Probing occurrence of phenylpropanoids in Morinda citrifolia in relation to foliar diseases

Accumulation of phenolic compounds in cell walls of different plant organs leading to increased lignification is an early defence response of plants against biotic stress. The aim of this work was to delineate occurrence of cell wall-bound (CWB) phenolic compounds in Morinda citrifolia leaves. Alkaline hydrolysis of the cell wall material of leaf tissues yielded 4-coumaric acid (4-CA) as the major bulk of the phenolic compounds in all Morinda germplasms. Next in line was 4-hydroxybenzoic acid. Other phenolics identified were vanillic acid, 4-hydroxybenzaldehyde, vanillin and ferulic acid. Concentrations of all the CWB phenolics were highest in the germplasm CHN-5, followed by the germplasm CHN-1. Incidentally, these two Morinda germplasms recorded lowest incidence of foliar diseases. Significantly higher amounts of 4-CA in combination with other phenolics may be the reasons for lowest incidence of foliar diseases in CHN-5 and CHN-1 germplasms of M. citrifolia.     

HPLC and GC-MS determination of bioactive compounds in microwave obtained extracts of three varieties of Labisia pumila Benth

Microwave extraction of phytochemicals from medicinal plant materials has generated tremendous research interest and shown great potential. This research highlights the importance of microwave extraction in the analysis of flavonoids, isoflavonoid and phenolics and the antioxidant properties of extracts from three varieties of the Malaysian medicinal herb, Labisia pumila Benth. High and fast extraction performance ability, equal or higher extraction efficiencies than other methods, and the need for small samples and reagent volumes are some of the attractive features of this new promising microwave assisted extraction (MAE) technique. The aims of the present research were to determine the foliar phenolics and flavonoids contents of extracts of three varieties of L. pumila obtained by a microwave extraction method while flavonoid, isoflavonoid and phenolic compounds were analyzed using RP-HPLC. Furthermore, the antioxidant activities were measured by the DPPH and FRAP methods and finally, the chemical composition of the crude methanolic extracts of the leaves of all three varieties were analyzed by GS-MS.     

N-(17-Acyloxy-acyl)-glutamines: novel surfactants from oral secretions of lepidopteran larvae

N-(17-Acyloxy-acyl)-glutamine conjugates such as N-(17-linolenoyloxy-linolenoyl)-glutamine (6), N-(17-linolenoyloxy-linoleoyl)-glutamine (7), N-(17-linoleoyloxy-linolenoyl)-glutamine (8), and N-(17-linoleoyloxy-linoleoyl)-glutamine (9) were identified as novel surfactants in the oral secretion of several lepidopteran larvae (S. exigua, S. littoralis, S. frugiperda, and H. virescens) by LC-MS/MS and chemical degradation. Authentic reference compounds were synthesized via a dissymmetric bis-Wittig approach and confirmed the assigned structures.     

Seasonal effects on bioactive compounds and antioxidant capacity of six economically important brassica vegetables

Research on natural and bioactive compounds is increasingly focused on their effects on human health, but there are unexpectedly few studies evaluating the relationship between climate and natural antioxidants. The aim of this study was analyze the biological role of six different Brassica vegetables (Brassica oleracea L. and Brassica rapa L.) as a natural source of antioxidant compounds. The antioxidant activity may be assigned to high levels of L-ascorbic acid, total phenolics and total flavonoids of each sample. The climate seasons affected directly the concentration of bioactive components and the antioxidant activity. Broccoli inflorescences and Portuguese kale showed high antioxidant activity in Spring-Summer whilst turnip leaves did so in Summer-Winter. The Brassica vegetables can provide considerable amounts of bioactive compounds and thus may constitute an important natural source of dietary antioxidants.     

