Lipophilic Extracts Research Articles

Extraction of cones, branches, needles and bark from Norway spruce (Picea abies) by supercritical carbon dioxide and soxhlet extractions techniques

Four low-value Norway spruce tree fractions - cones, branches, needles and bark, were separated from the main tree constituents for investigation of their lipophilic extractives; in order to identify potential sources of important chemicals for future biorefinery applications. For the first time, conventional soxhlet and supercritical carbon dioxide (scCO2) extraction techniques were used for extraction of organic compounds from these waste fractions. Identification and quantitation were done by silylation and GCMS. Soxhlet extraction led to total yields of 4–5 % for all fractions except for cones, where the extraction yield was approximately 2 %. With scCO2 extraction, the highest yield of extractives was obtained from the branches (ca. 5 %), whereas for needles, bark and cones the yield was approximately 3 %, 2 % and 1 %, respectively. Extracts from all four tree fractions contain fatty/resin acids, terpenes, stilbenes, sterols and some long chain alcohols. The components composition was different for each of the four fractions depending on the extraction technique, for example, stilbenes and sterols from branches are effectively obtained only with scCO2 extraction, whereas soxhlet extraction was more efficient for isolating terpenes, sterols and resin derivatives from cones and bark. Needles extractives, e.g. biologically active sterols and nonacosan-10-ol, important for hydrophobic coatings, can be efficiently obtained by both extraction techniques. These obtained results show that these tree fractions, often discarded or combusted, could generate a potentially important source of nutraceutical, pharmaceutical and commodity chemicals.

Exploring Pavlova pinguis chemical diversity: a potentially novel source of high value compounds

To uncover the potential of Pavlova pinguis J.C. Green as a natural source of value added compounds, its lipophilic extracts were studied before and after alkaline hydrolysis using gas chromatography-mass spectrometry (GC-MS). The GC-MS analysis of the lipophilic extracts showed a wide chemical diversity including 72 compounds distributed by fatty acids (29), sterols (14), fatty alcohols (13) and other lipophilic compounds (16). Fatty acids represented the main class of identified compounds presenting myristic, palmitic, palmitoleic and eicosapentaenoic acids as its main components. Through the ∑ω6/∑ω3 ratio (0.25) and sterol composition it was possible to observe that P. pinguis is a valuable source of ω3 fatty acids and stigmasterol (up to 43% of total sterols). After alkaline hydrolysis, fatty acids and fatty alcohols content increased by 32 and 14% respectively, in contrast to, monoglycerides which decreased by 84%. The long chain alcohols content enables the exploitation of this microalga as a source of these bioactive compounds. Smaller amounts of sugars and other compounds were also detected. The present study is a valuable reference to the metabolite characterization of P. pinguis and shows the potential of this microalga for nutraceutical and pharmaceutical industries.

Characterizing the Chemical Composition of Lipophilic Extracts from Acacia mearnsii Wood

The chemical composition of Acacia mearnsii wood extract is described in this paper for the first time. This wood is cultivated in Brazil and has been used to complement the demand for hardwood in the pulp industry. In this study, we performed extractions with acetone (total extracts) and dichloromethane (lipophilic extracts responsible for the pitch formation), with the obtained percentages being 1.68 and 0.68%, respectively. The lipophilic extracts were derivatized and analyzed by Fourier transform infrared spectroscopy (FTIR) and gas chromatography-mass spectrometry (GC-MS) before and after alkaline hydrolysis. The results showed that 57 compounds were detected in the lipophilic extracts and these are mainly constituted by fatty acids ca. 32.8 mg kg-1 and sterols 26.9 mg kg-1. These chemical classes have always been present in pitch deposits in the pulp industry. Therefore, these results may be used by pulp mills to establish strategies for pitch control and represent an important advance in the knowledge of A. mearnsii.

