Lupane triterpenoids,antioxidant potential and antimicrobial activity of Myrciaria floribunda (H. West ex Willd.) O. Berg.

Chemical composition of the methanol extract of Myrciaria floribunda leaves was investigated. The nor-lupane triterpenoids platanic acid and messagenic I acid were identified, along with other known triterpenoids (betulinic aldehyde, ursolic acid acetate and betulinic acid), a new lupane triterpenoid (2α,6α,30-trihydroxybetulinic acid) and the flavonoids catechin, quercetrin and mirycitrin. The structures were determined by spectroscopic methods (NMR, LC-MS, GC-MS). The major isolated compound was betulinic acid. The methanol extract and 2α,6α,30-trihydroxybetulinic acid were evaluated for their DPPH scavenging potential. The tested triterpenoid was one hundred times more active than betulinic acid, but less active than the extract. Screening for antimicrobial activity showed that the methanol extract was active against Staphylococcus aureus and Escherichia coli, but inactive against Candida albicans and Candida krusei, while 2α,6α,30-trihydroxybetulinic acid was inactive to all tested microorganisms.     

Simultaneous determination of five triterpene acids in rat plasma by liquid chromatography–mass spectrometry and its application in pharmacokinetic study after oral administration of Folium Eriobotryae effective fraction

Folium Eriobotryae effective fraction (FEA), the extract of Folium Eriobotryae, had been used as anti‐hyperglycemia and anti‐hyperlipemia medicine in China. A previous study indicated that euscaphic acid, maslinic acid, corosolic acid, oleanolic acid and ursolic acid, the five structurally similar triterpene acids (containing two groups of structural isomers), are the major components of FEA. In the present study, we developed a specific and reliable LC‐MS method for simultaneous determination of the five triterpene acids in rat plasma, and further investigated their pharmacokinetic properties after oral administration of FEA. Following a simple sample preparation, chromatographic separation was achieved on a C₁₈ column with a mobile phase composed of methanol–0.1% ammonium acetate (80:20, v/v). Quantification was achieved by monitoring the selected ions at m/z 487.6 for euscaphic acid, m/z 471.5 for maslinic acid and corosolic acid, m/z 455.5 for oleanolic acid and ursolic acid and m/z 469.5 for internal standard. The method was validated to be specific, accurate and precise over the concentration ranges of 10–3000 ng/mL with limits of detections of 5 ng/mL for the five triterpene acids. Finally, the method was successfully applied to the pharmacokinetic study of the five structurally similar triterpene acids in rats after oral administration of FEA. Copyright © 2015 John Wiley & Sons, Ltd.     

Synthesis of triterpenoid derivatives and their anti-tumor and anti-hepatic fibrosis activities

Abstract

Oleanolic acid (1), ursolic acid (2), hederagenin (3), betulinol (4), betulinic acid (5), and glycyrrhetinic acid (6) are obtained from acorn/licorice industrial wastes with common triterpenoid structure as a model set for esterification. Eight 3,4,5-methoxybenzoyl triterpenoid derivatives (1a–6a), including four new derivatives (1a, 3a–1, 3a–2, and 3a–3), are synthesized by classical procedures. Their antitumor and anti-hepatic fibrosis activities are evaluated on four human tumor cell lines and t-HSC/Cl-6 cells. Derivative 1a shows maximum antiproliferative effects against all cell lines, especially against tumor cells with IC₅₀ values in the range of 5.32–15.23?μM, but does not affect the viability of normal cells. The anti-tumor mechanisms of 1a are also investigated by western blot and docking studies. The 3,4,5-methoxybenzoyl triterpenoids offers an intriguing solution for naturally derived antitumor drugs and may be invaluable for further development of cancer therapy.     

Triterpenoids from Eucalyptus camaldulensis Dehnh. Tissue Cultures

A chemical study on tissue cultures from leaves and flowers of E. camaldulensis Dehnh . afforded the new natural product (2α,3β)‐2,3,23‐trihydroxy‐13,28‐epoxyurs‐11‐en‐28‐one (dryobalanolide) together with the known pentacyclic triterpenoids: betulinic acid, oleanolic acid, ursolic acid, (2α,3β)‐2,3,23‐trihydroxyolean‐12‐en‐28‐oic acid (arjunolic acid), (2α,3β)‐2,3,23‐trihydroxyurs‐12‐en‐28‐oic acid (asiatic acid), (2α)‐2‐hydroxyursolic acid, (2α)‐2‐hydroxyoleanolic acid (maslinic acid), as well as β‐sitosterol. The extracts and the isolated compounds were evaluated against eleven human pathogenic microorganisms, exhibiting a very interesting antibacterial spectrum of activities.     