固相微萃取-气相色谱/质谱测定植物叶片中的挥发性物质

采用固相微萃取（SPME)方法吸附植物叶片中的挥发性物质,然后采用气相色谱/质谱法（GC/MS）分析了挥发性物 质的成分。在45 ℃水浴温度下,采用Polyacrylate(85 μm)固相微萃取头,在广口瓶中植物叶片的上方顶空吸附60 min,然后进行GC/MS分析。结果表明,植物叶片中的挥发性物质得到了很好的分离,受山楂叶螨(Tetraychus vienneis) 危害严重的植物的完好叶片中的挥发性物质均含有顺-3-己烯-1-醇乙酸酯、顺-3-己烯-1-醇丁酸酯和α-法呢烯,且含量 较大。初步确定这些物质是对山楂叶螨具有引诱作用的主要物质,从而为利用天然生物活性物质防治山楂叶螨提供了理论 依据。     

The relationship of nitrogen and C/N ratio with secondary metabolites levels and antioxidant activities in three varieties of Malaysian kacip Fatimah (Labisia pumila Blume)

Kacip Fatimah (Labisia pumila Blume), one of the most famous and widely used herbs, especially in Southeast Asia, is found to have interesting bioactive compounds and displays health promoting properties. In this study, the antioxidant activities of the methanol extracts of leaves, stems and roots of three varieties of L. pumila (var. alata, pumila and lanceolata) were evaluated in an effort to compare and validate the medicinal potential of this indigenous Malaysian herb species. The antioxidant activity determined by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, as well as the total amount of phenolics and flavonoids were the highest in the leaves, followed by the stems and roots in all the varieties. A similar trend was displayed by the ferric reducing antioxidant potential (FRAP) activity, suggesting that the L. pumila varieties possess high foliar antioxidant properties. At low FRAP activity concentrations, the values of the leaves' inhibition activity in the three varieties were significantly higher than those of the stems and roots, with var. alata exhibiting higher antioxidant activities and total contents of phenolics and flavonoids compared to the varieties pumila and lanceolata. The high production of secondary metabolites and antioxidant activities in var. alata were firmly related to low nitrogen content and high C/N ratio in plant parts. The study also demonstrated a positive correlation between secondary metabolite content and antioxidant activities, and revealed that the consumption of L. pumila could exert several beneficial effects by virtue of its antioxidant activity.     

Metabolic fate of dietary volatile compounds in Pieris brassicae

In this work, the evolution of the qualitative and quantitative profile of the volatile fraction of Pieris brassicae after feeding on Brassica oleracea var. acephala (kale) was monitored through time. HS-SPME/GC-MS was applied to both the host plant and the living insect and its excrements. A total of seventy seven compounds (lipoxygenase pathway by-products, nitrogen compounds, norisoprenoids, sulphur compounds, terpenes, among others) were identified. Thirty eight compounds were identified in insect after 2 h of starvation and forty eight compounds in excrements. Qualitative and quantitative changes were detected along time. Dimethyldisulfide, dimethyltrisulfide, limonene and eugenol were major compounds for all analysed times in both matrices, being limonene an important compound in insect after starvation. The accumulation by P. brassicae of some compounds, such as limonene, was verified, suggesting a mechanism by which the insect can take benefit from bioactive constituents from the diet. Along with accumulation, complete excretion of some compounds, including nitrogen bearing compounds, by-products of glucosinolates was detected. These results reflect one of the strategies used to overcome plant barriers, namely detoxification of toxic compounds. The findings contribute to the knowledge of the metabolization of the volatile compounds in insects and contribute to the body of knowledge of this ecologic system.     

