Piperazine derivatives and bioactive compounds from red seaweed Haloplegma duperreyi: A novel source for inhibition of HIV-I

The bioprospecting of marine organisms for biotechnological applications has gained considerable interest in recent years. Given the increasing demand for sustainable bioactive compounds, this study aims to fill the gap by providing a comprehensive analysis of compounds present in red seaweed Haloplegma duperreyi Montague 1842, making it the first to utilize this particular seaweed species for its bioactive potential against Type 1 - Human Immunodeficiency Virus. This study exhibited promising results, where the methanolic extract showed the highest HIV-1 inhibition of 89.13 % at a concentration of 100 μg/mL with an IC₅₀ value of 8.405 μg/mL. Further fractionation yielded 12 distinct fractions, with PF3 demonstrating highest anti-HIV-1 activity, achieving 90.67 % inhibition and an IC₅₀ value of 5.557 μg/mL, which is close to the efficacy of positive control, zidovudine (AZT). Characterization of PF3 using FTIR, NMR, and GC–MS identified key functional groups such as NH, CO, CN, and CBr, indicative of piperazine derivatives, known for their diverse antiviral properties. The study calculated the therapeutic index (TI) for both the methanolic extract and PF3 fraction, with values of approximately 23 and 31, respectively, indicating a favourable safety profile for further studies. These findings highlights the potential of PF3 as a novel anti-HIV-1 agent, necessitating further isolation and structural elucidation of active compounds. This is the first report of anti-HIV-1 activity from Haloplegma duperreyi, highlighting marine-derived natural products as promising candidates for new anti-HIV therapies. This study contributes significantly to the field of marine natural product-based antiviral research, emphasizing the importance of marine biodiversity and its contributions to the blue economy.