The fruits of Canarium tramdenum are commonly used as foods and cooking ingredients in Vietnam, Laos, and the southeast region of China, whilst the leaves are traditionally used for treating diarrhea and rheumatism. This study was conducted to investigate the potential use of this plant bark as antioxidants, and α-amylase and α-glucosidase inhibitors. Five different extracts of C. tramdenum bark (TDB) consisting of the extract (TDBS) and factional extracts hexane (TDBH), ethyl acetate (TDBE), butanol (TDBB), and water (TDBW) were evaluated. The TDBS extract contained the highest amount of total phenolic (112.14 mg gallic acid equivalent per g dry weight), while the TDBB extract had the most effective antioxidant capacity compared to other extracts. Its IC₅₀ values were 12.33, 47.87, 33.25, and 103.74 µg/mL in 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis (ABTS), reducing power (RP), and nitric oxide (NO) assays, respectively. Meanwhile, the lipid peroxidation inhibition of the four above extracts was proximate to that of butylated hydroxytoluene (BHT) as a standard antioxidant. The result of porcine pancreatic α-amylase inhibition showed that TDB extracts have promising effects which are in line with the commercial diabetic inhibitor acarbose. Interestingly, the inhibitory ability on α-glucosidase of all the extracts was higher than that of acarbose. Among the extracts, the TDBB extract expressed the strongest activity on the enzymatic reaction (IC₅₀ = 18.93 µg/mL) followed by the TDBW extract (IC₅₀ = 25.27 µg/mL), TDBS (IC₅₀ = 28.17 µg/mL), and TDBE extract (IC₅₀ = 141.37 µg/mL). The phytochemical constituents of the TDB extract were identified by gas chromatography–mass spectrometry (GC-MS). The principal constituents included nine phenolics, eight terpenoids, two steroids, and five compounds belonging to other chemical classes, which were the first reported in this plant. Among them, the presence of α- and β-amyrins were identified by GC-MS and appeared as the most dominant constituents in TDB extracts (1.52 mg/g). The results of this study revealed that C. tramdenum bark possessed rich phenolics and terpenoids, which might confer on reducing risks from diabetes. A high quantity of α- and β-amyrins highlighted the potentials of anti-inflammatory, anti-ulcer, anti-hyperlipidemic, anti-tumor, and hepatoprotective properties of C. tramdenum bark.

Tridax procumbens L. is a medicinal plant and used as a drink to treat bronchial catarrh, diarrhea, dysentery and liver diseases. In this study, we evaluated the potential use of T. procumbens to treat hyperuricemia, oxidative stress, and bacterial infection. Ethyl acetate extract of this plant was separated to different fractions by column chromatography (CC) using chloroform and methanol as eluents and subjected to xanthine oxidase (XO) inhibitory, antioxidant, and antibacterial assays. The results showed that the F_45–47 fraction exhibited the strongest XO inhibitory activity (IC₅₀ = 133.17 µg/mL), while the F_48–50 fraction possessed maximum antioxidant activity assessed by DPPH (2,2-diphenyl-2-picrylhydrazyl) and ABTS (2,2’-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) assays (IC₅₀ = 0.51 and 1.04 mg/mL, respectively). In addition, the F_4–5 fraction presented the most effective inhibition on the growth of Escherichia coli, Staphylococcus aureus, Bacillus subtilis, and Proteus mirabilis. Gas chromatography-mass spectrophotometry (GS-MS) and liquid chromatography-electrospray ionization-mass spectrophotometry (LC-ESI-MS) results revealed that fatty acids, glycerides, and flavonoids were the major compounds of the F_45–47 fraction. Glycerides, triose sugar alcohols, and fatty acids were dominant compounds of the F_48–50 fraction, while sterols were principal components of the F_4–5 fraction. This study indicated that T. procumbens had potent inhibitory effects on XO inhibitory, antioxidant, and antibacterial activities. These biological activities may be attributed to the presence of fatty acids, flavonoids, and sterols in this plant. It is suggested that T. procumbens can be utilized as a healthy source to develop beverages and foods to treat antihyperuricemia, oxidative stress, and bacterial infection.

In this study, we evaluated antioxidant, antihyperuricemic, and herbicidal activities of essential oils (EOs) from Piper cubeba Bojer and Piper nigrum L.; two pepper species widely distributed in tropics, and examined their chemical compositions. Dried berries of P. cubeba and P. nigrum were hydro-distilled to yield essential oil (EO) of 1.23 and 1.11% dry weight, respectively. In the antioxidant assay, the radical scavenging capacities of P. cubeba EO against DPPH and ABTS free radicals were 28.69 and 24.13% greater than P. nigrum, respectively. In the antihyperuricemic activity, P. cubeba EO also exhibited stronger inhibitory effects on xanthine oxidase (IC₅₀ = 54.87 µg/mL) than P. nigrum EO (IC₅₀ = 77.11 µg/mL). In the herbicidal activity, P. cubeba EO showed greater inhibition on germination and growth of Bidens pilosa and Echinochloa crus-galli than P. nigrum EO. Besides, P. cubeba EO decreased 15.98–73.00% of photosynthesis pigments of B. pilosa and E. crus-galli, while electrolyte leakages, lipid peroxidations, prolines, phenolics, and flavonoids contents were increased 10.82–80.82% at 1.93 mg/mL dose. Gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) analyses revealed that P. nigrum and P. cubeba EOs principally possessed complex mixtures of monoterpenes and sesquiterpenes. Terpinen-4-ol (42.41%), α-copaene (20.04%), and γ-elemene (17.68%) were the major components of P. cubeba EO, whereas β-caryophyllene (51.12%) and β-thujene (20.58%) were the dominant components of P. nigrum EO. Findings of this study suggest both P. cubeba and P. nigrum EOs were potential to treat antioxidative stress and antihyperuricemic related diseases. In addition, the EOs of the two plants may be useful to control B. pilosa and E. crus-galli, the two invasive and problematic weeds in agriculture practice.