A new steroid glycoside and furochromones from Cyperus rotundus L

Further phytochemical investigation of the aerial parts of Cyperus rotundus L. afforded a new steroid glycoside named sitosteryl (6'-hentriacontanoyl)-beta-D-galactopyranoside (4) in addition to three furochromones, khellin (2), visnagin (3) and ammiol (9). Furthermore, benzo-alpha-pyrone (coumarin) (1), salicylic acid (5), caffeic acid (6), protocatechuic acid (7), p-coumaric acid (8), tricin (10) and isorhamnetin (11) were isolated. The structures of these compounds were established by spectroscopic methods. The isolated furochromones were tested for insect antifeedant activity against larvae Spodoptera littoralis when incorporated in artificial diet and offered to larvae in a chronic feeding bioassay. Also, visnagin, khellin and sitosteryl (6'-hentriacontanoyl)-beta-D-galactopyranoside showed strong cytotoxic activity against L5178y mouse lymphoma cells and were also active in the brine shrimp lethality test.     

Ultra‐fast liquid chromatography coupled with electrospray ionization time‐of‐flight mass spectrometry for the rapid phenolic profiling of red maple (Acer rubrum) leaves

The red maple (Acer rubrum) species is economically important to North America because of its sap, which is used to produce maple syrup. In addition, various other red maple plant parts, including leaves, were used as a traditional medicine by the Native Americans. Currently, red maple leaves are being used for nutraceutical and cosmetic applications but there are no published analytical methods for comprehensive phytochemical characterization of this material. Herein, a rapid and sensitive method using liquid chromatography with electrospray ionization time‐of‐flight tandem mass spectrometry was developed to characterize the phenolics in a methanol extract of red maple leaves and a proprietary phenolic‐enriched red maple leaves extract (Maplifa™). Time‐of‐flight mass spectrometry and tandem mass spectrometry experiments led to the identification of 106 phenolic compounds in red maples leaves with the vast majority of these compounds also detected in Maplifa™. The compounds included 68 gallotannins, 25 flavonoids, gallic acid, quinic acid, catechin, epicatechin, and nine other gallic acid derivatives among which 11 are potentially new and 75 are being reported from red maple for the first time. The developed method to characterize red maple leaves phenolics is rapid and highly sensitive and could aid in future standardization and quality control of this botanical ingredient.     

Essential oil and fractions isolated of Laurel to control adults and larvae of cattle ticks

Abstract

This study, was to evaluate the acaricidal effect of the essential oil (EO) and fractions (FR) obtained from Laurus nobilis leaves on Rhipicephalus (Boophilus) microplus. Eight fractions were obtained, however FR1: sabinene (37.83%), β-pinene (13.50%), 1,8-cineole (12.66%), α-pinene (12.56%) and FR8: α-terpineol (79.19%) were highlighted as to the larvicidal potential when submitted by Larval Packet Test. The EO was tested by the Adult Immersion Test, at concentrations of 200.00; 100.00 and 50.00?µL/mL caused mortality of engorged females, egg mass reduction and hatching inhibition. Two fractions are shown to be efficient in controlling larvae FR8 (LC₅₀?=?0.13?µL/mL, LC₉₉?=?0.51?µL/mL) and FR1 (LC₅₀?=?0.20?µL/mL, LC₉₉?=?0.56?µL/mL). The fractionation of EO was determinant to elucidate which compounds were responsible for the larvicidal potential. This study opens new perspectives to direct new bioassays with the compounds obtained in the fractionation, since they present high potential on cattle tick larvae.     

Differential content of secondary metabolites in diploid and tetraploid cytotypes of Siegesbeckia orientalis L.

Siegesbeckia orientalis L. is an annual herb widely distributed throughout the world and has many medicinal properties. In Chinese traditional system, it is popularly known as Xi-Xian and used for its anti-inflammatory properties. In the present study, two cytotypes (diploid and tetraploid) have been investigated for their secondary metabolites. The different plant parts have been explored in terms of total phenolics, total flavonoids, DPPH radical scavenging acitivity and total antioxidant capacity. Out of different plant parts, leaves have the maximum amount of secondary metabolites and antioxidant potential. HPTLC technique has been applied to quantify six marker compounds in the two cytotypes. Tetraploid cytotype has been compared with diploid cytotype, which shows that tetraploid has the maximum amount of studied secondary metabolites with high antioxidant potential.     

