Fast LC-MS quantification of ptesculentoside, caudatoside, ptaquiloside and corresponding pterosins in bracken ferns.

Ptaquiloside (PTA) is an illudane glycoside partly responsible for the carcinogenicity of bracken ferns (Pteridium sp.). The PTA analogues ptesculentoside (PTE) and caudatoside (CAU) have similar biochemical reactivity. However, both compounds are highly under-investigated due to the lack of analytical standards and appropriate methods. This study presents a robust method for preparation of analytical standards of PTE, CAU, PTA, the corresponding hydrolysis products: pterosins G, A and B, and an LC-MS based method for simultaneous quantification of the six compounds in bracken. The chromatographic separation of analytes takes 5 min. The observed linear range of quantification was 20-500 µg/L for PTA and pterosin B, and 10-250 µg/L for the remaining compounds (r > 0.999). The limits of detection were 0.08-0.26 µg/L for PTE, CAU and PTA and 0.01-0.03 µg/L for the pterosins, equivalent to 2.0-6.5 µg/g and 0.25-0.75 µg/g in dry weight, respectively. The method was applied on 18 samples of dried fern leaves from 6 continents. Results demonstrated high variation in concentrations of PTE, CAU and PTA with levels prior to hydrolysis up to 3,900, 2,200 and 2,100 µg/g respectively. This is the first analytical method for simultaneous and direct measurement of all six compounds. Its application demonstrated that bracken ferns contain significant amounts of PTE and CAU relative to PTA.

Discovery of indane propanamides as potent and selective TRPV1 antagonists.

A series of indane-type acetamide and propanamide analogues were investigated as TRPV1 antagonists. The analysis of structure-activity relationship indicated that indane A-region analogues exhibited better antagonism than did the corresponding 2,3-dihydrobenzofuran and 1,3-benzodioxole surrogates. Among them, antagonist 36 exhibited potent and selective antagonism toward capsaicin for hTRPV1 and mTRPV1. Further, in vivo studies indicated that antagonist 36 showed excellent analgesic activity in both phases of the formalin mouse pain model and inhibited the pain behavior completely at a dose of 1 mg/kg in the 2nd phase.

Four New Pterosins from Pteris cretica and Their Cytotoxic Activities.

Phytochemical investigation of the aerial parts of Pteris cretica led to the isolation and elucidation of nine pterosins, including four new pterosins, creticolacton A (1), 13-hydroxy-2(R),3(R)-pterosin L (2), creticoside A (3), and spelosin 3-O-ß-d-glucopyranoside (4), together with five known pterosins 5-9. Their structures were identified mainly on the basis of 1D and 2D NMR spectral data, ESI-MS and literature comparisons. Compounds 1 and 3 were new type of petrosins with a six membered ring between C-14 and C-15. The new compounds were tested in vitro for their cytotoxic activities against four human tumor cell lines (SH-SY5Y, SGC-7901, HCT-116, Lovo). Results showed that compounds 1 and 2 exhibited cytotoxic activity against HCT-116 cells with IC50 value of 22.4 µM and 15.8 µM, respectively.

Novel acceptor-donor-acceptor structured small molecule-based nanoparticles for highly efficient photothermal therapy.

Herein, acceptor-donor-acceptor structured small molecule (ITIC) based nanoparticles (NPs) were explored for photothermal therapy application. ITIC NPs show red-shift absorption in the near-infrared region, high photostability, and high photothermal conversion efficiency under laser irradiation, presenting both excellent cancer cell cytotoxicity in vitro and tumor ablation in vivo.

In vitro Anti-Trypanosomal Activities of Indanone-Based Chalcones.

Human African trypanosomiasis is a neglected infectious disease that affects mostly people living in the rural areas of Africa. Current treatment options are limited to just four drugs that have been in use of four to nine decades. The life-threatening toxic side-effects associated with the use of these drugs are disconcerting. Poor efficacy, low oral bioavailability, and high cost are other shortcomings of current HAT treatments. Evaluating the potentials of known hits for other therapeutic areas may be a fast and convenient method to discover new hit compounds against alternative targets. A library of 34 known indanone based chalcones was screened against T.b. brucei and nine potent hits, having IC50 values between 0.5-8.9 µM, were found. The SAR studies of this series could provide useful information in guiding future exploration of this class of compounds in search of more potent, safe, and low cost anti-trypanosomal agents. Graphical Abstract.