Different Strategies to Obtain Corn (Zea mays L.) Germ Extracts with Enhanced Antioxidant Properties

Maize ( Zea mays L.) germs are by-products from the milling industry. The objective of this work was to compare the phenolic and lipophilic antioxidant fractions of yellow and white corn varieties, provided by Corn Valley S.r.l. (Piumbega, Mantova, Italy) and among the raw materials most processed by the company. The phenolic fraction, extracted with ultrasound-assisted extraction, alone and in combination with chemical and enzymatic hydrolyses, was analyzed with high-performance thin-layer chromatography and reversed-phase high-performance liquid chromatography-diode array detector. Among the various extraction techniques used, the combination of sonication and alkaline hydrolysis proved to be an effective method for the extraction of phenolic compounds from yellow and white germs, with the highest ferulic acid concentrations (636.54 ± 3.71 and 569.23 ± 1.69 mg FA/g dried extract, respectively), total phenolic contents (844.5 ± 64.6 and 742.8 ± 15.44 mg gallic acid equivalents/g dried extract, respectively), and the best antioxidant activity (14.33 ± 0.48 and 11.41 ± 1.1 µg/mL, respectively). The lipophilic fraction, extracted using supercritical carbon dioxide was analyzed by gas chromatography-mass spectrometry. The unsaponifiable fractions were found to be 2.41% ± 0.24% in yellow corn and 1.85% ± 0.08% in white corn; β-sitosterol, campesterol, and stigmasterol were identified as the main phytosterols characterizing both lipophilic extracts which showed the most effective antioxidant activity (1.29 ± 0.26 mg/mL and 1.33 ± 0.21 mg/mL, respectively) compared with the control. Finally, the phenolic and lipophilic extracts obtained from maize by-products may be reintroduced into the health-oriented market as extracts enriched of high-added value biomolecules with antioxidant activity both as active molecules and as additives of natural origin.

Lipophilic extractives of the wood and bark from Eucalyptus pellita F. Muell grown in Merauke, Indonesia

Lipophilic extractives in the dichloromethane extract from Eucalyptus pellita wood and bark were identified by GC-MS. Of the various morphological parts, the bark samples contain more extractives than wood samples. The largest extractive content was measured in the bark of the top part. Four groups (i.e., free fatty acids, sterols-steroids, triterpenoids, and other compounds) were detected in all parts. Palmitic, oleic, and linoleic acids as well as β-sitosterol dominated among of the lipophilic extractives. Long chain fatty acids were the major lipophilic groups in heartwood. Sterols-steroids were the major components in the bottom and top part of the bark. Conversely, triterpenoids and short chain-fatty acids were the minor components in bottom and top part of the bark. Very long-chain fatty acids (i.e., docosanoic, lignoceric, and hexacosanoic) were also observed. The concentration of certain lipophilic constituents, e.g., stigmast-4-en-3-one, squalene, glycerol, oleic, linoleic, hexacosanoic, and β-sitosterol, was affected by position within the tree in axial and radial directions. The higher concentration of long chain fatty acids in the heartwood as well as sterols-steroids in the bark seems to be clearly disadvantage as far as pitch formation is concerned.

Modeling and optimization of supercritical carbon dioxide extraction for isolation of valuable lipophilic constituents from elderberry (Sambucus nigra L.) pomace

Supercritical carbon dioxide extraction (SFE-CO2) was employed and its parameters (pressure, temperature, time) were optimized in order to recover valuable non-polar constituents from elderberry juice processing by-products (pomace). Several other commonly applied hexane-utilizing fractionation techniques, namely pressurized liquid (PLE), ultrasound-assisted (UAE), Soxhlet and conventional solid-liquid (SLE, maceration) extractions, were used for comparison purposes. Under optimal SFE-CO2 conditions (53 °C, 35 MPa, 45 min), 14.05 g of the lipophilic fraction was recovered from 100 g of pomace, containing health beneficial polyunsaturated linoleic (42.0%) and α-linolenic (34.1%) fatty acids. In terms of extraction yields and time, the efficiency of SFE-CO2 was generally higher as compared to conventional Soxhlet and SLE, but lower than PLE and UAE. The cyanogenic glycoside sambunigrin content in elderberry pomace, all lipophilic extracts and extraction residues was very low (6.7–76.6 ng/100 g pomace) as compared to the EFSA’s acute reference dose for HCN (20 μg/kg BW). Generally, a small portion of antioxidants was recovered from elderberry pomace after lipophilic fractionation either with supercritical CO2 or hexane (TPC: 1.5–4.7 mg GAE/g, TEAC: 0.3–11.6 mg TE/g) and defatted elderberry pomace residues retained a considerable amount (>60%) of these bioactives.

