Chromatographic fingerprinting of epiphytic fungal strains isolated from Withania somnifera and biological evaluation of isolated okaramine H – PubMed Black Hawk Supplements

Abstract

Medicinal plants are “goldmines” of natural products, and continue to provide key scaffolds for drug development. They have immense therapeutic potential, encapsulating a plethora of metabolites within them, which have yet to be explored. Withania somnifera (L.) Dunal is one such medicinal plant known since time immemorial for its therapeutic activity in the Ayurveda system of medicine. Studies have revealed Nature’s marvel of these medicinal plants harbouring endophytic and epiphytic microorganisms from phyllosphere to rhizosphere. Chromatographic fingerprinting was carried out using HPTLC and HPLC on five epiphytic strains isolated from the leaves, stem and fruits of Withania somnifera. Out of five filamentous fungi, one fungus identified as Aspergillus aculeatus S20 was well explored. An indole alkaloid, okaramine H, was isolated using systematic chromatographic investigation at a retention time of 26.278 min showing λ_max at 206, 236, 284 and 370 nm. Confirmation was achieved using NMR and mass spectrometry (MS) as analytical techniques. Structure elucidation was done by studying the fragmentation pattern using MS/MS and an accurate mass was determined using HR-ESI-QTOF-MS showing m/z of 521.2546 [M + H]⁺. The percentage purity of isolated okaramine H was found to be >90. Well known for its insecticidal activity, okaramine H was explored for its antileishmanial activity against the Leishmania donovani parasite for the first time. Under in vitro conditions, the compound showed an inhibitory effect on Leishmania donovani promastigotes with an IC₅₀ of 147 μg mL^-1.

Similar articles

• Metabolomics of Withania somnifera (L.) Dunal: Advances and applications.

  Tetali SD, Acharya S, Ankari AB, Nanakram V, Raghavendra AS. Tetali SD, et al. J Ethnopharmacol. 2021 Mar 1;267:113469. doi: 10.1016/j.jep.2020.113469. Epub 2020 Oct 16. J Ethnopharmacol. 2021. PMID: 33075439 Review.

• Metabolic profiling for studying chemotype variations in Withania somnifera (L.) Dunal fruits using GC-MS and NMR spectroscopy.

  Bhatia A, Bharti SK, Tewari SK, Sidhu OP, Roy R. Bhatia A, et al. Phytochemistry. 2013 Sep;93:105-15. doi: 10.1016/j.phytochem.2013.03.013. Epub 2013 Apr 9. Phytochemistry. 2013. PMID: 23578960

• Withania somnifera chemotype NMITLI 101R significantly increases the efficacy of antileishmanial drugs by generating strong IFN-γ and IL-12 mediated immune responses in Leishmania donovani infected hamsters.

  Tripathi CD, Kushawaha PK, Sangwan RS, Mandal C, Misra-Bhattacharya S, Dube A. Tripathi CD, et al. Phytomedicine. 2017 Jan 15;24:87-95. doi: 10.1016/j.phymed.2016.11.012. Epub 2016 Nov 16. Phytomedicine. 2017. PMID: 28160866

• Withanolide production by fungal endophyte isolated from Withania somnifera.

  Sathiyabama M, Parthasarathy R. Sathiyabama M, et al. Nat Prod Res. 2018 Jul;32(13):1573-1577. doi: 10.1080/14786419.2017.1389934. Epub 2017 Oct 16. Nat Prod Res. 2018. PMID: 29034745

• Withania somnifera (L.) Dunal – Modern perspectives of an ancient Rasayana from Ayurveda.

  Mukherjee PK, Banerjee S, Biswas S, Das B, Kar A, Katiyar CK. Mukherjee PK, et al. J Ethnopharmacol. 2021 Jan 10;264:113157. doi: 10.1016/j.jep.2020.113157. Epub 2020 Aug 9. J Ethnopharmacol. 2021. PMID: 32783987 Review.