC), namely hexane extract, ethyl acetate extract, methanol extract and water extract, using DPPH• (1,1-diphenyl-2-picrylhydrazyl) and ABTS•+ (2,2′-azino-di-[3-ethylbenzthiazolinesulphonate]) radicals. The results showed that the highest antioxidant activity was found in methanol extract, followed by ethyl acetate extract with IC50 values of 0.6 mg/mL and 0.75 mg/mL, respectively. TEAC (Trolox equivalent antioxidant capacity) analysis confirmed the high antioxidant activity of methanol extract.
A Pyrone and Flavonoid Derivatives from Cryptocarya crassinervia and their Inhibitory Properties against Receptor Tyrosine Kinases Dian Nugraheni; Elvira Hermawati; Hendra Helmanto; Dikhi Firmansyah; Yana Maolana Syah; Lia Dewi Juliawaty
Journal of Mathematical and Fundamental Sciences Vol. 55 No. 3 (2024)
Publisher : Directorate for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.math.fund.sci.2024.55.3.5

Abstract

A new a-pyrone, i.e., cryptocrassinervione (1), and a new flavone glycoside, i.e., kaempferol-3-O-rhamnosyl-2-O-apiofuranoside (4), were isolated from EtOAc extract of Cryptocarya crassinervia leaves. Along with these compounds, two known flavone glycosides, namely afzelin (2) and quercitrin (3), were also isolated. The structures of the new compounds were determined based on NMR and mass spectral data. Compounds 1–4 were examined against eight receptor tyrosine kinases (RTKs) (EGFR, HER2, HER4, IGF1R, InsR, KDR, PDGFRα, and PDGFRβ), which showed that these compounds were moderately active against EGFR, with inhibition percentages of 55, 49, 41, and 44%, respectively. They were weakly active against HER2, with inhibitions of 17, 20, 18, and 16%, respectively. However, they were not active against the rest of the RTKs. Nevertheless, compounds 1–4 have potency as inhibitors of EGFR.
Formation and stability investigation of meso-hydroxy diacyl-dipyrromethane Ferryansyah, Mohammad Akbar; Santria, Anas; Ishikawa, Naoto; Firmansyah, Dikhi
Communications in Science and Technology Vol 10 No 1 (2025)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.10.1.2025.1593

Abstract

The oxidation of dipyrromethane by 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) generally produces dipyrrin, but in the presence of trace water, a meso-hydroxy dipyrromethane can be formed. To investigate this unusual product, we then studied meso-hydroxy bis(p-anisoyl)-p-fluorophenyl dipyrromethane (3) obtained from the oxidation of bis(p-anisoyl)-p-fluorophenyl dipyrromethane (2). Spectroscopic studies (1H-NMR, UV-Vis, and fluorescence), mass spectrometry, and computational analyses were performed to investigate this mechanism. Zinc complexation of compound 3 altered the 1H-NMR spectrum and shifted the absorption peak from 325 nm to 567 nm with “turn-on” fluorescence. Thermochemical studies have indicated that the formation of meso-hydroxy requires energy higher than dipyrrin. This study suggests that the electronic properties of meso-aryl and acyl groups are the key factors for the nucleophilic attack of water on cationic dipyrromethane intermediate. These results further improve the understanding of dipyrromethane oxidation pathways, which is crucial for the design and synthesis of dipyrrin-chemosensors.