Anna Gliszczyńska

Microbial transformation of (+)-nootkatone and the antiproliferative activity of its metabolites

Six metabolites were obtained as a result of microbial transformation of (+)-nootkatone (1) by the fungal strains: Botrytis, Didymosphaeria, Aspergillus, Chaetomium and Fusarium. Their structure were established as (+)-(4R,5S,7R,9R)-9α-hydroxynootkatone (2), (+)-(4R,5S,7R)-13-hydroxynootkatone (3) and (+)-(4R,5S,7R,9R,11S)-11,12-epoxy-9α-hydroxynootkatone (4), (+)-(4R,5S,7R,11S)-11,12-epoksynootkatone (5), (+)-(4R,5S,7R)-11,12-dihydroxynootkatone (6) and (+)-(4R,5S,7R)-7,11,12-trihydroxynootkatone (7) on the basis of their spectral data. Two products: (4) and (7) were not previously reported in the literature. The antiproliferative activity of (+)-nootkatone (1) and isolated metabolites (2-7) of its biotransformation has been evaluated.

Systemic deterrence of aphid probing and feeding by novel β-damascone analogues

Abstractβ-Damascone appeared a weak attractant close to not active to Myzus persicae, but modifications of its structure caused the avoidance of treated leaves by aphids during settling and reluctance to probe in simple choice- and no-choice experiments in previous studies. Here, the electrical penetration graph (EPG) technique, which allows monitoring of aphid probing within plant tissues, was applied to explore the biological background and localisation in plant tissues of the deterrent activities of β-damascone and its analogues. Activity of β-damascone and β-damascone-derived compounds depended on their substituents, which was manifested in the variation in the potency of the behavioural effect and differences in aphid probing phases that were affected. β-Damascone appeared a behaviourally inactive compound. The moderately active β-damascone ester affected aphid activities only during the phloem phase. The highly active deterrents—dihydro-β-damascol, β-damascone acetate, δ-bromo-γ-lactone, and unsaturated γ-lactone—affected pre-phloem and phloem aphid probing activities. The most effective structural modification that evoked the strongest negative response from M. persicae was the transformation of β-damascone into δ-bromo-γ-lactone. The behavioural effect of this transformation was demonstrated in frequent interruption of probing in peripheral tissues, which caused repeated failures in finding sieve elements, and reduction in the ingestion time during the phloem phase in favour of watery salivation. The inhibition of aphid probing at both the pre-phloem and phloem levels reveals the passage of the compounds studied through the plant surface and their distribution within plant tissues in a systemic way, which may reduce the risk of the transmission of non-persistent and persistent viruses.

Phosphatidylcholine with cis-9,trans-11 and trans-10,cis-12 Conjugated Linoleic Acid Isomers: Synthesis and Cytotoxic Studies

Novel phosphatidylcholines and lysophosphatidylcholines with cis-9,trans-11 and trans-10,cis-12 conjugated linoleic acid (CLA) were synthesized in high yields (75–99 %). The in vitro cytotoxic activities of these compounds against three human cancer cell lines (HL-60, MCF-7, and HT-29) were evaluated. The results revealed that there are differences in the activity between phosphatidylcholine with cis-9,trans-11 and trans-10,cis-12 CLA acyl groups. 1,2-Di(9Z,11E)-octadecadienoyl-sn-glycero-3-phosphocholine was the most potent cytotoxic agent among all tested CLA derivatives and its IC50 (concentration of a compound that inhibits the proliferation of 50 % of the cancer cell population) was 29.4 µM against HL-60. Moreover, phosphatidylcholines with CLA acyls exhibited much lower cytotoxicity against non-cancer cells (Balb/3T3) than free CLA isomers.

Synthesis of β-damascone derivatives with a lactone ring and their feeding deterrent activity against aphids and lesser mealworms

Starting from β-damascone, six new lactones were obtained. The Claisen–Johnson rearrangement of allylic alcohol and halolactonization of γ,δ-unsaturated acid were the key steps of the presented synthesis. The structures of the new derivatives were determined by spectroscopic data. The antifeedant activity of β-damascone towards two insect species with different feeding habits and food preferences, i.e., the peach-potato aphid Myzus persicae (Sulz.) and lesser mealworm, Alphitobius diaperinus Panzer, was studied, as well as the biological consequences of structural modification of the starting substrate. The successive structural modifications of β-damascone that resulted in the greatest antifeedant activity towards M. persicae were the incorporation of a lactone moiety and concomitant presence of bromine in the side chain. All β-damascone derivatives with a lactone moiety deterred the feeding of adults and larvae of A. diaperinus. Halo-δ-lactones were more active than halo-γ-lactones, and A. diaperinus adults were more sensitive to the compounds studied than larvae.

Enantioselective Microbial Hydroxylation as a Useful Tool in the Production of Jasmonate Derivatives with Aphid Deterrent Activity.

Microbial transformations of two natural compounds dihydrojasmone (1) and cis-jasmone (3) in the growing cultures of selected twenty strains have been investigated. The studies have demonstrated a biocatalytic potential of tested microorganisms for the enantioselective hydroxylation of jasmonates. The substrates underwent an effective regio- and stero-selective hydroxylation at the allylic position in the cyclopentenone ring, and the corresponding optically pure keto-alcohols (2, 4) were obtained. The process of biohydroxylation depended on the composition of reaction medium. In the studied cultures, (+)-(R)-4-hydroxydihydrojasmone (2) and (+) and (−)-4-hydroxyjasmone (4a, 4b) were produced in good yields and high enantiomeric excesses. Moreover, the introduction of the hydroxy group into the molecule of jasmonate ketones 1 and 3 leads to biologically active derivatives 2 and 4 that regulate the behaviour of aphids Myzus persicae by termination of their feeding.

