UHPLC/HR‐ESI‐MS/MS Profiling of Phenolics from Tunisian Lycium arabicum Boiss. Antioxidant and Anti‐lipase Activities’ Evaluation

This study was performed in the aim to evaluate nine different extracts from Tunisian Lycium arabicum for their total phenolic and total flavonoid contents, phytochemical analyses as well as their antioxidant and anti‐lipase activities. The in vitro antioxidant property was investigated using three complementary methods (DPPH, ferric reducing antioxidant power (FRAP), and β‐carotene‐linoleic acid bleaching assays) while anti‐lipase activity was evaluated using 4‐methylumbelliferyl oleate method. From all of the tested extracts the most potent found to be the polar MeOH extracts especially those of stems and leaves. In order to investigate the chemical composition of these extracts and possible correlation of their constituents with the observed activities, an UHPLC/HR‐ESI‐MS/MS analysis was performed. Several compounds belonging to different chemical classes were tentatively identified such as rutin and kampferol rutinoside, the major constituents of the leaves, and N‐caffeoyltyramine, lyciumide A, N‐dihydrocaffeoyltyramine as well as fatty acids: trihydroxyoctadecadienoic acid and hydroxyoctadecadienoic acid isomers were detected abundantly in the stems. These results showed that the MeOH extracts of stems and leaves of L. arabicum can be considered as a potential source of biological active compounds.     

Recent development of chemical components in propolis

Propolis is a resinous substance collected by honeybees from various plant sources. On account of its chemical composition, propolis possesses several biological and pharmacological properties. In recent years, many papers have provided information concerning its composition. This review compiles data from most studies of propolis, focusing on the chemical composition of ethanol extracts of propolis (EEP), water extracts of propolis (WEP), and volatile oils from propolis (VOP). The characteristic compounds of EEP are polyphenols including flavonoids and related phenolic acids, and flavonoids are the most abundant and effective parts. They are considered to contribute more to the antibacterial, antiviral, and antioxidant effects than the other constituents. The main flavonoids in EEP are pinocembrin, galangin, chrysin, quercetin, kaempferol, and naringenin. The constituents reported to be in WEP include phenolic acids, caffeoylquinic acid, 3-mono-O-caffeoylquinic acid, caffeic acid, flavonoids, etc. The propolis volatile compounds are benzyl alcohol, benzyl acetate, cinnamic alcohol, vanillin, eudensmol, cyclohexyl benzoate, and benzyl benzoate, which are responsible for several biological properties. As a natural mixture, propolis is widely used in medicine and cosmetics, as well as being a constituent of health foods. Since propolis has been used extensively, information on its composition is not only of interest to the academic field, but also to propolis users.     

Comparative Evaluation of the Chemical Composition,Antioxidant and Antimicrobial Activities of the Volatile Oils of Hawk Tea from Six Botanical Origins

In this study, volatile oils of six Hawk tea varieties were studied for their chemical composition, antioxidant and antimicrobial activities to screen the most suitable botanical origins of Hawk tea. A total of 72 components were separated and identified from the six oils. The major constituents of the volatile oils were: α‐pinene, camphene, limonene, 1,8‐cineole, linalool, cis‐nerolidol, and germacrene B. Moreover, the volatile oils were evaluated for antioxidant potential and antimicrobial activities. The results showed that all volatile oils exhibited acceptable antioxidant and antimicrobial activities, which suggested that these volatile oils may serve as natural alternatives to synthetic antioxidants and preservatives to be applied in food and pharmaceutical industries. Principal component analysis results denoted that some major compounds may be closely related to the antioxidant and antimicrobial activities. It also showed that the volatile oils from Litsea coreana var. lanuginosa and Litsea pungens Hemsl . were characterized by positive values of first two principal components, indicating higher active chemical compounds and antioxidant and antimicrobial activities compared with other species. Thus, they were temporarily considered as good sources of Hawk tea.     