Pharmacokinetic and pharmacodynamic evaluation of 5-methoxy-2-aminoindane (MEAI): A new binge-mitigating agent.

5-Methoxy-2-aminoindane (MEAI) is a novel psychoactive aminoindane derivative, exerting euphoric, alcohol-like tipsy experience and reduced desire to consume alcoholic beverages. Our previous toxicological evaluation of MEAI in rats, clearly indicated MEAI's potential to be further evaluated as a promising binge mitigating agent due to its favorable safety profile. In the light of these observations, we have determined MEAI's pharmacokinetic (PK) profile in rats and evaluated in-vitro its pharmacodynamics (PD) profile. Following oral and intravenous administration of MEAI, two metabolites were identified, namely, N-acetyl-MEAI and 5-hydroxy-N-acetyl-AI, arising from N-acetylation and oxidative demethylation. The PK-parameters of MEAI and N-acetyl-MEAI were derived from single i.v. bolus (10 mg/kg) and single oral doses (10 and 90 mg/kg) of MEAI to rats. MEAI displayed extensive total clearance (2.8 L/h/kg) and a very short plasma and brain half-life (0.5-0.7 h). At 10 mg/kg, MEAI displayed low oral bioavailability (25%) and a plasma to brain ratio in the range of 3-5.5, with brain MEAI peak levels attained rapidly. Non-linear pharmacokinetic behavior was observed in the 90 mg/kg oral group, in which the bioavailability increased by 500%. The non-linear behavior was also evident by the significant increase in plasma half-life of MEAI and its metabolite, N-acetyl-MEAI. N-acetyl-MEAI levels in plasma and brain were about ten times lower than the parent compound, indicative of its minor contribution to MEAI's pharmacological effect. MEAI displayed weak to moderate ligand binding inhibition at the 5-HT2B receptor, while the remaining neurochemical targets were unaffected. Further studies, in non-rodent species are required, in-order to assess MEAI's PK and PD profile adequately.

Modulatory effect of caffeic acid on cholinesterases inhibitory properties of donepezil.

Background Donepezil hydrochloride commonly used in the management of Alzheimer's disease (AD), exhibiting its inhibitory effects on acetylcholinesterase and butyrylcholinesterase activity thereby enhance cognitive function. Caffeic acid member of hydroxycinnamic acid is widely present in human diet. This study aims to investigate influence of caffeic acid on acetylcholinesterase and butyrylcholinesterase inhibitory properties of donepezil (in vitro). Methods 5 mg of donepezil was dissolved in 50 mL distilled water while 10 mg of caffeic acid was dissolved in 100 mL distilled water. Therefore, mixtures of samples were prepared as follows: A2=donepezil 0.075 mg/mL+caffeic acid 0.025 mg/mL; A3=donepezil 0.050 mg/mL+caffeic acid 0.050 mg/mL; A4=donepezil 0.025 mg/mL+caffeic acid 0.075 mg/mL. All samples were kept in the refrigerator at 4 °C for subsequent analysis. Results The result showed that all the combinations show an inhibitory effect on acetylcholinesterase and butyrylcholinesterase activity in vitro, with the combination A4=donepezil 0.025 mg/mL+caffeic acid 0.075 mg/mL had significant (p<0.05) highest inhibitory effect on acetylcholinesterase and butyrylcholinesterase activity in vitro. More so, all the samples were able to prevent pro-oxidants (FeSO4 and sodium nitroprusside [SNP] ) induced lipid peroxidation in rat brain homogenate, with the combination A4=donepezil 0.025 mg/mL+caffeic acid 0.075 mg/mL and A3=donepezil 0.050 mg/mL+caffeic acid 0.050 mg/mL had highest inhibitory effect against FeSO4 and SNP induced lipid peroxidation in rat brain homogenate in vitro respectively. Moreover, all the samples exhibit antioxidant properties as typified by their ability to chelate iron (II) ion (Fe2+), hydroxyl radical (OHÙ­) radical scavenging ability and ferric reducing property (FRAP). Conclusions Therefore, the combination of caffeic acid with donepezil enhances the antioxidant properties of donepezil. The combination of caffeic acid with donepezil could be a therapeutic aid in the management of AD, possibly with fewer side effects of donepezil. Nevertheless, the combination donepezil 0.025 mg/mL+caffeic acid 0.075 mg/mL acid look promising.

