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Upaya Optimasi Sintesis Pentapeptida Leu-Ala-Asn-Ala-Lys dengan Pengurangan Nilai Loading Resin Rani Maharani; Dessy Yulyani Kurnia; Ace Tatang Hidayat; Jamaludin Al-Anshori; Dadan Sumiarsa; Desi Harneti; Nurlelasari Nurlelasari
Chimica et Natura Acta Vol 8, No 1 (2020)
Publisher : Departemen Kimia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24198/cna.v8.n1.28671

Abstract

SCAP1 (Saccostrea Cucullata Antioxidant Peptide 1) dengan urutan asam amino LANAK (Leu-Ala-Asn-Ala-Lys) merupakan pentapeptida yang diisolasi dari hidrolisat tiram dan diketahui memiliki aktivitas antioksidan dengan scavenging radikal DPPH sebesar 83,79 ± 0,53%. Peptida ini telah berhasil dibuat dengan metode sintesis peptida fase padat dengan persen rendemen 8,28%. Rendahnya persen rendemen yang diperoleh disebabkan karena adanya dua residu Ala serta 1 residu Asn yang dapat menyebabkan agregasi. Nilai loading resin yang terlalu besar juga menjadi salah satu penyebab terbentuknya agregasi karena loading resin dilakukan selama 15 jam. Penelitian ini bertujuan untuk menyintesis senyawa SCAP1 dengan pengurangan nilai loading resin. Untuk meningkatkan persen rendemen dari penelitian sebelumnya, pada penelitian ini dilakukan optimasi sintesis terhadap SCAP1. Sintesis dilakukan dengan pengurangan nilai loading resin dengan cara mempersingkat waktu loading resin menjadi 4 jam. Senyawa SCAP1 hasil sintesis memiliki massa crude sebesar 119,5 mg dan berhasil dimurnikan menggunakan RP-HPLC preparatif dengan massa murni 10,6 mg dan rendemen 16%. Penelitian ini menunjukkan bahwa pengurangan loading resin meningkatkan rendemen SCAP1 dari 8,28% menjadi 16%.
Perbandingan Metode Uji Aktivitas Antioksidan DPPH, FRAP dan FIC Terhadap Asam Askorbat, Asam Galat dan Kuersetin Kiki Maesaroh; Dikdik Kurnia; Jamaludin Al Anshori
Chimica et Natura Acta Vol 6, No 2 (2018)
Publisher : Departemen Kimia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (200.022 KB) | DOI: 10.24198/cna.v6.n2.19049

Abstract

Antioksidan merupakan senyawa yang menghambat atau menunda reaksi oksidasi molekul dengan cara menghambat proses inisiasi atau propagasi reaksi oksidasi berantai. Struktur kimiawi antioksidan, sumber radikal bebas, dan sifat fisiko-kimia sediaan sampel yang berbeda dapat memberikan hasil uji aktivitas antioksidan yang beragam. Oleh karena itu, diperlukan suatu metode analisa aktivitas antioksidan yang selektif untuk suatu jenis sampel tertentu. Studi perbandingan metode uji aktivitas antioksidan DPPH, FRAP, dan FIC telah dilakukan terhadap asam askorbat (AA), asam galat (AG), dan kuersetin. Ketiga metode uji antioksidan dibedakan berdasarkan pada jenis mekanisme reaksinya, sedangkan sampel standar antioksidan dipilih berdasarkan struktur polihidroksi atau polifenol yang umumnya mewakili dasar struktur antioksidan bahan alam. Metode uji aktivitas antioksidan terhadap radikal DPPH ditemukan paling efektif dan efisien diantara ketiga metode uji yang digunakan dengan nilai IC50 berturut-turut 1,27; 2,44; dan 2,77 mg/L untuk AG, kuersetin dan AA. Adapun metode FIC terbukti paling tidak efektif dan efisien karena sensitivitasnya yang sangat rendah dan daya kelatnya lebih kecil dari 20%. Korelasi antara metode uji untuk semua standar antioksidan terbukti sangat tinggi (R>0,98), khususnya antara FRAP dan DPPH. Hal ini mengindikasikan adanya keterkaitan sangat kuat antara daya hambat radikal bebas dengan potensial reduksi senyawa polihidroksi (polifenol) terhadap ion besi. Secara umum kedua metode ini sangat dimungkinkan bisa saling menggantikan satu sama lain.
SYNTHESIS OF MENTHOL FROM PULEGOL CATALYZED BY Ni/γ-Al2O3 Jamaludin Al Anshori; Muchalal Muchalal; Sutarno Sutarno
Indonesian Journal of Chemistry Vol 9, No 1 (2009)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1522.675 KB) | DOI: 10.22146/ijc.21567

Abstract

Synthesis of menthol using Ni/γ-Al2O3 15% has been carried out started from pulegol as precursor. Structure elucidation of the products was achieved by GC-FID, GC-MS, FTIR, and 1H-NMR evidences. Isomers identification and their stability were determined by computational simulation. All experimental results were compared to the available literature. Ni/γ-Al2O3 catalyst was prepared by wet impregnation with precursor of Ni(NO3)2, followed by calcinations and reduction respectively. Characterization of the catalyst was performed by XRD and AAS. Synthesis was started by mixing pulegols with catalyst and then swirled it with hydrogen gas. Reaction temperature and duration were varied in order to obtain high yield with good selectivity. The results showed that the optimum condition of Ni/γ-Al2O3 catalytic hydrogenation of pulegol was achieved at 180 °C for 8 hours. The conversion of pulegol to menthol was 89% with stereo selectivity of 71% to (-)-menthol.
HIDROGENASI PULEGIL ASETAT DIKATALISIS Ni/γ-Al2O3 Jamaludin Al Anshori; Muchalal Muchalal
Jurnal Sains dan Terapan Kimia Vol 3, No 2 (2009)
Publisher : Program Studi Kimia, Universitas Lambung Mangkurat