Bioactive Attributes and Analysis of Electronic Nose Feature Signals of Colombian Stingless Bees Propolis

The volatile and non-volatile chemical composition and bioactivity of propolis from the species Apis mellifera has been widely studied, but there is very little knowledge regarding propolis of other bee species, which ultimately hinders their differentiation and potential use. In this work, 53 propolis samples of A. mellifera and four stingless bee species (Frieseomielitta sp., Melipona eburnea, Melipona sp., and Trigona sp.) were collected in Colombia. An electronic nose with 10 metal oxide semiconductor sensors (MOS) was used to generate a pattern of the representative volatile compounds of the samples. Ethanolic extracts were obtained to assess their antioxidant activity towards DPPH radical and ABTS radical cation, total phenolics, and color (CIELAB space). The results showed an overall similarity of the aromatic profiles between species. The antioxidant activity of Frieseomielitta sp. propolis was higher than that of A. mellifera and the other species, in correspondence with a higher phenolic content. CIELAB color parameter b* was the most differentiating variable among samples, indicating a variation of propolis colors between red and yellow. By combining the data from physico-chemical analysis and aromatic profile, it was possible to differentiate the propolis from each bee species, with the exception of those from Melipona sp. and Trigona sp., indicating their similarity. These results have practical significance since they are a starting point to recognizing and valuing native stingless bee propolis and their bioactive potential, which, in addition to geographical differentiation and further quality parameters evaluation, will enhance their commercial exploitation.     

Profiling the Lipophilic Fractions of Pithecellobium dulce Bark and Leaves Using GC/MS and Evaluation of Their Antioxidant,Antimicrobial and Cytotoxic Activities

Pithecellobium dulce has been used in traditional medicine to treat various ailments owing to its restorative properties. The biological activities and chemical profiles of the lipophilic fraction of P. dulce bark and leaves were assessed herein. Fatty acid methyl esters (FAME) and unsaponifiable matter (USM) were prepared and analyzed by GC/MS. A total of 40 compounds were identified in the bark saponifiable fraction, whereas 9 compounds were annotated in the leaves. Palmitic acid methyl ester was the major compound identified accounting for 41.48 % of the bark and 19.03 % of the leaves composition. Besides, linolenic acid methyl ester (22.40 %) and linoleic acid (12.69 %) were annotated in the leaves saponifiable fraction. A total of 63 compounds were detected in the bark USM and 4 compounds were identified in the leaves. Phytol represented the major component in the leaves (52.57 %) followed by lupeol (20.68 %) and lupenone (8.60 %). Meanwhile, n‐dodecane dominated in the bark USM accounting for 24.69 % of the total composition. The leaves and bark lipophilic fractions revealed moderate antioxidant and antibacterial activities. Both extracts showed no antifungal activity. No cytotoxicity was observed for both lipophilic fractions. P. dulce offers a good source of antioxidant compounds that can be introduced to food and pharmaceutical industry.     

Egyptian propolis: 3. Antioxidant,antimicrobial activities and chemical composition of propolis from reclaimed lands

The free radical scavenging effect of two propolis samples collected from reclaimed land, Egypt as well as of vitamin C and caffeic acid in 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical system was determined. The antimicrobial (Staphylococcus aureus; Escherichia coli and Candida albicans) activity was also investigated. The results of the free radical scavenging effect of El-Saff and Ismailia propolis showed a concentration-dependent activity. The antioxidant activity was varied according to the examined material. It was obvious that caffeic acid and vitamin C showed the highest activity if compared with the propolis samples. El- Saff propolis had a higher antioxidant activity than Ismailia propolis, it showed a higher antibacterial activity against Staphylococcus aureus and a higher anti-fungal activity against Candida albicans. While the Ismailia propolis had a higher antibacterial activity against Escherichia coli, than El-Saff propolis. The chemical composition of propolis samples was investigated by GC/MS, where 75 compounds were identified, 22 being new for propolis. The Ismailia propolis was characterized by the presence of a highly significant amount of aromatic acid esters (47.3%) and triterpenoids (17.3%), while El-Saff propolis contained 3% and 1.9% respectively. The new esters belonged to 4-methoxyhydrocinnamic acid, hydroferulic acid and ferulic acid. El-Saff propolis had a very high significant amount (27%) of 2,6-bis-(pentanyloxy)-4-pentanylphenethanol, which is also a new compound for propolis.     

