Witold Gładkowski

Trans-4-(4′-hydroxy-3′-methoxyphenyl)-5-(1-iodoethyl)dihydrofuran-2-one (IL), a vanillin-derived iodolactone with previously demonstrated biological activity, was incorporated into DPPC/cholesterol (DPPC/chol) liposomes to develop and characterize a lipid-based delivery system, with particular emphasis on the relationship between IL incorporation and the biophysical properties of the nanocarrier. The physicochemical stability of formulations containing 2, 5, 10, and 20 mol% IL was assessed using dynamic and electrophoretic light scattering (DLS/ELS), while the loading efficiency (LE%) of the highest IL concentration tested (20 mol%) was determined via ultracentrifugation, liquid–liquid extraction, and subsequent gas chromatography (GC) analysis. The formulation exhibited a high LE% of 87.6 ± 7.8%; however, as potential sedimentation of free IL cannot be ruled out, this value represents an indirect estimate of IL loading and remains a technical limitation of the assay. The effect of IL incorporation on bilayer organization was examined using three fluorescent probes, as well as attenuated total reflectance Fourier-transform infrared spectroscopy. DLS/ELS measurements demonstrated the most favorable colloidal stability for liposomes hydrated with milli-Q water and stored at 4 °C, as reflected by the maintenance of low PDI values, a relatively stable hydrodynamic diameter, and a negative zeta potential throughout the one-month storage period. Fluorescence spectroscopy demonstrated that IL modified the temperature-dependent organization of the DPPC/chol bilayer, with effects particularly evident at the membrane interface and, at elevated temperatures, in the hydrophobic region. Complementary ATR-FTIR analysis indicated that IL interacts with the polar headgroup and glycerol backbone regions without significantly disrupting acyl chain organization. Hemolytic assays further demonstrated the low membrane-damaging activity of IL-loaded liposomes in both crude dispersion fractions and the ultracentrifuged liposomal fraction. These results demonstrate that IL can be efficiently incorporated into DPPC/chol liposomes while maintaining favorable physicochemical stability and low hemolytic potential. The observed effect of the tested compound on bilayer organization without disrupting membrane integrity supports the need for further investigation of lipid formulations containing IL.

In this study, a two-step chemoenzymatic route was developed for the synthesis of symmetrical acylglycerol–stigmasterol conjugates bearing a stigmasterol moiety at the sn-2 position and saturated acyl chains (decanoyl, C10, or stearoyl, C18) at the sn-1,3 positions. The use of Candida antarctica lipase B (CALB) under mild conditions (0–5 °C) ensured high regioselectivity, successfully preventing acyl migration and eliminating the need for complex protection/deprotection steps. The impact of the synthesized conjugates on DPPC (1,2-dipalmitoyl-sn-glycero-3-phosphocholine) model lipid membranes was evaluated using dynamic light scattering (DLS), differential scanning calorimetry (DSC), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), and fluorescence spectroscopy. Incorporation of the conjugates broadened the main phase transition of DPPC, reduced membrane fluidity in the liquid-crystalline phase, and limited interfacial hydration in a concentration- and chain-length-dependent manner. The short-chain derivative (C10) maintained smaller, homogeneous liposomes and disrupted lipid packing in the gel phase, whereas the longer-chain derivative (C18) promoted stronger hydrophobic interactions within the bilayer core. These findings highlight the potential of chemoenzymatically derived lipid–phytosterol conjugates for the precise tailoring of nanocarriers in functional food and nutraceutical delivery systems.

Enantiomerically enriched vanillin-derived cis- and trans-β-aryl-δ-iodo-γ-lactones were synthesized using a chemoenzymatic pathway based on Candida antarctica lipase B (CALB)-catalyzed transesterification of racemic (E)-4-(4′-benzyloxy-3′-methoxyphenyl)but-3-en-2-ol, followed by Claisen rearrangement, hydrolysis, iodolactonization, and deprotection. The trans orientation of substituents on the γ-lactone ring of the target compounds was identified as the key structural feature enhancing cell-viability-reducing activity against selected human cancer cell lines. No statistically significant differences were observed between the enantiomerically enriched pairs of the studied lactones: the most active trans-δ-iodo-γ-lactones, 7b, exhibited similarly high potency (IC₅₀ = 3.98 ± 2.60 μM and 5.08 ± 1.30 μM) against the multidrug-resistant (MDR) gastric adenocarcinoma cell line EPG85-257RDB. Their IC₅₀ values were not significantly different from that determined for doxorubicin under the same experimental conditions (IC₅₀ = 5.48 ± 0.75 μM). Notably, both enantiomers exhibited high selectivity indices (SI = 9.22 and 10.19, respectively). TUNEL analysis demonstrated that enantiomer (4R,5S,6R)-7b induced concentration-dependent DNA fragmentation, increasing the percentage of TUNEL-positive cells from 8.30 ± 0.95% to 74.10 ± 4.26%. Flow cytometric analysis further revealed the pronounced accumulation of cells in the G2/M phase, with up to 55.25 ± 2.74% of cells detected at the highest tested concentration. The observed activity of enantiomerically enriched vanillin-derived trans-β-aryl-δ-iodo-γ-lactone 7b in the multidrug-resistant EPG85-257RDB cell line warrants its further investigation in additional drug-resistant cancer models.