Characterization of Hakea sericea Fruits Regarding Chemical Composition and Extract Properties

The chemical composition and anatomy of the woody follicles of the hakea fruits are characterized here for the first time, aiming at an appraisal of their potential valorization. Hakea sericea Schrader is a woody shrub with evergreen needle-like leaves and fruits composed of woody follicles that surround the seed. The woody follicles have two dehiscent valves containing a primary and a secondary wood growth distinguished by dark and pale color respectively. H. sericea was introduced as an ornamental and hedge plant but it became a major problem due to its invasive character. The woody follicles of the hakea fruits had the following chemical composition (dry mass): ash 1.1%, total extractives 7.4% mainly corresponding to polar compounds soluble in ethanol and water, lignin 29.0% and 62.6% polysaccharides. The polysaccharides showed a predominance of xylose (43.2% of total monosaccharides) and glucose (40.5%). The mineral composition of the hakea fruit contains substantial amounts of potassium. The main lipophilic extractives are bilobol derivatives (23.9–41.8% of the extract), alkanols (15.5–26.5%) and saturated alkanoic acids (10.6–13.1%). The ethanol–water H. sericea fruit extract contains total phenolics (186.3 mg GAE/g extract), flavonoids (67.7 mg CE/g extract) and condensed tannins (84.9 mg CE/g extract). The antioxidant activity was weak compared to known antioxidants (271.7 mg Trolox/g extract). H. sericea fruits fracture easily with predominance of larger particles and little formation of fines (5.8% of the total mass). The chemical characterization of different granulometric fractions showed that extractives were present preferentially in the finest fractions, particularly with enrichment in ethanol soluble compounds, with the exception of bilobol derivatives that were present in higher amounts in fines. Most promising valorization routes for the hakea fruits include a fractionation process for hemicelluloses to yield potentially valuable xylo-oligosaccharides (XOS) and the recovery of bilobol derivatives from the lipophilic extract given the potential application of these compounds in medicine.

Lipophilic extracts from leaves, inflorescences and fruits of Prunus padus L. as potential sources of corosolic, ursolic and oleanolic acids with anti-inflammatory activity

Chloroform extracts from leaves, inflorescences and fruits of Prunus padus were analysed for anti-inflammatory activity and accumulation of corosolic (CA), ursolic (UA) and oleanolic (OA) acids. The analytes were identified and quantified by GC-MS and UHPLC-PDA. Their total levels depend on plant material type and harvesting time, and varied from 0.25 mg/g DW in fruits, through 0.76–1.09 mg/g DW in flowers, to 1.41–4.54 mg/g DW in leaves. Significant variation in the leaf analytes contents was observed during vegetation with the peak amounts in autumn, which indicated the optimal harvesting season. The plant extracts inhibited pro-inflammatory enzymes (lipoxygenase and hyaluronidase) in a concentration-dependent manner, and their activity parameters correlated with the levels and activity of pure triterpene acids, especially CA and UA. The results of the comparison with the positive controls (heparin, indomethacin, dexamethasone) might partly support the application of P. padus in anti-inflammatory therapies, reported by traditional medicine.

