Isolation of ergosterol peroxide from Nomuraea rileyi infected larvae of tobacco cutworm

Abstract

In the search for potential cytotoxic substances produced by Nomuraea rileyi, an active compound was isolated from mycosed insects through an activity guided fractionation process. The compound, cytotoxic against the Sf9 insect cell line, was identified to be ergosterol peroxide (5a, 8a-epidioxy-24(R)-methylcholesta-6, 22-dien-3b-ol) using nuclear magnetic resonance techniques, infrared spectrometry, and mass spectroscopy. Anticancer screens demonstrated that ergosterol peroxide at micromolar concentrations inhibited the growth of hormone-dependent breast cancer cell line (T47D), hormone-independent breast cancer cell line (MDA-MB-231), human epidermoid carcinoma in mouth cell line (KB), human cervical carcinoma cell line (HeLa), lung cancer cell line (H69AR) and human cholangiocarcinoma cell line (HuCCA-1). Ergosterol peroxide showed moderate effects against Spodoptera litura larvae; 46.7% mortality via topical application after 7 day post-treatment whereas the insect's death was not found in per os application. The amounts of ergosterol peroxide produced by N. rileyi cultures under in vitro and in vivo were determined. The physiological levels of ergosterol peroxide detected in mycosed and mummified cadavers were very low (0.011 and 0.386 lg/larva) less then levels that either inhibited insect cell proliferation or caused insecticidal activity.

Effect of Marine Basidiomycetes Fulvifomes sp.-Derived Ergosterol Peroxide on Cytotoxicity and Apoptosis Induction in MCF-7 Cell Line

“…Accordingly, it upregulates the oxidative, stress-sensitive responsible genes and downregulates the STAT1 and interferon-inducible genes by increasing the intracellular levels of ROS [23]. Similarly, the anticancer activity of EP is in good agreement with previously published findings on the inhibition of cancer cell proliferation [24].…”

Isolation, purification and identification of biological compounds from Beauveria sp. and their evaluation as insecticidal effectiveness against Bemisia tabaci

“…and its activity against B. tabaci are in accordance with the ndings of R.M. Zolotar et al Similar results on insecticidal activity of ergosterol peroxide isolated from Nomuraea rileyi against tobacco cutworm were documented by Pannipa Prompiboon et al 32 who reported the moderate effects such as 46.7 % mortality was caused against Spodoptera litura larvae via topical application at an interval of one week with 90-120 µg / insect, whereas, our research results showed 38.33 % mortality at 72 h exposure at concentration of 50 ppm on B. tabaci. Additional biological activities of compounds ergosterol peroxide include antioxidant activities 33 , antimycobacterial activities 34 in ammatory activities 35 .…”

Identification of α-tocopherol and α-tocopheryl acetate from the cuticle of soybean pods armyworm (Spodoptera cosmioides)

“…However, S. cosmiodes has not been reported as a natural host for N. rileyi (Sosa-Gomez & Silva 2002) and it is not affected by the fungi at the different larval developmental stages. This fact leads to speculate that the presence of the well-known antioxidant vitamin E can be involved in S. cosmioides natural resistance towards the fungus, as one of the proposed mechanisms of N. rileyi pathogenicity is the breakdown of the larval cuticle through the generation of ergosterol peroxide (Prompiboon et al 2008). On the other hand, lack of vitamin E within the cuticle could explain the susceptibility of A. gemmatallis larvae to N. rileyi.…”