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (183.163 KB) | DOI: 10.20527/jstk.v3i2.2033

Abstract

Telah dilakukan hidrogenasi pulegil asetat dikatalisis Ni/γ-Al2O3 untuk mempelajari selektivitas katalis dan pengaruh durasi reaksi terhadap stereospesifitas katalis Ni/γ-Al2O3. Pulegil asetat diperoleh dari siklisasi sitronelal dengan anhidrida asam asetat dikatalisis ZnCl2 pada temperatur 80 oC dan durasi reaksi 3 jam. Ni/γ-Al2O3 dipreparasi dengan impregnasi Ni(NO3)2.6H2O ke dalam γ-Al2O3, dilanjutkan dengan kalsinasi dan reduksi pada temperatur ±500 oC secara berturut-turut. Aktivitas katalis diujikan pada hidrogenasi pada temperatur 200 oC dan durasi reaksi 2, 4, 6, 8 dan 10 jam. Reaksi dilakukan dengan menambahkan 2,5 mL pulegil asetat dan 0,25 g Ni/γ-Al2O3 ke dalam reaktor hidrogenasi. Produk yang terbentuk diidentifikasi dengan metode spektroskopi. Reaksi menunjukkan bahwa selektifitas hidrogenasi terjadi pada ikatan rangkap C=C pulegil asetat menghasilkan mentil asetat dan neo-mentil asetat. Hasil optimal dari hidrogenasi katalitik diperoleh pada temperatur 200 oC dan durasi reaksi 10 jam. Stereospesifitas produk sebesar 61,08% terhadap mentil asetat dan 33,85% terhadap neo-mentil asetat. Kata kunci : hidrogenasi, pulegil asetat, mentil asetat, neo-mentil asetat, katalis Ni/γ- Al2O3 
Metabolomic Profiling LC-MS Based Bioactive Compound of Sonneratia alba, Antioxidant Activities and Its In-silico molecular docking Studies Tarigan, Indra Lasmana; Latief, Madyawati; Anshori, Jamaludin Al; Melani, Fitria; Putri, Silvi Ayudiah; Husna, Naimul; Warni, Tri; Ramadhan, Ilham Ifandi; Yusnaidar, Yusnaidar; Sutrisno, Sustrisno
Molekul Vol 20 No 2 (2025)
Publisher : Universitas Jenderal Soedirman

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20884/1.jm.2025.20.2.13578

Abstract

ABSTRACT. Mangrove Perepat (Sonneratia alba) plants have various potentials that need to be utilized optimally because they have varying bioactive compound content. A comprehensive exploration of secondary metabolite compound content and plant bioactivity based on metabolomics and in-silico molecular docking is needed to see the effects of single or multiple compounds. This study aimed to obtain a profile of medicinal compounds from Perepat leaves as antioxidants. Extraction was carried out using five gradients of Ethanol: Water concentration. EP1 (water), EP2 (25% Ethanol), EP3 (50% Ethanol), EP4 (75% Ethanol), EP5 (100% Ethanol). The research was carried out through extraction, antioxidant determination, metabolomics, and molecular docking. Exploration data showed that increasing ethanol concentration increased phenolics, flavonoids, and antioxidant activity. EP5 has the highest total phenolics and flavonoids of 24.978 mgGAE/g and 42.97 mgQE/g, respectively, with an IC50 value of 8.263 ppm. Docking analysis of 37 test compounds identified 12 compounds with low binding energy, ranging from -7 to -9 kcal/mol, with the NADPH oxidase protein receptor (PDB ID: 2CDU). These compounds include kaempferol-3-rhamnoside, meperidine, apigenin-7-O-glucoside, 2-keto benzothiazole 54, methyl propanoic acid, salicyloylaminotriazole, salicylihalamide A, and gibberellin A7. Our findings suggest that S. alba extract holds potential for further exploration as a natural antioxidant source. Keywords: Antioxidant; In-silico; Metabolomics; S. alba
Synthesis of Two Analogues of Xylapeptide A and Their Potency as New Antimicrobial Agent Maharani, Rani; Muchlis, Handi Nugraha; Hidayat, Ace Tatang; Al-Anshori, Jamaludin; Nurlelasari, Nurlelasari; Harneti, Desi; Mayanti, Tri; Farabi, Kindi; Supratman, Unang
Indonesian Journal of Chemistry Vol 25, No 5 (2025)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.100353

Abstract

Xylapeptide A, derived from the fungus Xylaria sp. x Sophora tonkinensis, exhibits potent and selective antimicrobial properties. Our research group has successfully synthesized xylapeptide A. In our recent work, two xylapeptide A analogues (An1 and An2) were synthesized using a combination of solid- and solution-phase synthesis methods. The linear precursors of An1 and An2 were synthesized on 2-CTC resin with the Fmoc strategy. The coupling reagents HBTU/HOBt and HATU/HOAt were employed. Subsequently, the linear precursor was cleaved from the resin using either 20% TFA or a TFE mixture, and then cyclized in solution phase with HBTU. The synthesized products were purified using semi-preparative RP-HPLC, giving the percent yields 16% for An1 and 12% for An2. Both compounds were then characterized by HR-ToF-MS, 1H- and 13C-NMR. The synthesized xylapeptide A and its analogues were evaluated against Bacillus cereus, Bacillus subtilis, Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, and Candida albicans. The result showed that An2, possessing arginine residue, exhibited higher activity compared to xylapeptide A and An1. This research suggests that xylapeptide A analogues hold great promise as novel antimicrobial agents.