Three novel alkaloids from Portulaca oleracea L. and their anti-inflammatory bioactivities

Two new alkaloids from Portulaca oleracea L. and their anti-inflammatory and anticholinesterase activities

Two new alkaloids identified as 2-(((S,Z)-1-(1H-azirin-1-yl)-5-methylhex-1-en-3-yl)oxy)-6-(hydroxymethyl)tetrahydro-2H-pyran-3,4,5-triol and (S,Z)-1-(1H-azirin-1-yl)-5-methylhex-1-en-3-ol, named olerazirin A (1), olerazirin B (2), together with five known alkaloids, identified as cyclo (L-Val-L-Ala) (3), cyclo-(glycyl-L-leucine) (4), cyclo-(Gly-Phe) (5), cyclo (Ser-Phe) (6), (3S,6S)-3-[(1R)-1-hydroxyethyl]-6-(phenyl-methyl)-2,5-piperazinedione (7) were obtained from Portulaca oleracea L. using a range of chromatographic techniques, 1D and 2D NMR, and high-resolution electrospray ionisation time-of-flight mass spectroscopic methods, in which the compounds 3-7 were isolated from P. oleracea for the first time. In addition, the results showed that the compounds 1 and 2 have anti-inflammatory activities and compounds 1-3 and 5-7 exhibit the anticholinesterase activities.

Aptamers for the Delivery of Plant-Based Compounds: A Review

Natural compounds have a high potential for the treatment of various conditions, including infections, inflammatory diseases, and cancer. However, they usually present poor pharmacokinetics, low specificity, and even toxicity, which limits their use. Therefore, targeted drug delivery systems, typically composed of a carrier and a targeting ligand, can enhance natural product selectivity and effectiveness. Notably, aptamers-short RNA or single-stranded DNA molecules-have gained attention as promising ligands in targeted drug delivery since they are simple to synthesize and modify, and they present high tissue permeability, stability, and a wide array of available targets. The combination of natural products, namely plant-based compounds, with a drug delivery system utilizing aptamers as targeting agents represents an emerging strategy that has the potential to broaden its applications. This review discusses the potential of aptamers as targeting agents in the delivery of natural compounds, as well as new trends and developments in their utilization in the field of medicine.

Two novel ketone alkaloids from Portulaca oleraceaL. and their anti-inflammatory activities

Eleven compounds were obtained from Portulaca oleracea L., including two novel ketone alkaloids, (1, 2), 4-hydroxy-3-methoxybenzamide (3) (isolated for the first time), β-adenosine (4), oleracrylimide A and B (5, 6), oleracein H, C, D, Q and A (7-11). The two novel ketone alkaloids were identified as 5-acetyl-5-methylcyclopent-2-ene-1-carboxamide (1), named oleraciamide H, and (2 R,3S,4R,5R)-5-((R)-1,2-dihydroxyethyl)-3,4-dihydroxytetrahydrofuran-2-yl glycinate (2), named oleracone Q by spectroscopic methods, including 1D, 2D NMR and compound fingerprints. Additionally, their anti-inflammatory activities were tested via RAW 264.7 cells induced by LPS and found that they could significantly inhibit the release of IL-1β and TNF-α.

Two novel alkaloids from Portulaca oleracea L. and their anti-inflammatory bioactivities

Two novel alkaloids were identified as (E)-N-(4-3,4-dihydroxy-6-(hydroxymethyl)-5-3,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl)oxy)tetrahydro-2H-pyran-2-yl)oxy)-2,5-dihydroxyphenyl)-3-(4-hydroxyphenyl)acrylamide (1), named Oleracrylimide D, (E)-N-(4-3,4-dihydroxy-6-(hydroxymethyl)-5-3,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl)oxy)tetrahydro-2H-pyran-2-yl)oxy)-2,5-dihydroxyphenyl)-3-(4-hydroxy-3-methoxyphenyl)acrylamide (2), named Oleracrylimide E, isolated from Portulaca oleracea L. The structures were identified by spectroscopic methods, including 1D NMR, 2D NMR, and UHPLC-ESI-QTOF/MS methods, also, the anti-inflammatory bioactivities of the compounds were studied by ELISA method.

