Identification and determination of myriocin in Isaria cicadae and its allies by LTQ-Orbitrap-HRMS

Abstract

A hybrid linear ion trap-quadrupole-Orbitrap high-resolution mass spectrometry (LTQ-Orbitrap-HRMS) was used to qualitatively and quantitatively analyse the myriocin in Isaria cicadae and its allies. The samples were prepared with 95% methanol for 30 min by ultrasonic-assisted extraction. The target compound was purified by ODS solid-phase extraction (SPE) column. The enriched samples were identified by mass spectrometry. The results showed that the contents of myriocin in both wild and artificial Isaria cicadae were below the detection limit, while a strain of Ophiocordyceps longissima and Cordyceps cicadae Shing (Dujiaolong), both closely related to the Isaria cicadae, and its asexual mycelia are rich in myriocin. It suggests that it may be wrong to consider C. cicadae as I. cicadae’s teleomorph in Genbank or Mycobank in many published reports based on chemical classification, and the species rich in myriocin is probably not Isaria cicadae.

The complete mitochondrial genome of the Chan‐hua fungus Isaria cicadae: a tale of intron evolution in Cordycipitaceae

“…The two authoritative fungal taxonomy databases, Mycobank (http://www.mycobank.org/) and Species Fungorum (http://www.indexfungorum.org/), however, both accept I. cicadae and treat C. cicadae as a synonym of I. cicadae . A recent study suggested that C. cicadae may be different from I. cicadae since they showed difference in myriocin contents (Cheng et al ., ). In addition, in response to the ending of dual nomenclatural systems for pleomorphic fungi, a molecular phylogenetic investigation proposed names that should be maintained and names that should be rejected in Cordycipitaceae (Kepler et al ., ).…”

The biosynthetic logic and enzymatic machinery of approved fungi-derived pharmaceuticals and agricultural biopesticides

“…This α-amino fatty acid derived product is isolated from several genera of fungi, mostly by Myriococcum , 316 Melanconis 317 and Isaria . 318 It inhibits sphingosine biosynthesis by blocking the activity of serine palmitoyltransferase, which is a potent immunosuppressant with 10- to 100-fold more activity than that of immunosuppressant 94 . 319,320 It further served as the leading structure of fingolimod, which was approved by the FDA and became the first oral drug available for the treatment of relapsing–remitting forms of multiple sclerosis.…”

Cordyceps inhibits ceramide biosynthesis and improves insulin resistance and hepatic steatosis

“…Myriocin was extracted from Cordyceps using a similar protocol described before 71 . Briefly, extraction of myriocin was performed by weighing 0.5 g of dried Cordyceps powder which was then sonicated with 95% methanol (MeOH) (3 × 10 mL) for 40 min at 40 °C.…”