Hasil Pencarian  ::  Simpan CSV :: Kembali

"Infeksi bakteri telah menjadi masalah kesehatan publik yang signifikan secara global. Oleh sebab itu, kebutuhan akan agen antibakteri baru terus dikembangkan untuk mencegah penyebaran bakteri. Kumarin dan turunannya dikenal memiliki aktivitas biologi yang luas, termasuk antibakteri. Dalam penelitian ini, telah berhasil disintesis senyawa turunan 4-metilkumarin yaitu 3-asetil-4-metilkumarin (1), etil-4-metil-kumarin-3-karboksilat (2), dan 3-siano-4-metilkumarin (3) melalui reaksi kondensasi Knoevenagel yang dikatalisis oleh NaOH menggunakan metode MAOS. Senyawa 1 (43,54%) berhasil disintesis dalam kondisi bebas pelarut dengan mereaksikan 2-hidroksi asetofenon dan etil asetoasetat (1:1, mol/mol) dengan katalis NaOH 30% mol pada suhu 80oC selama 7 menit. Dengan memodifikasi waktu dan suhu reaksi pada kondisi optimum sintesis senyawa 1, senyawa 2 (28,00%) dan 3 (51,56%) berturut-turut berhasil disintesis menggunakan dietilmalonat dan etil sianoasetat sebagai pengganti metilen aktifnya. Penggunaan malononitril sebagai metilen aktif menghasilkan senyawa 3 dalam bentuk campuran berbagai turunan heterosiklik sebagai produk samping. Senyawa hasil sintesis diidentifikasi menggunakan KLT dan uji titik leleh, serta dikarakterisasi menggunakan FTIR, UV-Vis, NMR, dan LC-MS. Evaluasi aktivitas antibakteri dengan metode difusi cakram terhadap produk sintesis menunjukkan senyawa 1, 2, 3, dan campuran 3 memiliki aktivitas penghambatan lemah terhadap bakteri gram negatif, E. coli. Sementara hanya senyawa campuran 3 yang memberikan aktivitas penghambatan lemah terhadap bakteri S. aureus.

---

Bacterial infections have become a significant public health issue globally. Therefore, the need for new antibacterial agents continues to emerge to prevent the spread of bacteria. Coumarins and their derivatives are known to have a wide range of biological activities, including antibacterial. In this study, 4-methyl coumarin derivatives afforded, including 3-acetyl-4-methyl coumarin (1), ethyl-4-methyl-coumarin-3-carboxylate (2), and 3-cyano-4-methyl coumarin (3). through the Knoevenagel condensation reaction catalyzed by NaOH using the MAOS method. Compound 1 (43.54%) was formed under solvent-free conditions by reacting 2-hydroxy acetophenone and ethyl acetoacetate (1:1, mol/mol) with 30% mol NaOH catalyst at 80oC for 7 minutes. Modification of reaction time and temperature of optimum condition shows the formation of compounds 2 (28.00%) and 3 (51.56%). The use of malononitrile as active methylene induces compound 3 in the form of a mixture with various heterocyclic derivatives as a by-product. The synthesized compounds were identified using TLC and melting point tests and characterized using FTIR, UV-Vis, NMR, and LC-MS. Evaluation of antibacterial activity by disc diffusion method shows that compounds 1, 2, 3, and mixtures 3 showed weak inhibitory activity against gram-negative bacteria, namely E. coli. Meanwhile, only mixtures compound 3 showed weak inhibitory activity against S. aureus bacteria."