This paper reports the successive isolation and purification of bioactive compounds from the stem bark of Jatropha podagrica, a widely known medicinal plant. The ethyl acetate extract of the stem bark exhibited the strongest antioxidant activity assessed by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging, and ferric reducing antioxidant power (FRAP) assays (IC₅₀ = 46.7, 66.0, and 492.6, respectively). By column chromatography (CC) with elution of hexane and ethyl acetate at 8:2, 7:3, and 6:4 ratios, the isolation of this active extract yielded five fractions (C1–C5). Chemical structures of the constituents included in C1–C5 were elucidated by gas chromatography-mass spectrometry (GC-MS), electrospray ionization-mass spectrometry (ESI-MS), and nuclear magnetic resonance (NMR) and resolved as methyl gallate (C1, C2, C3, C4), gallic acid (C1, C2), fraxetin (C2, C3, C4, C5), and tomentin (C3). Mixture C2 (IC₅₀ DPPH and ABTS = 2.5 µg/mL) and C3 (IC₅₀ FRAP = 381 µg/mL) showed the highest antioxidant properties. Among the isolated fractions, C4 was the most potential agent in growth inhibition of six bacterial strains including Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Listeria monocytogenes, Bacillus subtilis, and Proteus mirabilis (MIC = 5, 20, 30, 20, 25, and 20 mg/mL, respectively). All identified constituents exerted an inhibitory activity on the growth of Lactuca sativa, of which the mixture C3 performed the maximal inhibition on shoot (IC₅₀ = 49.4 µg/mL) and root (IC₅₀ = 47.1 µg/mL) growth. Findings of this study suggest that gallic acid, methyl gallate, fraxetin, and tomentin isolated from J. podagrica possessed antioxidant, antibacterial, and growth inhibitory potentials.

The root of Rumex crispus L. has been shown to possess anti-gout and anti-diabetic properties, but the compounds responsible for these pharmaceutical effects have not yet been reported. In this study, we aimed to isolate and purify active components from the root of R. crispus, and to evaluate their anti-radical, anti-gout and anti-diabetic capacities. From the ethyl acetate (EtOAc) extract, two compounds, chrysophanol (1) and physcion (2), were isolated by column chromatography with an elution of hexane and EtOAc at a 9:1 ratio. Their structures were identified by spectrometric techniques including gas chromatography-mass spectrometry (GC-MS), electrospray ionization-mass spectrometry (ESI-MS), X-ray diffraction analyses and nuclear magnetic resonance (NMR). The results of bioassays indicated that (1) showed stronger activities than (2). For antioxidant activity, (1) and (2) exhibited remarkable DPPH radical scavenging capacity (IC₅₀ = 9.8 and 12.1 µg/mL), which was about two times stronger than BHT (IC₅₀ = 19.4 µg/mL). The anti-gout property of (1) and (2) were comparable to the positive control allopurinol, these compounds exerted strong inhibition against the activity of xanthine oxidase (IC₅₀ = 36.4 and 45.0 µg/mL, respectively). In the anti-diabetic assay, (1) and (2) displayed considerable inhibitory ability on α-glucosidase, their IC₅₀ values (IC₅₀ = 20.1 and 18.9 µg/mL, respectively) were higher than that of standard acarbose (IC₅₀ = 143.4 µg/mL). Findings of this study highlight that (1) and (2) may be promising agents to treat gout and diabetes, which may greatly contribute to the medicinal properties of Rumex crispus root.

There is currently much interest in finding new phytochemicals among plants and fungi as nature-based alternatives to replace problematic herbicides such as glyphosate, which are preferentially used in agricultural production. We discovered striking herbicidal potency in Cordyceps militaris (L.) and identified cordycepin as its principal plant growth inhibitor. Cordycepin obtained as an ethyl acetate extract was subjected to column chromatography and evaluated for its bioassay-guided phytotoxic capacity against Raphanus sativus (radish), showing a maximum inhibition on germination and growth of radish (IC₅₀ = 0.052–0.078 mg/mL). Gas chromatography-mass spectrometry (GC-MS) (m/z: 251.2) and liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) ([M + Na]⁺ m/z: 274.1; [M + H]⁺ m/z: 252.1) analyses confirmed cordycepin as the major component of the tested column fraction (55.38%). At 0.04 mg/mL, cordycepin showed 3.8–5.9- and 3.3–3.7-fold greater inhibition of the germination and growth of radish than benzoic acid (BA) and glyphosate, respectively. Compared with BA, isolated cordycepin reduced plant chlorophyll and carotenoid contents (2.0–9.5 -fold), while proline, total phenolic and total flavonoid contents were increased 1.2–1.8-fold. Finally, cordycepin promoted electrolyte leakage and malondialdehyde accumulation in radish aerial parts. Thus, cordycepin successfully isolated from Cordyceps militaris is a highly potent plant growth inhibitor with pending worldwide patent and may become a potential plant-based novel alternative to the disputed glyphosate.