Bis-Amiridines as Acetylcholinesterase and Butyrylcholinesterase Inhibitors: N-Functionalization Determines the Multitarget Anti-Alzheimer’s Activity Profile

Using two ways of functionalizing amiridine—acylation with chloroacetic acid chloride and reaction with thiophosgene—we have synthesized new homobivalent bis-amiridines joined by two different spacers—bis-N-acyl-alkylene (3) and bis-N-thiourea-alkylene (5) —as potential multifunctional agents for the treatment of Alzheimer’s disease (AD). All compounds exhibited high inhibitory activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) with selectivity for BChE. These new agents displayed negligible carboxylesterase inhibition, suggesting a probable lack of untoward drug–drug interactions arising from hydrolytic biotransformation. Compounds 3 with bis-N-acyl-alkylene spacers were more potent inhibitors of both cholinesterases compared to compounds 5 and the parent amiridine. The lead compounds 3a–c exhibited an IC₅₀(AChE) = 2.9–1.4 µM, IC₅₀(BChE) = 0.13–0.067 µM, and 14–18% propidium displacement at 20 μM. Kinetic studies of compounds 3a and 5d indicated mixed-type reversible inhibition. Molecular docking revealed favorable poses in both catalytic and peripheral AChE sites. Propidium displacement from the peripheral site by the hybrids suggests their potential to hinder AChE-assisted Aβ₄₂ aggregation. Conjugates 3 had no effect on Aβ₄₂ self-aggregation, whereas compounds 5c–e (m = 4, 5, 6) showed mild (13–17%) inhibition. The greatest difference between conjugates 3 and 5 was their antioxidant activity. Bis-amiridines 3 with N-acylalkylene spacers were nearly inactive in ABTS and FRAP tests, whereas compounds 5 with thiourea in the spacers demonstrated high antioxidant activity, especially in the ABTS test (TEAC = 1.2–2.1), in agreement with their significantly lower HOMO-LUMO gap values. Calculated ADMET parameters for all conjugates predicted favorable blood–brain barrier permeability and intestinal absorption, as well as a low propensity for cardiac toxicity. Thus, it was possible to obtain amiridine derivatives whose potencies against AChE and BChE equaled (5) or exceeded (3) that of the parent compound, amiridine. Overall, based on their expanded and balanced pharmacological profiles, conjugates 5c–e appear promising for future optimization and development as multitarget anti-AD agents.     

Antifungal Activity of Chemical Constituents from Piper pesaresanum C. DC. and Derivatives against Phytopathogen Fungi of Cocoa

In this study, the antifungal potential of chemical constituents from Piper pesaresanum and some synthesized derivatives was determined against three phytopathogenic fungi associated with the cocoa crop. The methodology included the phytochemical study on the aerial part of P. pesaresanum, the synthesis of some derivatives and the evaluation of the antifungal activity against the fungi Moniliophthora roreri, Fusarium solani and Phytophthora sp. The chemical study allowed the isolation of three benzoic acid derivatives (1–3), one dihydrochalcone (4) and a mixture of sterols (5–7). Seven derivatives (8–14) were synthesized from the main constituents, of which compounds 9, 10, 12 and 14 are reported for the first time. Benzoic acid derivatives showed strong antifungal activity against M. roreri, of which 11 (3.0 ± 0.8 µM) was the most active compound with an IC₅₀ lower compared with positive control Mancozeb^® (4.9 ± 0.4 µM). Dihydrochalcones and acid derivatives were active against F. solani and Phytophthora sp., of which 3 (32.5 ± 3.3 µM) and 4 (26.7 ± 5.3 µM) were the most active compounds, respectively. The preliminary structure–activity relationship allowed us to establish that prenylated chains and the carboxyl group are important in the antifungal activity of benzoic acid derivatives. Likewise, a positive influence of the carbonyl group on the antifungal activity for dihydrochalcones was deduced.     