A validated spectrophotometric method for quantification of prenylated flavanones in pacific propolis from Taiwan

Introduction – Because of its chemical diversity, the only way to standardise propolis is to specify multiple standards for different propolis types according to the corresponding chemical profile. So far, this has been done only for European propolis. Objective – To develop a rapid low‐cost spectrophotometric procedure for quantification of bioactive prenylated flavanones in Taiwanese propolis. Methodology – The proposed method quantifies the total flavanones on the basis of their absorption as coloured phenylhydrazones formed by interaction with 2,4‐dinitrophenylhydrazine. The procedure was validated through model mixture of compounds representing the composition of Taiwanese propolis according to previous studies. The major flavanones of the propolis samples (propolins C, D, F and G) were quantified by HPLC. Antiradical activity against DPPH was also measured. The DNP (dinitrophenylhydrazine) spectrophotometric method is applied for the first time for quantification of prenylated flavanones. Results – Spectophotometric procedure applicable to new type propolis (Macaranga type) was developed with recovery between 105 and 110% at the concentration range of 0.573–1.791 mg/mL. Six propolis samples were analysed by spectrophotometry using the procedure developed and validated, and by HPLC as the results demonstrated satisfactory agreement. Neither the spectrophotometric data nor the values measured by HPLC showed significant correlation with the antiradical activity against DPPH. Conclusion – The proposed spectrophotometric procedure is useful for routine analyses of Macaranga‐type propolis, because of its simplicity, repeatability and acceptable accuracy. Its application to a number of commercial samples could be used as a basis for standardisation and quality control of Pacific propolis. Copyright © 2009 John Wiley & Sons, Ltd.     

Chemical properties and antioxidant and antimicrobial activities of slovenian propolis

The chemical composition as well as the antioxidant and antimicrobial activities of two EtOH extracts of propolis (PEEs) from Slovenia were determined. EtOH was used as extracting solvent at 70 and 96%, providing the extracts PEE70 and PEE96, respectively. The extraction with 70% EtOH was more efficient than that with 96% EtOH, as the PEE70 was richer in total phenolic compounds than the PEE96. The Slovenian propolis was characterized by different phenolic acids and flavonoids. The PEE96 was slightly richer in three specific compounds, i.e., caffeic acid, ferulic acid, and luteolin, while all other substances detected showed higher contents in the PEE70. The PEE70 showed a stronger reducing power and ability to scavenge free radicals and metal ions than the PEE96. Both PEEs were in the main more effective against Gram-positive bacteria than against fungi and Gram-negative bacteria like Salmonella and Escherichia coli, with the exception of Campylobacter. The PEE96 decreased the intracellular oxidation in Saccharomyces cerevisiae in a dose-dependent manner. The antimicrobial activities and antioxidant properties were related to the total phenolic contents. The two PEEs have the potential for use as natural antimicrobial and antioxidant additives in foods.     

Comparison of Phytochemical Composition and Biological Activities of Rubus ulmifolius Extracts Originating from Four Regions of Tunisia

In the current study, the phenolic composition, antioxidant and antimicrobial activities of extracts from Rubus ulmifolius Schott leaves harvested in four localities (Sejnen, Tabarka, Faija and Ain drahem) in Tunisia were investigated for the first time. Great differences were found for the chemical composition, total phenol contents and biological activities among the evaluated extracts. HPLC analysis of methanolic extracts showed that the dominant compounds were kaempferol 3‐O‐rutinoside and naringenine. In addition, significant correlations were observed between antioxidant activities and phenolic contents. In fact, leaves collected from Sejnen presented higher total phenol content (53.32 mg GAE/g DW) and antioxidant activities (IC₅₀ = 39.40 mg/l) than the others samples. All extracts showed significant antimicrobial activity against six used bacteria with the inhibition zones diameters and minimal inhibitory concentration values were in the range of 8 – 16 mm and 6.25 – 25 mg/ml, respectively. The highest antimicrobial activities were recorded in Sejnen extract against Gram‐positive bacteria.     

