Three Novel Alkaloids from Portulaca oleracea L. and Their Anti-inflammatory Effects

Abstract

Three novel carbon skeleton alkaloids, named oleracimine (1), oleracimine A (2), and oleracone A (3), with one novel azulene carbon skeleton compound, oleracone B (4), and one known compound, β-carboline (5), were first isolated from Portulaca oleracea L. The structures were determined using spectroscopic methods, including one- and two-dimensional nuclear magnetic resonance and high-resolution electrospray ionization time-of-flight mass spectrometry techniques. In addition, oleracimine (1) was used to investigate the anti-inflammatory effects on lipopolysaccharide-stimulated macrophages. The results of enzyme-linked immunosorbent assay, western blot, and real-time polymerase chain reaction showed that oleracimine (1) remarkably inhibited nitric oxide production and could dose-dependently decrease the secretions of interleukin 6, tumor necrosis factor α, nitric oxide, and prostaglandin E2 in cell culture supernatants as well as the mRNA of cyclooxygenase-2 and inducible nitric oxide synthase.

An Unusual Homoisoflavanone from Portulaca oleracea

“…It has been used in folk medicine as a diuretic, an antispasmodic, an antipyretic, an antiseptic, a vermifuge, an antiscorbutic, an analgesic, a muscle relaxant, and so on . A variety of biologically active compounds have been isolated from it . In our continuing search for bioactive compounds from P. oleracea , one new homoisoflavanones ( 5 ), along with six known compounds, portulacanones A‐D ( 1 – 4 , 6 ) and 2,2′‐dihydroxy‐4′,6′‐dimethoxychalcone ( 7 ) were isolated.…”

Fermented Portulaca oleracea L. Juice: A Novel Functional Beverage with Potential Ameliorating Effects on the Intestinal Inflammation and Epithelial Injury

“…P. oleracea L. has a huge potential as a raw substrate to develop novel functional foods, dietary supplements, or pharmaceutical preparations due to the high level of nutrients and biologically active compounds (e.g., polysaccharides, ω-3 and ω-6 fatty acids, cerebrosides, bioactive alkaloids, phenolics, carotenoids, and vitamins). Overlapping or complementary pharmacological effects (e.g., neuroprotective, antimicrobial, antidiabetic, antioxidant, anti-inflammatory, anti-ulcerogenic, and anticancer) define the biogenic profile of this plant substrate [6,7,8]. Ameliorating effects on inflammatory bowel diseases (IBS) symptoms through the modulation of the pro-inflammatory cytokines levels has been recently associated with the P. oleracea extracts [9].…”

“…Ameliorating effects on inflammatory bowel diseases (IBS) symptoms through the modulation of the pro-inflammatory cytokines levels has been recently associated with the P. oleracea extracts [9]. Although their pharmacological effects are well documented [6,7,8], few studies have been addressed to exploit the use of P. oleracea as a functional beverage [10]. Recently, lactic fermentation has been proposed as a biotechnological option to enrich the profile of biogenic compounds of common purslane ( Portulaca oleracea L.) [10].…”

“…Recently, lactic fermentation has been proposed as a biotechnological option to enrich the profile of biogenic compounds of common purslane ( Portulaca oleracea L.) [10]. Lactic fermentation was shown to enhance the levels of γ-aminobutyric acid (GABA) and linalool, in addition to modifying the profiles of alkaloids and polyunsaturated fatty acids [6]. Supported by these previous findings, our study exploited the same fermentation protocol to improve the restoring effects of P. oleracea juice towards intestinal inflammation and epithelial injury.…”

Natural Products Research in China From 2015 to 2016

“…The stems of Artocarpus nanchuanensis (Jinfoshan Mountain, Chongqing, China) contained four new stilbene derivatives, hypargystilbenes B–E, among which hypargystilbenes B ( 477 ), D ( 478 ), and E ( 479 ) were inhibitory toward PTP1B with IC 50 values of 3.23, 37.31, and 2.53 nM, respectively (oleanolic acid, 1.60 nM) (Zhang et al, 2015j ). Portulacatone ( 480 ) (Yue et al, 2015 ), oleraceins K ( 481 ) and L ( 482 ) (Jiao et al, 2015b ), isolated from Portulaca oleracea (Shandong, China) displayed dose-dependent DPPH radical scavenging activities with EC 50 values of 14.36, 15.30, and 16.13 μM, better than vitamin C. Portulaca oleracea was also the source of the new alkaloids, oleracimine ( 483 ), oleracimine A ( 484 ), and oleracone A ( 485 ), as well as azulene compound, oleracone B ( 486 ) (Li et al, 2016b ).…”