Two new flavonol glycosides from Sarcopyramis bodinieri var. delicate

Characterization and Quantification of Phenolic Constituents in Peach Blossom by UPLC-LTQ-Orbitrap-MS and UPLC-DAD

Peach blossom comes from the flower of Prunus persica (L.) Batsch, which is used as herbal tea and medicine in China and Korea. It could promote defecation and alleviate the abdominal pain. In this paper, the methods, ultra-performance liquid chromatography (UPLC) method coupled with electrospray ionization hybrid linear trap quadrupole orbitrap mass spectrometry (LTQ OrbitrapMS) and UPLC system coupled with a diode array detector (DAD), were developed for the qualitative and quantitative analysis of the flavonoids and phenolic acids in peach blossoms. Eight standards were divided into 3 types according to their basic skeletons: phenolic acids, quercetin-type flavonoids, and kaempferol-type flavonoids. The MSn fragmentation behaviors and diagnostic ions of these 3 types of compounds were proposed to aid the structural identification of components in peach blossom extract. By extracting the diagnostic ions from the mass spectrum in negative mode, a total of 25 compounds, including 8 phenolic acids and 17 flavonoids, were screened out. Among these compounds, 5 compounds (chlorogenic acid, ferulic acid, rutin, hyperoside, and isoquercetrin) were quantitated by UPLC-DAD. The linearity, precision, accuracy, limit of detection, and limit of quantitation were validated for the quantification method. The validated method was applied to assay 9 batches of peach blossoms from different regions. This study was the first report on the systematic qualitative analysis of compounds in peach blossom, providing insights into the quality control of peach blossom.

Hypoglycemic activity and constituents analysis of blueberry (Vaccinium corymbosum) fruit extracts

BACKGROUND

To investigate hypoglycemic activity and elucidate the active composition of the fruit blueberry (Vaccinium corymbosum).

METHODS

Methanol extracts of blueberry (MEB) were separated using a D101 macroporous resin column to yield quinic acid derivative (Fr.1)- and flavonoid (Fr.2)-rich fractions. The effects of the blueberry extracts on mRNA expression of GLUT-2 (glucose transporter type 2) and PPARγ (peroxisome proliferator-activated receptor-γ), as well as on the activities of PPRE (peroxisome proliferator response element) and NF-κB were analyzed in LO2 normal liver cells. Real-time PCR was used to detect the expression of GLUT-2, PPARγ, TNF-α, IL-1β, and IL-6 mRNA. The PPRE and NF-κB activities were detected by a luciferase reporter assay. Western blotting was used to detect the levels of PPARγ, GLUT-2, and p65. The active compositions were isolated using various chromatography columns, and were analyzed by NMR.

RESULTS

mRNA and protein expression of GLUT-2 and PPARγ were significantly increased upon treatment with 400 μg/mL extracts of blueberry (P<0.05). The PPRE activity was also significantly increased in a dose-dependent manner upon administration of MEB (P<0.05). Furthermore, the NF-κB activity induced by lipopolysaccharides was inhibited by MEB (P<0.05). No fraction separated from MEB exhibited PPRE activation or NF-κB inhibition activity. Blueberry extract may execute its hypoglycemic activity by stimulating expression of GLUT-2 and PPARγ, and by inhibiting the inflammatory pathway. Together, quinic acid derivatives and flavonoids may result in a synergistic effect. Fourteen phenolic acids, including eight flavonoids, four quinic acid derivatives, and two other phenolic acids, were isolated and identified, and caffeoylquinic acid derivatives and quercetin glycosides were found to be the major constituents of blueberry.

CONCLUSION

Blueberry may have hypoglycemic activity that functions through synergistic effects with caffeoylquinic acid derivatives and quercetin glycosides.

Ferulic Acid and Naturally Occurring Compounds Bearing a Feruloyl Moiety: A Review on Their Structures, Occurrence, and Potential Health Benefits

The ubiquitous compound 4-hydroxy-3-methoxycinnamic acid, also known as ferulic acid (FA), constitutes a bioactive ingredient of many foods that may offer beneficial effects against disorders related to oxidative stress, including cancer, diabetes, and neurodegenerative diseases. This review discusses the antioxidant properties of FA, establishing relationships to several biological activities already described for this natural product. Next, 387 naturally occurring compounds, all isolated from plants and published between 1990 and 2015, the structures of which bear 1 or more feruloyl moieties, are covered in this review along with their structural formulas, botanical sources, and bioactivities. The compounds' distribution, structural patterns, bioactivities, and perspectives on food research are also succinctly discussed.

Isolation of flavonoids and triterpenoids from the fruits of Alphitonia neocaledonica and evaluation of their anti-oxidant, anti-tyrosinase and cytotoxic activities

INTRODUCTION

Alphitonia neocaledonica (Rhamnaceae) is an endemic tree of New Caledonia. Although three flavonoids have been identified in the leaves, the secondary metabolite profile of the fruits has never been investigated.

OBJECTIVE

Phytochemical investigation of A. neocaledonica fruits and evaluation of their anti-oxidant, anti-tyrosinase and cytotoxic activities.

