Coumaric Acid Derivatives Research Articles

Morphometric and biochemical screening of old mulberry trees (Morus alba L.) in the former sericulture region of Slovenia

Over centuries, in many European countries, the white mulberry trees (<em>Morus alba</em> L.) became an integral part of the cultural landscape, bearing witness to past sericulture activities. The distribution records of white mulberry trees in the cultural landscape are incomplete and in general poorly documented. The aim of the presented research was to collect data regarding geographical locations of mulberry trees and to define their morphological and biochemical variability in Goriška region, one of the historical sericulture regions in Slovenia. Principal component analysis of all morphometrical leaf traits allowed us to characterize two separate groups of morphotypes. Recordings of the tree pruning management revealed that annual base cutting is traditionally used in Goriška region. Significant correlations between pruning management and leaf morphology traits showed that frequently pruned trees form larger leaves. Biochemically, mulberry leaves are shown to be rich in proteins containing threonine, arginine, asparagine, serine, and glutamine as the most prominent free amino acids. The main phenolic compounds were identified as caffeoylquinic acid derivatives, quercetin malonyl-hexoside, rutin, kaempferol acetyl-hexoside, quercetin-3-glucoside, and <em>p</em>-coumaric acid derivatives. The difference in concentrations of the investigated metabolites is correlated either with the pruning management or the morphotype. Pruning significantly affected the levels of asparagine, alanine, and serine, which were higher in the annually pruned trees regardless of the morphotype. Furthermore, we were able to confirm a significant effect of pruning on total phenolics as well as on the levels of rutin, quercetin malonyl-hexoside, and quercetin-3-glucoside contents. Multivariate analysis allowed us to determine seven chemotypes with distinctive biochemical traits. Our results are the basis for defining superior high-yielding genotypes with optimum metabolic composition for both silkworm feeding as well as for innovative usage in food processing and pharmaceutical industries.

Experimental and computational study of the pKa of coumaric acid derivatives

The dissociation constant (pKa) of a drug is a key parameter in drug discovery and pharmaceutical formulation. The hydroxy substituent has a significant effect on the acidity of hydroxycinnamic acid. In this work, the acidic constants of coumaric acids are obtained experimentally by spectrophotometry using the chemometric method and calculated theoretically using ab initio quantum mechanical method at the HF/6‐31G* level of theory in combination with the SMD continuum solvation method. Rank annihilation factor analysis (RAFA) is an efficient chemometric technique based on the elimination of the contribution of one of the chemical components from the data matrix. RAFA cannot be performed because the pure spectrum of HA− is not available. So, two‐rank annihilation factor analysis (TRAFA) is proposed for the determination of the pKa OF H2A. A comparison between the pKa values obtained previously by TRAFA for the molecules o‐coumaric acid (4.13, 9.58), m‐coumaric acid (4.48, 10.35), and p‐coumaric acid (4.65, 9.92) makes it clear that there is good agreement between the results obtained by TRAFA and ab initio quantum mechanical method.

Comparison of the Malpighian tubules and fat body transcriptional profiles of Zophobas morio larvae (Coleoptera: Tenebrionidae)

The Malpighian tubules in insects play an essential role in osmoregulation, through the transport of ions during excretion, whereas the fat body is usually associated with the intermediary metabolism. The tubules also are involved in excretion of organic solutes and xenobiotics. However, with the exception of a preliminary transcriptional survey of the Zophobas morio (Tenebrionidae) larval tubules, there are no detailed transcriptional analysis of this organ in Coleoptera. A luciferase-like enzyme that displays weak luminescence activity in the presence of firefly D-luciferin and ATP was cloned from the tubules of Z. morio larvae. In order to better understand the molecular physiology of Malpighian tubules and fat body in Coleoptera larvae, and to investigate the occurrence and functions of AMP-CoA ligases in these tissues, we performed a comparative transcriptional analysis of these tissues using Z. morio giant-mealworms. As expected, the tubules displayed organic and inorganic transporters, xenobiotic metabolism enzymes, V-ATPases, channels, and pumps. The fat body showed proteins that are synthesized in this tissue and secreted to the hemolymph, as well as enzymes involved in lipid and carbohydrate metabolism. These tissues are also involved in common pathways, such as nitrogen metabolism to degradation/excretion, eye pigments biosynthesis, immunity, and detoxification. The presence of coumarate-CoA ligase-like enzymes in these tissues suggest their involvement in the degradation of coumaric acid derivatives obtained from the diet, or alternatively, in the biosynthesis of compounds structurally related to coumaric acids such as eye pigments. Our results confirm to the physiological versatility of tubules and fat body in larval Coleoptera.