"Sintesis senyawa fenolipid berbasis asam risinoleat telah dilakukan pada penelitian ini. Sebelum sintesis fenolipid, dilakukan metilasi terhadap asam risinoleat terlebih dahulu. Keberhasilan reaksi metilasi diuji dengan penentuan persen konversi dan identifikasi menggunakan instrumentasi FTIR. Keberhasilan metilasi ditunjukkan dengan hilangnya gugus O-H karboksilat pada produk metilasi yang berada pada bilangan gelombang 3200-2400 cm-1 dengan persen konversi sebesar 94%. Sintesis senyawa fenolipid dilakukan dengan mereaksikan metil ester hasil sintesis dengan asam galat, menggunakan katalis ZnCl2 pada suhu 70 – 80 oC. Kedua reaksi dilakukan selama 6 jam dalam sistem refluks. Rendemen senyawa fenolipid hasil sintesis adalah 70,7%. Hasil sintesis diidentifikasi menggunakan instrumentasi FTIR dan juga dilihat keberhasilannya menggunakan KLT. Campuran kloroform/metanol (93:7) digunakan sebagai eluen pada KLT yang menghasilkan perbedaan nilai Rf pada ketiga sampel yang diuji. Nilai Rf yang dimiliki oleh senyawa fenolipid hasil sintesis 0,84, nilai ini merupakan nilai terbesar, sehingga menunjukkan bahwa senyawa tersebut memiliki sifat paling nonpolar dibanding yang lain. Selanjutnya identifikasi FTIR menghasilkan pita serapan baru yang kuat pada bilangan gelombang 758,06 cm-1 yang mengindikasikan adanya gugus C-H aromatik (tekuk) pada produk hasil sintesis yang mengindikasikan keberhasilan dari proses sintesis yang dilakukan. Uji aktivitas antioksidan senyawa fenolipid dengan metode DPPH menunjukkan nilai persen inhibisi dengan kisaran 30-33%. Uji emulsifier senyawa fenolipid hasil sintesis menunjukkan kestabilan emulsi yang cukup baik pada pengamatan hingga 24 jam, dengan tipe emulsi yang terbentuk yaitu air dalam minyak (W/O). Selain itu, dilakukan analisis potensi antibakteri senyawa fenolipid terhadap bakteri Propionibacterium acnes dan Staphylococcus epidermidis.

---

Synthesis of phenolipid compounds based on ricinoleic acid has been carried out in this study. Before phenolipid synthesis, methylation of ricinoleic acid is carried out first. The success of the methylation reaction was tested by determining percent conversion and identification using FTIR instrumentation. The success of methylation is shown by the loss of the carboxylic O-H group in the methylation product which is at wave number 3200-2400 cm-1 with a conversion percentage of 94%. Synthesis of phenolipid compounds was carried out by reacting the synthesized methyl esters with gallic acid, using a ZnCl2 catalyst at 70-80 oC. Both reactions are carried out for 6 hours in the reflux system. The yield of synthesized phenolipid compounds is 70.7%. The synthesis results were identified using FTIR instrumentation and seen its success using TLC. A mixture of chloroform/methanol (93: 7) was used as an eluent in TLC which resulted in different Rf values in the three samples tested. The Rf value owned by the synthesized phenolipid compound is 0.84, this value is the largest value, thus indicating that the compound has the most nonpolar properties compared to the others. Furthermore, identification of FTIR produced a strong new absorption band at wave number 758.06 cm-1 indicating the presence of aromatic C-H groups (bending) on the synthesized product which indicated the success of the synthesis process carried out. The antioxidant activity test of phenolipid compounds with DPPH method showed a value of percent inhibition in the range of 30-33%. The emulsifier test of the phenolipid compound synthesized showed the stability of the emulsion was quite good at observations of up to 24 hours, with the type of emulsion formed, namely water in oil (W / O). In addition, an analysis of the antibacterial potential of phenolipid compounds against Propionibacterium acnes and Staphylococcus epidermidis was carried out."

"Copper(II) and nickel(II) complexes of 14-membered hexaazamacrocyclic ligand with C-methyl substituent have been synthesized by one-pot reaction and characterized by elemental analyses, FT-IR, electronic spectra, and LC-MS. Complex types are [Cu(C18H42N6)(ClO4)2] (1), [Ni(C18H42N6)](ClO4)2 (2), and [Cu(C22H50N6)(ClO4)2] (3). The results of spectroscopic techniques indicated that both complexes 1 and 3 containing copper(II) are octahedral geometry, whereas the complex 2 is a square-planar geometry in which the metal center coordinates to the four nitrogen atoms of macrocyclic ligand in a square planar fashion.All complexes were also screened for their antibacterial activity against on two bacteria strains. These results show that copper(II) and nickel(II) complexes were tested for antibacterial activity against gram positive, Staphylococcus aureus which was more active than the against gram negative, bacteria Escherichia coli.The results showed a good antibacterial activity of all complexes which suggests their potential applications as antibacterial agents."

