New Caffeic Acid Derivatives as Antimicrobial Agents: Design, Synthesis, Evaluation and Docking

Encapsulation of phenolic acids within food-grade carriers systems: a systematic review

Phenolic acids are natural compounds with potential therapeutic effects against various diseases. However, their incorporation into food and pharmaceutical products is limited by challenges such as instability, low solubility, and reduced bioavailability. This systematic review summarizes recent advances in phenolic acid encapsulation using food-grade carrier systems, focusing on proteins, lipids, and polysaccharides. Encapsulation efficiency, release behavior, and bioavailability are examined, as well as the potential health benefits of encapsulated phenolic acids in food products. Strategies to address limitations of current encapsulation systems are also proposed. Encapsulation has emerged as a promising method to enhance the stability and bioavailability of phenolic acids in food products, and various encapsulation technologies have been developed for this purpose. The use of proteins, lipids, and carbohydrates as carriers in food-grade encapsulation systems remains a common approach, but it is associated with certain limitations. Future research on phenolic acid encapsulation should focus on developing environmentally friendly, organic solvent-free, low-energy, scalable, and stable encapsulation systems, as well as co-encapsulation methods that combine multiple phenolic acids or phenolic acids with other bioactive substances to produce synergistic effects.

The anticancer impacts of free and liposomal caffeic acid phenethyl ester (CAPE) on melanoma cell line (A375)

The deadliest type of skin cancer, malignant melanoma, is also the reason for the majority of skin cancer-related deaths. The objective of this article was to investigate the efficiency of free caffeic acid phenethyl ester (CAPE) and liposomal CAPE in inducing apoptosis in melanoma cells (A375) in in vitro. CAPE was loaded into liposomes made up of hydrogenated soybean phosphatidylcholine, cholesterol, and 1,2-distearoyl-sn-glycero-3 phosphoethanolamine-N-[methoxy (polyethylene glycol)-2000], and their physicochemical properties were assessed. (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) test was performed for comparing the cytotoxicity of free CAPE and liposomal CAPE at dosages of 10, 15, 25, 50, 75 and the highest dose of 100 μg/mL for period of 24 and 48 h on A375 cell line to calculate IC50. Apoptosis and necrosis were evaluated in A375 melanoma cancer cells using flow cytometry. Atomic force microscopy was utilized to determine the nanomechanical attributes of the membrane structure of A375 cells. To determine whether there were any effects on apoptosis, the expression of PI3K/AKT1 and BAX/BCL2 genes was analyzed using the real-time polymerase chain reaction technique. According to our results, the maximum amount of drug release from nanoliposomes was determined to be 91% and the encapsulation efficiency of CAPE in liposomes was 85.24%. Also, the release of free CAPE was assessed to be 97%. Compared with liposomal CAPE, free CAPE showed a greater effect on reducing the cancer cell survival after 24 and 48 h. Therefore, IC50 values of A375 cells treated with free and liposomal CAPE were calculated as 47.34 and 63.39 μg/mL for 24 h. After 48 h of incubation of A375 cells with free and liposomal CAPE, IC50 values were determined as 30.55 and 44.83 μg/mL, respectively. The flow cytometry analysis revealed that the apoptosis induced in A375 cancer cells was greater when treated with free CAPE than when treated with liposomal CAPE. The highest nanomechanical changes in the amount of cell adhesion forces, and elastic modulus value were seen in free CAPE. Subsequently, the greatest decrease in PI3K/AKT1 gene expression ratio occurred in free CAPE.

Efficient One-Pot Synthesis of Novel Caffeic Acid Derivatives as Potential Antimalarials

New protocol for the preparation of the novel caffeic acid derivatives using the Wittig reaction has been applied to follow the principles of green chemistry. The compounds have been evaluated against chloroquine-sensitive and chloroquine-resistant P. falciparum strains. Their cytotoxicity to normal human dermal fibroblasts and their propensity to induce hemolysis have been also determined. Ethyl (2E)-3-(2,3,4-trihydroxyphenyl)-2-methylpropenoate has exhibited the highest antiplasmodial activity against P. falciparum strains without the cytotoxic and hemolytic effects. This derivative is significantly more potent than caffeic acid parent structure. The application of our one-step procedure has been shown to be rapid and efficient. It allows for an easy increase of input data to refine the structure-activity relationship model of caffeates as the antimalarials. The one-step approach meets the conditions of "atom economy" and eliminates hazardous materials. Water has been used as the effective medium for the Wittig reaction to avoid toxic organic solvents.

