Czesław Wawrzeńczyk

Enantiospecific Effect of Pulegone and Pulegone-Derived Lactones on Myzus persicae (Sulz.) Settling and Feeding

The effect of pulegone chiral center configuration on its antifeedant activity to Myzus persicae was examined. Biological consequences of structural modifications of (R)-(+)- and (S)-(−)-pulegone, the lactonization, iodolactonization, and incorporation of hydroxyl and carbonyl groups were studied, as well. The most active compounds were (R)-(+)-pulegone (1a) and δ-hydroxy-γ-spirolactones (5S,6R,8S)-(−)-6-hydroxy-4,4,8-trimethyl-1-oxaspiro[4.5]decan-2-one (5b) and (5R,6S,8S)-6-hydroxy-4,4,8-trimethyl-1-oxaspiro[4.5]decan-2-one (6b) derived from (S)-(−)-pulegone (1b). The compounds deterred aphid probing and feeding at preingestional, ingestional, and postingestional phases of feeding. The preingestional effect of (R)-(+)-pulegone (1a) was manifested as difficulty in finding and reaching the phloem (i.e., prolonged time preceding the first contact with phloem vessels), a high proportion of probes not reaching beyond the mesophyll layer before first phloem phase, and/or failure to find sieve elements by 20% of aphids during the 8-hr experiment. The ingestional activity of (R)-(+)-pulegone (1a) and hydroxylactones 5b and 6b resulted in a decrease in duration of phloem sap ingestion, a decrease in the proportion of aphids with sustained sap ingestion, and an increase in the proportion of aphid salivation in phloem. δ-Keto-γ-spirolactone (5R,8S)-(−)-4,4,8-trimethyl-1-oxaspiro[4.5]decan-2,6-dione (8b) produced a weak ingestional effect (shortened phloem phase). The postingestional deterrence of (R)-(+)-pulegone (1a) and δ-hydroxy-γ-spirolactones (5R,6S,8R)-(+)-6-hydroxy-4,4,8-trimethyl-1-oxaspiro[4.5]-decan-2-one (5a), 5b, (5S,6R,8R)-6-hydroxy-4,4,8-trimethyl-1-oxaspiro[4.5]decan-2-one (6a), 6b, and δ-keto-γ-spirolactone 8b prevented aphids from settling on treated leaves. The trans position of methyl group CH3–8 and the bond C5–O1 in lactone 6b appeared to weaken the deterrent activity in relation to the cis diastereoisomer (5b).

Enzymatic enrichment of egg-yolk phosphatidylcholine with α-linolenic acid

Abstractα-Linolenic acid (ALA) was incorporated at 28% into the sn-1 position of egg-yolk phospatidylcholine using Novozyme 435 in one-step transesterification process. Using phospholipase A2 in a two-step process gave 25% incorporation of ALA into the sn-2 position.

Lactones. Part 15: Synthesis of chiral spirolactones with a carane system—insect feeding deterrents

Abstract Starting from (+)-3-carene 1 several spirolactones with carane backbone were synthesized. δ-Hydroxy-γ-lactone 5 was obtained by acidic lactonization of a γ,δ-epoxy ester. Iodolactone 8 and bromolactone 9 were products of iodolactonization of γ,δ-unsaturated acid 7 and bromolactonization of γ,δ-unsaturated ester 3 respectively. The halo lactones were subjected to reductive dehalogenation with tributyltin hydride and dehydrohalogenation with DBU. The structures of the lactones obtained were confirmed by X-ray analysis and spectral data.

Terpenoid lactones with the p-menthane system as feeding deterrents to the lesser mealworm, Alphitobius diaperinus

The application of antifeedants, often in combination with other methods within integrated pest management (IPM) strategies, has proven to be a good way to control insect pests. Little is known about compounds that have antifeedant activity against the lesser mealworm, Alphitobius diaperinus Panzer (Coleoptera: Tenebrionidae). The antifeedant properties of optically pure isomers of pulegone and isopulegol and some enantiomeric pairs of bicyclic terpenoid lactones with the p‐menthane system, derived from these isomeric starting compounds, were studied in choice and no‐choice tests with the lesser mealworm. The original monoterpenes and γ‐spirolactones were weak feeding deterrents to larvae and adults of A. diaperinus. The δ‐hydroxy‐γ‐spirolactones showed significant activity against adults, but substituting the hydroxy group with a ketone group considerably reduced the deterrent activity of the resulting δ‐keto‐γ‐spirolactones. The bicyclic γ‐hydroxy‐δ‐lactones with condensed rings and with the (1S,6R,8R)‐(+) and (1R,6S,8S)‐(–) configuration of the chiral centres, and δ‐hydroxy‐γ‐lactone (1S,4S,6S)‐(+) were very strong antifeedants to both larvae and adults. The hydroxy groups and the configuration of the chiral centres of the molecules were very important features for determining the antifeedant activity of the lactones tested. Generally, the compounds studied were better antifeedants to adults than to larvae.

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.