"Kurkumin merupakan senyawa diarilheptanoid yang dapat diisolasi dari rimpang kunyit, senyawa ini bertanggung jawab atas warna kuning yang ditimbulkan oleh kunyit. Selain itu, kurkumin memiliki bioaktivitas sebagai antimikroba, antiinflamasi, antikanker, antidiabetes, dan antioksidan. Modifikasi struktur kurkumin banyak dikembangkan karena beberapa penelitian menunjukkan adanya peningkatan bioaktivitas senyawa hasil modifikasi. Pada penelitian ini, dilakukan sintesis modifikasi kurkumin-sulfanilamida dan dikarakterisasi untuk diuji aktivitas antibakterinya terhadap bakteri gram negatif, E. coli, serta bakteri gram positif, S. aureus dan B. subtilis. Penelitian ini dimulai dengan mengekstraksi kurkuminoid dari rimpang kunyit, lalu diikuti isolasi kurkumin menggunakan metode kromatografi kolom, dengan eluen DCM:MeOH (97:3)v/v, hasilnya dikonfirmasi melalui KLT dengan eluen yang sama, selanjutnya dikarakterisasi menggunakan spektrofotometer UV-Vis dan FTIR. Setelah itu, dilakukan sintesis derivat kurkumin-isoksazol dengan menambahkan hidroksilamin hidroklorida pada kurkumin yang telah larut dalam piridin. Optimasi suhu dan waktu yang di dapat dari sintesis ini adalah pada 70oC selama 8 jam, dengan persen hasil 78,80%. Sulfanilamida ditambahkan pada isoksazol untuk memodifikasi gugus OH fenol dari struktur kurkumin dengan penambahan asam asetat glasial, campuran ditriturasi menggunakan etanol, kemudian direfluks selama 20 menit, persen hasil senyawa kurkumin-sulfanilamida yang diperoleh sebesar 64,87%. Senyawa kurkumin-sulfanilamida menunjukkan aktivitas yang lebih baik terhadap bakteri gram negatif dibandingkan gram positif, dengan diameter zona hambat 11 mm.

---

Curcumin is a diarylheptanoid compound which is isolated primary from tumeric rizhome, is responsible for the yellow color caused by turmeric. In addition, curcumin exhibits a variety of interesting biological activities such as antimicrobial, anti-inflammatory, anticancer, antidiabetic, and antioxidants. Structure modifications of curcumin have been developed because several studies have shown an increase in bioactivity. In this study, a sulfanilamide-contained curcumin compound was synthesized and characterized to investigate its antibacterial activity against E. coli, S. aureus and B. subtilis. This research was started by extracting curcuminoids from tumeric followed by isolation curcumin using column chromatography with DCM:MeOH (97:3)v/v as eluent, the result was confirmed through TLC with the same eluent, and was characterized using UV-Vis spectrophotometry and FTIR. Afterwards, curcumin-derived compounds containing isoxazole were synthesized by adding hydroxylamine hydrochloride into curcumin, which has dissolved in piridin. Optimization of temperature and time obtained from this synthesis was 70oC for 8 hours, resulted in 78,80% yield. Sulfanilamide was added to isoxazole to modify OH phenol of curcumin structure by adding glacial acetic acid, the mixture was triturated with ethanol and refluxed for 20 minutes, yield of this compound was 64,87%. Curcumin-sulfanilamide compound provide better activity against E. coli than S. Aureus and B. subtillis, with diameter of inhibition zone was 11 mm."