A series of novel vanillin-derived halolactones bearing a phenolic ring at the β-position were comprehensively evaluated for their antioxidant and anti-inflammatory properties. The most active derivative, trans-4-(4′-hydroxy-3′-methoxyphenyl)-5-(1-iodoethyl)dihydrofuran-2(3H)-one (LV2), exhibited strong antioxidant activity in the ABTS assay (EC₅₀ = 35.65 ± 2.34 μM), comparable with Trolox^® and superior to the reference compound in the UV-C-induced oxidative stress assay (IC₅₀ = 48.67 ± 5.46 μM). Among the tested lactones, LV2 showed moderate anti-inflammatory activity in the COX-1 and COX-2 inhibition assays. Further studies revealed that iodolactone LV2 exhibited high antiproliferative activity in the MTT assay, particularly against the LM-MEL-75 and EPG85-257RDB cell lines (IC₅₀ = 8.67 ± 10.61 μM and 7.37 ± 3.23 μM, respectively), along with high selectivity (selectivity indices > 5). The effects of iodolactone LV2 on various lipid membranes were examined using fluorometric methods, while its impact on human red blood cell morphology was evaluated by analyzing erythrocyte shape changes. The influence of LV2 on model membrane organization was further investigated using attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). All spectroscopic studies confirmed the lactone’s interaction with polar regions of model membranes, demonstrating its capacity to modulate membrane-associated functions. This multifunctional bioactivity positions iodolactone LV2 as a promising candidate for further anticancer studies.

A series of novel γ-halo-δ-lactones and δ-halo-γ-lactones bearing a phenolic ring at the β-position were synthesized from vanillin. The divergent seven-step synthetic route commenced with the benzyl protection of the hydroxy group of the starting material, followed by a four-step transformation that led to the corresponding β-aryl-γ,δ-unsaturated carboxylic acids. Subsequent halolactonization (iodo-, bromo-, and chlorolactonization), followed by selective benzyl deprotection, gave the target halolactones. The structures of all intermediates and final lactones were confirmed by comprehensive spectroscopic analyses, including NMR and HRMS. The resulting halolactones were evaluated for antiproliferative activity against two canine (CLBL-1, CLB70) and two human (T-24, CaCo-2) cancer cell lines, as well as non-cancerous mouse embryonic fibroblasts (NIH/3T3). Hemolytic assays were performed to assess toxicity against human red blood cells (RBCs). Among the tested lactones, the transδ-iodo-γ-lactone was the most active, particularly against CLBL-1 and T-24 cells. All compounds demonstrated no inhibitory effects on normal fibroblasts and no hemolytic toxicity. This favorable selectivity profile positions this group of lactones, particularly trans-δ-iodo-γ-lactone, as a promising candidate for further development as potential anticancer agents.

A series of novel γ-halo-δ-lactones and δ-halo-γ-lactones bearing a phenolic ring at the β-position was synthesized from the naturally occurring aromatic aldehyde vanillin. The seven-step synthetic route commenced with benzyl protection of the hydroxy group of the starting material, followed by the synthesis of a γ,δ-unsaturated carbox-ylic acid, subsequent halolactonization (iodo-, bromo-, and chlorolactonization), and concluded with selective benzyl deprotection. The structures of all synthesized com-pounds were confirmed by comprehensive spectroscopic analyses, including NMR and HRMS. The resulting halolactones were evaluated for antiproliferative activity against two canine (CLBL-1, CLB70) and two human (T-24, CaCo-2) cancer cell lines, with non-cancerous mouse embryonic fibroblasts (NIH/3T3) serving as controls. Hemolytic assays were performed to assess toxicity toward human red blood cells (RBCs). All compounds demonstrated selective inhibition of cancer cell proliferation, exhibiting no inhibitory effects on normal fibroblasts and no hemolytic toxicity. Among the tested lactones, the trans δ-iodo-γ-lactone was the most potent, particularly against CLBL-1 and T-24 cells. These findings underscore the potential of vanillin-derived halolactones as selective anticancer agents with an advantageous safety profile, owing to their lack of toxicity toward non-malignant cells.