METHODS

A hydromethanolic extract was fractionated by liquid-liquid extraction to obtain ethyl acetate and n-butanolic fractions. The ethyl-acetate-soluble part was purified by silica-gel column chromatography and high-performance liquid chromatography (HPLC). The n-butanol-soluble part was fractionated by centrifugal partition extraction (CPE) and the collected fractions were further purified by centrifugal partition chromatography (CPC) and HPLC. The chemical structures of the purified compounds were identified by nuclear magnetic resonance and mass spectrometry.

RESULTS

Three triterpenoids and one flavonoid were isolated from the ethyl-acetate-soluble part. Fractions enriched in triterpenoids, flavonoids and catechin derivatives were obtained from the n-butanol-soluble part. Gallocatechin and flavonoids were obtained as pure compounds by further CPC and HPLC purification. The n-butanolic-soluble part showed anti-oxidant and anti-tyrosinase activities due to the presence of tannins and gallocatechin. The triterpenoid alphitolic acid showed a moderate cytotoxic activity against KB cell line (median inhibition concentration = 8.5 μM).

CONCLUSIONS

Nine known compounds including three triterpenes, five flavonoids and (+) gallocatechin, as well as a new 3-O-(6-E-feruloyl)-β-D-glucopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 2)-]α-L-rhamnopyranosyl-quercetin, were isolated from A. neocaledonia fruits. The hydromethanolic extract possesses a potential cytotoxic activity due to the presence of triterpenes, and it can also be valuable as a cosmetic ingredient for its anti-oxidant and anti-tyrosinase activities.

Two new acylated flavonol glycosides from the seeds of Lepidium sativum

Two new acylated flavonol glycosides named kaempferol-3-O-(2-O-sinapoyl)-β-D-galactopyranosyl-(1 → 2)-β-D-glucopyranoside-7-O-α-L-rhamnopyranoside (1) and quercetin-3-O-(6-O-benzoyl)-β-D-glucopyranosyl-(1 → 3)-β-D-galactopyranoside-7-O-α-L-rhamnopyranoside (2), were isolated together with six known compounds from the seeds of L. sativum. Their structures were elucidated on the basis of spectroscopic analysis and chemical methods. In vitro 1 and 2 inhibited nitric oxide production in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells, with IC50 values of 25.36 and 25.08 µM, respectively.

Medicinal flowers. XXXVIII. structures of acylated sucroses and inhibitory effects of constituents on aldose reducatase from the flower buds of Prunus mume

The methanolic extract from the flower buds of Prunus mume, cultivated in Zhejiang province, China, showed an inhibitory effect on aldose reductase. From the methanolic extract, five new acylated sucroses, mumeoses F-J, were isolated together with 29 known compounds. The chemical structures of the new compounds were elucidated on the basis of chemical and physicochemical evidence. The inhibitory effects of the isolated compounds on aldose reductase were also investigated. Acylated quinic acid analogs, which are one of the major compounds of the flower buds of P. mume, were shown to substantially inhibit aldose reductase. In particular, mumeic acid-A was found to exhibit a potent inhibitory effect [IC50=0.4 µm].

Acylated sucroses and acylated quinic acids analogs from the flower buds of Prunus mume and their inhibitory effect on melanogenesis

The methanolic extract from the flower buds of Prunus mume, cultivated in Zhejiang Province, China, showed an inhibitory effect on melanogenesis in theophylline-stimulated B16 melanoma 4A5 cells. From the methanolic extract, five acylated sucroses, mumeoses A-E, and three acylated quinic acid analogs, 5-O-(E)-p-coumaroylquinic acid ethyl ester, and mumeic acid-A and its methyl ester, were isolated together with 13 known compounds. The chemical structures of the compounds were elucidated on the basis of chemical and physicochemical evidence. Inhibitory effects of the isolated compounds on melanogenesis in theophylline-stimulated B16 melanoma 4A5 cells were also investigated. Acylated quinic acid analogs substantially inhibited melanogenesis. In particular, 5-O-(E)-feruloylquinic acid methyl ester exhibited a potent inhibitory effect [inhibition (%): 21.5±1.0 (P<0.01) at 0.1 μM]. Moreover, its biological effect was much stronger than that of the reference compound, arbutin [inhibition (%): 10.6±0.6 (P<0.01) at 10 μM]. Interestingly, the obtained acylated quinic acid analogs displaying melanogenesis inhibitory activity showed no cytotoxicity [cell viability >97% at 10 μM]. It is concluded that acylated quinic acid analogs are promising therapeutic agents for the treatment of skin disorders.

Structures of acylated sucroses and an acylated flavonol glycoside and inhibitory effects of constituents on aldose reductase from the flower buds of Prunus mume

Five new acylated sucroses, mumeoses K-O, and a new acylated flavonol glycoside, mumeflavonoside A, were isolated from the flower buds of Prunus mume, cultivated in Zhejiang province, China. The chemical structures of the new compounds were elucidated on the basis of chemical and physicochemical evidence. The inhibitory effects of the isolated acylated sucroses and flavonol glycosides on aldose reductase were also investigated. Several flavonol glycosides including mumeflavonoside A were shown to inhibit aldose reductase.