Neuraminidase Inhibitor of Garcinia atroviridis L. Fruits and Leaves Using Partial Purification and Molecular Characterization

Neuraminidase (NA) is an enzyme that prevents virions from aggregating within the host cell and promotes cell-to-cell spread by cleaving glycosidic linkages to sialic acid. The best-known neuraminidase is the viral neuraminidase, which present in the influenza virus. Thus, the development of anti-influenza drugs that inhibit NA has emerged as an important and intriguing approach in the treatment of influenza. Garcinia atroviridis L. (GA) dried fruits (GAF) are used commercially as seasoning and in beverages. The main objective of this study was to identify a new potential neuraminidase inhibitor from GA. A bioassay-guided fractionation method was applied to obtain the bioactive compounds leading to the identification of garcinia acid and naringenin. In an enzyme inhibition study, garcinia acid demonstrated the highest activity when compared to naringenin. Garcinia acid had the highest activity, with an IC₅₀ of 17.34–17.53 µg/mL or 91.22–92.21 µM against Clostridium perfringens-NA, and 56.71–57.85 µg/mL or 298.32–304.31 µM against H1N1-NA. Based on molecular docking results, garcinia acid interacted with the triad arginine residues (Arg118, Arg292, and Arg371) of the viral neuraminidase, implying that this compound has the potential to act as a NA enzyme inhibitor.     

The Impact of Halogen Substituents on the Synthesis and Structure of Co-Crystals of Pyridine Amides

Strategies for co-crystal synthesis tend to employ either hydrogen- or halogen-bonds between different molecules. However, when both interactions are present, the structural influence that they may exert on the resulting assembly is difficult to predict a priori. To shed some light on this supramolecular challenge, we attempted to co-crystallize ten aliphatic dicarboxylic acids (co-formers) with three groups of target molecules; N-(pyridin-2-yl)picolinamides (2Pyr-X), N-(pyridin-2-yl)nicotinamides (3Pyr-X), N-(pyridin-2-yl)isonicotinamides (4Pyr-X); X=Cl/ Br/ I. The structural outcomes were compared with co-crystals prepared from the non-halogenated targets. As expected, none of the reactions with 2Pyr-X produced co-crystals due to the presence of a very stable intramolecular N-H···N hydrogen bond. In the 3Pyr series, all six structures obtained showed the same synthons, –COOH···N(py) and –COOH···N(py)-NH, that were found in the non-halogenated parent 3Pyr and were additionally accompanied by structure directing X···O(OH) interactions (X=Br/I). The co-crystals of the unhalogenated parent 4Pyr co-crystals assembled via intermolecular –COOH···N(py) and –COOH···N(py)-NH synthons. Three of the analogues 4Pyr-X co-crystals displayed only COOH···N(py) and –COOH···N(py)-NH interactions. The three co-crystals of 4Pyr-X with fumaric acid (for which no analogues structures with 4Pyr are known) formed –COOH···N(py)-NH and –NH···O=C hydrogen bonds and showed no structure-directing halogen bonds. In three co-crystals of 4Pyr-I in which –COOH···N(py)-NH hydrogen bond was present, a halogen-bond based –I···N(py) synthon replaced the –COOH···N(py) motif observed in the parent structures. The structural influence of the halogen atoms increased in the order of Cl < Br < I, as the size of σ-holes increased. Finally, it is noteworthy that isostructurality among structures of the homomeric targets was not translated to structural similarities between their respective co-crystals.     

Exploring Amantadine Derivatives as Urease Inhibitors: Molecular Docking and Structure–Activity Relationship (SAR) Studies

This article describes the design and synthesis of a series of novel amantadine-thiourea conjugates (3a–j) as Jack bean urease inhibitors. The synthesized hybrids were assayed for their in vitro urease inhibition. Accordingly, N-(adamantan-1-ylcarbamothioyl)octanamide (3j) possessing a 7-carbon alkyl chain showed excellent activity with IC₅₀ value 0.0085 ± 0.0011 µM indicating that the long alkyl chain plays a vital role in enzyme inhibition. Whilst N-(adamantan-1-ylcarbamothioyl)-2-chlorobenzamide (3g) possessing a 2-chlorophenyl substitution was the next most efficient compound belonging to the aryl series with IC₅₀ value of 0.0087 ± 0.001 µM. The kinetic mechanism analyzed by Lineweaver–Burk plots revealed the non-competitive mode of inhibition for compound 3j. Moreover, in silico molecular docking against target protein (PDBID 4H9M) indicated that most of the synthesized compounds exhibit good binding affinity with protein. The compound 3j forms two hydrogen bonds with amino acid residue VAL391 having a binding distance of 1.858 Å and 2.240 Å. The interaction of 3j with amino acid residue located outside the catalytic site showed its non-competitive mode of inhibition. Based upon these results, it is anticipated that compound 3j may serve as a lead structure for the design of more potent urease inhibitors.     