In vitro antioxidant and inhibitory activity of water decoctions of carob tree (Ceratonia siliqua L.) on cholinesterases, α-amylase and α-glucosidase

This work reports the in vitro inhibitory activity of water decoctions of leaves, germ flour, pulp, locust bean gum and stem bark of carob tree on α-amylase, α-glucosidase, acetylcholinesterase and butyrylcholinesterase. The antioxidant activity and the chemical characterisation of the extracts made by spectrophotometric assays and by high-performance liquid chromatography are also reported. Leaves and stem bark decoctions strongly inhibited all the enzymes tested, had significant antioxidant activity and the highest total phenolics content. The major compounds were identified as gallic acid in the leaves and gentisic acid in the stem bark.     

A dereplication strategy for the identification of new phenolic compounds from Anvillea radiata (Coss. & Durieu)

Phenolic compounds were selectively extracted from aerial parts of Anvillea radiata using Accelerated Solvent Extraction (ASE) in two steps. Given the two molecular families (flavonoids and germacranolides) described as present in the plant material, a first extraction step using chloroform as the extraction solvent was carried out to remove the germacranolides, the most abundant compounds. The minor phenolic compounds were then selectively extracted and enriched from the plant residue by methanol. Characterization of twenty five phenolic compounds in the methanolic extract was performed using HPLC-DAD-ESI-MS/MS and HPLC-HRMS analyses. Seven compounds corresponded to chlorogenic acid and dicaffeoylquinic acid derivatives and eighteen flavonoids (from which five aglycones and thirteen glycosides) were identified and some of them for the first time.The presence of these phenolic compounds, identified in the whole aerial parts, was then followed in each organ (flower, leave and stem). The chromatographic profiles of the stem and leave were very close, while the flower one was more different. However most of the compounds identified in aerial parts were recovered in each organ, mainly difference on peak intensity could be observed. The most abundant compound in flowers was found to be a di-caffeoylquinic acid derivative while isorhamnetin and spinacitin diglucoside derivatives were the most abundant ones in stems and leaves.     

Blotting Assisted by Heating and Solvent Extraction for DESI-MS Imaging

Imprints of potato sprout (Solanum tuberosum L.), gingko leaves (Gingko biloba L.) and strawberries (Fragaria x ananassa Duch.) were successfully imaged by desorption electrospray ionization mass spectrometry (DESI-MS) on TLC plates through blotting assisted by heating and/or solvent extraction. Ion images showing the distribution of significant compounds such as glycoalkaloid toxins in potato sprout, ginkgolic acids and flavonoids in ginkgo leaves, and sugars and anthocyanidin in strawberry were obtained. Practical implications of this work include analysis of a wide range of irregular or soft materials by different imprinting conditions without requiring the addition of matrices or use of specific kinds of surfaces.

Phenolic compounds of mountain tea from the Balkans: LC/DAD/ESI/MSn profile and content

