<i>In Vitro</i> Anti-HIV Activity of Partially Purified Coumarin(s) Isolated from Fungal Endophyte, <i>Alternaria</i> Species of <i>Calophyllum inophyllum</i>

Abstract

5 totally different endophytic fungal species were isolated from bark and leaf parts of Calophyllum inophyllum. Leaf part yielded Trichoderma harzianum and Alternaria species, whereas bark showed the presence of Fusarium species, Aspergillus species and unidentified fungi. Two solvents (hexane and methanol) were used for endophytic fungal extraction and the Alternaria species had shown the presence of coumarin whereas Trichoderma harzianum in methanol extract and Fusarium species in hexane extract had shown the coumarin(s) in all the four methods tested. The total coumarin yield was more in microwave assistance method, the methanol Alternaria species (3.941 ± 0.082) stood first, followed by hexane extract of Alternaria species (3.254 ± 0.082), Fusarium species (2.532 ± 0.082) and Trichoderma harzianum (2.294 ± 0.082), the plant extract showed 4.149 + 0.053. The methanol extract of Alternaria species inhibited the activity of HIV-Reverse Transcriptase (RT) (82.81 ± 1.0), integrase (98%) and protease (78) in maximum level followed by hexane extract of Alternaria species (71.12 ± 0.9, 89, 68), Fusarium species (63.92 ± 1.8, 67, 66) and Trichoderma harzianum (56.69 ± 0.9, 71, 63). The endophytic fungi Alternaria species inhibited all the three viral enzymes at maximum level and it was more than standard drug. However, in order to know possible anti-HIV, it is necessary to isolate active coumarin from the Alternaria species and the mechanism of action will be studied in future studies. * Corresponding author. M. Govindappa et al. 322

<i>In Vitro</i> and <i>In Silico</i> Antioxidant, Anti-Diabetic, Anti-HIV and Anti-Alzheimer Activity of Endophytic Fungi, <i>Cladosporium uredinicola</i> Phytochemicals

“…The similar types of phytochemicals were also observed from different endophytes 2H-1-Benzopyran-2-one [24], 3-Benzofurancarboxylic acid [25], Hymecromone [26], 16-Octadecanoic acid, methyl ester [27], alloisoimperatorin [28], Z,E-2-Methyl-3,13-octadecadien-1-ol [29], [Z]-Cinnamic acid, 2-diphenylmethyleneamino-, methyl ester [30].…”

“…The C. uredinicola extract had shown inhibition of HIV-1 proteins viz., protease, RT, protease and gp120. The C. uredinicola was inhibited RT activity strongly (83.81+2.14) and it was high compared to standard AZT (74.36+1.89) (Table 3) [27,43]. Similarly, the gp120 (80.24+2.4) (Table 4), protease (77.63+2.14) ( Table 5), integrase (79.43+2.14) ( Table 6) proteins activity was decreased due to C. uredinicola extract.…”

Secondary metabolites produced by endophytic fungi, Alternaria alternata, as potential inhibitors of the human immunodeficiency virus

“…Alternaria species in endophytic lifestyle have been shown to exhibit anti-HIV activities and some of the active compounds and their mechanism of action have been elucidated ( Wellensiek et al, 2013 ; Eram et al, 2018 ). For example, in a study by Bashyal et al (2014) they isolated alterotoxins from A. tenuissima and Govindappa et al (2015) isolated coumarins from Alternaria species.…”

“… Ma et al (2013) reported anti-HIV reverse transcriptase activity of a PHP protein isolated from Peganum harmala seeds with 50% inhibitory concentration at 1.5 µM. Govindappa et al (2015) revealed that partially purified coumarins isolated from fungal endophytes, Alternaria sp. displayed high inhibition on three viral enzymes, HIV-1 Reverse Transcriptase, which was inhibited by 82.81% (control, heparin = 74.54% inhibition), integrase enzyme activity which was inhibited by 98% and protease activity was inhibited by 78%.…”

“…Methanolic extracts (100 μg/ml) of Padina tetrastromatica inhibited HIV-1 by more than 50% and showed a significant reduction in HIV-1 p24 levels after 7 days of incubation. The methanol extract of Alternaria species inhibited the activity of HIV-1 Reverse Transcriptase (82.81 ± 1.0) ( Govindappa et al, 2015 ). The low level of p24 in the cell culture of PBMC and CD4 + T cells indicates the antiviral activity elicited by the Alternaria crude extract, which confirms the results obtained from the luciferase-based antiviral activity ( Figure 3 ).…”