Two New Metabolites from the Endophytic Fungus Alternaria sp. A744 Derived from Morinda officinalis.

Two new compounds isobenzofuranone A (1) and indandione B (2), together with eleven known compounds (3-13) were isolated from liquid cultures of an endophytic fungus Alternaria sp., which was obtained from the medicinal plant Morinda officinalis. Among them, the indandione (2) showed a rarely occurring indanone skeleton in natural products. Their structures were elucidated mainly on the basis of extensive spectroscopic data analysis. All of the compounds were evaluated with cytotoxic and α-glucosidase inhibitory activity assays. Compounds 11 and 12 showed significant inhibitory activities against four tumor cell lines; MCF-7, HepG-2, NCI-H460 and SF-268, with IC50 values in the range of 1.91-9.67 µM, and compounds 4, 5, 9, 10, 12 and 13 showed excellent inhibitory activities against α-glucosidase with IC50 values in the range of 12.05-166.13 µM.

Cytotoxic pterosins from Pteris multifida roots against HCT116 human colon cancer cells.

Two new pterosin glycosides, (2S,3S)-pterosin C 3-O-ß-d-(4'-(E)-caffeoyl)-glucopyranoside (1) and (2S,3S)-pterosin C 3-O-ß-d-(6'-(E)-p-coumaroyl)-glucopyranoside (2), were isolated from Pteris multifida (Pteridaceae) roots along with ten known pterosin compounds (3-12). The chemical structures of the isolated compounds were elucidated by extensive analysis of the 1D, 2D NMR, HRESIMS, and CD spectroscopic data. The cytotoxicities of 1-12 against HCT116 human colorectal cancer cell line were evaluated. Among the isolates, compound 1 showed moderate antiproliferative activity in HCT116 cells with an IC50 value of 8.0±1.7µM. Additionally, 1 induced the upregulation of the caspase-9 and procaspase-9 levels in Western blots and increased the annexin V/propidium iodide (PI)-positive cell population in flow cytometry.

Toxicological evaluation of 5-methoxy-2-aminoindane (MEAI): Binge mitigating agent in development.

5-Methoxy-2-aminoindane (MEAI) is a psychoactive compound of the aminoindane class, which in recent years has been recreationally used by many people, who reported of a mild euphoric, alcohol-like tipsy experience and reduced desire to consume alcoholic beverages. In the light of these observations it was decided to progress MEAI through a preliminary drug development route and evaluate the acute and subacute toxicity of MEAI administrated orally to Sprague Dawley rats, as well as to determine potential in-vitro cytotoxic and mutagenic effects using state-of-the-art protocols. Furthermore, the interaction of MEAI at the highest non-toxic concentration (100mg/L) with ethanol at cytotoxic levels of 6% and 7.5% was explored, in order to identify possible additive or synergistic effects. MEAI showed a good safety profile in rats at 10 and 30mg/kg body weight, corresponding to the human doses of 1.6mg/kg and 4.8mg/kg body weight, respectively. Cytotoxic effect was demonstrated using concentrations of 500 and 1000mg/L with calculated IC50 value of 368.2mg/L for rat brain striatum primary neurons and 403.1mg/L for human primary healthy hepatocytes. The combination of 6% or 7.5% ethanol with 100mg/L MEAI revealed no statistically significant increase of cytotoxic effect. Further studies, especially long term chronic and addictive behavior studies, are required in-order to assess MEAI safety profile.

Design, synthesis, in-silico and biological evaluation of novel donepezil derivatives as multi-target-directed ligands for the treatment of Alzheimer's disease.

