Acylated flavonol glycosides from leaves of Planchonia grandis

Acylated flavonoid glycosides from Barringtonia pendula and their inhibition on lipopolysaccharide-induced nitric oxide production in RAW264.7 cells

Six new acylated flavonoid glycosides namely barringosides J - O (1-6) along with tephrokaempferoside and barringoside D were isolated from the branches and leaves of Barringtonia pendula. The structural elucidation was confirmed by extensive analysis of their spectroscopic data including HRQTOFMS, 1D and 2D NMR experiments. Moderate inhibitory effects on LPS-induced NO production in RAW264.7 cells were observed for barringosides M (4) and N (5) with IC50 values of 48.40 ± 3.01 and 56.61 ± 3.87 μM, whereas weak inhibition was found for compounds 1-3, 6, and 7 with IC50 values ranging from 64.91 ± 3.68 to 79.80 ± 3.90 μM.

Kaempferol: Antimicrobial Properties, Sources, Clinical, and Traditional Applications

Flavonoids are a category of plant-derived compounds which exhibit a large number of health-related effects. One of the most well-known and studied flavonoids is kaempferol, which can be found in a wide variety of herbs and plant families. Apart from their anticarcinogenic and anti-inflammatory effects, kaempferol and its associated compounds also exhibit antibacterial, antifungal, and antiprotozoal activities. The development of drugs and treatment schemes based on these compounds is becoming increasingly important in the face of emerging resistance of numerous pathogens as well as complex molecular interactions between various drug therapies. In addition, many of the kaempferol-containing plants are used in traditional systems all over the world for centuries to treat numerous conditions. Due to its variety of sources and associated compounds, some molecular mechanisms of kaempferol antimicrobial activity are well known while others are still under analysis. This paper thoroughly documents the vegetal and food sources of kaempferol as well as the most recent and significant studies regarding its antimicrobial applications.

Phytochemical profile and ethnopharmacological applications of Lecythidaceae: An overview

ETHNOPHARMACOLOGICAL RELEVANCE

The family Lecythidaceae has about 25 genera and 400 identified species, which are distributed especially in the pantropical region, mostly found in the tropics of Central and South America, Southeast Asia and Africa. The third most abundant family in Amazonian forests and the genus Eschweilera, with the large number of species in Lecythidaceae.

AIM OF THE REVIEW

The present review compiles information since the 1934s about of ethnopharmacology, and chemical constituents of species of Lecythidaceae, as well as a summary of the bioactivities shown by the extracts, fractions, and secondary metabolites.

MATERIALS AND METHODS

All relevant information on ethnopharmacology, and chemical constituents of species of Lecythidaceae were gathered from electronic databases including Web of Science, Science Direct, Elsevier, ResearchGate, and Google Scholar. Information was also obtained from local books, PhD. and MSc. Dissertations.

RESULTS

The phytochemical diversity of the family was demonstrated with 180 different metabolites that have been reported from 25 species, most of them being triterpenes or flavonoids. The pharmacological studies carried out with the extracts, fractions and compounds showed promising antibacterial, antifungal, anti-inflammatory, antinociceptive, cytotoxic and antioxidant activities.

CONCLUSION

The present review provides an insight into ethnopharmacology, phytochemistry and pharmacology of species of Lecythidaceae. Based on the pharmacological studies it has been found that different plant species of Lecythidaceae possess a wide range of bioactivities such as anti-arthritic, anti-inflammatory, antileishmanial, antibacterial and antifungal. These activities are due to the presence of bioactive compounds including triterpenoids and their glycosides derivatives, flavonoids, steroids, sesquiterpenoids, alkaloids, and other compounds. However, there are many plants, which have not been assessed pharmacologically and hence warrant further studies.

Anti-radical flavonol glycosides from the aerial parts of Cleome chelidonii L.f

Eleven previously undescribed flavonoid glycosides, named cleomesides C-M, along with five known compounds, were isolated from the aerial parts of Cleome chelidonii L.f. (Cleomaceae). All flavonol glycosides were esterified derivatives of 3,7-O-diglycosides of quercetin or kaempferol. Their structures were elucidated by analysis of the 1D and 2D NMR spectra, HR-ESI-MS data, UV spectra, optical rotation and by comparison with literature data. The DPPH radical scavenging properties of the flavonoid glycosides were studied in order to appreciate the effect of the glycoside parts and of the ester groups on this activity compared with the quercetin and kaempferol aglycones. An acetate at position 3 of rhamnose linked to C-7 of flavonol, gave compounds with the strongest antiradical activity. An aromatic ester group at position 6 of terminal glucose of diglycoside chain linked to C-3 of flavonol did not seem to influence the antiradical activity.