Natural Compounds with Antifungal Properties against Candida albicans and Identification of Hinokitiol as a Promising Antifungal Drug

Candida albicans is an opportunistic yeast that causes most fungal infections. C. albicans has become increasingly resistant to antifungal drugs over the past decade. Our study focused on the identification of pure natural compounds for the development of antifungal medicines. A total of 15 natural compounds from different chemical families (cinnamic derivatives, aromatic phenols, mono- and sesquiterpenols, and unclassified compounds) were screened in this study. Among these groups, hinokitiol (Hi), a natural monoterpenoid extracted from the wood of the cypress family, showed excellent anti-C. albicans activity, with a MIC value of 8.21 µg/mL. Hi was selected from this panel for further investigation to assess its antifungal and anti-inflammatory properties. Hi exhibited significant antifungal activity against clinically isolated fluconazole- or caspofungin-resistant C. albicans strains. It also reduced biofilm formation and hyphal growth. Treatment with Hi protected Caenorhabditis elegans against infection with C. albicans and enhanced the expression of antimicrobial genes in worms infected with C. albicans. Aside from its antifungal activities against C. albicans, Hi challenge attenuated the LPS-induced expression of pro-inflammatory cytokines (IL-6, IL-1β, and CCL-2) in macrophages. Overall, Hi is a natural compound with antifungal and anti-inflammatory properties, making Hi a promising platform with which to fight against fungal infections.

Chemo-Enzymatic Synthesis and Biological Assessment of p-Coumarate Fatty Esters: New Antifungal Agents for Potential Plant Protection

One trend in agriculture is the replacement of classical pesticides with more ecofriendly solutions, such as elicitation, which is a promising approach consisting of stimulating the natural immune system of a plant to improve its resistance to pathogens. In this fashion, a library of p-coumaric-based compounds were synthesized in accordance with as many principles of green chemistry as possible. Then, these molecules were tested for (1) the direct inhibition of mycelium growth of two pathogens, Botrytis cinerea and Sclerotinia sclerotiorum, and (2) plasma membrane destabilization in Arabidopsis and rapeseed. Finally, the protective effect was evaluated on an Arabidopsis/B. cinerea pathosystem. Total inhibition of the growth of both fungi could be achieved, and significant ion leakage was observed using dihydroxylated fatty p-coumarate esters. A direct effect on plants was also recorded as a ca. three-fold reduction in the necrosis area.

Antimicrobial Activity of Catechol-Containing Biopolymer Poly[3-(3,4-dihydroxyphenyl)glyceric Acid] from Different Medicinal Plants of Boraginaceae Family

This study reports the antimicrobial activities of the biopolymers poly[3-(3,4-dihydoxyphenyl)glyceric acid] (PDHPGA) and poly[2-methoxycarbonyl-3-(3,4-dihydroxyphenyl)oxirane] (PMDHPO), extracted from the six plants of Boraginaceae family: Symphytum asperum (SA), S. caucasicum (SC), S. gr and iflorum (SG), Anchusa italica (AI), Cynoglosum officinale (CO), and Borago officinalis (BO) collected in various parts of Georgia. The study revealed that the antibacterial activities were moderate, and biopolymers from only three plants showed activities against all tested bacteria. Biopolymers from CO stems as well as SC and AI did not show any activity except low activity against a resistant P. aeruginosa strain, which was the most resistant among all three resistant strains. On the other hand, the antifungal activity was better compared to the antibacterial activity. Biopolymers from BO stems exhibited the best activities with MIC/MFC at 0.37-1.00 mg/mL and 0.75-1.5 mg/L, respectively, followed by those from SG stems. Biopolymers from SC and AI roots showed antifungal activities against all six fungi, in contrast to the antibacterial activity, while biopolymers from CO stems and SA roots had activities against four fungi and one fungus, respectively. The sugar-based catechol-containing biopolymers from BO stems demonstrated the best activities among all tested biopolymers against T. viride, P. funiculosum, P. cyclpoium var verucosum, and C. albicans (MIC 0.37 mg/mL). In addition, biopolymers from SG stems were half as active against A. fumigatus and T. viride as ketoconazole. Biopolymers from all plant materials except for CO stems showed higher potency than ketoconazole against T. viride. For the first time, it was shown that all plant materials exhibited better activity against C. albicans, one of the most dreadful fungal species.