"Resistensi bakteri merupakan kemampuan bakteri bertahan hidup dari senyawa antibakteri akibat adanya mutasi. Untuk menghadapi fenomena tersebut, dibutuhkan senyawa baru yang memiliki aktivitas antibakteri dengan mekanisme penghambatan yang berbeda. 2-Kuinolon merupakan senyawa heterosiklik yang dikenal memiliki aktivitas antibakteri yang dapat diisolasi dari tanaman dan disintesis di laboratorium. Dalam studi ini, dilakukan sintesis senyawa turunan 4-metil-2-kuinolon menggunakan bantuan iradiasi microwave tanpa pelarut dari o-, m-, p-aminoanilin (fenilendiamina) serta m-hidroksianilin (m-aminofenol) dengan etilasetoasetat dan kehadiran katalis asam AlCl3 sesuai reaksi kondensasi Pechmann-like. Senyawa turunan 4-metil-2-kuinolon kemudian dianalisis aktivitas antibakterinya menggunakan metode difusi cakram terhadap Escherichia coli (gram negatif) dan Staphylococcus aureus (gram positif). Sintesis menggunakan m-aminoanilin dan m-hidroksianilin menghasilkan 7-amino-4-metil-2-kuinolon (43,42%) dan 7-hidroksi-4-metil-2-kuinolon (26,36%) dalam kondisi reaksi iradiasi microwave 800 W, rasio mol anilin:etil asetoasetat 1:1 (mol/mol), katalis 10% (b/b), dan tanpa pelarut selama 5 menit. Sintesis dari o- dan p-aminoanilin menghasilkan suatu senyawa campuran. Seluruh senyawa hasil sintesis selanjutnya diidentifikasi dengan KLT dan diuji titik lelehnya serta dikarakterisasi dengan FTIR, UV-Vis, NMR, dan LC-MS. Hasil pengujian antibakteri menunjukkan keempat senyawa hasil sintesis memiliki aktivitas antibakteri sedang terhadap E. coli dengan zona inhibisi 6-10 mm dan tidak aktif terhadap S. aureus pada rentang konsentrasi 62,5-1000 ppm. Oleh karena itu, senyawa turunan 4-metil-2-kuinolon hasil sintesis berpotensi digunakan sebagai antibakteri terhadap bakteri E. coli.

---

Antibacterial resistance is an adaptive change in bacteria (mutation) that allows them to grow in the presence of an antibiotic that would normally kill them. To overcome this problem, a new antibacterial compound with different bacteria inhibition mechanisms is needed. 2-Quinolones are heterocyclic compounds with an antibacterial activity that can be isolated from plants and synthesized in the laboratory. In this study, derivatives of 4-methyl-2-quinolone are synthesized using microwave irradiation from o-, m-, p-aminoaniline (phenylenediamine), and m-hydroxyaniline (m-aminophenol) with ethyl acetoacetate in the presence of AlCl3 as a catalyst. Antibacterial activity of 4-methyl-2-quinolone derivatives were evaluated against Escherichia coli and Staphylococcus aureus using the disc diffusion method. 7-amino-4-methyl-2-quinolone (43,42%) and 7-hydroxy-4-methyl-2-quinolone (26,36%) were obtain from m-aminoaniline dan m-hydroxyaniline precursor, respectively, under conditions of 800 W microwave irradiation without solvent for 5 minutes, mole ratio of aniline: ethyl acetoacetate 1:1 (mole/mole), and 10% (w/w) catalyst. Synthesis of derivatives 4-methyl-2-quinolone from o- and p-aminoaniline produce a mixed compound. All synthesized compounds were identified by TLC and melting points, followed by further characterization using FTIR, UV-Vis, NMR, and LC-MS. The results of the antibacterial test showed that the four synthesized compounds had moderate antibacterial activity against E. coli with 6-10 mm of inhibition zone and inactive against S. aureus in the range of 62.5-1000 ppm concentration. Therefore, the derivatives of 4-methyl-2-quinolone have the potential to an antibacterial against E. coli bacteria."

"Nanopartikel merupakan senyawa dengan ukuran 1-100nm. Pembuatan nanopartikel dapat dilakukan dengan tiga cara, baik secara kimia, fisika, maupun biologi (green synthesis). Pembuatan nanopartikel secara Green synthesis yang dimediasi oleh tanaman menarik perhatian peneliti karena relatif aman, murah, mudah dilakukan, dan ramah lingkungan. Pembuatan nanopartikel CuCo2O4 sebagai katalis secara green synthesis melibatkan tumbuhan (Vitis Vinifera) pada bagian daunnya. Menggunakan tumbuhan sebagai media sintesis dilpilih karena kandungan fitokimia pada tumbuhan memiliki sifat pereduksi dan agen penstabil. Nanopartikel CuCo2O4 berhasil disintesis dan dapat digunakan sebagai katalis pada reaksi Doebner untuk menghasilkan suatu senyawa derivat quinoline-4-carboxylic acid. Reaksi Doebner melibatkan anilin, asam piruvat dan senyawa aldehid aromatik. Senyawa derivat quinoline-4-carboxylic acid hasil sintesis dikonfirmasi secara KLT, IR, UV-Vis, dan LCMS. Hasil karakterisasi menunnjukkan telah terbentuk senyawa quinoline-4-carboxylic acid yang sesuai. Penggunaan katalis CuCo2O4 menghasilkan produk sebesar 60,30% pada produk 1 ; 77,83% pada produk 2; 19,23% pada produk 3; dam 19,98% pada produk 4. Masing-masing produk dilakukan pengujian antikanker dan diperoleh data IC50<200µg/L yang menunjukkan tingkat sitotoksik yang sedang untuk semua produk hasil sintesis.