A new liquid chromatography method with charge aerosol detector (CAD) for the determination of phospholipid classes. Application to milk phospholipids

A new rapid method for the quantitative analysis of five classes of phospholipids (PLs) (phosphatidylcholine--PC, lysophosphatidylcholine--LPC, phosphatidylethanolamine--PE and phosphatidylserine--PS and phosphatidylinositol--PI) using liquid chromatography with charge aerosol detector (CAD) is described. The separation of the compounds of interest was achieved on a diol stationary phase with a mobile phase consisting of 13% HCOOH, hexane and 2-propanol in 19 min elution program, including 10 min equilibration of the column. The method was applied to characterize the phospholipid fractions of cow milk. PLs present in cow milk were separated by solid-phase extraction (SPE) procedure with Si cartridges before LC analysis with recovery ranging from 95.3% to 104.4%. The use of CAD detection of the eluted compounds was precise, linear and sensitive.

Insect growth regulators. XVI Syntheses of juvenoids with the 3,3-dimethylcyclohexane system

New cyclic juvenoids containing the 3,3-dimethylcyclohexane (esters16,18,22,26, and ethers28 a, b) or the 5,5-dimethyl-2-cyclohexene system (esters15,17,21,25, and ethers27 a,b) have been obtained by a several-step synthesis starting from dimedone (1). The compounds obtained exhibited morphogenetic activity against larvae ofDysdercus cingulatus and they were inactive on pupae ofTenebrio molitor.ZusammenfassungAusgehend von Dimedon (1) wurden in mehrstufigen Synthesen neue, cyclische Juvenoide hergestellt, die das 3,3-Dimethylcyclohexan- (Ester16,18,22,26 und Ether28 a, b) oder 5,5-Dimethyl-2-cyclohexen-System (Ester15,17,21,25 und Ether27 a, b) enthalten. Die erhaltenen Verbindungen zeigen morphogenetische Aktivität gegenüber Larven vonDysdercus cingulatus und sind inaktiv gegenüber Puppen vonTenebrio molitor.

Synthesis of piperitone-derived halogenated lactones and their effect on aphid probing, feeding, and settling behavior{{

Five racemic and five enantiomeric pairs of new halolactones with the p-menthane system were obtained in two or three step synthesis from racemic and optically active cis- and trans-piperitols. The key steps of the syntheses were the Claisen-Johnson rearrangement of piperitols to γ,δ-unsaturated esters and haloloctonization of γ,δ-unsaturated esters or acids. The structures of the compounds were confirmed by spectroscopic and crystallographic data. Antifeedant activity of all iodo-, bromo- and chlorolactones and racemic piperitone against Myzus persicae was examinated. The effect of these compounds on probing, feeding, and settling behavior of M. persicae in vivo was studied.

Piperitone-derived saturated lactones: synthesis and aphid behavior-modifying activity.

Two racemic and two enantiomeric pairs of new saturated lactones with the p-menthane system were obtained. The lactones were synthesized from racemic and enantiomerically enriched cis- and trans-piperitols, which were obtained from piperitone. The structures of the compounds were confirmed by spectroscopic data. The antifeedant activity of piperitone to Myzus persicae was studied, and the biological consequences of structural modifications of piperitone, that is, lactonization and chiral center configuration, were examined as well. The behavioral responses of M. persicae to piperitone and piperitone-derived saturated lactones were investigated to reveal the biological background of their deterrent activity. Piperitone appeared rather neutral or weakly deterrent to aphids. The introduction of a lactone moiety into a piperitone molecule dramatically changed its biological activity. All piperitone-derived lactones evoked negative aphid responses. However, the deterrent activity of individual compounds varied in potency, the time of expression, and the duration of the effect, depending on the spatial structure of the lactone. Lactones (1R,3S,6R)-3-isopropyl-6-methyl-9-oxabicyclo[4.3.0]nonan-8-one and trans-3-isopropyl-6-methyl-9-oxabicyclo[4.3.0]nonan-8-one showed the broadest ranges and the highest potencies and durabilities of deterrent activity to M. persicae: they acted immediately after application, caused a cessation of probing before aphids reached phloem elements, and decreased the quality of phloem sap.

An LC method for the analysis of phosphatidylcholine hydrolysis products and its application to the monitoring of the acyl migration process

An assay for quantitative analysis of phosphatidylcholine (1,2-dipalmitoyl-sn-glycero-3-phosphocholine) and its hydrolysis products: 1-hydroxy-2-palmitoyl-sn-glycero-3-phosphocholine and 1-palmitoyl-2-hydroxy-sn-glycero-3-phosphocholine, sn-glycero-3-phosphocholine and palmitic acid using high-performance liquid chromatography with charge aerosol detector (CAD) was developed. The separation of the compounds of interest was achieved on a reversed-phase/hydrophilic interaction stationary phase with a mobile phase consisting of acetonitrile:methanol:10mM ammonium acetate solution. The method was applied to control the acyl migration process of LPC regioisomers in the most common solvents used in the synthesis or modification of PC.