Combined extracts of Echinacea angustifolia DC. and Zingiber officinale Roscoe in softgel capsules: Pharmacokinetics and immunomodulatory effects assessed by gene expression profiling

Background and objectiveEchinacea angustifolia DC. and Zingiber officinale Roscoe are two natural products with documented immunomodulatory activity, both able to modulate the expression of important immune-related genes. Thus, their use in combination seems to be particularly promising. In this context, we have considered the oral supplementation of a highly standardized lipophilic extract combining both above-mentioned phytocomplexes, formulated in attractive softgel capsules, with two objectives: on the one hand to study oral pharmacokinetic of main active extracts’ components and on the other hand to examine the immunomodulation and anti-inflammatory properties by gene expression profiling. MethodsSoftgel capsules containing a combination of E. angustifolia DC. and Z. officinale Roscoe (5 mg and 25 mg, respectively) were given by oral administration to 10 healthy volunteers. The plasma concentrations of dodeca-2E,4E,8Z,10E/Z-tetraenoic isobutylamide (tetraene) for E. angustifolia DC., 6-gingerol and 6-shogaol (free and glucuronide) for Z. officinale Roscoe were determined by LC-MS analysis, and the pharmacokinetic analysis was performed. To understand the functional mechanisms responsible for the documented health benefits, we also examined the overall transcriptional remodeling induced in the peripheral blood mononuclear cells and performed an integrative functional analysis on the generated gene expression. ResultsAll bioactive components were absorbed very rapidly, and their tmax were detected in plasma from 30 min to 1.40 h. The peak concentrations of tetraene, 6-gingerol, 6-shogaol and their glucuronide metabolites were 14.74, 5.66, 9.25, 29.2 and 22.24 ng/ml, respectively. Integrated analysis performed on the generated gene expression data highlighted immunomodulatory and anti-inflammatory effects similar to those exerted by hydrocortisone. ConclusionThese data demonstrated that the bioactive ingredients are highly and rapidly absorbed from softgel capsules containing the combination of the above-mentioned lipophilic extracts, providing evidence to support their immunomodulatory and anti-inflammatory properties. These data also help in defining the mechanistic pathways underlying the health benefits of these plant-derived bioactive compounds.

Effect of lipophilic sea buckthorn extract on cream cheese properties.

The aim of this study was to evaluate the physico-chemical, microbiological, sensory properties and antioxidant activity of the functional cream cheese prepared with lipophilic extracts of sea buckthorn (Hippophae rhamnoides L.). The first step of the research consisted of an evaluation of the physico-chemical characteristics and the antioxidant capacity of the sea buckthorn lipophilic extracts. The sea buckthorn extracts had a significant antioxidant capacity (67.04 ± 2.67%), a content of total carotenoids of 8.27 ± 0.01mgL-1 and a content of total polyphenols of 1842.86 ± 1.41mg/100gdry vegetal material. The addition of the sea buckthorn extracts did not negatively affect the fresh cream cheese's sensory characteristics. The addition of sea buckthorn extracts to the cream cheese resulted in an increase of antiradical activity and dry matter content, a decrease in acidity and higher growth inhibitition of germs.

Vine Waste Valorisation: Integrated Approach for the Prospection of Bioactive Lipophilic Phytochemicals.

Substantial amounts of vine wastes are produced during vineyard management, and the chemical profiling of high-value lipophilic phytochemicals is becoming crucial in order to find a complementary route towards their integrated valorisation. The prospection of bioactive phytochemicals from unripe grape, vine shoot, vine cane, stalk and leaf dichloromethane extracts was carried out by gas chromatography–mass spectrometry (GC–MS), analysing samples from a mixture of four red Vitis vinifera L. varieties (Baga, Aragonez, Água Santa and Shiraz), collected at Bairrada Appellation, as a representative case study of typical multi-variety Portuguese vineyards. Vine wastes showed distinct amounts of lipophilic extract, ranging from 0.68% (vine canes) to 13.35% (vine leaves) at dry weight (dw). Thirty-three components were identified, including fatty acids and alcohols, sterols and triterpenoids accounting for amounts from 118.9 mg/100 g dw to 1512.0 mg/100 g dw. The integrated study revealed that unripe grape, stalk and leaf dichloromethane extracts stood out as possible sources of triterpenic compounds (103.2 to 653.5 mg/100 g dw), with lupeol, ursolic and oleanolic acids prevailing. Leaf extract is also reported as an undervalued source of α-tocopherol, as the major component detected in this matrix (300.5 mg/100 g dw). These exploratory results are a relevant contribution for the exploitation of undervalued vine residues as a source of health-promoting components with the potential to be used as supplements or nutraceutical ingredients.