---

Nanoparticles are compounds with a size of 1-100nm. The manufacture of nanoparticles can be done in three ways, either chemically, physically, or biologically (green synthesis). The production of nanoparticles by means of plant-mediated green synthesis has attracted the attention of researchers because it is relatively safe, inexpensive, easy to perform, and environmentally friendly. Making CuCo2O4 nanoparticles as a catalyst by means of green synthesis involves plants (Vitis Vinifera L) in their leaves. Using plants as a synthesis medium was chosen because the phytochemicals in plants have reduced and stabilizing properties. CuCo2O4 nanoparticles have been successfully synthesized and can be used as a catalyst in the Doebner reaction to produce a quinoline-4-carboxylic acid derivative compound. The Doebner reaction involves aniline, pyruvic acid and aromatic aldehydes. The synthesized quinoline-4-carboxylic acid derivatives were confirmed by TLC, IR, UV-Vis, and LCMS. The characterization results showed that a suitable quinoline-4-carboxylic acid compound had been formed. The use of CuCo2O4 catalyst produces a product of 60.30% in product 1; 77.83% in product 2; 19.23% in product 3; and 19.98% in product 4. Anticancer testing was carried out for each product and IC50<200µg/L data was obtained which indicated a moderate cytotoxic level for all synthesized products."

"Infeksi saluran kemih terkait kateter (catheter related urinary tract infections/CRUTI) adalah infeksi yang didapat ketika menjalani perawatan di rumah sakit yang dapat memperburuk resistensi antibakteri dan menjadi penyebab utama dari masalah kesehatan masyarakat. Dalam studi ini, bentonit digunakan sebagai matriks pendukung nanopartikel perak, AgNP-NaAlg disintesis menggunakan green method yang mana NaAlg bertindak sebagai agen pereduksi dan penstabil AgNP menghasilkan nanokomposit Bentonit/AgNP-NaAlg yang aktivitas bakterinya dipelajari. Keberhasilan AgNP-NaAlg didukung dengan karakterisasi menggunakan UV-Vis, FTIR, XRD, PSA, dan SEM-EDS. Hasil PSA diperoleh ukuran partikel 91.28 nm yang memiliki distribusi partikel paling baik dan stabil dengan konsentrasi AgNO3 0.06% dan nanokomposit Bentonit/AgNP-NaAlg menggunakan FTIR, XRD, SEM-EDS, TEM, AAS, TGA dan hasil TEM diperoleh ukuran rata-rata partikel AgNp sekitar 16.332 nm. Bentonit dapat menurunkan ukuran partikel, meningkatkan stabilitas termal diamati dengan TGA, juga meningkatkan kapasitas retention dan menurunnya kapasitas release maksimumnya. Hasil uji aktivitas antibakteri pada AgNP-NaAlg dan nanokomposit Bentonit/AgNP-NaAlg dengan metode difusi cakram diperoleh hasil zona hambat yang baik dan efektivitas yang kuat terhadap terhadap bakteri gram positif (Staphylococcus aureus) dan gram negatif (Escherichia coli). Jadi, AgNP dengan green method berbasis biopolimer yang dikombinasikan dengan bentonit dapat dikembangkan sebagai material nano menunjukkan efek sinergis sebagai aplikasi antibakteri yang potensial di masa depan.