Lipid oxidation and changes in the phenolic profile of watercress (Nasturtium officinale L.) leaves during frying

Watercress leaves were fried in sunflower oil and analysed for lipid oxidation and phenolic compounds by high-performance liquid chromatography with diode array detection (HPLC–DAD). Results revealed that total phenolic contents and radical scavenging activity decreased significantly at the initial stages and were stable in frying oil, indicating stability of frying oil. A significant increase occurred in chlorophylls of watercress leaves and frying oil. HPLC chromatograms showed a total of 12 phenolic compounds containing caftaric acid (17.3–31.8 µg/g), sinapic acid derivative (11.2–14.4 µg/g), 4-O-caffeoylquinic acid (9.98–12.8 µg/g), 4-O-feruloyl quinic acid (8.47–13.4 µg/g), caffeoyl feruloyl quinic acid (7.31–11.7 µg/g) and 5-O-caffeoylquinic acid (3.73–6.51 µg/g) as major compounds. A significant increase in the caffeic acid, caffeoyl hexose, chlorogenic acid, caftaric acid, coumaric acid derivatives and 3, 4-di-O-caffeoylquinic acid was observed, while a decrease occurred in Sinapic acid derivative, 5-O-caffeoylquinic acid, 4-O-caffeoylquinic acid, 4-O-feruloyl quinic acid and caffeoyl feruloyl quinic acid. Frying of watercress leaves increase the bioavailability of medicinally important phenolic compounds and also help to stabilise the frying oil.

In vitro antioxidant, antilipoxygenase and antimicrobial activities of extracts from seven climbing plants belonging to the Bignoniaceae

ObjectivesThis study aimed to evaluate the in vitro antioxidant capacity, to determine the anti-inflammatory effect due to lipoxygenase inhibition and to test the antimicrobial activity of ethanolic extracts from leaves of seven climbing species belonging to the Bignoniaceae family. These species are Adenocalymma marginatum (Cham.) DC., Amphilophium vauthieri DC., Cuspidaria convoluta (Vell.) A. H. Gentry, Dolichandra dentata (K. Schum.) L. G. Lohmann, Fridericia caudigera (S. Moore) L. G. Lohmann, Fridericia chica (Bonpl.) L. G. Lohmann and Tanaecium selloi (Spreng.) L. G. Lohmann. MethodsThe antioxidant activity was evaluated using three methods, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power. Lipoxygenase-inhibiting activity was assayed spectrophotometrically; the result was expressed as percent inhibition. The antimicrobial activity was assessed using the agar disk diffusion method. Minimal inhibitory concentration (MIC) and minimal bactericidal/fungicidal concentration were also determined for each extract against 12 pathogenic bacterial strains of Staphylococcus aureus and seven fungal strains of the Candida genus. The identification of the major compounds present in the most promising extract was established by high-performance liquid chromatography–tandem mass spectrometry. ResultsC. convoluta, F. caudigera, and F. chica exhibited the best antioxidant activity by scavenging DPPH and ABTS+ radicals and reducing Fe3+ ion. These extracts showed a notable inhibition of lipoxygenase. F. caudigera was found to have the lower MIC value against S. aureus strains and six Candida species. The extracts of F. caudigera and C. convoluta were active even against methicillin-resistant S. aureus. C. convoluta had higher total phenol content, better antioxidant activity and superior anti-inflammatory and antimicrobial activity. The main phenolic compounds found in this extract were coumaric and hydroxybenzoic acid derivatives and glycosylated and nonglycosylated flavones. ConclusionMost of the extracts exhibited antioxidant activity as well as in vitro inhibition of lipoxygenase. The excellent antimicrobial activity of T. selloi and F. chica supports their use in traditional medicine as antiseptic agents. The extracts of F. caudigera and C. convoluta, both with notable biological activities in this study, could be used as herbal remedies for skin care. In addition, this study provides, for the first time, information about phenolic compounds present in C. convoluta.

Targeted Analysis of the Concentration Changes of Phenolic Compounds in Persian Lime (Citrus latifolia) during Fruit Growth.