Lipophilic fraction and its antioxidant capacity in sixteen spelt genotypes cultivated in Poland

This study analysed the intra-genotype variation of the spelt grain lipid fraction, including the content of total lipids, sterols, tocols, carotenoids, composition of fatty acids and resultant antioxidant capacity (ORAC and DPPH assays) of grain lipophilic extract. The sample material was composed of sixteen spelt genotypes grown under the same environment conditions in Poland (location, climate and agriculture treatment). The obtained results showed relatively narrow intra-genotype variation in determined lipid content, phytochemicals and fatty acid shares, followed by the highest variation in antioxidant capacity. For phytochemicals and antioxidant capacity, the most outstanding was Line 54–76, which was the richest source of sterols and had the highest antioxidant capacity (approx. 2-times higher in relation to other genotypes).

Lipophilic and hydrophilic leaf extracts of Portulaca oleracea (Purslane) disrupts female sex hormones in albino rats (Rattus norvegicus)

Background and aimDecoctions and infusions from the aerial parts of Portulaca oleracea Linn., especially the leaves and stems, are used by traditional medicine practitioners in Nigeria to enhance fertility in humans. The scarcity of literature on the use of this plant for the said purpose as well as its efficacy prompted this research. Study investigated effect of lipophilic and hydrophilic leaf extracts of Portulaca oleracea on oestrous cycle, female sex hormones at various phases of oestrous cycle and ovarian and uterine histomorphology in albino rats. Experimental procedureExperimental animals were randomly divided into 7 groups of 5 rats each. Group A (control) received 0.5 ml 20% Tween 80 (vehicle), groups B, C & D received 125, 250 & 500 mg/kg of the lipophilic extract respectively and E, F & G received 125, 250 & 500 mg/kg of the hydrophilic extract respectively for 21 days. Oestrous cycle was assessed daily. At the end, blood samples (for hormones) and ovarian &uterine sections (histoarchitecture) were collected. Results and conclusionBoth extracts had no significant (p > 0.05) effect on oestrous cycle, ovarian & uterine histoarchitecture and female sex hormones except at proestrus phase where significant (p < 0.05) decrease in LH and FSH was recorded. P.oleracea as used in this study may have deleterious effect on female reproductive system as shown by the disruption of the hormones at proestrus phase. This can form a basis to refute the use of P.oleracea leaf extracts in enhancing fertility as it has been shown to affect the gonadotropins involved in folliculogenesis.

Primary Screening of Antioxidant Activity, Total Polyphenol Content, Carotenoid Content, and Nutritional Composition of 13 Edible Flowers from Japan.

Thirteen edible flowers, which are used as food ingredients in Japan, were evaluated as possible sources of antioxidants and biological compounds. The nutritional composition, total polyphenol content (TPC), carotenoid content, and antioxidant activity of the edible flowers were determined based on the oxygen radical absorbance capacity (ORAC). Water was the main constituent of edible flowers, and carbohydrates were the primary macronutrients. The TPC of the edible flowers varied from 1.47 to 13.08 mg gallic acid equivalent/g fresh weight (FW). Carotenoids, including β-carotene and β-cryptoxanthin, were detected mainly in the edible flowers with petal colors ranging from yellow to orange, but especially in primula and cosmos yellow flowers, which have yellow petals. The ORAC value of the hydrophilic extract (HORAC) of edible flowers was higher than the ORAC value of the lipophilic extract (LORAC). The total antioxidant capacity (TAC) ranged from 33.03 to 320.36 μM Trolox equivalent/g FW. The highest TPC and TAC were observed in cosmos yellow flowers. On the basis of Pearson’s correlation coefficient, the HORAC value and the TPC of the analyzed edible flowers were highly correlated (r=0.736). This preliminary study indicates that edible flowers are a potential source of antioxidants, and the addition of edible flowers to the human diet may be associated with health benefits.