A New Type of Anatolian Propolis: Evaluation of Its Chemical Composition,Activity Profile and Botanical Origin

This study was undertaken to analyze the phenolic profiles of 19 propolis samples from Turkey by using a high‐performance thin‐layer chromatographic (HPTLC) method in order to identify their plant origins. Furthermore, their antioxidant and antimicrobial activity profiles were comparatively evaluated. For the appraisal of antioxidant potential, total phenolic (TPC) and total flavonoid contents (TFC) of propolis samples were firstly determined and then their effects on free radicals were evaluated by FRAP, ABTS^.+, CUPRAC, DPPH^. and HPTLC‐DPPH^. methods. Antimicrobial activity of propolis samples against Staphylococcus aureus (ATCC 6538), Pseudomonas aeruginosa (ATCC 15442), Escherichia coli (ATCC 11229) and Candida albicans ATCC 10231 were determined by disc diffusion and broth dilution methods. HPTLC fingerprinting analyses revealed that O‐type (botanical origin from Populus nigra L.) was the primarily available propolis type in Turkey. Moreover, 3‐O‐methylquercetin (3MQ) rich propolis was identified as a new propolis type for the first time. Principal component analysis (PCA) indicated that 3MQ‐type propolis differs from the O‐type. Antioxidant activity studies showed that O‐type of propolis possesses higher antioxidant effect than the other tested propolis types. Quercetin, caffeic acid, caffeic acid phenethyl ester (CAPE) and galangin were determined to contribute significantly to the antioxidant potential of O‐type propolis among others. Propolis extracts exerted moderate antimicrobial activity against the tested microorganisms with MIC values between the ranges of 128–512 μg/mL.     

Analysis of bioactive compounds and chemical composition of Malaysian stingless bee propolis water extracts

Propolis is a resinous substance collected by stingless bees containing bioactive compounds which exert various biological properties. The present study focused on the evaluation of chemical profiles produced by three Indo-Malayan stingless bee propolis extracted using water. Fresh propolis was collected from the same area and ecosystem conditions in Selangor, Malaysia, namely Tetrigona apicalis, Tetrigona binghami, and Heterotrigona fimbriata. The bioactive compounds and chemical composition of propolis extracts were then analyzed using gas chromatography–mass spectrometry (GC–MS). Results showed that propolis from the three different stingless bee species consisted of major groups such as sugar (31.4%), carboxylic acid (17.1%), terpenoid (14.3%), sugar alcohol (11.4%), hydrocarbon (5.7%), aldehyde (5.7%) amino acid (2.9%) and other constituents (11.4%). Heterotrigona fimbriata displayed the highest amount for both total phenolics (13.21 mg/mL) and flavonoids (34.53 mg/mL) compared to other propolis extracts. There is also no significant difference detected between all samples since p ≤ 0.05. In conclusion, this study shows that Malaysian stingless bee propolis contain bioactive components that have great potential to be used for their therapeutic and medicinal benefits. However, more investigations and analysis of stingless bee propolis need to be carried out in order to enhance the understanding and applications of propolis in the future.     

Comparative Studies of Phytochemical Screening,HPLC‐PDA‐ESI‐MS/MS‐LC/HR‐ESI‐MS Analysis,Antioxidant Capacity and in Vitro Fermentation of Officinal Sage (Salvia officinalis L.) Cultivated in Different Biotopes of Northwestern Tunisia