Screening of Potential Thrombin and Factor Xa Inhibitors from the Danshen–Chuanxiong Herbal Pair through a Spectrum–Effect Relationship Analysis

In this study; a spectrum–effect relationship analysis combined with a high-performance liquid chromatography–mass spectrometry (LC–MS) analysis was established to screen and identify active components that can inhibit thrombin and factor Xa (THR and FXa) in Salviae Miltiorrhizae Radix et Rhizoma–Chuanxiong Rhizoma (Danshen–Chuanxiong) herbal pair. Ten potential active compounds were predicted through a canonical correlation analysis (CCA), and eight of them were tentatively identified through an LC–MS analysis. Furthermore; the enzyme inhibitory activity of six available compounds; chlorogenic acid; Z-ligustilide; caffeic acid; ferulic acid; tanshinone I and tanshinone IIA; were tested to verify the feasibility of the method. Among them; chlorogenic acid was validated to possess a good THR inhibitory activity with IC₅₀ of 185.08 µM. Tanshinone I and tanshinone IIA are potential FXa inhibitors with IC₅₀ of 112.59 µM and 138.19 µM; respectively. Meanwhile; molecular docking results show that tanshinone I and tanshinone IIA; which both have binding energies of less than −7.0 kcal·mol⁻¹; can interact with FXa by forming H-bonds with residues of SER214; GLY219 and GLN192. In short; the THR and FXa inhibitors in the Danshen–Chuanxiong herbal pair have been successfully characterized through a spectrum–effect relationship analysis and an LC–MS analysis.     

Triterpenes and Phenolic Compounds from the Fungus Fuscoporia torulosa: Isolation,Structure Determination and Biological Activity

Investigation of the methanol extract of the poroid fungus Fuscoporia torulosa resulted in the isolation of a novel triterpene, fuscoporic acid (1), together with inoscavin A and its previously undescribed Z isomer (2 and 3), 3,4-dihydroxy-benzaldehide (4), osmundacetone (5), senexdiolic acid (6), natalic acid (7), and ergosta-7,22-diene-3-one (8). The structures of fungal compounds were determined on the basis of NMR and MS spectroscopic analyses, as well as molecular modeling studies. Compounds 1, 6–8 were examined for their antibacterial properties on resistant clinical isolates, and cytotoxic activity on human colon adenocarcinoma cell lines. Compound 8 was effective against Colo 205 (IC₅₀ 11.65 ± 1.67 µM), Colo 320 (IC₅₀ 8.43 ± 1.1 µM) and MRC-5 (IC₅₀ 7.92 ± 1.42 µM) cell lines. Potentially synergistic relationship was investigated between 8 and doxorubicin, which revealed a synergism between the examined compounds with a combination index (CI) at the 50% growth inhibition dose (ED₅₀) of 0.521 ± 0.15. Several compounds (1 and 6–8) were tested for P-glycoprotein modulatory effect in Colo 320 resistant cancer cells, but none of the compounds proved to be effective in this assay. Fungal metabolites 2–5 were evaluated for their antioxidant activity using the oxygen radical absorbance capacity (ORAC) and DPPH assays. Compounds 4 and 5 were found to have a considerable antioxidant effect with EC₅₀ 0.25 ± 0.01 (DPPH) and 12.20 ± 0.92 mmol TE/g (ORAC). The current article provides valuable information on both the chemical and pharmacological profiles of Fuscoporia torulosa, paving the way for future studies with this species.     

Molecular Umbrella as a Nanocarrier for Antifungals

A molecular umbrella composed of two O-sulfated cholic acid residues was applied for the construction of conjugates with cispentacin, containing a “trimethyl lock” (TML) or o-dithiobenzylcarbamoyl moiety as a cleavable linker. Three out of five conjugates demonstrated antifungal in vitro activity against C. albicans and C. glabrata but not against C. krusei, with MIC₉₀ values in the 0.22–0.99 mM range and were not hemolytic. Antifungal activity of the most active conjugate 24c, containing the TML–pimelate linker, was comparable to that of intact cispentacin. A structural analogue of 24c, containing the Nap-NH₂ fluorescent probe, was accumulated in Candida cells, and TML-containing conjugates were cleaved in cell-free extract of C. albicans cells. These results suggest that a molecular umbrella can be successfully applied as a nanocarrier for the construction of cleavable antifungal conjugates.     