Twenty-one samples of Sideritis species (S. scardica, S. raeseri, S. taurica, S. syriaca and S. perfoliata) from various locations on the Balkan Peninsula were evaluated for their chemical constituents. Chemical analyses were focused on secondary metabolites, particularly phenolic compounds, which have several roles in the plant physiological processes and have demonstrated significant health beneficial effects. The occurrence of hydroxycinnamic acids, phenylethanoid glycosides and flavonoids has been investigated in taxonomically related taxa of the genus Sideritis. A systematic method for phenolic compounds identification was developed using tandem mass spectrometry coupled to high performance liquid chromatography with diode array detection. Scanning for precursor ions of commonly found phenolics in Sideritis species using LC/MS11 with an ion trap instrument permitted the specific determination of hydroxycinnamic acid derivatives, and phenylethanoid and flavonoid glycosides. Further characterization of each phenolic compound was performed using MS/MS product-ion analysis and common-neutral-loss analysis. This on-line technique allowed identification of three hydroxycinnamic acid derivatives, eight phenylethanoid glycosides, and twenty-four flavonoid glycosides. All the taxa analysed produced very similar phenolic patterns characterized by the presence of 5-caffeoylquinic acid, lavandulifolioside, verbascoside, hypolaetin 7-O-[6'-O-acetyl]-allosyl(1-->2)glucoside, apigenin 7-(4"-p-coumaroylglucoside), 4'-O-methylisoscutellarein 7-O-[6'-O-acetyl]-allosyl(1-->2)glucoside, and minor amounts of isoverbascoside, apigenin 7-O-allosyl(1-->2)glucoside, isoscutellarein 7-O-allosyl-(1-->2)-[6"-O-acetyl]-glucoside, hypolaetin 7-O-allosyl-(1-->2)-[6"-O-acetyl]-glucoside and 4'-O-methylhypolaetin 7-O-[6'-O-acetyl]-allosyl-(1-->2)-[6"-O-acetyl]-glucoside. These results show that the investigated species are systematically very closely related. Phenylethanoid glycosides and flavonoid acetylglycosides are dominant and constitute 90% of the total phenolic compounds compared with hydroxycinnamic acid and flavonoid 7-O-glycosides. Principal component analysis (PCA) was performed for the nature and content of the different compounds to be correlated to the particular Sideritis species and also to the locations.     

Antioxidant,anti-lipidemic,hypoglycemic and antiproliferative effects of phenolics from Cortex Mori Radicis

Cortex Mori Radicis (CMR) is enriched in various phenolics, this study aimed to estimate the antioxidant effect, enzyme (lipase, α-amylase, α-glucosidase and acetyl-cholinesterase) inhibition and the anti-proliferative effect of the phenolic compounds in CMR. However, the amount of these compounds obtained from CMR is highly dependent on the processing conditions. In this study, the processing parameters of extracting the phenolics from CMR using ultrasonic technique pooled with high-speed shearing extraction (UTPHSE) were optimized. Subsequently, the phenolics from Cortex Mori Radicis (PCMR) were purified using AB-8 macroporous resin, and their chemical analysis, antioxidant, enzyme inhibition, and antiproliferative activities were studied. Based on our findings, the optimal parameters of UTPHSE were: L/S ratio 25.8:1 (mL/g), voltage 81.0 V, ultrasonic temperature 51.8 ℃ and ultrasonic time 289 s. And under the optimal extraction conditions, the extraction rate of the PCMR was 0.531 ± 0.004%. Compared with PCMR, the contents of “total phenolics, flavonoids, flavonols, flavanols and phenolic acids” increased 2.30, 2.67, 2.59, 3.63 and 2.72 times in the purified phenolics from Cortex Mori Radicis (PPCMR), respectively. In addition, PPCMR depicted significant DPPH, ABTS⁺ and superoxide anion radicals’ scavenging capability, reducing power, ferric ion reducing antioxidant power (FRAP) and remarkable inhibitory activities on “lipase, alpha-amylase, alpha-glucosidase, and the proliferation of HeLa, HepG2 and NCI-H460”. At the same time, the morphological changes of HeLa, HepG2 and NCI-H460 cells suggested that PPCMR could effectively inhibit the proliferation of tumor cells in vitro. Therefore, PPCMR have good potential as natural antioxidants, antilipidemic, hypoglycemic, and antineoplastic agents in functional foods and pharmaceuticals.     

HPLC-DAD Quantification of Phenolic Compounds Contributing to the Antioxidant Activity of Maclura pomifera,Ficus carica and Ficus elastica Extracts

Abstract

The concentration and antioxidant activity of the known phenolics macluraxanthone, rutin, chlorogenic acid, and psoralen present in M. pomifera, F. carica, and F. elastica extracts were determined to evaluate the plant extracts potency as new antioxidant suppliers.