Isoprenoid-phospholipid conjugates as potential therapeutic agents: Synthesis, characterization and antiproliferative studies

The aim of this research was to extend application field of isoprenoid compounds by their introduction into phospholipid structure as the transport vehicle. The series of novel isoprenoid phospholipids were synthesized in high yields (24–97%), their structures were fully characterized and its anticancer activity was investigated in vitro towards several cell lines of different origin. Most of synthesized compounds showed a significantly higher antiproliferative effect on tested cell lines than free terpene acids. The most active phosphatidylcholine analogue, containing 2,3-dihydro-3-vinylfarnesoic acids instead of fatty acids in both sn-1 and sn-2 position, inhibits the proliferation of colon cancer cells at 13.6 μM.

Synthesis and Biological Evaluation of Novel Phosphatidylcholine Analogues Containing Monoterpene Acids as Potent Antiproliferative Agents.

The synthesis of novel phosphatidylcholines with geranic and citronellic acids in sn-1 and sn-2 positions is described. The structured phospholipids were obtained in high yields (59–87%) and evaluated in vitro for their cytotoxic activity against several cancer cell lines of different origin: MV4-11, A-549, MCF-7, LOVO, LOVO/DX, HepG2 and also towards non-cancer cell line BALB/3T3 (normal mice fibroblasts). The phosphatidylcholines modified with monoterpene acid showed a significantly higher antiproliferative activity than free monoterpene acids. The highest activity was observed for the terpene-phospholipids containing the isoprenoid acids in sn-1 position of phosphatidylcholine and palmitic acid in sn-2.

Dehalogenation Activity of Selected Fungi Toward δ-Iodo-γ-Lactone Derived from trans,trans-Farnesol.

Time‐course of biotransformation of racemic trans‐4‐((E)‐4′,8′‐dimethylnona‐3′,7′‐dien‐1‐yl)‐5‐iodomethyl‐4‐methyldihydrofuran‐2‐one (1) in fungal and yeast cultures was investigated. In these conditions, the substrate 1 was enantioselectively dehalogenated yielding 4‐((E)‐4′,8′‐dimethylnona‐3′,7′‐dien‐1‐yl)‐4‐methyl‐5‐methylenedihydrofuran‐2‐one (2) and its structure was established based on the spectroscopic data. The most effective biocatalyst used was Didymosphaeria igniaria, which catalyzed the process with highest rate and enantioselectivity (ee of product = 76%). The antiproliferative activity of δ‐iodo‐γ‐lactone 1, product of its biotransformation 2, and starting substrate (farnesol) were evaluated toward two cancer cell lines: A549 (human lung adenocarcinoma) and HL‐60 (human promyelocytic leukemia).

Alkyl-Substituted δ-Lactones Derived from Dihydrojasmone and Their Stereoselective Fungi-Mediated Conversion: Production of New Antifeedant Agents.

A chemoenzymatic method was applied to obtain optically pure alkyl-substituted δ-lactones. First, chemical Baeyer–Villiger oxidation of dihydrojasmone (1) was carried out, affording two new alkyl-substituted δ-lactones: 3,4-dihydro-5-methyl-6-pentyl-2H-pyran-2-one (2) and 5-methyl-6-pentyl-1,13-dioxabicyclo[4.1.0]heptan-2-one (3). In the next step, fungal strains were investigated as biocatalysts to enantioselective conversion of δ-lactones (2) and (3). The fungal cultures: Fusarium culmorum AM10, Fusarium equiseti AM15 and Beauveria bassiana AM278 catalyzed the stereoselective hydration of the double bond of lactone (2) (ee = 20%–99%) while Didymosphaeria igniaria KCh6670 proved to be the best biocatalyst for the reduction of carbonyl group in the epoxylactone (3) (ee = 99%). In both cases, chiral oxyderivatives were obtained in low to high yields (7%–91%). The synthetic lactones (2), (3) and its derivatives (4), (5) were tested for their antifeedant activity towards larvae and adults of lesser mealworm (Alphitobius diaperinus Panzer) and peach potato aphid (Myzus persicae [Sulzer]) and some of them were active towards studied insects.

Positional analysis of phosphatidylcholine and phosphatidylethanolamine via LC with a charged aerosol detector.

A new method for the positional analysis of egg yolk phospholipids (PLs) (phosphatidylcholine-PC, phosphatidylethanolamine-PE) using liquid chromatography with charge aerosol detector (CAD) is described. The method is based on six-step procedure: 1) extraction of phospholipids from tissue sample, 2) separation of lipid classes by solid phase extraction (SPE), 3) complete regiospecific hydrolysis of phospholipids by phospholipase A2 (PLA2), 4) separation of reaction products (fatty acids from sn-2 position and 1-acyl lysophospholipids) by SPE, 5) chemical hydrolysis of 1-acyl lysophospholipids, and 6) analysis of obtained fatty acids by LC with charge aerosol detection (CAD). Total time of enzymatic hydrolysis of PLs ranged from 10-30min. The reaction products were separated by SPE in three-step gradient elution procedure. Chloroform: methanol mixtures were used as eluents to obtain pure fractions of FAs from sn-2 position of PL and 1-acyl lysoPL (chemically hydrolyzed to FAs). FAs were separated by reversed-phase LC using a gradient elution and detected using CAD detector. This combination enables determination of all fatty acids in a single analysis, and without the sample derivatization. The method was optimized and the response of CAD, linearity, precision and sensitivity of the method were studied.