Retrofractamide B

Amide alkaloids characterization and neuroprotective properties of Piper nigrum L.: A comparative study with fruits, pericarp, stalks and leaves.[Pubmed:34474242]

Food Chem. 2021 Aug 10;368:130832.

Piper nigrum L. is commonly used worldwide and its pericarp, stalks, leaves will be major wastes materials. 42 amide alkaloids were identified in black, white pepper and pericarp by UHPLC-LTQ-Orbitrap HRMS method, followed by 40 constituents in stalks and 36 constituents in leaves. 8 amide alkaloids were reported for the first time in P. nigrum. An ultra-high-performance supercritical fluid chromatography (UHPSFC)-MS method was firstly applied to simultaneously determine 9 characteristic constituents (piperine, piperlonguminine, piperanine, pipercallosine, dehydropipernonaline, pipernonatine, Retrofractamide B, pellitorine and guineensine). The most abundant compound in each extract was piperine with a concentration from 0.10 to 12.37 mg/g of dry weight. The fruits, pericarp and leaves extracts could improve cell viability in 6-OHDA-induced SK-N-SH and SH-SY5Y cells. The results showed the characteristics of amide alkaloids of different parts of P. nigrum and evaluated their neuroprotective activities.

LC-HRMS/MS-based phytochemical profiling of Piper spices: Global association of piperamides with endocannabinoid system modulation.[Pubmed:33641990]

Food Res Int. 2021 Mar;141:110123.

The plant genus Piper comprises extensively consumed spice taxa like black pepper (P. nigrum L.) or long pepper (P. longum L.). The chronic dietary use of different Piper spices has been associated with different health benefits, though the molecular mechanisms remain poorly understood. The aim of this work was to perform the liquid-chromatography-high-resolution tandem mass spectrometry (LC-HRMS/MS) profiling and LC-DAD quantification of piperamides in several Piper species and varieties and study their ability to modulate the endocannabinoid system (ECS). LC-HRMS/MS analysis revealed a number of 42 piperamides grouped into six structural classes, with 22 of them, notably piperine, Retrofractamide B, guineensine, piperchabamide C, being also quantified by LC-DAD. The multivariate analysis showed that P. nigrum and P. longum are very similar with respect to their piperamide profile, while the other Piper spices (P. retrofractum, P. guineense, P. cubeba, P. borbonense) might have significantly different metabolite patterns. The results from the biological assays confirmed that guineensine and total piperamides are strongly correlated with anandamide (AEA) cellular uptake inhibition. While none of the Piper spice extracts showed binding activity at cannabinoid CB1 receptors, some P. nigrum varieties exhibited moderate binding interactions with CB2 receptors. Overall, the analytical profiling enabled global annotations of piperamides associated to cannabimimetic effects in Piper spices.

New amides and gastroprotective constituents from the fruit of Piper chaba.[Pubmed:14994194]

Planta Med. 2004 Feb;70(2):152-9.

The 80 % aqueous acetone extract from the fruit of Piper chaba was found to show protective effects on ethanol- and indomethacin-induced gastric lesions in rats. From the aqueous acetone extract, four new amides named piperchabamides A ( 1), B ( 2), C ( 3), and D ( 4) were isolated, and their structures were determined on the basis of chemical and physicochemical evidence. In addition, the gastroprotective effects of the principal constituents, piperine ( 5), piperanine ( 6), pipernonaline ( 7), dehydropipernonaline ( 8), piperlonguminine ( 9), Retrofractamide B ( 10), guineensine ( 11), N-isobutyl-(2 E,4 E)-octadecadienamide ( 12), N-isobutyl-(2 E,4 E,14 Z)-eicosatrienamide ( 13), and methyl piperate ( 14), were examined. As a result, compounds 5 - 10 and 12 - 14 significantly inhibited ethanol-induced gastric lesions at a dose of 25 mg/kg, p. o., while 5, 7, 8, 10, 12, and 13 also significantly inhibited indomethacin-induced gastric lesions at the same dose.