The quantification of the compounds was obtained by HPLC-DAD. The antioxidant activity of plant extracts and compounds was evaluated using DPPH and ABTS methods. The results seem to indicate that these extracts can be promising as new antioxidant suppliers, particularly F. carica and F. elastica leaves because only about 30% and about 50%, respectively, of the total activity was due to the phenolics determined.     

Domestication of Plants of Ugni molinae Turcz (Myrtaceae) Interferes in the Biology of Chilesia rudis (Lepidoptera: Erebidae) Larvae

In terms of the domestication process in murtilla, studies have found changes in the concentration of phenolic compounds, with reduction of chemical defense of plants, depending on the change in the feeding behavior of insects. Thus, we hypothesized that the domestication of Ugni molinae decreases the content of phenolic compounds and modifies the feeding preference of Chilesia rudis larvae. Leaves of three parental ecotypes and four cultivated ecotypes were used in preference experiments to evaluate the mass gain and leaves consumption of larvae. Phenolic extracts from leaves of U. molinae were analyzed by HPLC. Identified compounds were incorporated in an artificial diet to assess their effect on mass gain, consumption, and survival of the larvae. The presence of phenolic compounds in bodies and feces was also evaluated. In terms of choice assays, larvae preferred parental ecotypes. Regarding compounds, vanillin was the most varied between the ecotypes in leaves. However, plant domestication did not show a reduction in phenolic compound concentration of the ecotypes studied. Furthermore, there was no clear relation between phenolic compounds and the performance of C. rudis larvae. Whether this was because of sequestration of some compounds by larvae is unknown. Finally, results of this study could also suggest that studied phenolic compounds have no role in the C. rudis larvae resistance in this stage of murtilla domestication process.     

Chemical composition and α-amylase inhibitory activity of the essential oil from Sabina chinensis cv. Kaizuca leaves

Sabina chinensis cv. Kaizuca (SCK) is a variant of S. chinensis L. The essential oil from its leaves exhibited α-amylase inhibitory activity in vitro and the IC₅₀ value was 187.08 ± 0.56 μg/mL. Nineteen compounds were identified from this essential oil by gas chromatography–mass spectrometry (GC-MS) analysis. The major compounds identified were bornyl acetate (42.6%), elemol (20.5%), β-myrcene (13.7%) and β-linalool (4.0%). In order to study the reason of the α-amylase inhibitory activity of this essential oil, the identified compounds were docked with α-amylase by molecular docking individually. Among these compounds, γ-eudesmol exhibited the lowest binding energy (?6.73 kcal/mol), followed by α-copaen-11-ol (?6.66 kcal/mol), cubedol (?6.39 kcal/mol) and α-acorenol (?6.12 kcal/mol). The results indicated that these compounds were the active ingredients responsible for the α-amylase inhibitory activity of essential oil from SCK.     

Comparison of continuous subcritical water extraction and hydrodistillation of marjoram essential oil.

Continuous subcritical water extraction (CSWE) and hydrodistillation were compared for the extraction of essential oil from marjoram leaves. Ground marjoram leaves (0.4 g) were subjected to dynamic extraction with water at 50 bar, 150 degrees C and 2 ml/min for 15 min. Hydrodistillation was performed treating 140 g of marjoram leaves with 1000 ml of water for 3 h. When CSWE was used the compounds were removed from the aqueous extract by a single extraction with 5 ml of hexane, detected by gas chromatography-flame ionization detection (GC-FID) and identified by mass spectrometry, electronic impact. The CSWE method is quicker (15 min versus 3 h), provides a more valuable essential oil (with higher amounts of oxygenated compounds and no significant presence of terpenes) and allows substantial savings of costs, in terms both of energy and plant material. The efficiency (in terms of volume of essential oil/1 g of plant) of CSWE is 5.1 times higher than that provided by hydrodistillation. The precision of the overall method (CSWE combined with GC-FID) is good (RSD less than 7.5%) for n = 5.