Influence of Bracken Fern (Pteridium caudatum L. Maxon) Pre‐treatment on Extraction Yield of Illudane Glycosides and Pterosins

Abstract

Glycoside extraction suffers from substantial yield loss of all illudane glycosides and indigenous pterosins in all sample pre-treatments studied relative to fresh frond material.

Presence of the carcinogen ptaquiloside in fern-based food products and traditional medicine: Four cases of human exposure

“…This study demonstrates that fresh bracken collected in the wild and prepared as a traditional vegetable dish following Asian guides by increasing pH of boing water has a very high content of PTA compared to the fresh plant material. These findings support other studies concerned with illudane glycoside extraction and the effect of pH ( Ayala-Luis et al, 2006 ; Cáceres-Peña et al, 2013 ). Hot water extraction is one of the best extraction methods for PTA, preserving the toxin for analytical methods.…”

“…pH was measured twice in all batches. PTA and PtB were extracted using a modified method by Cáceres-Peña et al (2013) : Approximately 20 g fresh crosier was extracted with 100 mL 90 °C deionised water for 5 min in a kitchen blender, following centrifugation of 3 times 10 mL aliquots for 10 min at 9000 rpm and PTA/PtB measured in the supernatant (triplicate; final validated method). The samples were prepared within 15 min of cooking and kept at −18 °C until analysis.…”

Ptaquiloside in Irish Bracken Ferns and Receiving Waters, with Implications for Land Managers

“…The sampling and extraction protocols used the most recent developments from other researchers investigating ptaquiloside [33,46]. Water samples were collected in 100 mL amber bottles and buffered with 2.5 mL of 0.3 M ammonium acetate buffer, adjusted to pH 5 with glacial acetic acid [33].…”

“…Each composite vegetation sample was placed in an opaque polyethylene bag and placed in a cooler box. The following day, pinnulae were stripped off and hard rachis were discarded [46]. Samples were mixed to homogenise and a subsample of fresh blades (6 g) was extracted twice with 90˝C MilliQ water (200 mL) in a fast rotating blender for 5 min.…”

Screening for Ptaquiloside in Ferns: Using Herbarium Specimens for Qualitative Mapping Purposes

“…However, the conversion rate of PTA to PtB, and the resulting difference in PtB yield is unknown making comparisons of papers and results difficult (e.g. Agnew and Lauren, ; Cáceres‐Peña et al , ; Clauson‐Kaas et al , ; Fletcher et al , , ; Rasmussen et al , ; Virgilio et al , ). PTA is also an emerging environmental toxin, and has attracted attention during the last decade from environmental researchers and authorities.…”