A novel series of donepezil based multi-functional agents "(E)-5,6-dimethoxy-2-(4-(4-substituted piperazin-1-yl)benzylidene)-2,3-dihydro-1H-inden-1-ones" have been designed and synthesized as potential anti-Alzheimer's agents. In-vitro studies revealed that these compounds demonstrated moderate to good AChE and Aß aggregation inhibitory activity. These derivatives are also endowed with admirable antioxidant activity. Among the entire series compounds IP-9, IP-13 and IP-15 appeared as most active multi-functional agents and displayed marked AChE inhibitory, Aß disaggregation and antioxidant activity. Studies indicate that IP-13 and IP-15 showed better AChE inhibitory activity than the standard drug donepezil and IP-9, IP-13 as well as IP-15 exhibited better Aß aggregation inhibitory activity than curcumin. These compounds (IP-9, IP-13 and IP-15) successfully diminished H2O2 induced oxidative stress in SH-SY5Y cells and displayed excellent neuroprotective activity against H2O2 as well as Aß induced toxicity in SH-SY5Y cells in a concentration dependent manner. Moreover, these derivatives did not exert any significant toxicity in neuronal SH-SY5Y cells in cytotoxicity assay. To elucidate the plausible binding mode of the compounds IP-9, IP-13 and IP-15, molecular docking studies and molecular dynamics (MD) simulation studies were also performed and the results indicate their significant interactions with the active sites of AChE as well as Aß1-42 peptide. Thus, the present study evidently showed that IP-9, IP-13 and IP-15 are potent multi-functional agents against Alzheimer's disease and might serve as promising lead candidates for anti-Alzheimer drug development.

Pterosin Sesquiterpenoids from Pteris cretica as Hypolipidemic Agents via Activating Liver X Receptors.

Four new pterosin sesquiterpenoids (1-4), a new ent-kaurane diterpenoid (17), and 18 known compounds were isolated from the aerial parts of Pteris cretica L. The structures of the isolates were elucidated based on spectroscopic data analysis, and their absolute configurations were determined by comparison of experimental and calculated electronic circular dichroism spectra. The compounds were evaluated for lipid-lowering effects in 3T3-L1 adipocytes. Compounds 4, 8, 17, and 22 were more potent than the positive control, berberine, in decreasing triglycerides activity, with compound 4 exerting the most potent activity. Compound 4 activated LXRα/ß in a HEK 293T cell-based reporter gene assay. Molecular dynamic simulations revealed that compound 4 activates liver X receptors (LXRs) through hydrogen bonding with the residues of LXRα/ß, suggesting that compound 4 reduces total triglycerides through the regulation of LXRα/ß.

Design, synthesis and evaluation of novel indandione derivatives as multifunctional agents with cholinesterase inhibition, anti-ß-amyloid aggregation, antioxidant and neuroprotection properties against Alzheimer's disease.

A series of novel 2-(4-(4-substituted piperazin-1-yl)benzylidene)-1H-indene-1,3(2H)-diones were designed, synthesized and appraised as multifunctional anti-Alzheimer agents. In vitro studies of compounds 27-38 showed that these compounds exhibit moderate to excellent AChE, BuChE and Aß aggregation inhibitory activity. Notably, compounds 34 and 38 appeared as most active multifunctional agents in the entire series and exhibited excellent inhibition against AChE (IC50=0.048µM: 34; 0.036µM: 38), Aß aggregation (max% inhibition 82.2%, IC50=9.2µM: 34; max% inhibition 80.9%, IC50=10.11µM: 38) and displayed significant antioxidant potential in ORAC-FL assay. Both compounds also successfully diminished H2O2 induced oxidative stress in SH-SY5Y cells. Fascinatingly, compounds 34 and 38 showed admirable neuroprotective effects against H2O2 and Aß induced toxicity in SH-SY5Y cells. Additionally, both derivatives showed no considerable toxicity in neuronal cell viability assay and represented drug likeness properties in the primarily pharmacokinetics study. All these results together, propelled out that compounds 34 and 38 might serve as promising multi-functional lead candidates for treatment of AD in the future.

Antiaggregation Potential of Padina gymnospora against the Toxic Alzheimer's Beta-Amyloid Peptide 25-35 and Cholinesterase Inhibitory Property of Its Bioactive Compounds.

Inhibition of ß-amyloid (Aß) aggregation in the cerebral cortex of the brain is a promising therapeutic and defensive strategy in identification of disease modifying agents for Alzheimer's disease (AD). Since natural products are considered as the current alternative trend for the discovery of AD drugs, the present study aims at the evaluation of anti-amyloidogenic potential of the marine seaweed Padina gymnospora. Prevention of aggregation and disaggregation of the mature fibril formation of Aß 25-35 by acetone extracts of P. gymnospora (ACTPG) was evaluated in two phases by Thioflavin T assay. The results were further confirmed by confocal laser scanning microscopy (CLSM) analysis and Fourier transform infrared (FTIR) spectroscopic analysis. The results of antiaggregation and disaggregation assay showed that the increase in fluorescence intensity of aggregated Aß and the co-treatment of ACTPG (250 µg/ml) with Aß 25-35, an extensive decrease in the fluorescence intensity was observed in both phases, which suggests that ACTPG prevents the oligomers formation and disaggregation of mature fibrils. In addition, ACTPG was subjected to column chromatography and the bioactivity was screened based on the cholinesterase inhibitory activity. Finally, the active fraction was subjected to LC-MS/MS analysis for the identification of bioactive compounds. Overall, the results suggest that the bioactive compound alpha bisabolol present in the alga might be responsible for the observed cholinesterase inhibition with the IC50 value < 10 µg/ml for both AChE and BuChE when compared to standard drug donepezil (IC50 value < 6 µg/ml) and support its use for the treatment of neurological disorders.