Distribution profile of iridoid glycosides and phenolic compounds in two Barleria species and their correlation with antioxidant and antibacterial activity

INTRODUCTION

Barleria prionitis is known for its medicinal properties from ancient times. Bioactive iridoid glycosides and phenolic compounds have been isolated from leaves of this plant. However, other parts of a medicinal plants are also important, especially roots. Therefore, it is important to screen all organs for complete chemical characterization.

METHOD

All parts of B. prionitis, including leaf, root, stem and inflorescence in search of bioactive compounds, with a rapid and effective metabolomic method. X500R QTOF system with information dependent acquisition (IDA) method was used to collect high resolution accurate mass data (HRMS) on both the parent (MS signal) and their fragment ions (MS/MS signal). ESI spectra was obtained in positive ion mode from all parts of the plant. A comparative analysis of antioxidant and antibacterial activity was done and their correlation study with the identified compounds was demonstrated. Principal component analysis was performed.

RESULT

Iridoid glycosides and phenolic compounds were identified from all parts of the showing variability in presence and abundance. Many of the compounds are reported first time in B. prionitis. Antioxidant and antibacterial activity was revealed in all organs, root being the most effective one. Some of the iridoid glycoside and phenolic compounds found to be positively correlated with the tested biological activity. Principal component analysis of the chemical profiles showed variability in distribution of the compounds.

CONCLUSION

All parts of B. prionitis are rich source of bioactive iridoid glycosides and phenolic compounds.

Antifungal effects and active compounds of the leaf of Allium mongolicum Regel

Taking plant metabolites as material to develop new biological fungicides is still an important mission for pesticide development, and the preliminary study confirmed that Allium mongolicum showed a certain inhibitory effect on plant pathogens. In this study, the antifungal activity of extracts of A. mongolicum was studied and the compounds were isolated, purified, and identified by HPLC, NMR, and ESI-MS. The methanol extract of A. mongolicum exhibited certain inhibitory activity against almost all nine tested pathogens at concentration of 0.5 mg/ml. Sixteen compounds were isolated and purified from the extract, which were identified as nine flavonoids, six phenolic acids, and an amino acid. Among them, cinnamic acid derivatives 1, 2, and 3 and flavonoids 7, 8, 9, and 13 were separated in A. mongolicum for the first time.

nor 3′-Demethoxyisoguaiacin from Larrea tridentata Is a Potential Alternative against Multidrug-Resistant Bacteria Associated with Bovine Mastitis

Bovine mastitis is one of the most common diseases in dairy cows, and it causes significant economic losses in dairy industries worldwide. Gram-positive and Gram-negative bacteria can cause bovine mastitis, and many of them have developed antimicrobial resistance. There is an urgent need for novel therapeutic options to treat the disease. Larrea tridentata-derived compounds represent an important potential alternative treatment. The aim of the present study was to isolate and characterize antibacterial compounds from Larrea tridentata against multidrug-resistant bacteria associated with bovine mastitis. The L. tridentata hydroalcoholic extract (LTHE) exhibited antibacterial activity. The extract was subjected to a bipartition, giving an aqueous fraction (moderate antibacterial activity) and an organic fraction (higher antibacterial activity). Chromatographic separation of the organic fraction enabled us to obtain four active sub-fractions. Chemical analyses through HPLC techniques were conducted for the LTHE, fractions, and sub-fraction Ltc1-F3, from which we isolated two compounds, characterized by ¹H and ¹³C NMR analyses. Compound nor-3 demethoxyisoguaiacin exhibited the best antibacterial activity against the evaluated bacteria (MIC: 0.01–3.12 mg/mL; MBC: 0.02–3.12 mg/mL). The results indicated that nor-3 demethoxyisoguaiacin can be used as an alternative treatment for multidrug-resistant bacteria associated with mastitis.