Synthesis of Lipophilic Esters of Tyrosol, Homovanillyl Alcohol and Hydroxytyrosol.

Low-molecular weight phenols such as tyrosol, homovanillyl alcohol and hydroxytyrosol are valuable compounds that exhibit a high number of health-promoting effects such as antioxidant, anti-inflammatory and anticancer activity. Despite these remarkable properties, their applications such as dietary supplements and stabilizers of foods and cosmetics in non-aqueous media are limited for the hydrophilic character. With the aim to overcome this limitation, the paper describes a simple and low-cost procedure for the synthesis of lipophilic esters of tyrosol, homovanillyl alcohol and hydroxytyrosol. The reactions were carried out under mild and green chemistry conditions, at room temperature, solubilizing the phenolic compounds in dimethyl carbonate, an eco-friendly solvent, and adding a little excess of the appropriate C2–C18 acyl chloride. The final products were isolated in good yields. Finally, according to the “circular economy” strategy, the procedure was applied to hydroxytyrosol-enriched extracts obtained by Olea europaea by-products to prepare a panel of lipophilic extracts that are useful for applications where solubility in lipid media is required.

Synergism and Aggregation in Multi-Extractant Solvent Extraction Systems

ABSTRACT Several combinations of lipophilic extractants have been studied with the objective of investigating the synergistic behavior of metal ion extraction and its relation to reverse micelle formation. Combinations of acidic and neutral extracting reagents that have displayed synergic behavior in other studies were tested. While most of these either showed limited synergy or no correlation with water uptake under the conditions used here, two of the systems showed extraction synergy. These two extraction systems: 2-bromodecanoic acid with 2,2ʹ:6ʹ,2ʺ-terpyridine; and tributyl phosphine oxide with 2-thenoyltrifluoroacetone were modeled based on two different theoretical approaches: microemulsion-assisted extraction; or the formation of mixed complexes in the organic phase. Comparisons between the two models showed that in the case of bromodecanoic acid and terpyridine the approach of mixed complexes provided a somewhat better fit while the second system was not modeled well with either approach. Further work on the species present in the organic phase is needed to determine the role, if any, of aggregates in synergistic solvent extraction systems.

Carotenoids and lipophilic antioxidant capacities of tomato purées as affected by high hydrostatic pressure processing

SummaryThe effect of high hydrostatic pressure (HHP) (450–550–650 MPa/5–10–15 min) on the carotenoid profile of purées obtained from commercial tomato varieties (Maliniak, Cerise, Black Prince and Lima) was investigated. The carotenoids profile was analysed using high performance liquid chromatography (HPLC‐DAD). Photochemiluminescence (PCLACL), ferric‐reducing antioxidant power (FRAP) and cyclic voltammetry (CV) assays were used to determine the antioxidant capacity of the lipophilic extracts. The results demonstrated that at certain processing conditions, HHP distinctly enhanced antioxidant capacity of the studied material. A significant reduction in lycopene and β‐Carotene concentration was observed for all the HHP‐treated purées. In contrast, lutein found in the purée extracts of Cerise and Black Prince tomatoes was slightly affected at 550 MPa/5 min and 650 MPa/5 min. Among all the carotenoids studied, lutein strongly and significantly affected PCLACL and CV parameters. In contrast, lycopene had a negligible effect on the examined parameters.