Evaluation of the anti-inflammatory and antioxidative potential of four fern species from China intended for use as food supplements.

Inflammation plays a major role in many diseases, for instance in arteriosclerosis, rheumatoid arthritis, autoimmune disorders and cancer. Since many plants contain compounds with anti-inflammatory activity, their consumption may be able to prevent the development of inflammatory-based diseases. Edible ferns are some of the most important wild vegetables in China and have traditionally been used both for dietary and therapeutic purposes. In this study we investigated the anti-inflammatory and antioxidant potential of fern extracts from Matteuccia struthiopteris, Osmundajaponica, Matteuccia orientalis and Pteridium aquilinum intended for use as nutraceuticals. Two modes of action were investigated: the inhibition of the pro-inflammatory gene expression of interleukin-1 beta (IL1-ß) and interleukin-6 (IL6), and the gene expression of iNOS by LPS-elicited macrophages. The results showed a decrease of IL1-ß gene expression for the five fern extracts. This effect was more pronounced for the extracts prepared from the roots of O. japonica (IC50 of 17.8 µg/mL) and the young fronds of M orientalis (50.0 µg/mL). Regarding the indirect measurement of NO, via iNOS gene expression, an interesting decrease of 50% was obtained with the extract of M. orientalis fronds at a low concentration (20 µg/mL) compared with P. aquilinum fronds (160 µg/mL) and leaves of O. japonica. The latter showed a higher decrease but at a high concentration of extract (160 µg/mL). The five fern extracts were also evaluated for their ability to scavenge 2,2-diphenyl-l-picrylhydrazyl (DPPH) radicals and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). All fern extracts exhibited antioxidant effects but the roots of O. japonica and the fronds of M orientalis were most efficient. The HPLC-MS analysis of the constituents of the fern extracts confirmed the presence of chlorogenic acid, caffeic acid, p-coumaric acid, ferulic acid, kaempferol and apigenin, molecules known to exhibit antiinflammatory and/or antioxidant properties.

Biopolymer-based transdermal films of donepezil as an alternative delivery approach in Alzheimer's disease treatment.

Matrix type transdermal films of donepezil (DNP) as an alternative delivery approach was designed to improve patient compliance to Alzheimer disease treatment. Sodium alginate, a natural polysaccharide, was used as matrix-forming agent in the optimization of transdermal films. Propylene glycol and dl-limonene was added into films as a plasticizer and permeation enhancer, respectively. As well as mechanical strength and bioadhesiveness of optimized transdermal films of DNP, the impact of dl-limonene concentration in films on DNP in vitro permeation across pig skin was assessed. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) measurements were carried out to examine the effects of enhancer on in vitro conformational order of the stratum corneum intercellular lipids following permeation study. Results showed that transdermal formulations of DNP were suitable due to both mechanical and bioadhesive features of the films. In vitro skin permeation study indicated that dl-limonene at a concentration of 3% was optimum with high drug flux. ATR-FTIR results confirmed a more fluidized stratum corneum lipid state in the presence of dl-limonene, indicating its permeation enhancement effect. Regarding to achieve therapeutic levels of DNP, it seems to be feasible deliver DNP with transdermal films for the management of Alzheimer disease.

New pterosin sesquiterpenes and antitubercular constituents from Pteris ensiformis.

Two new pterosin sesquiterpenes, (2S)-13-hydroxypterosin A (1) and (2S,3S)-12-hydroxypterosin Q (2), were isolated from the whole plants of Pteris ensiformis, together with six known compounds. The structures of 1 and 2 were determined through extensive 1D/2D-NMR and MS analyses. Compound 2 exhibited antitubercular activity (MIC 6.25 µg/ml) against Mycobacterium tuberculosis H37 Rv in vitro.