Caffeic and 3-(3,4-dihydroxyphenyl)glyceric acid derivatives as antimicrobial agent: biological evaluation and molecular docking studies

Herein we report the evaluation of the antimicrobial activity of some previously synthesized 3-(3,4-dihydroxyphenyl)glyceric acid in benzylated and in free 3,4 hydroxy groups in catechol moiety along with some caffeic and 3-(3,4-dihydroxyphenyl)glyceric acid amides using the microdilution method. The evaluation revealed that compounds showed in general moderate to low activity with MIC in range of 0.36-4.5 mg/mL. Compounds were also studied against three resistant bacteria strains MRSA (Methicillin-resistant Staphylococcus aureus), E. coli and P. aeruginosa. Seven out of ten compounds were more potent than reference drugs ampicillin and streptomycin against MRSA, while against another two resistant strains seven compounds showed low activity and the rest were inactive. Antifungal activity of the tested compounds was much better than antibacterial, with MIC in the range of 0.019-3.0 mg/mL. Compounds #7 and 15 showed good activity against all fungi tested, being more potent than ketoconazole and in some case even better than bifonazole used as reference drugs. Docking studies revealed that the most active compound #7 binds to the haem group of the enzyme in the same way as ketoconazole.

Enzymatic Synthesis and Antimicrobial Activity of Oligomer Analogues of Medicinal Biopolymers from Comfrey and Other Species of the Boraginaceae Family

This study reports the first enzymatic synthesis leading to several oligomer analogues of poly[3-(3,4-dihydroxyphenyl)glyceric acid]. This biopolymer, extracted from plants of the Boraginaceae family has shown a wide spectrum of pharmacological properties, including antimicrobial activity. Enzymatic ring opening polymerization of 2-methoxycarbonyl-3-(3,4-dibenzyloxyphenyl)oxirane (MDBPO) using lipase from Candida rugosa leads to formation of poly[2-methoxycarbonyl-3-(3,4-dibenzyloxyphenyl)oxirane] (PMDBPO), with a degree of polymerization up to 5. Catalytic debenzylation of PMDBPO using H₂ on Pd/C yields poly[2-methoxycarbonyl-3-(3,4-dihydroxyphenyl)oxirane] (PMDHPO) without loss in molecular mass. Antibacterial assessment of natural polyethers from different species of Boraginaceae family Symhytum asperum, S. caucasicum,S. grandiflorum, Anchusa italica, Cynoglossum officinale, and synthetic polymers, poly[2-methoxycarbonyl-3-(3,4-dimethoxyphenyl)oxirane (PMDMPO) and PMDHPO, reveals that only the synthetic analogue produced in this study (PMDHPO) exhibits a promising antimicrobial activity against pathogenic strains S.aureus ATCC 25923 and E.coli ATCC 25922 the minimum inhibitory concentration (MIC) being 100 µg/mL.

Novel Thiazole-Based Thiazolidinones as Potent Anti-infective Agents: In silico PASS and Toxicity Prediction, Synthesis, Biological Evaluation and Molecular Modelling

AIMS AND OBJECTIVE

The infectious disease treatment remains a challenging concern owing to the increasing number of pathogenic microorganisms associated with resistance to multiple drugs. A promising approach for combating microbial infection is to combine two or more known bioactive heterocyclic pharmacophores in one molecular platform. Herein, the synthesis and biological evaluation of novel thiazole-thiazolidinone hybrids as potential antimicrobial agents were dissimilated.

MATERIALS AND METHODS

The preparation of the substituted 5-benzylidene-2-thiazolyimino-4- thiazolidinones was achieved in three steps from 2-amino-5-methylthiazoline. All the compounds have been screened in PASS antibacterial activity prediction and in a panel of bacteria and fungi strains. Minimum inhibitory concentration and minimum bacterial concentration were both determined by microdilution assays. Molecular modeling was conducted using Accelrys Discovery Studio 4.0 client. ToxPredict (OPEN TOX) and ProTox were used to estimate the toxicity of the title compounds.

