Antioxidant effect and chemical composition of Ananas comosus [L.] Merr. peels from Peruvian northern / Efecto antioxidante y composición química de las cascaras de Ananas comosus [L.] Merr. del norte peruano

Pineapple peels has several beneficial properties including antioxidant activity. We investigated the antioxidant effect of five different peels of pineapple lyophilized extracts, not adsorbed and adsorbed onto Amberlite. They were examined using total phenolic contents (TPC), antioxidant effect by 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging and ferric reducing antioxidant power (FRAP). In addition, we analyzed the chemical composition by HPLC-ESI-QTOF-MS/MS. The main constituents of pineapple peels were tentatively identified as quercetin glycosides and N,N'-diferuloylspermidine. We conclude that the antioxidant activity in pineapple peels from District of Poroto, Province of Trujillo, Region of La Libertad, can be associated with the presence of flavonoid and spermidines.

Las cáscaras de piña tienen varias propiedades beneficiosas, incluida la actividad antioxidante. Investigamos el efecto antioxidante de cinco exfoliaciones diferentes de extracto liofilizado de piña, no adsorbidas y adsorbidas en Amberlita. Se examinaron utilizando los contenidos fenólicos totales (TPC), el efecto antioxidante mediante la eliminación del radical 1,1-difenil-2-picril-hidrazilo (DPPH) y el poder férrico antioxidante reductor (FRAP). Además, analizamos la composición química por HPLC-ESI-QTOF-MS/MS. Los principales constituyentes de las cáscaras de piña se identificaron tentativamente como glucósidos de quercetina y N,N'- diferuloylspermidina. Concluimos que la actividad antioxidante en las cáscaras de piña del Distrito de Poroto, Provincia de Trujillo, Región de La Libertad, puede estar asociada con la presencia de flavonoides y espermidinas.

Identification and characterization of phenolics and terpenoids from ethanolic extracts of Phyllanthus species by HPLC-ESI-QTOF-MS/MS / 药物分析学报

Phyllanthus species plants are a rich source of phenolics and widely used due to their medicinal properties. A liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was developed using high-pressure liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (HPLC-ESI-QTOF-MS/MS) for the identification and characterization of quercetin, kaempferol, ellagic acid and their derivatives in ethanolic extracts of Phyllanthus species. The chromatographic separation was carried out on Thermo Betasil C8 column (250 mm×4.5 mm, 5 μm) using 0.1% formic acid in water and 0.1% formic acid in methanol as the mobile phase. The identification of diagnostic fragment ions and optimization of collision energies were carried out using 21 reference standards. Totally 51 compounds were identified which include 21 compounds identified and characterized unambiguously by comparison with their authentic standards and the remaining 30 were tentatively identified and characterized in ethanolic extracts of P. emblica, P. fraternus, P. amarus and P. niruri.

Structural characterization of monoterpene indole alkaloids in ethanolic extracts of Rauwolfia species by liquid chromatography with quadrupole time-of-flight mass spectrometry / 药物分析学报

Rauwolfia species (Apocynaceae) are medicinal plants well known worldwide due to its potent bioactive monoterpene indole alkaloids (MIAs) such as reserpine, ajmalicine, ajmaline, serpentine and yohimbine. Reserpine, ajmalicine and ajmaline are powerful antihypertensive, tranquilizing agents used in hypertension. Yohimbine is an aphrodisiac used in dietary supplements. As there is no report on the comparative and comprehensive phytochemical investigation of the roots of Rauwolfia species, we have developed an efficient and reliable liquid chromatography-tandem mass spectrometry (LC–MS/MS) method for ethanolic root extract of Rauwolfia species to elucidate the fragmentation pathways for dereplication of bioactive MIAs using high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (HPLC–ESI–QTOF–MS/MS) in positive ion mode. We identified and established diagnostic fragment ions and fragmentation pathways using reserpine, ajmalicine, ajmaline, serpentine and yohimbine. The MS/MS spectra of reserpine, ajmalicine, and ajmaline showed C-ring-cleavage whereas E-ring cleavage was observed in serpentine via Retro Diels Alder (RDA). A total of 47 bioactive MIAs were identified and characterized on the basis of their molecular formula, exact mass measurements and MS/MS analysis. Reserpine, ajmalicine, ajmaline, serpentine and yohimbine were unambiguously identified by comparison with their authentic standards and other 42 MIAs were tentatively identified and characterized from the roots of Rauwolfia hookeri, Rauwolfia micrantha, Rauwolfia serpentina, Rauwolfia verticillata, Rauwolfia tetraphylla and Rauwolfia vomitoria. Application of LC–MS followed by principal component analysis (PCA) has been successfully used to discriminate among six Rauwolfia species.