Euphormins A and B,New Pyranocoumarin Derivatives from Euphorbia formosana Hayata,and Their Anti-Inflammatory Activity

Euphormin-A (1) and euphormin-B (2), two new pyranocoumarin derivatives, and forty known compounds (3–42) were isolated from Euphorbia formosana Hayata (Euphorbiaceae). The chemical structures of all compounds were established based on spectroscopic analyses. Several isolates were evaluated for their anti-inflammatory activity. Compounds 1, 2, 10, 18, 25, and 33 significantly inhibited against superoxide anion generation and elastase release by human neutrophils in response to formyl-L-methionyl-L-leucyl-L-phenylalanine/cytochalasin B (fMLP/CB). Furthermore, compounds 25 and 33 displayed the most potent effects with IC₅₀ values of 0.68 ± 0.18 and 1.39 ± 0.12 µM, respectively, against superoxide anion generation when compared with the positive control (2.01 ± 0.06 µM).     

Indole- and Pyrazole-Glycyrrhetinic Acid Derivatives as PTP1B Inhibitors: Synthesis,In Vitro and In Silico Studies

Regulating insulin and leptin levels using a protein tyrosine phosphatase 1B (PTP1B) inhibitor is an attractive strategy to treat diabetes and obesity. Glycyrrhetinic acid (GA), a triterpenoid, may weakly inhibit this enzyme. Nonetheless, semisynthetic derivatives of GA have not been developed as PTP1B inhibitors to date. Herein we describe the synthesis and evaluation of two series of indole- and N-phenylpyrazole-GA derivatives (4a–f and 5a–f). We measured their inhibitory activity and enzyme kinetics against PTP1B using p-nitrophenylphosphate (pNPP) assay. GA derivatives bearing substituted indoles or N-phenylpyrazoles fused to their A-ring showed a 50% inhibitory concentration for PTP1B in a range from 2.5 to 10.1 µM. The trifluoromethyl derivative of indole-GA (4f) exhibited non-competitive inhibition of PTP1B as well as higher potency (IC₅₀ = 2.5 µM) than that of positive controls ursolic acid (IC₅₀ = 5.6 µM), claramine (IC₅₀ = 13.7 µM) and suramin (IC₅₀ = 4.1 µM). Finally, docking and molecular dynamics simulations provided the theoretical basis for the favorable activity of the designed compounds.     

Facile One-Pot Multicomponent Synthesis of Pyrazolo-Thiazole Substituted Pyridines with Potential Anti-Proliferative Activity: Synthesis,In Vitro and In Silico Studies

Pyrazolothiazole-substituted pyridine conjugates are an important class of heterocyclic compounds with an extensive variety of potential applications in the medicinal and pharmacological arenas. Therefore, herein, we describe an efficient and facile approach for the synthesis of novel pyrazolo-thiazolo-pyridine conjugate 4, via multicomponent condensation. The latter compound was utilized as a base for the synthesis of two series of 15 novel pyrazolothiazole-based pyridine conjugates (5–16). The newly synthesized compounds were fully characterized using several spectroscopic methods (IR, NMR and MS) and elemental analyses. The anti-proliferative impact of the new synthesized compounds 5–13 and 16 was in vitro appraised towards three human cancer cell lines: human cervix (HeLa), human lung (NCI-H460) and human prostate (PC-3). Our outcomes regarding the anti-proliferative activities disclosed that all the tested compounds exhibited cytotoxic potential towards all the tested cell lines with IC₅₀ = 17.50–61.05 µM, especially the naphthyridine derivative 7, which exhibited the most cytotoxic potential towards the tested cell lines (IC₅₀ = 14.62–17.50 µM) compared with the etoposide (IC50 = 13.34–17.15 µM). Moreover, an in silico docking simulation study was performed on the newly prepared compounds within topoisomerase II (3QX3), to suggest the binding mode of these compounds as anticancer candidates. The in silico docking results indicate that compound 7 was a promising lead anticancer compound which possesses high binding affinity toward topoisomerase II (3QX3) protein.     