RESULTS

PASS prediction revealed the potentiality antibacterial property of the designed thiazolethiazolidinone hybrids. All tested compounds were found to kill and to inhibit the growth of a vast variety of bacteria and fungi, and were more potent than the commercial drugs, streptomycin, ampicillin, bifomazole and ketoconazole. Further, in silico study was carried out for prospective molecular target identification and revealed favorable interaction with the target enzymes E. coli MurB and CYP51B of Aspergillus fumigatus. Toxicity prediction revealed that none of the active compounds was found toxic.

CONCLUSION

Substituted 5-benzylidene-2-thiazolyimino-4-thiazolidinones, endowing remarkable antibacterial and antifungal properties, were identified as a novel class of antimicrobial agents and may find a potential therapeutic use to eradicate infectious diseases.

Evaluation of the In Vitro Cytotoxic Activity of Caffeic Acid Derivatives and Liposomal Formulation against Pancreatic Cancer Cell Lines

Pancreatic cancer belongs to the most aggressive group of cancers, with very poor prognosis. Therefore, there is an important need to find more potent drugs that could deliver an improved therapeutic approach. In the current study we searched for selective and effective caffeic acid derivatives. For this purpose, we analyzed twelve compounds and evaluated their in vitro cytotoxic activity against two human pancreatic cancer cell lines, along with a control, normal fibroblast cell line, by the classic MTT assay. Six out of twelve tested caffeic acid derivatives showed a desirable effect. To improve the therapeutic efficacy of such active compounds, we developed a formulation where caffeic acid derivative (7) was encapsulated into liposomes composed of soybean phosphatidylcholine and DSPE-PEG₂₀₀₀. Subsequently, we analyzed the properties of this formulation in terms of basic physical parameters (such as size, zeta potential, stability at 4 °C and morphology), hemolytic and cytotoxic activity and cellular uptake. Overall, the liposomal formulation was found to be stable, non-hemolytic and had activity against pancreatic cancer cells (IC₅₀ 19.44 µM and 24.3 µM, towards AsPC1 and BxPC3 cells, respectively) with less toxicity against normal fibroblasts. This could represent a promising alternative to currently available treatment options.

Benzylidene-carbonyl compounds are active against itraconazole-susceptible and itraconazole-resistant Sporothrix brasiliensis

We evaluated the antifungal activity of benzylidene-carbonyl compounds (LINS03) based on the structure of gibbilimbol from Piper malacophyllum Linn. Five analogues (1-5) were synthetized following a classic aldol condensation between an aromatic aldehyde and a ketone, under basic conditions. These were tested against itraconazole-susceptible (n = 3) and itraconazole-resistant (n = 5) isolates of Sporothrix brasiliensis by M38-A2 guidelines of CLSI. All of them were fungistatic (MIC ranged of 0.11-0.22 mg/mL (1); 0.08-0.17 mg/mL (2); 0.05-0.1 mg/mL (3); 0.04-0.33 mg/mL (4); and 0.04-0.3 mg/mL (5)), highlighting compounds 2 and 3. As fungicidal, compounds 1 and 2 were highlighted (MFC ranged of 0.22-0.89 mg/mL and 0.08-1.35 mg/mL, respectively), compared with the remaining (0.77-> 3.08 mg/mL (3); 0.08-> 2.6 mg/mL (4); and 0.59-> 2.37 mg/mL (5)). The inhibitory activity was related to the benzylidene-carbonyl, whereas the phenol group and the low chain homolog seems to contribute to some extent to the fungicidal effect. Compound 2 highlighted due to the considerable fungistatic and fungicidal activities, including itraconazole-resistant Sporothrix brasiliensis. These findings support the potential usefulness of benzylidene-carbonyl compounds as promising prototypes for the development of antifungal against sporotrichosis by Sporothrix brasiliensis, including against itraconazole-resistant isolates.