The aim of this research was to design and synthesize new lipid conjugates of 7-DHC that could serve as a new storage form of esterified provitamin D₃, increasing the reservoir of this biomolecule in the epidermis and enabling controlled production of vitamin D₃ even during periods of sunlight deficiency. Acylglycerol and glycerophospholipid containing succinate-linked provitamin D₃ at the sn-2 position of the glycerol backbone were synthesized from dihydroxyacetone (DHA) and sn-glycerophosphocholine (GPC), respectively. The three-step synthesis of 1,3-dipalmitoyl-2-(7-dehydrocholesterylsuccinoyl)glycerol involved the esterification of DHA with palmitic acid, reduction of the carbonyl group, and conjugation of the resulting 1,3-dipalmitoylglycerol with 7-dehydrocholesterol hemisuccinate (7-DHC HS). The use of NaBH₃CN as a reducing agent was crucial to avoid acyl migration and achieve the final product with 100% regioisomeric purity. For the preparation of 1-palmitoyl-2-(7-dehydrocholesterylsuccinoyl)-sn-glycero-3-phosphocholine, a two-step process was applied, involving the esterification of GPC at the sn-1 position with palmitic acid, followed by the conjugation of 1-palmitoyl-sn-glycero-3-phosphocholine with 7-DHC HS. Alongside the main product, a small amount of its regioisomer with provitamin D₃ linked at the sn-1 position and palmitic acid at the sn-2 position was detected, indicating acyl migration from the sn-1 to the sn-2 position in the intermediate 1-palmitoyl-sn-glycerophosphocholine. The synthesized novel lipids were fully characterized using spectroscopic methods. They can find applications as novel lipid-based prodrugs as additives to sunscreen creams.

Two novel lipids, acylglycerol and glycerophospholipid containing succinate-linked provitamin D3 at sn-2 position of glycerol backbone, have been synthesized from dihydroxyacetone (DHA) and sn-glycerophosphocholine (GPC), respectively. Three-step synthesis of 1,3-dipalmitoyl-2-(7-dehydrocholesterylsuccinoyl)glycerol involved esterification of DHA with palmitic acid, reduction of carbonyl group and conjugation of resulting 1,3-dipalmitoylglycerol with 7-dehydrocholesterol hemisuccinate (7-DHC HS). Using NaBH3CN as a reducing agent was crucial to avoid any acyl migration and obtain the final product with 100% regioisomeric purity. 1-Palmitoyl-2-(7-dehydrocholesterylsuccinoyl)-sn-glycero-3-phosphocholine was produced in two-step process by the esterification of GPC at sn-1 position with palmitic acid and subsequent conjugation of 1-palmitoyl-sn-glycero-3-phosphocholine with 7-DHC HS. Apart from the main product, some amount of its regioisomer containing provitamin D3 linked at sn-1 position and palmitic acid at sn-2 position was detected which indicated the acyl migration of palmitic acid from sn-1 to sn-2 position in the intermediate 1-palmitoyl-sn-glycerophosphocholine. Synthesized novel lipids were fully characterized by spectroscopic data. They can find application as novel lipid-based prodrugs as the additives to sunscreen creams, providing controlled release of provitamin D3 in the epidermis.

Natural and synthetic lactones containing an aromatic ring exhibit a number of biological properties, e.g. antiproliferative, antifeedant or antimicrobial activity. This review deals with the synthesis and biological properties of lactones containing an aromatic substituent in the β-position of the lactone ring. The described group of compounds includes halolactones, hydroxylactones, unsaturated lactones and products of reductive dehalogenation of iodolactones. In addition to chemical transformations, biotechnological methods for obtaining optically active lactones have also been described, including the use of lipases in the chemoenzymatic pathway leading to the production of halolactones, kinetic separation of hydroxylactones in the process of enzymatic transesterification, microbial hydrolytic dehalogenation of iodolactones and enantioselective hydrolysis of the lactone ring. The biological activity of the obtained β-aryllactones was also briefly characterized

Four compounds with lactone moiety were synthesized from chalcone 1 in three- or four-step synthesis. γ-Bromo-δ-lactone 5 was the only product of bromolactonization of acid 4 whereas bromolactonization of ester 3, apart from lactone 5 also afforded its isomer 6 and two diastereoisomeric δ-hydroxy-γ-lactones 7 and 8. Lactone 8 was also obtained in 88% yield as a product of simultaneous dehalogenation and translactonization of γ-bromo-δ-lactone 5 by Penicillum frequentans AM 359. Chalcone-derived lactones 5–8 were subjected to the tests on antimicrobial activity and the results compared with activity of starting chalcone 1. Obtained lactones 5–8 in most cases limited the growth of tested bacterial and fungal strains. The highest activity was found for δ-hydroxy-γ-lactone 8 which completely inhibited the growth of Staphylococcus aureus, Fusarium graminearum, Aspergillus niger, and Alternaria sp. The introduction of lactone moiety into chalcone scaffold significantly improved antimicrobial activity of the compound: γ-bromo-δ-lactone 6 and δ-hydroxy-γ-lactone 8 were significantly stronger growth inhibitors of S. aureus and F. graminearum. In the case of the latter, a clear positive effect of the lactone function on the antifungal activity was also observed for γ-bromo-δ-lactone 5.