Design,Synthesis, and Antimicrobial Activity of Certain New Indole-1,2,4 Triazole Conjugates

The increasing prevalence of microbial infections and the emergence of resistance to the currently available antimicrobial drugs urged the development of potent new chemical entities with eminent pharmacokinetic and/or pharmacodynamic profiles. Thus, a series of new indole-triazole conjugates 6a-u was designed and synthesized to be assessed as new antimicrobial candidates using the diameter of the inhibition zone and minimum inhibitory concentration assays against certain microbial strains. Their in vitro antibacterial evaluation revealed good to moderate activity against most of the tested Gram-negative strains with diameter of the inhibition zone (DIZ) values in the range of 11–15 mm and minimum inhibition concentration (MIC) values around 250 µg/mL. Meanwhile, their in vitro antifungal evaluation demonstrated a potent activity against Candida tropicalis with MIC value as low as 2 µg/mL for most of the tested compounds. Moreover, compound 6f is the most potent congener with an MIC value of 2 µg/mL against Candida albicans.     

Fatty Acid Analysis,Chemical Constituents,Biological Activity and Pesticide Residues Screening in Jordanian Propolis

Propolis is a resinous natural product collected by honeybees (Apis mellifera and others) from tree exudates that has been widely used in folk medicine. The present study was carried out to investigate the fatty acid composition, chemical constituents, antioxidant, and xanthine oxidase (XO) inhibitory activity of Jordanian propolis, collected from Al-Ghour, Jordan. The hexane extract of Jordanian propolis contained different fatty acids, which are reported for the first time by using GC-FID. The HPLC was carried out to identify important chemical constituents such as fatty acids, polyphenols and α-tocopherol. The antioxidant and xanthine oxidase inhibitory activities were also monitored. The major fatty acid identified were palmitic acid (44.6%), oleic acid (18:1∆⁹cis, 24.6%), arachidic acid (7.4%), stearic acid (5.4%), linoleic acid (18:2∆^9–12cis, 3.1%), caprylic acid (2.9%), lignoceric acid (2.6%), cis-11,14-eicosaldienoic acid (20:2∆^11–14cis, 2.4%), palmitoleic acid (1.5%), cis-11-eicosenoic acid (1.2%), α–linolenic acid (18:3∆^9–12–15cis, 1.1%), cis-13,16-docosadienoic acid (22:2∆^13–16cis, 1.0%), along with other fatty acids. The major chemical constituents identified using gradient HPLC-PDA analysis were pinocembrin (2.82%), chrysin (1.83%), luteolin-7-O-glucoside (1.23%), caffeic acid (1.12%), caffeic acid phenethyl ester (CAPE, 0.79%), apigenin (0.54%), galangin (0.46%), and luteolin (0.30%); while the minor constituents were hesperidin, quercetin, rutin, and vanillic acid. The percentage of α-tocopherol was 2.01 µg/g of the lipid fraction of propolis. Antioxidant properties of the extracts were determined via DPPH radical scavenging. The DPPH radical scavenging activities (IC₅₀) of different extracts ranged from 6.13 to 60.5 µg/mL compared to ascorbic acid (1.21 µg/mL). The xanthine oxidase inhibition (IC₅₀) ranged from 75.11 to 250.74 µg/mL compared to allopurinol (0.38 µg/mL). The results indicate that the various flavonoids, phenolic compounds, α-tocopherol, and other constituents which are present in propolis are responsible for the antioxidant and xanthine oxidation inhibition activity. To evaluate the safety studies of propolis, the pesticide residues were also monitored by LC-MS-MS 4500 Q-Trap. Trace amounts of pesticide residue (ng/mL) were detected in the samples, which are far below the permissible limit as per international guidelines.     

Synthesis of Novel Thiazole Derivatives Bearing β-Amino Acid and Aromatic Moieties as Promising Scaffolds for the Development of New Antibacterial and Antifungal Candidates Targeting Multidrug-Resistant Pathogens

Rapidly growing antimicrobial resistance among clinically important bacterial and fungal pathogens accounts for high morbidity and mortality worldwide. Therefore, it is critical to look for new small molecules targeting multidrug-resistant pathogens. Herein, in this paper we report a synthesis, ADME properties, and in vitro antimicrobial activity characterization of novel thiazole derivatives bearing β-amino acid, azole, and aromatic moieties. The in silico ADME characterization revealed that compounds 1–9 meet at least 2 Lipinski drug-like properties while cytotoxicity studies demonstrated low cytotoxicity to Vero cells. Further in vitro antimicrobial activity characterization showed the selective and potent bactericidal activity of 2a–c against Gram-positive pathogens (MIC 1–64 µg/mL) with profound activity against S. aureus (MIC 1–2 µg/mL) harboring genetically defined resistance mechanisms. Furthermore, the compounds 2a–c exhibited antifungal activity against azole resistant A. fumigatus, while only 2b and 5a showed antifungal activity against multidrug resistant yeasts including Candida auris. Collectively, these results demonstrate that thiazole derivatives 2a–c and 5a could be further explored as a promising scaffold for future development of antifungal and antibacterial agents targeting highly resistant pathogenic microorganisms.     