Constituents of Clinopodium Umbrosum

The isolation and identification of fifteen crystalline components from the whole herb of Clinopodium umbrosum (Bieb.) C. Koch (Labiatae) are described. Their structures were determined on the basis of spectral evidence and chemical transformation. These compounds include five steroids (α-spinasterone, β-sitosterol, stigmasterol, α-spinasterol, and α-spinasteryl-3-O-β-glucopyranoside), four triterpenoids (3β-hydroxyurs-11-en-28,13-olide, betulinic acid, oleanolic acid, ursolic acid), four flavonoids (luteolin, luteolin-7-O-β-glucopyranoside, apigenin-7-O-β-glucuronide, and apigenin-7-O-β-methylglucuronate), and two lignolic acids [3-(3,4-dihydroxyphenyl)- lactic acid and rosmarinic acid].     

Simultaneous determination of five triterpenic acids in four Corydalis herb medicines by reversed-phase high performance liquid chromatography–fluorescence-mass spectrometer (RP-HPLC–FLD-MS) based on pre-column derivatization

A rapid and sensitive reversed-phase high performance liquid chromatography– fluorescence-mass spectrometer (RP-HPLC–FLD-MS) method based on pre-column derivatization using 2-(5-benzoacridine)ethyl-p-toluenesulfonate (BAETS) as labelling reagent has been developed for simultaneous determination of five triterpenic acids (asiatic acid (AA), maslinic acid (MA), corosolic acid (CA), oleanolic acid (OA), and betulinic acid (BA). The presented method was validated for linearity (correlation coefficient R² > 0.9994), precision (RSD 2.1%–3.9%) and reproducibility (RSD 0.01%–2.1%). The limits of detection (LODs) and the limits of quantitation LOQs were within the range of 0.71–1.02 ng mL^?1 and 2.28–3.24 ng mL^?1, respectively. The proposed method was successfully applied to simultaneously determine five triterpenic acids of four Corydalis plants and showed satisfactory reproducibility and credibility. Moreover, several main parameters affecting extraction procedure and derivatization efficiency were investigated by response surface methodology (RSM), respectively. Triterpenic acid content in four Corydalis plants was measured according to the established method and the results indicated that triterpenic acid contents were various in different organs and herbs.     

The Presence of a Cyclohexyldiamine Moiety Confers Cytotoxicity to Pentacyclic Triterpenoids

Pentacyclic triterpenoids oleanolic acid, ursolic acid, betulinic acid, and platanic acid were acetylated and converted into several amides 9–31; the cytotoxicity of which has been determined in sulforhodamine B assays employing seral human tumor cell lines and nonmalignant fibroblasts. Thereby, a betulinic acid/trans-1,4-cyclohexyldiamine amide showed excellent cytotoxicity (for example, EC₅₀ = 0.6 μM for HT29 colon adenocarcinoma cells).     

Antioxidant and Anticholinesterase Activities of Extracts and Phytochemicals of Syzygium antisepticum Leaves

Bioassay-guided separation of young leaves extracts of Syzygium antisepticum (Blume) Merr. & L.M. Perry led to the isolation of four triterpenoids (betulinic acid, ursolic acid, jacoumaric acid, corosolic acid) and one sterol glucoside (daucosterol) from the ethyl acetate extract, and three polyphenols (gallic acid, myricitrin, and quercitrin) from the methanol (MeOH) extract. The MeOH extract of S. antisepticum and some isolated compounds, ursolic acid and gallic acid potentially exhibited acetylcholinesterase activity evaluated by Ellman’s method. The MeOH extract and its isolated compounds, gallic acid, myricitrin, and quercitrin, also strongly elicited DPPH radical scavenging activity. In HEK-293 cells, the MeOH extract possessed cellular antioxidant effects by attenuating hydrogen peroxide (H₂O₂)-induced ROS production and increasing catalase, glutathione peroxidase-1 (GPx-1), and glutathione reductase (GRe). Furthermore, myricitrin and quercitrin also suppressed ROS production induced by H₂O₂ and induced GPx-1 and catalase production in HEK-293 cells. These results indicated that the young leaves of S. antisepticum are the potential sources of antioxidant and anticholinesterase agents. Consequently, S. antisepticum leaves are one of indigenous vegetables which advantage to promote the health and prevent diseases related to oxidative stress.     