We aimed in the present study to investigate the chemical composition, the antioxidant capacities as well as the in vitro fermentation properties of Salvia officinalis leaves aqueous extract (SOLAE) grown in four regions of northwestern Tunisia. Our data firstly indicated a spatial variation (P<0.05) in condensed tannins, total lipids, polyphenols and flavonoids contents. The HPLC‐PDA‐ESI‐MS/MS‐LC/HR‐ESI‐MS technique allowed to the identification of 13 phenolic compounds and showed that protocatechuic acid is the major constituent of the plant leaves grown in Tabarka, Ain Draham and Testour. The SOLAE of the plant grown in Tabarka presents the most potent scavenging activity against DPPH radical and had the highest percentage of inhibition. More importantly, we found in the present study that the digestibility of dry matter and in vitro fermentation showed a significant variation between the regions and the animal species. Also, we showed a very positive correlation between antioxidant properties and phenolic compounds contents. In conclusion, we suggest that SOLAE had potential beneficial effects owing in part to its antioxidant and ROS scavenging activities. Therefore, S. officinalis can be proposed as an additive food for animals’ nutrition and health.     

Antioxidant,Anti‐inflammatory and Cytotoxic Activities of Polyphenols Extracted from Chroogomphus rutilus

Chroogomphus rutilus is a rare fungal species that grows under pine trees and is now widely used as a functional food and pharmaceutical product. However, the chemical constituents and biological activities of Chroogomphus rutilus have been relatively limited. The present study aimed at determining the total polyphenols and flavonoids contents, biological activities and main phenolic compounds of Chroogomphus rutilus from different geographical origins at the stipe and pileus. The results suggested that Chroogomphus rutilus polyphenol extracts revealed a higher antioxidant, anti‐inflammatory, and cytotoxic activities, and there were significant differences between samples from different locations and regions. Correlation analysis showed that the contents of total polyphenols and flavonoids were significantly correlated with antioxidant and anti‐inflammatory activities. However, only the content of total flavonoids was significantly correlated with cytotoxicity, which means that the cytotoxicity of Chroogomphus rutilus polyphenol extracts may be regulated by flavonoids or other compounds. HPLC‐DAD analysis revealed that the main phenolic compound was protocatechuic acid, followed by baicalin, p‐hydroxyphenylacetic acid and p‐hydroxybenzoic acid, but comparing with the pileus extracts, the stipe extracts can be considered as a higher concentration of phenolic compounds. Therefore, antioxidant, anti‐inflammatory and cytotoxic activities of Chroogomphus rutilus polyphenol extracts could be due to the identified compounds. This study investigated a deep knowledge about the constituents and activities of Chroogomphus rutilus and provided the reference for its application in food and pharmaceutical.     

Comprehensive Study of Mediterranean (Croatian) Propolis Peculiarity: Headspace,Volatiles, Anti‐Varroa‐Treatment Residue,Phenolics, and Antioxidant Properties

Eight propolis samples from Croatia were analyzed in detail, to study the headspace, volatiles, anti‐Varroa‐treatment residue, phenolics, and antioxidant properties. The samples exhibited high qualitative/quantitative variability of the chemical profiles, total phenolic content (1,589.3–14,398.3 mg GAE (gallic acid equivalent)/l EtOH extract), and antioxidant activity (11.1–133.5 mmol Fe²⁺/l extract and 6.2–65.3 mmol TEAC (Trolox^® equivalent antioxidant capacity)/l extract). The main phenolics quantified by HPLC‐DAD at 280 and 360 nm were vanillin, p‐coumaric acid, ferulic acid, chrysin, galangin, and caffeic acid phenethyl ester. The major compounds identified by headspace solid‐phase microextraction (HS‐SPME), simultaneous distillation extraction (SDE), and subsequent GC‐FID and GC/MS analyses were α‐eudesmol (up to 19.9%), β‐eudesmol (up to 12.6%), γ‐eudesmol (up to 10.5%), benzyl benzoate (up to 28.5%), and 4‐vinyl‐2‐methoxyphenol (up to 18.1%). Vanillin was determined as minor constituent by SDE/GC‐FID/MS and HPLC‐DAD. The identified acaricide residue thymol was ca. three times more abundant by HS‐SPME/GC‐FID/MS than by SDE/GC‐FID/MS and was not detected by HPLC‐DAD.     