Biocidal Activity of a Nanoemulsion Containing Essential Oil from Protium heptaphyllum Resin against Aedes aegypti (Diptera: Culicidae)

This work aimed to prepare a nanoemulsion containing the essential oil of the Protium heptaphyllum resin and evaluate its biocidal activities against the different stages of development of the Aedes aegypti mosquito. Ovicide, pupicide, adulticide and repellency assays were performed. The main constituents were p-cymene (27.70%) and α-pinene (22.31%). The developed nanoemulsion showed kinetic stability and monomodal distribution at a hydrophilic–lipophilic balance of 14 with a droplet size of 115.56 ± 1.68 nn and a zeta potential of −29.63 ± 3.46 mV. The nanoemulsion showed insecticidal action with LC₅₀ 0.404 µg·mL⁻¹ for the ovicidal effect. In the pupicidal test, at the concentration of 160 µg·mL⁻¹, 100% mortality was reached after 24 h. For adulticidal activity, a diagnostic concentration of 200 µg·mL⁻¹ (120 min) was determined. In the repellency test, a concentration of 200 µg·mL⁻¹ during the 180 min of the test showed a protection index of 77.67%. In conclusion, the nanobiotechnological product derived from the essential oil of P. heptaphyllum resin can be considered as a promising colloid that can be used to control infectious disease vectors through a wide range of possible modes of applications, probably as this bioactive delivery system may allow the optimal effect of the P. heptaphyllum terpenes in aqueous media and may also induce satisfactory delivery to air interfaces.     

Activity of Compounds from Temperate Propolis against Trypanosoma brucei and Leishmania mexicana

Ethanolic extracts of samples of temperate zone propolis, four from the UK and one from Poland, were tested against three Trypanosoma brucei strains and displayed EC₅₀ values < 20 µg/mL. The extracts were fractionated, from which 12 compounds and one two-component mixture were isolated, and characterized by NMR and high-resolution mass spectrometry, as 3-acetoxypinobanksin, tectochrysin, kaempferol, pinocembrin, 4′-methoxykaempferol, galangin, chrysin, apigenin, pinostrobin, cinnamic acid, coumaric acid, cinnamyl ester/coumaric acid benzyl ester (mixture), 4′,7-dimethoxykaempferol, and naringenin 4′,7-dimethyl ether. The isolated compounds were tested against drug-sensitive and drug-resistant strains of T. brucei and Leishmania mexicana, with the highest activities ≤ 15 µM. The most active compounds against T. brucei were naringenin 4′,7 dimethyl ether and 4′methoxy kaempferol with activity of 15–20 µM against the three T. brucei strains. The most active compounds against L. mexicana were 4′,7-dimethoxykaempferol and the coumaric acid ester mixture, with EC₅₀ values of 12.9 ± 3.7 µM and 13.1 ± 1.0 µM. No loss of activity was found with the diamidine- and arsenical-resistant or phenanthridine-resistant T. brucei strains, or the miltefosine-resistant L. mexicana strain; no clear structure activity relationship was observed for the isolated compounds. Temperate propolis yields multiple compounds with anti-kinetoplastid activity.     

