KAJIAN POTENSI PIGMEN Spirulina platensis SEBAGAI KANDIDAT ANTIDIABETES TIPE-2 MENGGUNAKAN SIMULASI MOLECULAR DOCKING

ABSTRAK Diabetes melitus tipe-2 merupakan penyakit metabolik yang diakibatkan oleh rendahnya kadar insulin sehingga menyebabkan meningkatnya kadar gula darah. Mikroalga Spirulina platensis mengandung pigmen feofitin, β-karoten, zeaxantin, dan fikosianobilin yang berpotensi menghambat kerja enzim yang berhubungan dengan diabetes melitus. Pada penelitian ini dilakukan kajian potensi dan mekanisme molekuler beberapa pigmen Spirulina platensis sebagai kandidat antidiabetes tipe-2 melalui pendekatan in silico menggunakan docking molekuler. Simulasi yang dilakukan meliputi penentuan afinitas, interaksi molekuler dan jenis inhibisi antara pigmen terhadap enzim α-amilase, α-glukosidase, dipeptidil peptidase-IV (DPP-IV), dan glukosa-6-fosfat dehidrogenase (G6PD). Tahapan penelitian meliputi preparasi protein, validasi metode docking, optimasi dan preparasi ligan, proses docking, dan analisis hasil docking menggunakan beberapa perangkat lunak diantaranya AutodockTools 1.5.6, AutodockVina 1.1.2, PyMOL 2.4, dan Discovery Studio Visualization 2020. Sebagai pembanding digunakan akarbosa, linagliptin dan polidatin. Hasil yang diperoleh menunjukan bahwa afinitas pengikatan pigmen feofitin, β-karoten, dan fikosianobilin dengan α-amilase lebih tinggi berturut-turut 0,4; 2, dan 2,6 kkal/mol dari akarbosa. Afinitas pengikatan antara pigmen feofitin, β-karoten, dan fikosianobilin dengan α-glukosidase adalah sama, 1,2, dan 1,6 kkal/mol lebih tinggi dari akarbosa. Kompleks antara β-karoten dan fikosianobilin dengan DPP-IV lebih tinggi 0,5 dan 0,3 kkal/mol dari linagliptin, serta antara pigmen feofitin, β-karoten, dan fikosianobilin dengan G6PD lebih tinggi 0,2; 1, dan 1,4 kkal/mol dari polidatin. Pigmen feofitin, β-karoten, dan fikosianobilin berinteraksi dengan keempat enzim melibatkan ikatan hidrogen, interaksi hidrofobik, gaya van der Waals, dan interaksi lainnya. Pigmen feofitin, β-karoten, dan fikosianobilin menginhibisi enzim α-amilase, α-glukosidase, DPP-IV secara kompetitif, dan G6PD secara bukan kompetitif. Berdasarkan hasil simulasi dapat disimpulkan bahwa pigmen feofitin, β-karoten, dan fikosianobilin berpotensi sebagai kandidat antidiabetes. Penelitian empirik perlu dilakukan untuk mengetahui lebih lanjut efektifitas feofitin, β-karoten, dan fikosianobilin sebagai antidiabetes. ABSTRACT Diabetes mellitus type-2 is a metabolic disease triggered by low insulin production, which causes an increase of blood glucose levels. Microalgae Spirulina platensis contains pigments of pheophytin, β-carotene, zeaxanthin, and phycocyanobilin which are potential in inhibiting several enzymes–associated with diabetes mellitus. Here, this study aims to screen the potential and molecular mechanisms of Spirulina platensis’s pigments as antidiabetic type-2 candidates through in silico approach using molecular docking. The simulation was analysed the binding affinity, molecular interactions and the type of inhibition among pigments against the enzymes α-amylase, α-glucosidase, dipeptidyl peptidase-IV (DPP-IV), and glucose-6-phosphate dehydrogenase (G6PD). The research stages included protein preparation, validation of the docking method, optimization and preparation of ligands, the docking process, and visualization using several software including AutodockToolsv 1.5.6, AutodockVina 1.1.2, PyMOL 2.4, and Discovery Studio Visualization 2020. The activities of the target compounds were compared to acarbose, linagliptin and polydatin. The results showed that binding affinity of pheophytin, β-carotene, and phycocyanobilin pigments to α-amylase were 0.4, 2, and 2.6 kcal/mol higher than those of acarbose. Binding affinity was also found between pheophytin, β-carotene, and phycocyanobilin pigments with α-glucosidase that reached same affinity, 1.2, and 1.6 kcal/mol higher than acarbose. The complex of β-carotene, and phycocyanobilin pigments 0.5 and 0.3 kcal/mol of linagliptin with DPP-IV, and complex of pheophytin, β-carotene, and phycocyanobilin with G6PD are 0.2, 1, and 1.4 kcal/mol higher from polydatin. Pheophytin, β-carotene, and phycocyanobillin pigments interact with that of four enzymes through hydrogen bonding, hydrophobic interactions, van der Waals forces, and other interactions. Pheophytin, β-carotene and phycocyanobilin pigments inhibited α-amylase, α-glucosidase, DPP-IV competitively, and G6PD enzymes not competitively. Based on the simulation, it can be concluded that pheophytin, β-carotene, and phycocyanobilin pigments are potential to be used as antidiabetic candidates. However, experimental research needs to be done for further check the effectiveness of pheophytin, β-carotene and phycocyanobilin as antidiabetic