Acylated flavonol glycosides from the flower of Elaeagnus angustifolia L

Seven acylated flavonol glycosides named elaeagnosides A-G, in addition to seven known flavonoids were isolated from the flowers of Elaeagnus angustifolia. Their structures were elucidated by different spectroscopic methods including 1D, 2D NMR experiments and HR-ESI-MS analysis. In order to identify natural antioxidant and tyrosinase inhibitor agents, the abilities of these flavonoids to scavenge the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and to inhibit tyrosinase activity were evaluated. Results revealed that two of these compounds had significant anti-oxidant effect and one compound showed weak tyrosinase-inhibitory activity compared with kojic acid, quercetin, or ascorbic acid, which were used as positive control.

Anti-inflammatory activity of ethanol extract and fractions from Couroupita guianensis Aublet leaves

ETHNOPHARMACOLOGICAL RELEVANCE

Couroupita guianensis Aublet, 'macacarecuia', 'abricó-de-macaco', 'castanha-de-macaco' and 'amêndoa-dos-andes', is found in tropical regions and is widely used in the treatment of tumors, pain, and inflammatory processes.

AIM OF THE STUDY

Ethanol extract and hexane and ethyl acetate fractions were evaluated in models of inflammatory pain (formalin-induced licking) and acute inflammation (carrageenan-induced peritonitis).

MATERIALS AND METHODS

Ethanol extract, hexane and ethyl acetate fractions (10, 30 or 100 mg/kg, p.o.) and the reference drugs dexamethasone (5 mg/kg), morphine (5 mg/kg, s.c.), and acetylsalicylic acid (100 mg/kg, p.o.) were tested in formalin-induced licking response and carrageenan-induced peritonitis.

RESULTS

All three doses from Couroupita guianensis fractions significantly reduced the time that the animal spent licking the formalin-injected paw in first and second phases. However, only higher doses (30 and 100 mg/kg) were able to inhibit the leukocyte migration into the peritoneal cavity after carrageenan injection. In this model, the 100 mg/kg dose almost abolished the cell migration. It was also observed that protein concentration resulted from extravasation to the peritoneum and nitric oxide (NO) productions were significantly reduced. Cytokines production was differently affected by the treatment. TNF-α production was reduced after ethanol extract and ethyl acetate fraction pre-treatment whereas hexane fraction had effect only with 100 mg/kg dose. IL-1β production was inhibited only after hexane fraction pre-treatment. The inhibitory effect observed was not due to a direct cytotoxic effect on cells nor to a NO-scavenger activity. The effect was due to a direct inhibition on NO production by the cells.

CONCLUSIONS

The results show that Couroupita guianensis fractions have anti-inflammatory effect, partly due to a reduction on cell migration and a inhibition on cytokines and inflammatory mediators production.

Clematis vitalba L. aerial part exhibits potent anti-inflammatory, antinociceptive and antipyretic effects

Extracts obtained from the dried aerial parts of Clematis species are used as folk remedy worldwide for the treatment of various inflammatory ailments such as rheumatism and to reduce fever. In order to test the effectiveness of extracts, fractions and subfractions from dried Clematis vitalba L. (Ranunculaceae) aerial parts were studied on mice. Extracts are shown to have a potent effect on carrageenan-induced hind paw edema and acetic acid-induced increased vascular permeability models. Through bioassay-guided fractionation procedures a new C-glycosylflavon, 4'-O-coumaroyl-isovitexine (vitalboside) was isolated as the main active ingredient of the aerial parts. Vitalboside showed a potent and dose-dependent (in 75 and 150 mg/kg does, per os) in vivo anti-inflammatory activity against acute (carrageenan-, serotonin- and PGE(2)-induced hind paw edema model, castor oil-induced diarrhea), subacute (subcutaneous air-pouch) and chronic (Freund's complete adjuvant-induced arthritis) models of inflammation. The same compound was also isolated as the main antinociceptive principle which was assessed by using the models based on the inhibition of p-benzoquinone-induced writhings, as well as antipyretic activity against Freund's complete adjuvant-induced increased body temperature. Acute and subchronic toxicity studies were also performed.

A new stilbene glucoside from the roots of Polygonum multiflorum Thunb

One new stilbene glucoside (6), along with five known compounds (1-5), were isolated from the roots of Polygonum multiflorum Thumb., and their chemical structures established based on physicochemical and spectroscopic data. Of the compounds, compound 3 showed DNA topoisomerase I and II inhibitory activities.

Solanoflavone, a new biflavonol glycoside fromSolanum melongena: Seeking for anti-inflammatory components

A new biflavonol glycoside named as solanoflavone (1) was isolated from aerial part of Solanum melongena. The chemical structure was elucidated as isorhamnetin-3-O-beta-D-glucopyranoside-(4'-->O-->4''')-galangin-3''-O-beta-D-glucopyranoside on the basis of physicochemical and spectroscopic methods, including 2D NMR spectral techniques.