Recent development of chemical components in propolis

Propolis is a resinous substance collected by honeybees from various plant sources. On account of its chemical composition, propolis possesses several biologi-cal and pharmacological properties. In recent years, many papers have provided information concerning its composi-tion. This review compiles data from most studies of propolis, focusing on the chemical composition of ethanol extracts of propolis (EEP), water extracts of propolis (WEP), and volatile oils from propolis (VOP). The characteristic compounds of EEP are polyphenols includ-ing flavonoids and related phenolic acids, and flavonoids are the most abundant and effective parts. They are considered to contribute more to the antibacterial, antiviral, and antioxidant effects than the other constituents. The main flavonoids in EEP are pinocembrin, galangin, chrysin, quercetin, kaempferol, and naringenin. The constituents reported to be in WEP include phenolic acids, caffeoylquinic acid, 3-mono-O-caffeoylquinie acid, caffeic acid, flavonoids, etc. The propolis volatile compounds are benzyl alcohol, benzyl acetate, cinnamic alcohol, vanillin, eudensmol, cyclohexyl benzoate, and benzyl benzoate, which are responsible for several biological properties. As a natural mixture, propolis is widely used in medicine and cosmetics, as well as being a constituent of health foods. Since propolis has been used extensively, information on its composition is not only of interest to the academic field, but also to propolis users.     

LC/MS/MS Phenolic Profile,Antioxidant Capacity,Angiotensin-Converting Enzyme (ACE) and Glutathione S Transferase (GST) Inhibitory Properties of Ultrasound-Assisted Propolis Extracts

Resinous beehive product propolis has many biological activities. It contains various aromatic substances that have great differences in their chemical composition depending on the natural flora. Thus, chemical characterization and biological properties of propolis samples is an important subject for the pharmaceutical industry. In this study, the propolis samples collected from three cities in Turkey were prepared as methanol (MEP), ethanol (EEP), chloroform (ChlEP), hexane (HxEP), and ethyl acetate (EAEP) extracts using an ultrasonic assisted technique. The antioxidant capacities of the samples were evaluated by free radical scavenging activity (DPPH), cation radical scavenging activity (ABTS), and reducing activity (CUPRAC) and (FRAP). The strongest biological activities were detected in ethanol and methanol extracts. Enzyme inhibition of the propolis samples were determined against the human glutathione S-transferase (GST) and angiotensin converting enzyme (ACE). IC₅₀ values of MEP1, MEP2, and MEP3 samples against the ACE were found as 13.9 μg/mL, 14.8 μg/mL, and 12.8 μg/mL, while against the GST IC₅₀ values of MEP1, MEP2, and MEP3 samples were as 5.92 μg/mL, 9.49 μg/mL, and 5.72 μg/mL. To know the possible causes of the biological test results advanced LC/MS/MS method was applied. trans-ferulic acid, kaempferol, and chrysin were found as the most abundant phenolic compounds in each sample. The propolis extracts obtained using the proper solvent have a good potential to be used in pharmaceuticals to treat the diseases related to oxidative damage, hypertension, and inflammation. Finally, the interactions between chrysin, trans-ferulic acid and kaempferol molecules with ACE and GST receptors were analyzed using molecular docking study. Selected molecules interact with active residues by binding to the active site of the receptors.     

Dittrichia graveolens (L.) Greuter Essential Oil: Chemical Composition,Multivariate Analysis,and Antimicrobial Activity

The chemical composition and in vitro antimicrobial activities of Dittrichia graveolens (L.) Greuter essential oil was studied. Moreover, using agglomerative hierarchical cluster (AHC) and principal component analyses (PCA), the interrelationships of the D. graveolens essential‐oil profiles characterized so far (including the sample from this study) were investigated. To evaluate the chemical composition of the essential oil, GC‐FID and GC/MS analyses were performed. Altogether, 54 compounds were identified, accounting for 92.9% of the total oil composition. The D. graveolens oil belongs to the monoterpenoid chemotype, with monoterpenoids comprising 87.4% of the totally identified compounds. The major components were borneol (43.6%) and bornyl acetate (38.3%). Multivariate analysis showed that the compounds borneol and bornyl acetate exerted the greatest influence on the spatial differences in the composition of the reported oils. The antimicrobial activity against five bacterial and one fungal strain was determined using a disk‐diffusion assay. The studied essential oil was active only against Gram‐positive bacteria.     