Study on Determination of Triterpenoids in Chaenomeles by High Performance Liquid Chromatography and Sample Preparation with Matrix Solid Phase Dispersion

A new method for the simultaneous determination of the major triterpenoids in Chaenomeles (Chinese medicinal herb) by high performance liquid chromatography (HPLC) and sample preparation with matrix solid phase dispersion (MSPD) was developed. A 0.1 g of sample was placed into an agate mortar and gently blended with 0.4 g silica gel to obtain a homogeneous mixture. This mixture was introduced into a Teflon cartridge, and the triterpenoids fraction was eluted from the cartridge with dichloromethane‐acetone (85:15). The residue was dissolved with methanol after the evaporation of the solvent (dichloromethane and acetone). The triterpenoids were separated on a ZORBAX Stable Bound (4.6 mm × 100 mm, 1.8 μm) C₁₈ column by gradient elution with acetonitrile and water as the mobile phase and detected with evaporative light scattering detection. This method provides good reproducibility and sensitivity for the quantification of seven major triterpenoids, namely erythodiol, betulin, acetyl ursolic acid, ursolic acid, oleanolic acid, betulinic acid, pomolic acid, respectively. The relative standard derivations of overall intra‐day variations were less than 2.0%, and the relative standard derivations of inter‐day variations were less than 2.5%. The standard recoveries (three different concentrations of markers: 0.1, 0.5 and 2.0 mg) ranged from 97‐103%. The results demonstrate that this method is simple, sensitive, selective, and suitable for the quality control of this commonly used Chinese medicinal herb.     

Isolation and characterization of triterpenes from the leaves of Orthosiphon stamineus

Orthosiphon stamineus, Benth, belonging to the family Lamiaceae, is a medicinal plant growing wild in tropical countries. Seven triterpenes, ursolic acid, oleanolic acid, betulinic acid, hydroxybetulinic acid, maslinic acid, α-amyrin and β-amyrin have been isolated from the leaves of Orthosiphon stamineus. The structures of these compounds have been established by spectroscopic methods. α-Amyrin was isolated from this plant for the first time.     

Olive-Derived Triterpenes Suppress SARS COV-2 Main Protease: A Promising Scaffold for Future Therapeutics

SARS CoV-2 pandemic is still considered a global health disaster, and newly emerged variants keep growing. A number of promising vaccines have been recently developed as a protective measure; however, cost-effective treatments are also of great importance to support this critical situation. Previously, betulinic acid has shown promising antiviral activity against SARS CoV via targeting its main protease. Herein, we investigated the inhibitory potential of this compound together with three other triterpene congeners (i.e., ursolic acid, maslinic acid, and betulin) derived from olive leaves against the viral main protease (M^pro) of the currently widespread SARS CoV-2. Interestingly, betulinic, ursolic, and maslinic acids showed significant inhibitory activity (IC₅₀ = 3.22–14.55 µM), while betulin was far less active (IC₅₀ = 89.67 µM). A comprehensive in-silico analysis (i.e., ensemble docking, molecular dynamic simulation, and binding-free energy calculation) was then performed to describe the binding mode of these compounds with the enzyme catalytic active site and determine the main essential structural features required for their inhibitory activity. Results presented in this communication indicated that this class of compounds could be considered as a promising lead scaffold for developing cost-effective anti-SARS CoV-2 therapeutics.     

