4 research outputs found
The Effects Of Gamma Irradiation On Microbiological Safety, Biological Activities And Gallic Acid Content Of Euodia Malayana, Gnetum Gnemon And Khaya Senegalensis
Medicinal plants such as herbs and spices are often contaminated with high levels of bacteria, fungus and yeasts. Therefore, medicinal plants can be decontaminated using gamma irradiation to sterilize the microorganisms effectively. The aim of this study is to evaluate the effects of gamma radiation treatment on three medicinal plants, namely Euodia malayana, Gnetum gnemon and Khaya senegalensis at two different forms; methanol leaf extracts and dried leaves respectively. The microbial limit test studies indicated the suitable dosage of minimum and maximum gamma irradiation was 6-12 kGy for leaf extracts and 9-13 kGy for dried leaves of all the medicinal plants
Potential anti-viral compounds from Malaysian Plant Natural Product Repository and Database (MyNature50000) for DENV2
Dengue virus (DENV) is a globally significant human pathogen that annually infects more than ∼300 million of the Earth’s population. While the clinically approved anti-dengue vaccine, Dengvaxia is available for treating such infection, its treatment is limited to those infected with DENV of serotypes 3 and 4 only. However, the vaccine is no longer available to treat dengue infections following the suspended use of Dengvaxia after several discoveries on the side effects of the vaccine on humans. In view of this recent development, a collection of plant extracts in the MyNature50000 library showing potential anti-dengue activities were explored. In this work, the DENV2 NS2B-NS3 bioassay was setup and optimized to evaluate the potential inhibitory activity of plant extracts stored in the MyNature50000 natural product collections. A total of 150 plants were examined using the high-throughput screening assay, among which four candidate plants showed potential as inhibitors of the DENV2 NS2B-NS3 protease, with exceptional inhibition activity >95% with corresponding IC50 values ranging within 2 − 5 µg/mL. Two local plants, Syzygium campanulatum (‘Kelat Paya’) and Syzygium grande (‘Keriang Batu’), were phytochemically analyzed and the data revealed existence of cyclododecane, n-hexadecanoic acid and caryophyllene, all of which are compounds well-known for their inhibitory activity against DENV2 NS2B-NS3. Additionally, MTT assays showed that both plants were mildly cytotoxic on mammalian cell lines, with IC50 values >20 µg/mL, indicating their prospective use as drugs to combat DENV
Synthesis and biological activity of imidazole phenazine derivatives as potential inhibitors for NS2B-NS3 dengue protease
A series of new imidazole-phenazine derivatives were synthesized via a two-step process. The condensation of 2,3-diaminophenazine and benzaldehyde derivatives proceeds with intermediate formation of an aniline Schiff base, which undergoes subsequent cyclodehydrogenation in situ. The structures of the synthesized compounds were characterized by 1D and 2D NMR, FTIR and HRMS. A total of thirteen imidazole phenazine derivatives were synthesized and validated for their inhibitory activity as anti-dengue agents by an in vitro DENV2 NS2B-NS3 protease assay using a fluorogenic Boc-Gly-Arg-Arg-AMC substrate. Two para-substituted imidazole phenazines, 3e and 3k, were found to be promising lead molecules for novel NS2B-NS3 protease inhibitors with IC50 of 54.8 μM and 71.9 μM, respectively, compared to quercetin as a control (IC50 104.8 μM). The in silico study was performed using AutoDock Vina to identify the binding energy and conformation of 3e and 3k with the active site of the DENV2 NS2B-NS3 protease Wichapong model. The results indicate better binding properties of 3e and 3k with calculated binding energies of −8.5 and −8.4 kcal mol−1, respectively, compared to the binding energy of quercetin of −7.2 kcal mol−1, which corroborates well with the experimental observations