---

Catheter-related urinary tract infections (CRUTI) are hospital-acquired infections that can worsen antibacterial resistance and become a major cause of public health problems. In this study, bentonite was used as a supporting matrix for silver nanoparticles, AgNP-NaAlg was synthesized using a green method in which NaAlg acted as a reducing and stabilizing agent for AgNP to produce Bentonite / AgNP-NaAlg nanocomposites whose bacterial activity was studied. The success of AgNP-NaAlg was supported by characterization using an UV-Vis, FTIR, XRD, PSA, and SEM-EDS. The PSA results obtained a particle size of 91.28 nm which had the best and most stable particle distribution with a concentration of 0.06% AgNO3 and Bentonite / AgNP-NaAlg nanocomposites using FTIR, XRD, SEM-EDS, TEM, AAS, TGA and TEM results obtained mean particle size AgNP is approximately 16,332 nm. Bentonite can decrease the particle size, increase the thermal stability observed with TGA, also increase its retention capacity and decrease its maximum release capacity. The results of the antibacterial activity tests on AgNP-NaAlg and Bentonite / AgNP-NaAlg nanocomposites using the disk diffusion method obtained good inhibition zone results and strong effectiveness against gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria. Thus, AgNP with the biopolymer-based green method combined with bentonite can be developed as a nanomaterial showing a synergistic effect as a potential antibacterial application in the future."

"ABSTRAKDerivat kromen telah dilaporkan memiliki berbagai aktivitas biologis, seperti antioksidan, antibakteri, antikanker, anti-poliferatif, dan anti-inflammatory. Pendekatan melalui reaksi multikomponen (multi-component reactions, MCR) merupakan suatu strategi yang efektif, karena transformasi dan pembentukan ikatan pada sintesis kimia organik dilakukan dalam satu wadah dan umumnya tidak memerlukan proses pemisahan senyawa intermediet, sehingga dapat mengurangi limbah kimia, mempersingkat waktu reaksi, menghemat energi dan reagen, serta mempermudah aspek praktik. Tujuan dari penelitian ini adalah mengkaji efektivitas sintesis derivat kromen melalui reaksi multikomponen dengan menggunakan katalis Fe3O4/kampor yang mampu menghasilkan yield memuaskan dan pengujian aktivitas beberapa produk yang diperoleh sebagai antioksidan dan antibakteri.Penelitian dilakukan dalam empat tahap. Tahap pertama adalah sintesis dan pengujian efektivitas aktivitas katalitik nanopartikel magnetik Fe3O4/kampor yang disertai karakterisasi menggunakan FT-IR, XRD, PSA, SEM-EDS, dan TEM. Tahap kedua adalah screening kondisi optimum reaksi dalam mensintesis derivat kromen menggunakan substrat berupa benzaldehida, malononitril, dan dimedon. Reaksi tersebut diamati dengan menggunakan TLC, produk yang terbentuk dikristalisasi, dan dihitung yield produk dengan memvariasikan jenis pelarut, suhu reaksi, dan jumlah katalis. Tahap ketiga adalah menginvestigasi ruang lingkup metode dengan memvariasikan substrat berupa aromatik aldehida (4-hidroksi benzaldehida), metilen aktif (malononitril), dan β-diketon (asam barbiturat dan asam thiobarbiturat). Hasil reaksi dikarakterisasi dengan menggunakan melting point, FT-IR, spektrofotometer UV-Vis, dan GC-MS. Tahap keempat adalah pengujian aktivitas derivat kromen sebagai antioksidan dan antibakteri secara in vitro.Kampor dapat dimanfaatkan sebagai katalis dalam bentuk nanopartikel magnetik Fe3O4/kampor setelah melewati karakterisasi menngunakan FT-IR, XRD, PSA, SEM-EDS, dan TEM. Preparasi berpengaruh terhadap ukuran nanopartikel magnetik dan ukuran partikel tersebut berkorelasi negatif dengan yield produk sintesis berupa senyawa derivat kromen 4a. Fe3O4/kampor FC3 merupakan katalis dengan ukuran paling kecil (19,24 nm/XRD; 37,18 nm/PSA; 37,43 nm/SEM) yang mampu menghasilkan yield sebesar 91,70% selama 1 menit dalam kondisi microwave. Kondisi terbaik yang mampu menghasilkan yield paling tinggi adalah dengan menggunakan 4% nanokatalis Fe3O4/kampor FC3 pada suhu 80 ℃ selama 40 menit dalam pelarut etanol:air (4:1) yang mampu menghasilkan yield sebesar 93,15%. Metode sintesis derivat kromen melalui reaksi multikomponen dengan menggunakan katalis Fe3O4/kampor FC3 dapat digunakan pada berbagai substrat berupa aromatik aldehida berupa benzaldehida dan 4-hidroksi benzaldehida; metilen aktif berupa malononitril; dan β-diketon berupa dimedon, asam barbiturat, dan asam thiobarbiturat, menghasilkan produk 4a (93,15%), 4b (88,85%), dan 4c (87,32%). Produk yang memiliki aktivitas antioksidan terbaik adalah 4c (IC50: 5,10 ppm). Produk 4a memiliki aktivitas antibakteri yang kuat terhadap bakteri Gram-negatif, terutama P. aeruginosa (18,08 mm); sedangkan produk 4c memiliki aktivitas antibakteri yang kuat terhadap bakteri Gram-positif terutama, B. cereus (16,90 mm).