Determination of oleanolic and ursolic acid in Chinese herbs using HPLC and γ-CD as mobile phase modifier

To separate and determine oleanolic acid and ursolic acid, a rapid and accurate HPLC using γ‐CD as the mobile phase additive was developed. The effect of CD nature and concentration, and the acidity of the mobile phase on the chromatographic behavior of two bioactive triterpenes were systematically studied. Two bioactive triterpenes were completely separated (R = 3.11) on a Kromasil^® C₁₈ column (150×4.6 mm id, 5 μm) with the mobile phase consisting of acetonitrile/0.1% phosphoric acid with 2 mM γ‐CD as the mobile phase modifier (60:40, v/v). The flow rate was set at 1.0 mL/min and the eluent was detected at 210 nm for two bioactive triterpenes. The linearity of the method was excellent (r=0.9999) over the studied range of 6–300 μg/mL for oleanolic acid, and 12–600 μg/mL for ursolic acid. The LOD and LOQ were 1.5 and 5.0, 1.0 and 3.0 μg/mL for oleanolic acid and ursolic acid, respectively. The optimized method was successfully applied to separate and determine two bioactive triterpenes in five Chinese herbs. It is concluded that this method could be used for rapid and accurate qualitative and quantitative analysis of the two bioactive triterpenes in Chinese herbs.     

Quality assessment of Fructus Ligustri Lucidi by the simultaneous determination of six compounds and chemometric analysis

A comprehensive strategy was designed for the quality assessment of Fructus Ligustri Lucidi, a well‐known and commonly used herbal medicine in clinical practice in China. First, a simple and stable method of high‐performance liquid chromatography was developed for the simultaneous quantitative analysis of six compounds, namely, salidroside, nuzhenide, specnuezhenide, oleanic acid, ursolic acid, and acetyl oleanic acid in Fructus Ligustri Lucidi. The separation of analytes was conducted on a C₁₈ column (200 mm × 4.6 mm, 5 μm) at 30°C, and the wavelength of UV detector was set at 210 nm. In quantitative analysis, all of the calibration curves showed good linear regression (R² > 0.9994) within the tested ranges, and the mean recoveries of three different concentrations ranged from 95.21–102.34%. The described method was applied to determine 11 batches of samples collected from different stores in China. Then multiple chemometrics analysis including hierarchical cluster analysis and principal component analysis were performed to classify samples and search significant compounds. Three notable compounds, specnuezhenide, oleanic acid, and acetyl oleanic acid, were discovered for better quality control compared with those stated in the China pharmacopeia. The results demonstrated that this strategy could be readily utilized for the comprehensive quality control of Fructus Ligustri Lucidi.     

Quantitative determination of three pentacyclic triterpenes from five Swertia L. species endemic to Western Ghats,India, using RP-HPLC analysis

Aim of this study was to identify pentacyclic triterpenoids betulinic acid (BA), oleanolic acid (OA) and ursolic acid (UA) from five Swertia species endemic to Western Ghats, which are used as substitutes as well as adulterants to Swertia chirayita. Our results indicate that the concentration of active compound vary largely among and within the species from different localities. OA was found in a higher amount in all species compared to BA and UA. From the results, it was clear that BA, OA and UA are present in the endemic species collected from Western Ghats, thus advocating the use of these species as alternate sources to S. chirayita. This in due course may release pressure of exploitation from natural resources of S. chirayita and help to bring it out from an endangered category from conservation point of view.     

Analysis of four pentacyclic triterpenoid acids in several bioactive botanicals with gas and liquid chromatography and mass spectrometry detection

Several pentacyclic triterpenoid acids including betulinic, oleanolic, and ursolic acids were reported to have health beneficial properties such as antiviral and anti‐inflammatory properties, as well as the capability to inhibit “in vitro” the development of various cancer cell types. For this reason betulinic, oleanolic, and ursolic acids are used as neutraceuticals. For the analysis of the pentacyclic triterpenoid acids in complex plant materials, an improved scheme was developed, involving a qualitative screening using silylation and gas chromatography with mass spectrometry analysis, followed by quantitation using a novel liquid chromatography with tandem mass spectrometry procedure. The use of the two methods provides more reliable information regarding the plant materials with unknown composition. Besides betulinic, oleanolic, and ursolic acids that were analyzed, by this procedure a fourth pentacyclic triterpenoid acid was identified and quantitated that was not previously reported to be present in plants. This acid has been identified as 3β‐3‐hydroxy‐lupa‐18,20(29)‐dien‐28‐oic acid. The newly identified acid has a structure as a derivative of lupane, although lupane with a double bond in the 18‐position was not previously reported as present in plants. The new liquid chromatography with tandem mass spectrometry procedure developed for this study offers a very low limit of quantitation, excellent precision, and robustness. Rosemary was found to contain the largest levels of pentacyclic triterpenoid acids among all the analyzed botanicals.     