Citrus fruits possess a high content of phenolic compounds; however, few studies have focused on the changes occurring during fruit growth. In this study, the changes in the concentration of 20 flavonoids, 4 phenolic acids, and their biosynthetic precursors phenylalanine and tyrosine have been evaluated during fruit maturation (14 weeks). Extracts from all samples, obtained by ultrasound assistance, were analyzed by liquid chromatography coupled to tandem mass spectrometry with a triple quad system (LC-QqQ MS/MS). In general, the concentration of flavanones, which represented over 70% of the studied phenols, and flavones increased during fruit growth, reaching their maximum concentration around week 12. In general, flavanols and phenolic acids exhibited their maximum concentration at week 5 and then decreasing significantly during the rest of maturation. Phenylalanine and tyrosine showed a sinuous behavior during fruit growth. Partial least-squares showed a clear differentiation among fruits belonging to different maturation stages, coumaric acid derivatives being the most influential variables on the projection.

Postharvest UV-C application to improve health promoting secondary plant compound pattern in vegetable amaranth

Abstract Vegetable amaranth (Amaranthus cruentus L.) is gaining importance among the African indigenous leafy vegetables (AIVs) in the diets of many households in Africa. However, improper processing, handling, and storage of AIVs often result in faster deterioration thus high quantitative and qualitative losses with reduced availability of these highly nutritive and health promoting plants. Targeted application of UV-C has been shown to induce beneficial physiological responses of crops after harvest. The present study was conducted to evaluate the effects of postharvest UV-C application on health promoting secondary plant compounds of vegetable amaranth cv. Madiira. Eight weeks after planting, leaves were harvested and treated with UV-C (254 nm) at either 1.7 kJ m−2 or 3.4 kJ m−2 while untreated leaves served as control. The leaves were kept up to 4 d and 14 d at 20 °C (65% RH) and 5 °C (85% RH), respectively. Characteristic health promoting plant compounds, such as vitamin E, carotenoids, flavonoids, phenolic acids, as well as glutathione peroxidase (GPOX) activity and antioxidant capacity (TEAC) and their correlations were analyzed. Results showed that the accumulation of secondary metabolites was dependent on UV-C dosage, storage temperature and duration. Vitamin E, carotenoids (e.g. lycopene, β-carotene and lutein), flavonoids (e.g. quercetin and kaempferol derivatives), phenolic acids (e.g. ferulic, coumaric and caffeic acid derivatives) as well as GPOX activity and TEAC increased in UV-C treated vegetable amaranth leaves compared with the untreated samples. Furthermore, there was a relationship in most studied secondary compounds and TEAC. The UV-C effects at both storage conditions were comparable for most studied compounds while storage duration variedly affected the compounds studied. The increase in the studied secondary plant compounds is attributed to their plant defense mechanism against oxidative damage of plant tissues by UV-C irradiation. This could be an important strategy in reducing the loss of secondary plant compounds, hence maintaining nutritional and health promoting properties of AIVs during postharvest supply chain.

Biological activities and chemical composition of Brazilian Bromeliaceae species: a systematic review

Studies of Bromeliaceae species have demonstrated the presence of a large variety of chemical constituents that have important biological activities such as: antimicrobial, antihelmintic, antinociceptive, antitumor, antiulcer and gastroprotective. Thus, this systematic review reports the studies in the literature about the biological activities and chemical composition of Brazilian Bromeliaceae species. The terms “Bromeliaceae”, “phytochemistry” and “pharmacology” were used to search articles in the databases LILACS, PUBMED, SCIELO, SCIENCE DIRECT and SCOPUS published until January 2016. From a total of 652 studies found, 14 met the inclusion and exclusion criteria and were selected for the research. Moreover, the present review identified 10 chemically defined natural molecules reported in the literature obtained from Brazilian Bromeliaceae species, belonging to the classes of flavonoids, coumaric acid derivatives and sterols. The data reviewed here suggest that there is a large chemical and pharmacological potential in species of Bromeliaceae, which justifies the interest in studying these plants.

Polyphenolic composition and antioxidant activity of the under-utilised Prunus mahaleb L. fruit.

