ChemInform Abstract: A New Tricyclic Alkaloid from Portulaca oleracea L.

Abstract

An ew tricyclic alkaloid named portulacatone (1), i.e.,5 ,6-dihydro-8,9-dihydroxy-11H-pyrrolo [2,1-b][3]benzazepin-11-one,together with eightknowncompounds,methyl 4-hydroxyphenylacetate (2), phydroxybenzaldehyde (3), vanillin (4), protocatechualdehyde (5), p-hydroxybenzoic acid (6), iseluxine (7), oleracein E( 8), and (þ)-(R)-feruloylm alate (9)w ere isolated from aerial parts of Portulaca oleracea L. Their structures were elucidated based on spectroscopicanalyses.Among them,compounds 1 -7 and 9 were isolated from this medicinal plant for the first time.Compounds 1 and 7 showed dosedependent scavenginga ctivities against DPPH (2,2-diphenyl-1-picryl-hydrazyl)f ree radical, with EC 50 valueso f1 4.36 mm and 9.98 mm,r espectively,m ore potent than the natural antioxidant vitamin C (EC 50 20.72 mm). (Fig. 1)were isolated. Among them,compounds 1 -7 and 9 were isolated from this medicinal plantf or the first time.H erein, we report the structure elucidation of compound 1,a nd DPPH free radical scavengingactivities of 1 and 7.

Development Status of Chemical Constituents and Pharmacological Effects of Portulaca Oleracea L

“…Portulaca is rich in organic acid compounds, among which phenolic acid compounds are trans-3lupeol palmitate ferulic acid, 2,2'-dihydroxy-4',6'-dimethoxy Kichalcone [8], 3,4-dihydroxybenzoic acid [14], caffeic acid [28], p-hydroxybenzoic acid [30], ferulic acid, 4-hydroxy-5-methylfuran-3-Carboxylic acid, 5-hydroxymethylfuroic acid [31], vanillic acid, salicylic acid, protocatechuic acid, gallic acid, coumaric acid, p-hydroxybenzoic acid; low molecular weight organic acid compounds include citric acid, succinic acid acid [15], oxalic acid, monomethyl succinate [31], 5-dimethylcitric acid, malic acid [32], fumaric acid, L4-methylmalate, L-methyl citrate, apple acid L-dimethyl ester, methyl malate, benzoic acid; fatty acids are tetracosanoic acid [7], tridecanoic acid, octanoic acid, 9,12-octadecadienoic acid, eicosatrienoic acid, behenic acid, linolenic acid, octadecane [29], palmitic acid [34], stearic acid [31] [35]and linoleic acid. At the same time, it was detected that Portulaca oleracea L. contains arachidonic acid and DHA, which are extremely rare in other plants.…”

“…Portulaca also contains alcohol and ester compounds inositol [9], n-hexadecanol, linoleic acid triglyceride, ryegrassin, (-)-dehydrovomifoliol, n-triacontanol [16], alpha -Palmitic acid monoglyceride [26], 3, 4-dihydroxyphenethyl alcohol [31]; in addition, it also contains syringin [33] and portulacoside A [38], a new compound -Portulaca Amaranthine B, C, D, methyl 4hydroxyphenylacetate [30], portulaceramide A [41].…”