---

ABSTRACTChromene derivatives have been reported showing a wide range of biological activities such as anticancer, antibacterial, antioxidant, anti-proliferative, and anti-inflammatory. Multi-component reactions (MCRs) method is an effective strategy, since the transformation and the formation of chemical bonds in organic synthesis carried out in one flask without isolation of intermediates. Therefore, those MCRs have generated some benefits such as being effectively reducing chemical waste, shorten reaction time, saving chemical reagents and solvents, as well as simplify pratical aspects. The aim of this research is to examine the effectiveness of the synthesis of chromene derivatives using Fe3O4/camphor as catalyst with satisfactory yield as well as to evaluate the remarkable activity of obtained products as antioxidant and antibacterial agent.This research was carried out in four stages. The first stage was evaluation of the effectiveness of the synthesis and catalytic activity of magnetic nanoparticle Fe3O4/camphor as well as its characterization using FT-IR, XRD, SEM-EDS, PSA, and TEM. The second stage was the screening of optimum reaction condition of the synthesis of chromene derivatives using substrates of benzaldehyde, malononitrile, and dimedone, in a condition of different types of solvents, reaction temperature, and the amount of catalyst. The reaction was observed using TLC, the obtained products were recrystallized, and yield products were calculated. The third stage was to investigate the scope of the method by varying the substrate of aromatic aldehyde (4-hydroxy benzaldehyde), active methylene (malononitrile), and β-diketones (barbituric acid and thiobarbiturat acid). The results of reactions were characterized by melting point, FT-IR, UV-Vis spectrophotometer, and GC-MS. The fourth stage is to evaluate the activity of the obtained product of chromene derivatives as antioxidant and antibacterial agent by in vitro assays.Camphor can be applied as a catalyst in the form of magnetic nanoparticle Fe3O4/camphor after characterization using FT-IR, XRD, PSA, SEM-EDS, and TEM. The preparation of magnetic nanoparticle affected the size of the nanoparticles and this size is negatively correlated with the yield of synthesized products of compound 4a. Nanoparticle Fe3O4/camphor FC3 is the smallest size catalyst (19.24 nm/XRD; 37.18 nm/PSA; 37.43 nm/SEM) with 91.70% yield for 1 minute using microwave method. The optimum conditions that show the highest yield (93.15%) is to use 4% of nanocatalyst Fe3O4/camphor FC3 at the temperature of 80 ℃ for 40 minutes in ethanol:water (4:1). This method of the synthesis of chromene derivatives through multicomponent reactions using the catalyst Fe3O4/kampor FC3 also applied on wide range of substrates of aromatic aldehydes such as benzaldehyde and 4-hydroxy benzaldehyde; active methylene of malononitrile; and β-diketones such dimedone, barbituric acid, and thiobarbiturat acid, producing poducts of 4a (93.15%), 4b (88.85%), and 4c (87.32%). Compound 4c showed the strongest antioxidant activity (IC50: 5.10 ppm) compared to 4a, 4b, and the standards. Compound 4a showed a strong antibacterial activity against Gram-negative bacteria, especially P. aeruginosa (18.08 mm); while compound 4c showed a strong antibacterial activity against Gram-positive bacteria, particularly B. cereus (16.90 mm)."