Development of a novel fluorine-18 labeled deuterated fluororasagiline ([(18)F]fluororasagiline-D2) radioligand for PET studies of monoamino oxidase B (MAO-B).

The objective of this study was to synthesize and evaluate a novel fluorine-18 labeled deuterium substituted analogue of rasagiline (9, [(18)F]fluororasagiline-D2) as a potential PET radioligand for studies of monoamine oxidase B (MAO-B). The precursor compound (6) and reference standard (7) were synthesized in multi-step syntheses. Radiolabeling of 9 was accomplished by a two-step synthesis, compromising a nucleophilic substitution followed by hydrolysis of the sulfamidate group. The incorporation radiochemical yield from fluorine-18 fluoride was higher than 30%, the radiochemical purity was >99% and the specific radioactivity was >160GBq/µmol at the time of administration. In vitro compound 7 inhibited the MAO-B activity with an IC50 of 173.0±13.6nM. The MAO-A activity was inhibited with an IC50 of 9.9±1.1µM. The fluorine-18 version 9 was characterized in the cynomolgus monkey brain where a high brain uptake was found (275% SUV at 4min). There was a higher uptake in the striatum and thalamus compared to the cortex and cerebellum. A pronounced blocking effect (50% decrease) was observed in the specific brain regions after administration of l-deprenyl (0.5mg/kg) 30min prior to the administration of 9. Radiometabolite studies demonstrated 40% of unchanged radioligand at 90min post injection. An efficient radiolabeling of 9 was successfully established and in the monkey brain 9 binds to MAO-B rich regions and its binding is blocked by the selective MAO-B compound l-deprenyl. The radioligand 9 is a potential candidate for human PET studies.

Stereodivergent SN2@P reactions of borane oxazaphospholidines: experimental and theoretical studies.

The stereodivergent ring-opening of 2-phenyl oxazaphospholidines with alkyl lithium reagents is reported. N-H oxazaphospholidines derived from both (+)-cis-1-amino-2-indanol and (-)-norephedrine provide inversion products in a highly stereoselective process. In contrast, N-Me oxazaphospholidines yield ring-opening products with retention of configuration at the P center, as previously reported by Jugé and co-workers. As a result, from a single amino alcohol auxiliary, both enantiomers of key P-stereogenic intermediates could be synthesized. Theoretical studies of ring-opening with model oxazaphospholidines at the DFT level have elucidated the streochemical course of this process. N-H substrates react in a single step via preferential backside S(N)2@P substitution with inversion at phosphorus. N-methylated substrates react preferentially via a two-step frontside S(N)2@P, yielding a ring-opened product in which the nucleophilic methyl binds to P with retention of configuration. DFT calculations have shown that the BH3 unit is a potent directing group to which the methyl lithium reagent coordinates via Li in all the reactions studied.

Influence of bracken fern (Pteridium caudatum L. Maxon) pre-treatment on extraction yield of illudane glycosides and pterosins.

INTRODUCTION: Bracken (Pteridium spp) illudane glycosidess are labile biologically active terpenoids that undergo decomposition in mild alkali or acid, heat and enzymatic reactions. Hypothetically, quantitation of these weakly chromophoric carcinogens may be challenged by plant sample preparation procedures that may alter the yield of isolates. OBJECTIVE: To study the influence of common plant sample pre-treatments on the recovery of Pteridium caudatum illudane glycoside carcinogens, ptaquiloside (1a), caudatoside (1c) and ptaquiloside Z (1d), and associated pterosins A, B and Z (2a, b, c) using HPLC-DAD. METHOD: Bracken fronds were divided in equal left/right sections. One section was subjected to high vacuum desiccation (VD) and the other to freeze-drying (FD), air drying at room temperature (AD) for 7 days, air drying at 70 °C for 72 h (HD), or no treatment (fresh frond, FF). Quantitation was achieved by brief hot-water extraction, base-acid transformation of 1a, 1c and 1d to 2a, b, c and HPLC-DAD analysis against standards. RESULTS: Substantial differences in extraction yields were found for all illudane glycosides in the order FF > FD ≈ VD > AD > HD. Illudane instability to HD was 1c > 1d > 1a. Significant losses also were recorded in yields of Pterosins A, B and Z. CONCLUSION: 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.