Origin of the synergistic effects of bimetallic nanoparticles coupled with a metal oxide heterostructure for accelerating catalytic performance

Precisely tuning bicomponent intimacy during reactions by traditional methods remains a formidable challenge in the fabrication of highly active and stable catalysts because of the difficulty in constructing well‐defined catalytic systems and the occurrence of agglomeration during assembly. To overcome these limitations, a PtRuPNiO@TiO x catalyst on a Ti plate was prepared by ultrasound‐assisted low‐voltage plasma electrolysis. This method involves the oxidation of pure Ti metal and co‐reduction of strong metals at 3000°C, followed by sonochemical ultrasonication under ambient conditions in an aqueous solution. The intimacy of the bimetals in PtRuPNiO@TiO x is tuned, and the metal nanoparticles are uniformly distributed on the porous titania coating via strong metal‒support interactions by leveraging the instantaneous high‐energy input from the plasma discharge and ultrasonic irradiation. The intimacy of PtRuPNiO@TiO x increases the electron density on the Pt surface. Consequently, the paired sites exhibit a high hydrogen evolution reaction activity (an overpotential of 220 mV at a current density of 10 mA cm−2 and Tafel slope of 186 mV dec−1), excellent activity in the hydrogenation of 4‐nitrophenol with a robust stability for up to 20 cycles, and the ability to contrast stated catalysts without ultrasonication and plasma electrolysis. This study facilitates industrially important reactions through synergistic chemical interactions

Confinement and synergy effects of supported-confined bimetal catalysts with superior stability and catalytic activity

Bimetallic nanocrystals have attracted considerable attention because of their complicated systems, which are far superior to those of their individual constituents. A TiO2-confined PtMnP bimetallic catalyst (PtMnP@TiO2) was prepared using an ultrasonic-assisted coincident strategy, which demonstrated exceptional catalytic activity in the universal hydrogen evolution reaction (HER). Owing to the bimetallic synergistic effect and TiO2 confinement, PtMnP@TiOx showed ultrasmall metal nanoparticles (NPs), a higher active Pt0 content, adequate activation at the porous surface, and abundant acid sites. Simulations were performed to visualize the strain properties of Mn and Pt during the bending process and demonstrate the high activity of Pt. The Pt-Mn bimetallic catalysts were enriched with Pt NPs, convoyed by electron transfer from Mn to Pt. Briefly, PtMnP@TiO2 showed robust evolution reaction activities (an overpotential of 220 mV at a current density of 10 mA cm−2 and a Tafel slope of 186 mV dec−1) and the ability to contrast stated catalysts without ultrasonication-plasma. This protocol revealed that the geometrical and electronic effects of Pt and P surrounding the Mn species in PtMnP@TiO2 were crucial for increasing the catalytic activity (99%) and durability (over 20 cycles), which were far superior to those of other reported catalysts

Microalgae as a potential sustainable solution to environment health

Cyanobacteria such as Spirulina platensis secretes numerous biomolecules while consuming CO2 for photosynthesis which can reduce the environmental pollution as it can also be grown in wastewater. These biomolecules can be further processed in numerous pathways such as feed, fuel, pharmaceuticals, and nutraceuticals. This study aims to screen the potential molecular mechanisms of pigments from cyanobacteria as antidiabetic type-2 candidates through molecular docking. The activities of the test compounds were compared to commercial diabetic drugs, such as acarbose, linagliptin and polydatin. The results indicated that the binding affinity of pheophytin, β-carotene, and phycocyanobilin to α-amylase were 0.4, 2, and 2.6 kcal/mol higher than that of acarbose with α-amylase. Binding affinity between pheophytin, β-carotene, and phycocyanobilin with α-glucosidase were found to be comparable, which resulted 1.2, and 1.6 kcal/mol higher than that of acarbose with α-glucosidase. Meanwhile, binding activity of β-carotene and phycocyanobilin with DPP-IV were 0.5 and 0.3 kcal/mol higher than that of linagliptin with DPP-IV, whereas pheophytin, β-carotene, and phycocyanobilin with Glucose-6-phosphate dehydrogenase (G6PD) were 0.2, 1, and 1.4 kcal/mol higher from that of polydatin with G6PD. Moreover, pheophytin, β-carotene and phycocyanobilin were likely to inhibit α-amylase, α-glucosidase, and DPP-IV competitively, while uncompetitively for G6PD. Thus, the integration of molecular docking and experimental approach, such as in vitro and in vivo studies may greatly improve the discovery of true bioactive compounds in cyanobacteria for type 2 diabetes mellitus drugs and treatments. © 2022 Elsevier Lt