Three Novel 24,30‐Dinortriterpenoids,Paeonenoides A–C,from Paeonia veitchii

Three novel 24,30‐dinortriterpenoids named paeonenoides A–C ( 1 – 3 ) and the four related acetonide derivatives 4 – 7 , most likely artifacts of isolation, together with a known triterpenoid, akebonic acid ( 8 ), were isolated from the root cortex of Paeonia veitchii. Their structures were established by spectroscopic means. The 24,30‐dinor skeleton of triterpenoids occurs rarely in nature.     

Triterpenoid‐Based Self‐Healing Supramolecular Polymer Hydrogels Formed by Host–Guest Interactions

Pentacyclic triterpenoids, a class of naturally bioactive products having multiple functional groups, unique chiral centers, rigid skeletons, and good biocompatibility, are ideal building blocks for fabricating versatile supramolecular structures. In this research, the natural pentacyclic triterpenoid glycyrrhetinic acid (GA) was used as a guest molecule for β‐cyclodextrin (β‐CD) to form a GA/β‐CD (1:1) inclusion complex. By means of GA and β‐CD pendant groups in N,N′‐dimethylacrylamide copolymers, a supramolecular polymer hydrogel can be physically cross‐linked by host–guest interactions between GA and β‐CD moieties. Moreover, self‐healing of this hydrogel was observed and confirmed by step‐strain rheological measurements, whereby the maximum storage modulus occurred at a [GA]/[β‐CD] molar ratio of 1:1. Additionally, these polymers displayed outstanding biocompatibility. The introduction of a natural pentacyclic triterpenoid into a hydrogel system not only provides a biocompatible guest–host complementary GA/β‐CD pair, but also makes this hydrogel an attractive candidate for tissue engineering.     

Triterpenoids from the Edible Leaves of Photinia serrulata

Five new triterpenoids, serrulatins A–E ( 1 – 5 ), including two new artifacts, together with ten known serrulatins, were isolated from the edible leaves of Photinia serrulata after extraction and purification. Their structures were identified on the basis of spectroscopic methods including 2D NMR experiments. Compounds 1 and 3 are unusual ursolic triterpenoids characterized by the occurrence of a C(13)?C(18) bond.     

New Triterpenoid Fatty Acid Esters from the Small Twigs of Viburnum Odoratissimum

α‐Amyrin margarate ( 1 ), moretenyl margarate ( 2 ) and moretenyl palmitate ( 3 ), three triterpenoid fatty acid esters, have been isolated from the acetone extract of the small twigs of Viburnum odoratissimum in addition to the three known compounds, α‐amyrin palmitate ( 4 ), ursolic acid ( 7 ) and vibsanin‐K ( 8 ). The structures of compounds 1–3 were elucidated based on extensive spectroscopic analysis and alkaline hydrolysis. Preliminary pharmacological studies revealed that vibsanin‐K and ursolic acid exhibited significant cytotoxicity against human gastric (NUGC) and oral epidermoid (HONE‐1) tumor cells at a concentration of 50 μg/mL while compounds 1–3 were inactive.     

Optimization of microwave‐assisted extraction followed by RP‐HPLC for the simultaneous determination of oleanolic acid and ursolic acid in the fruits of Chaenomeles sinensis

An optimized microwave‐assisted extraction (MAE) method and an efficient HPLC analysis method were developed for fast extraction and simultaneous determination of oleanolic acid and ursolic acid in the fruit of Chaenomeles sinensis. The open vessel MAE process was optimized by using a central composite experimental design. The optimal conditions identified were microwave power 600 W, temperature 52°C, solvent to material ratio 32 mL/g and extraction time 7 min. The results showed that MAE is a more rapid extraction method with higher yield and lower solvent consumption. The HPLC–photodiode array detection analysis method was validated to have good linearity, precision, reproduction and accuracy. Compared with conventional extraction and analysis methods, MAE–HPLC–photodiode array detection is a faster, convenient and appropriate method for determination of oleanolic acid and ursolic acid in the fruits of C. sinensis.