Optimising the Polyphenolic Content and Antioxidant Activity of Green Rooibos (Aspalathus linearis) Using Beta-Cyclodextrin Assisted Extraction

Antioxidant activity associated with green rooibos infusions is attributed to the activity of polyphenols, particularly aspalathin and nothofagin. This study aimed to optimise β-cyclodextrin (β-CD)-assisted extraction of crude green rooibos (CGRE) via total polyphenolic content (TPC) and antioxidant activity assays. Response surface methodology (RSM) permitted optimisation of β-CD concentration (0–15 mM), temperature (40–90 °C) and time (15–60 min). Optimal extraction conditions were: 15 mM β-CD: 40 °C: 60 min with a desirability of 0.985 yielding TPC of 398.25 mg GAE·g⁻¹, metal chelation (MTC) of 93%, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging of 1689.7 µmol TE·g⁻¹, ferric reducing antioxidant power (FRAP) of 2097.53 µmol AAE·g⁻¹ and oxygen radical absorbance capacity (ORAC) of 11,162.82 TE·g⁻¹. Aspalathin, hyperoside and orientin were the major flavonoids, with quercetin, luteolin and chrysoeriol detected in trace quantities. Differences (p < 0.05) between aqueous and β-CD assisted CGRE was only observed for aspalathin reporting the highest content of 172.25 mg·g⁻¹ of dry matter for extracts produced at optimal extraction conditions. Positive, strong correlations between TPC and antioxidant assays were observed and exhibited regression coefficient (R²) between 0.929–0.978 at p < 0.001. These results demonstrated the capacity of β-CD in increasing polyphenol content of green rooibos.     

Chemical Constituents of Cassia abbreviata and Their Anti-HIV-1 Activity

Three new (1–3) and 25 known compounds were isolated from the crude extract of Cassia abbreviata. The chemical structures of new compounds were established by extensive spectroscopic analyses including 1D and 2D NMR and HRESIMS. Cassiabrevone (1) is the first heterodimer of guibourtinidol and planchol A. Compound 2 was a new chalcane, while 3 was a new naphthalene. Cassiabrevone (1), guibourtinidol-(4α→8)-epiafzelechin (4), taxifolin (8), oleanolic acid (17), piceatannol (22), and palmitic acid (28), exhibited potent anti-HIV-1 activity with IC₅₀ values of 11.89 µM, 15.39 µM, 49.04 µM, 7.95 µM, 3.58 µM, and 15.97 µM, respectively.     

Properties of Banana (Cavendish spp.) Starch Film Incorporated with Banana Peel Extract and Its Application

The objective of this study was to develop an active banana starch film (BSF) incorporated with banana peel extract. We compared the film’s properties with commercial wrap film (polyvinyl chloride; PVC). Moreover, a comparison of the quality of minced pork wrapped during refrigerated storage (7 days at ±4 °C) was also performed. The BSF with different concentrations of banana peel extract (0, 1, 3, and 5 (%, w/v)) showed low mechanical properties (tensile strength (TS): 4.43–31.20 MPa and elongation at break (EAB): 9.66–15.63%) and water vapor permeability (3.74–11.0 × 10⁻¹⁰ g mm/sm² Pa). The BSF showed low film solubility (26–41%), but excellent barrier properties to UV light. The BSF had a thickness range of 0.030–0.047 mm, and color attributes were: L* = 49.6–51.1, a* = 0.21–0.43, b* = 1.26–1.49. The BSF incorporated with banana peel extracts 5 (%, w/v) showed the highest radical scavenging activity (97.9%) and inhibitory activity of E. coli O157: H7. The BSF showed some properties comparable to the commercial PVC wrap film. Changes in qualities of minced pork were determined for 7 days during storage at ±4 °C. It was found that thiobarbituric acid reactive substances (TBARS) of the sample wrapped with the BSF decreased compared to that wrapped with the PVC. The successful inhibition of lipid oxidation in the minced pork was possible with the BSF. The BSF incorporated with banana peel extract could maintain the quality of minced pork in terms of oxidation retardation.     

Supercritical carbon dioxide extraction of Usnea longissima (L.) Ach.: Optimization by Box-Behnken design (BBD)

Usnic acid (UA) was extracted from Usnea longissima (L.) Ach. in supercritical carbon dioxide (SC-CO₂) medium. The selected process parameters were extraction temperature (35–45 °C), amount of co-solvent (0%–5%) and extraction time (5–9 h). These parameters were applied to Box-Behnken design (BBD) belonging to response surface methodology (RSM) to determine optimum process parameters for the highest amount of UA in the extract. g UA/100g lichen, extraction yield % and UA content values were calculated in the range of 0.045–0.317, 2.77–5.4 and 71%–82% in different experimental conditions, respectively. The optimum conditions were predicted as 42 °C, 4.3% (ethanol) and 7.48 h. It was determined that the predicted and experimental values of g UA/100g lichen were compatible, and the suggested model was valid.