Hydrofluoric Acid and Other Impurities in Toxic Perfluorooctane Batches

PurposeThe complications with cytotoxic perfluorooctane (PFO) batches reported in 2015 were attributed to reactive underfluorinated impurities whose chemical identity and behavior still need to be clarified.Material and MethodsWe analyzed original packaged samples of Ala®octa batches involved in several reported cases of retinal toxicity. (A) The impurity profile was determined. (B) pH and fluoride ion content were measured. (C) Extraction with olive oil was performed to investigate differences in lipophilia among perfluorinated liquid (PFCL) as a measure for penetration of lipophilic cell membranes followed by measurements (A) and (B).Results(A) The detected impurities can be divided into: (1) reactive underfluorinated compounds and their degradation products including hydrogen fluoride (HF), (2) nonreactive underfluorinated compounds, (3) surface active compounds, (4) nonreactive fluorinated compounds, and (5) leachables from primary packaging components. The highest acute toxic potential is associated with the impurities of group (1). (B) HF was detected as a degradation product of reactive underfluorinated impurities by relying on the pH values and fluoride ion content of the water extracts. (C) Lipophilic impurities dissolved in PFO migrate into lipophilic extraction medium. In particular, HF is rapidly transferred in this way.ConclusionsHF as degradation product of unstable or reactive underfluorinated contaminants seems of particular importance triggering the acute toxicity of affected PFO. Contamination related toxicity and unwanted side effects can only be reliably excluded via analytical controlled multistage, high-purification processes.Translational RelevanceIn Ala®octa batches different impurities show retinal toxicity. HF seems of particular importance of the acute toxicity of PFO.

Characterization of walnut, almond, and pine nut shells regarding chemical composition and extract composition

The shells of three important food nuts, walnut, almond, and pine nut, were studied in view of valorization as residues. The shells differed chemically: walnut shells had 10.6% extractives, 30.1% lignin, and 49.7% polysaccharides; almond shells 5.7% extractives, 28.9% lignin, and 56.1% polysaccharides; and pine nut shells 4.5% extractives, 40.5% lignin, and 48.7% polysaccharides. The polysaccharide composition also differed, e.g., glucose/xylose ratio of 1.12, 0.94, and 2.29 for walnut, almond, and pine nut shells, respectively. Walnut and almond shells have a SG lignin (S/G 1.6 and 1.0, respectively) and pine nut shell a G lignin. The lipophilic extracts contained mostly saturated and unsaturated alkanoic acids. The ethanol-water extracts contained total phenolics, flavonoids, and condensed tannins. The antioxidant activity was moderate (IC50 15.2, 7.9, and 8.2 μg/mL for walnut, almond, and pine nut). The three nut shells fractured easily with little formation of fines.

Chemovariation and antibacterial activity of extracts and isolated compounds from species of Ixora and Greenea (Ixoroideae, Rubiaceae).

BackgroundA large number of secondary metabolites can be obtained from plants used for traditional medicine in two related genera (Ixora and Greenea) in the subfamily Ixoroideae (Rubiaceae), but there are only a few detailed studies on their bioactivities. Therefore, the main goals of this study were to determine the antibacterial activities of lipophilic extracts from plants of some Ixora and Greenea species native to Thailand, and to isolate some pure compounds from those extracts. Moreover, we compared the occurrence of compounds in different plant parts of samples from different habitats to better understand their variation.MethodsA total of 56 lipophilic extracts were obtained from the leaves, stem bark, and root bark of eight Ixora and two Greenea species collected at various locations in Thailand. Isolated compounds were identified using nuclear magnetic resonance. Antimicrobial activities were evaluated against four Gram-positive and nine Gram-negative human pathogenic bacterial strains.ResultsExtracts from I. javanica, I. nigricans, I. brunonis, and G. montana, along with isolated scopoletin, exhibited antibacterial activities against Gram-positive methicillin-resistant Staphylococcus aureus ATCC 43300, with minimum inhibitory concentration values ranging from 64 to 256 µg/mL. The occurrence of scopoletin, isofraxidin, and geniposidic acid in lipophilic extracts showed some variation among different plant parts and species.ConclusionsLipophilic extracts of Ixora and Greenea species have the potential to be developed as anti-Gram-positive agents, in particular to counter infections of methicillin-resistant S. aureus strains. The chemical profiles showed differences between floristic regions but similarity within the same plant parts.