Chemical Composition and Aroma Evaluation of Essential Oils from Evolvulus alsinoides L.

The aim of this study was to investigate the chemical composition and the odor‐active compounds of the essential oils from Evolvulus alsinoides, which is a well‐known edible and medicinal plant. The volatile compounds in the oils were identified by hydrodistillation (HD) and solvent‐assisted flavor evaporation (SAFE) in combination with GC, GC/MS, GC/O (=olfactometry), aroma extract dilution analysis (AEDA), and relative flavor activities (RFA values). The most abundant compound in the HD oil was cis‐α‐necrodol (12.62%), an irregular monoterpene with a cyclopentane skeleton, which is very unusual in the plant kingdom. In the SAFE oil, the main components included 2‐butoxyethanol (9.01%), benzyl alcohol (8.01%), and γ‐butyrolactone (7.37%). Through sensory analysis, 21 aroma‐active compounds were identified by GC/O. The most intense aroma‐active compounds in the HD oil were hexan‐1‐ol and γ‐nonalactone, both of which showed high RFA values. α‐Methyl‐γ‐butyrolactone and dimethyl sulfone contributed more strongly to the aroma of the SAFE oil. These results imply that the essential oils of E. alsinoides deserve further investigation in the food industry.     

Effect of Egyptian propolis on the susceptibility of LDL to oxidative modification and its antiviral activity with special emphasis on chemical composition

The antioxidant activity of eight Egyptian propolis samples from different localities was evaluated by the antioxidative potential and capacity of the DPPH-ESR signal, superoxide anion generated in the xanthine-xanthine oxidase (XOD) system and low density lipoprotein (LDL) peroxidation assay. As, F, Is and D samples showed the highest antioxidative capacity and potential, respectively. The El, IsR, Is, D and So samples exhibited highly significant antioxidant activity in the XOD system and in LDL peroxidation assays. The antiviral activity of propolis samples was investigated. They showed variations in their activity; sample D induced the highest antiviral activity against Newcastle disease virus and infectious bursal disease virus. 42 Polyphenolic compounds were identified by HPLC; 13 aromatic acids, esters and alcohols were present, 29 flavonoids were identified, 6 of them being new to propolis.     

Phenolic Compounds and Antioxidant Activity of Different Organs of Potentilla fruticosa L. from Two Main Production Areas of China

This report compared the phenolic compounds and antioxidant activity of the leaves, flowers, and stems of Potentilla fruticosa L. collected from two main production areas of P. R. China (Taibai Mountains and the Qinghai Huzhu Northern Mountains). The results indicated that there were significant differences in the phenol contents and antioxidant activities among the different organs and between the two productions. High‐performance liquid‐chromatography analysis indicated that hyperoside, (+)‐catechin, ellagic acid, and rutin were the primary compounds in leaves and flowers; for stems, the content of six phenolic compounds, from two productions, were the lowest. The 1,1‐diphenyl‐2‐picryl hydrazyl (DPPH), 2,2‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid) di‐ammonium salt (ABTS), ferric reducing power (FRAP), lipid peroxidation assays, and microbial test system (MTS) were used to evaluate the antioxidant activity. The results demonstrated that the leaves from two productions exhibited powerful antioxidant activity than other organs, which did not significantly differ from that of the positive control (rutin), followed by the flowers and stems. The correlation between the content of phytochemicals and the antioxidant activities of different organs showed that the total phenol, tannin, hyperoside, and (+)‐catechin contents may influence the antioxidant activity, and these compounds can be used as markers for the quality control of P. fruticosa.