Ismiyarto Ismiyarto
Department of Chemistry, Faculty of Science and Mathematics, Diponegoro University, Semarang|Diponegoro University|Indonesia

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Endophytic Bacteria Producing Alkaloid as Antibacterial and Antioxidant Agent from Hibiscus tiliaceus Leaves Purbowatiningrum Ria Sarjono; Aulia Anggraeni; Ismiyarto Ismiyarto; Ngadiwiyana Ngadiwiyana
Jurnal Kimia Sains dan Aplikasi Vol 27, No 3 (2024): Volume 27 Issue 3 Year 2024
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jksa.27.3.137-144

Abstract

Hibiscus tiliaceus is known to have antibacterial activity. One of the antibacterial compounds contained in the hibiscus plant is alkaloid. Alkaloids can also be obtained from endophytic bacteria that are in symbiosis with hibiscus leaves. It is known that endophytes can produce the same or similar secondary metabolites as their host plants. Medicinal plants have been proven to be a source of microorganisms that can make certain metabolites. Our previous research succeeded in isolating the endophytic bacteria Staphylococcus warneri strain 25 from waru leaves (Hibiscus tiliaceus), which had antioxidant and antibacterial activity and contained saponins and alkaloids. In this study, alkaloids were extracted from the endophytic bacteria found in waru leaves. Subsequently, their bioactivity was assessed for antibacterial properties against Escherichia coli, Salmonella typhi, and Staphylococcus aureus using the well diffusion method. Additionally, their antioxidant activity was evaluated through the DPPH method, with gallic acid serving as the standard. A cyclic amine alkaloid compound was isolated, exhibiting a Minimum Inhibitory Concentration (MIC) of 23 ppm against E. coli, S. typhi, and S. aureus bacteria, accompanied by inhibitory zones measuring 7 mm, 8 mm, and 6 mm, respectively. Additionally, the compound had very strong antioxidant activity, with an IC50 value of 50.11 ppm.
Isolation of Phenolic Acids from Land Kale (Ipomoea reptans Poir) and Antioxidant Activity Enny Fachriyah; Sofiana Nur Aziiza; Ismiyarto Ismiyarto; Purbowatiningrum Ria Sarjono; Dwi Hudiyanti; Sumariyah Sumariyah
Jurnal Kimia Sains dan Aplikasi Vol 27, No 1 (2024): Volume 27 Issue 1 Year 2024
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jksa.27.1.1-7

Abstract

Land kale or Ipomoea reptans Poir is widely consumed by Indonesian people. Land kale plants can be used as natural antioxidants because they contain polyphenolic compounds, one of which is phenolic acid. This research was carried out to determine the antioxidant activity and isolate phenolic acid compounds contained in land kale plants (Ipomoea reptans Poir). The sample used was an ethanol extract of land kale. The total phenolics were determined using the Folin-Ciocalteu method. Phenolic acids were isolated using alkaline hydrolysis and acid hydrolysis and without hydrolysis methods. Separation of isolates was carried out using the TLC method. The structure was identified using UV-Vis spectrophotometry and LC-MS/MS. Antioxidant activity was measured using the DPPH method. The total phenolics of land kale ethanol extract were 71.2420 ± 0.0791 mg/g GAE. TLC showed that the HB, HA, and TH fractions contained caffeic acid and ferulic acid compounds. Separation of the (HB) fraction produced three isolates: B2 with a yellow color, B3 with a slightly yellowish color, and B4 which is colorless. Isolate B2 was identified as potentially containing caffeic acid, while isolate B3 was indicated to potentially contain ferulic acid through analysis using a UV-Vis spectrophotometer. Isolate B4 was thought to have a hydroxybenzoic acid framework after being determined using LC-MS/MS. The ethanol extract of land kale has strong antioxidant activity because it produces an IC50 value of 94.83 mg/L.