Steryl esters and phenylethanol esters from Syringa komarowii

Phytochemical study and immunomodulatory activity of Fraxinus excelsior L

OBJECTIVES

Fraxinus excelsior L. (FE) is traditionally used to treat inflammatory and pain disorders. This study aimed to identify the constituents of FE leaves and evaluate the effects of its n-hexane (FEH), ethyl acetate (FEE), methanol (FEM) extracts and constituents on the viability of THP-1 cells and their ability to release pro-inflammatory cytokines.

METHODS

THP-1 cell viability was assessed using an MTT assay. The immunomodulatory activity was evaluated by measuring tumour necrosis factor-alpha (TNF-α) and interleukin 12 (IL-12) released by lipopolysaccharide-stimulated THP-1 cells using enzyme-linked immunosorbent assays.

KEY FINDINGS

Triterpenes, tyrosol esters, alkanes, phytyl and steryl esters, pinocembrin and bis(2-ethylhexyl)phthalate were isolated from FE. The tyrosol esters showed no significant effect on THP-1 cell viability. FEH, FEE, FEM, and pinocembrin, ursolic acid, oleanolic acid had IC50 values of 56.9, 39.9, 124.7 µg/ml and 178.6, 61.5 and 199.8 µM, respectively. FE extracts, ursolic acid, oleanolic acid and pinocembrin significantly reduced TNF-α/IL-12 levels. The tyrosol esters did not significantly affect TNF-α/IL-12 production.

CONCLUSIONS

FE was able to reduce pro-inflammatory cytokine production indicating a mechanistic focus in its use for inflammation and pain. Further investigations are warranted to unravel the mode of action of the tested constituents and discover other potentially active compounds in FE extracts.

Traditional uses, phytochemistry and pharmacology of genus Syringa: A comprehensive review

ETHNOPHARMACOLOGICAL RELEVANCE

Genus Syringa, which belongs to Oleaceae family, contains 21 accepted species mainly distributed in Southeast Europe, Japan, China, Himalayas, etc. The various parts of Syringa species have been used as traditional Chinese herbal medicines for treatment of cough, myocardial ischemia, acute icteric hepatitis, diarrhea, conjunctivitis, bronchitis and other ailments.

AIM OF THE STUDY

A more comprehensive and in-depth review about the phytochemistry, pharmacology, traditional medicinal uses and clinical applications as well as toxicology of Syringa have summarized and hope to provide a relatively novel angle for further clinical applicantion on genus.

MATERIALS AND METHODS

The literatures about Syringa were collected via a series of scientific search engines including Web of Science, PubMed, Elsevier, Google Scholar, SciFinder and CNKI.

RESULTS

The phytochemical studies revealed that about 302 compounds include phenylpropanoids, iridoids, phenylethanols, flavonoids, triterpenes and other minor compounds have been isolated and identified from Syringa species. Phenylpropanoids and iridoids are the main constituents among these compounds and may be responsible for the activities directly or indirectly. As traditional medicine, Syringa applied to treat cough, diarrhea, acute icteric hepatitis, vomit, abdominal pain, bronchitis and other ailments. Most of traditional uses are related the biological activities and confirmed by modern studies. Pharmacological researches in vitro and in vivo revealed that the extracts and pure compounds possessed significantly hepatoprotective, anti-inflammatory, antimicrobial, antioxidant, antitumor, antiviral, cardioprotective, immunomodulatory and other activities.

CONCLUSIONS

The phytochemistry, pharmacology, traditional uses and clinical applications described in this article demonstrated that Syringa species possessed a huge number of activities and these findings will promote the further action mechanisms studies. However, fewer preclinical and clinical studies are focued on the pharmacokinetics of crudes extracts and conpounds from Syringa. The explored of new agents with Syringa species as ingredients may be limited. It points to the further in-depth investigations on pharmacokinetics as well as toxicological are essential in future for assessment the effectiveness and safety of drug.

Isolation of tyrosine derived phenolics and their possible beneficial role in anti-inflammatory and antioxidant potential of Tithonia tubaeformis

The methanolic extract of aerial parts of Tithonia tubaeformis showed significant antioxidant activity in DPPH assay. It was subjected to bioassay guided fractionation affording more active ethyl acetate fraction which on further purification led to the isolation and identification of a series of bioactive phenolic compounds having important biosynthetic relationship. Of these, 4-hydroxyphenethyl henicosanoate (tithonoid) is a new compound. Moreover, in the carrageenan induced paw edema test, significant attenuation of inflammation was also produced by the extract at 50-200 mg/kg. The structures of all the constituents were determined through spectroscopic methods. It is the first systematic biological and chemical investigation on T. tubaeformis, which showed that phenolics may play an important role in the antioxidant and anti-inflammatory activity of the plant, probably through synergism.

Non-alkaloid Constituents from Mahonia bealei

A phytochemical investigation of an ethyl acetate fraction of Mahonia bealei trunks led to the isolation of three new and four known compounds. By means of NMR and MS spectroscopic methods, the structure of the new compounds was elucidated as bishexadecyl epiphyllate (1), 3-(4-hydroxy-3,5-dimethoxyphenyl)-3-ethoxy-2-sulfopropane-1-ol (2), and 6α-acetoxystigmastan-3β-ol (3).

Phytochemical and pharmacological progress on the genus Syringa

Genus Syringa, belonging to the Oleaceae family, consists of more than 40 plant species worldwide, of which 22 species, including 18 endemic species, are found in China. Most Syringa plants are used in making ornaments and traditional medicines, whereas some are employed for construction or economic use. Previous studies have shown that extracts of Syringa plants mainly contain iridoids, lignans, and phenylethanoids that have antitumor, antihypertensive, anti-oxidant, and anti-inflammatory activities. This study reviews phytochemical and pharmacological progress on Syringa in the recent 20 years and discusses the future research prospects to provide a reference in further promotion and application of the genus.

Graphical Abstract

Preparative separation and enrichment of syringopicroside from Folium syringae leaves with macroporous resins

Syringopicroside is the major constituent in Folium syringae leaves with known pharmacological activities. In this study, a simple method for preparative separation of syringopicroside from F. syringae leaves with macroporous resins was developed. Adsorption characteristics of syringopicroside on six types of macroporous resins, including ADS-8, ADS-17, D141, NKA-9, HPD450, and HPD600, have been compared, among which D141 resin showed the best adsorption and desorption capacities for syringopicroside. Adsorption isotherms were used to D141 resin at different temperatures and fitted well to Langmuir and Freundlich equations. Dynamic adsorption and desorption tests were performed on D141 resin-packed column to optimize the separation process of syringopicroside. After one run with D141 resin, the content of syringopicroside was increased 24-fold from 2.32% to 55.74% with a recovery yield of 92.16%. The chromatographic process optimized in this work avoids toxic organic solvent and, thus, is a promising basis for large-scale preparation of syringopicroside.

Spathoside, a cerebroside and other antibacterial constituents of the stem bark of Spathodea campanulata

Spathoside, a new cerebroside was isolated from the stem bark of Spathodea campanulata, besides known compounds (n-alkanes, linear aliphatic alcohols, sitosterol and their esters, beta-sitosterol-3-O-beta-D-glucopyranoside, oleanolic acid, pomolic acid, p-hydroxybenzoic acid and phenylethanol esters). The structures of the isolated compounds were established by spectroscopic studies. The antibacterial activity of the isolated compounds against a wide range of microorganisms was examined. They inhibited significantly the growth of some gram-positive and -negative bacteria.