A new alkaloid and two organic acids from Portulaca oleracea L. and their bioactivities

A new alkaloid, identified as 1-benzyl-2-nitroso-1,2,3,4-tetrahydroisoquinoline-6,7-diol, named oleraisoquinoline (1), and five organic acids and two esters, identified as 5-(hydroxymethyl)furan-2-carboxylic acid (2), 1H-pyrrole-2,5-dicarboxylic acid (3), (7E,10E)-octadeca-7,10-dienoic acid (4), (10E,13E)-octadeca-10,13-dienoic acid (5), (7E,10E)-hexadeca-7,10-dienoic acid (6), methyl tridecanoate (7) and methyl (9E,12E)-octadeca-9,12-dienoate (8), were isolated from Portulaca oleracea L., among which compounds 2 and 4‒7 were isolated for the first time. Moreover, the anti-inflammatory activities of compounds 1‒3 were studied, especially, compound 1 presented good inhibitory effects on the production of inflammatory factors IL-1β and TNF-α.

A novel skeleton alkaloid from Portulaca oleracea L. and its bioactivities

A novel skeleton alkaloid was obtained from Portulaca oleracea L., which was identified as 10,11-dihydroxybenzo[5',6'] pentaleno[1',2':3,4]pyrrolo[2,1-b]oxazol-7(11bH)-one, named oleracone M, and its structure was determined using UHPLC-ESI-QTOF/MS, 1D NMR and 2D NMR spectroscopy, and circular dichroism. Then the bioactivities of the compound were investigated including the anti-inflammatory, anti-acetylcholinesterase and antioxidant activities. The results showed that the novel skeleton alkaloid exhibited the potent effect on inhibiting the secretion of IL-1β at 10 μM, anticholinesterase activity with IC50 value of 49.58 μM, and antioxidant activity with IC50 value of 66.43 μM.

The Most Potent Natural Pharmaceuticals, Cosmetics, and Food Ingredients Isolated from Plants with Deep Eutectic Solvents

There is growing interest in reducing the number of synthetic products or additives and replacing them with natural ones. The pharmaceutical, cosmetic, and food industries are especially focused on natural and bioactive chemicals isolated from plants or microorganisms. The main challenge here is to develop efficient and ecological methods for their isolation. According to the strategies and rules of sustainable development and green chemistry, green solvents and environmentally friendly technologies must be used. The application of deep eutectic solvents as efficient and biodegradable solvents seems to be a promising alternative to traditional methods. They are classified as being green and ecological but, most importantly, very efficient extraction media compared to organic solvents. The aim of this review is to present the recent findings on green extraction, as well as the biological activities and the possible applications of natural plant ingredients, namely, phenolics, flavonoids, terpenes, saponins, and some others. This paper thoroughly reviews modern, ecological, and efficient extraction methods with the use of deep eutectic solvents (DESs). The newest findings, as well as the factors influencing the efficiency of extraction, such as water content, and hydrogen bond donor and acceptor types, as well as the extraction systems, are also discussed. New solutions to the major problem of separating DESs from the extract and for solvent recycling are also presented.

Two new natural products from Portulaca oleracea L. and their bioactivities

Two new natural products, belonging to alkaloids, identified as ((2R,3S,4R,5R)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-3,4-dihydroxytetrahydrofuran-2-yl)methyl acetate (1) and (5-hydroxypyridin-2-yl)methyl acetate (2), were isolated from Portulaca oleracea L. The structures were identified by spectroscopic methods, including 1D, 2D NMR, and UHPLC-ESI-QTOF/MS methods. Meanwhile, the anti-inflammatory and anticholinesterase bioactivities were found in these two compounds.

Michael Addition of 3-Oxo-3-phenylpropanenitrile to Linear Conjugated Enynones: Approach to Polyfunctional δ-Diketones as Precursors for Heterocycle Synthesis

Reaction of linear conjugated enynones, 1,5-diarylpent-2-en-4-yn-1-ones [Ar¹C≡CCH=CHC(=O)Ar²], with 3-oxo-3-phenylpropanenitrile (NCCH₂COPh) in the presence of sodium methoxide MeONa as a base in MeOH at room temperature for 4–26 h affords polyfunctional δ-diketones as a product of regioselective Michael addition to the double carbon–carbon bond of starting enynones. The δ-diketones have been formed as mixtures of two diastereomers in a ratio of 2.5:1 in good general yields of 53–98%. A synthetic potential of the obtained δ-diketones has been demonstrated by heterocyclization with hydrazine into substututed 5,6-dihydro-4H-1,2-diazepine.