The identification of novel plant-based functional foods or nutraceutical ingredients that possess bioactive properties with antioxidant function has recently become important to the food, nutraceutical and cosmetic industries. This study evaluates the polyphenolic composition, identifies bioactive compounds and assays the total antioxidant capacity of Prunus mahaleb L. fruits collected from different populations and sampling years in the countryside around Bari (Apulia Region, Italy). We identified nine polyphenolic compounds including major anthocyanins, coumaric acid derivatives and flavonols from P. mahaleb fruits. The anthocyanin content (in some populations > 5 g kg(-1) fresh weight; FW) in the fruit was comparable to that reported for so-called superfruits such as bilberries, chokeberries and blackcurrants. Coumaric acid derivatives comprised a large portion of the total polyphenolic content in the P. mahaleb fruits. Antioxidant activities, assessed using ORAC and TEAC assays, measured up to 150 and 45 mmol Trolox equivalents kg(-1) FW, respectively. Therefore antioxidant capacity of P. mahaleb fruits is relatively high and comparable to that of superfruit varieties that are often used in commercial nutraceutical products. Our findings suggest that mahaleb fruit (currently not consumed fresh or used in other ways) could serve as a source of bioactive compounds and therefore find interest from the functional food and nutraceutical industries, as a natural food colorant and antioxidant ingredient in the formulation of functional foods. © 2015 Society of Chemical Industry.

Acylated Flavonoid from Vaccinium Corymbosum (Ericaceae) Flowers with Yeast α-Glucosidase Inhibitory Activity

Purpose: To isolate and identify chemical constituents with yeast α-glucosidase inhibitory activity from the methanol extract of V. myrtillus (blueberry) flowers.Methods: The active fraction (ethyl acetate extract) were chromatographed on C18 MPLC column, Sephadex LH-20 column and semi-preparative HPLC column. The isolated compounds were identified by the extensive 1H-nuclear magnetic resonance spectroscopy (NMR), 13C-NMR, 2D-NMR and high resolution mass spectral (HR-MS) analyses.Results: Two phenolic compounds, an acylated flavonoid and a coumaric acid derivative, were isolated and identified as isorhamnetin-3-O-(6''-O-coumaroyl)-β-D-glucoside (1) and cis-cinnamic acid methyl (2). Compound 1 showed powerful α-glucosidase inhibitory activity and in this regard, was superior to the positive drug, acarbose.Conclusion: Compounds 1 and 2 were isolated for the first time from this species and the genus of Vaccinium. This is the first report on characterization of these phenolic compounds and the possible utilization of blueberry flowers for nutraceutical and functional food applications.Keywords: Vaccinium corymbosum, Blueberry, Acylated flavonoid, Yeast α-Glucosidase, Inhibitory activity, Nutraceuticals

Ramorinoa girolae Speg (Fabaceae) seeds, an Argentinean traditional indigenous food: Nutrient composition and antioxidant activity

Ramorinoa girolae Speg. seeds were characterized in terms of phenolic and flavonoid contents, multi-element profile, fatty acid composition and antioxidant activity. The MeOH extract of seeds showed a strong scavenging capacity against the DPPH free radical, inhibition of lipid peroxidation in erythrocytes and reducing power. A significant positive correlation between the total phenolic content and the antioxidant activity of extracts suggests that such compounds could be responsible for the antioxidant capacity of the seeds. Five phenolic compounds were identified by liquid chromatography tandem electrospray ionization mass spectrometry (LC–ESI-MS/MS) and high-resolution electrospray ionization time-of-flight mass spectrometry (LC–ESI-TOF-MS): a coumaric acid derivative, epigallocatechin, catechin-O-glucoside, procyanidin B (catechin dimer), catechin, and two unknown compounds. The presence of catechins suggests health benefits. The seeds also contained a high concentration of monounsaturated fatty acids (≈71%), especially oleic acid, and a low percentage of polyunsaturated fatty acids (≈14%). K, Mg and Ca were major elements, potassium accounting for 59% of the element content. The main roles of these elements can be described as maintenance of pH and osmotic pressure, nerve conductance, muscle contraction, energy production and almost all other aspects of biological life. The observed phenolic content and antioxidant activity of the seeds is an indication of their ability to offer potential health benefits. This is the first report of R. girolae to validate its popular reputation as a nutritionally healthy food.

Phenolic Profile and Antioxidant Activity of Date-Pits of Seven Algerian Date Palm Fruit Varieties

The total phenolic content of methanol and ethyl-acetate extracts of pits from seven Algerian palm date (Phœnix dactylifera L.) fruit varieties was estimated by the Folin-Ciocalteau method. Their respective antioxidant activities were evaluated by the DPPH· and the Co(II)-EDTA luminol chemiluminescence tests and their phenolic profile was established by LC-DAD-MS (ESI− and ESI+). The total phenolic content of the methanolic extracts ranged from 27.2 to 38.5 mg of caffeic acid equivalents CAE/100 g fresh weight, while the ethyl acetate extracts gave contents ranging from 22.8 to 42.6 mg CAE/100 g fresh weight. The antiradical and the hydroxyl scavenging activities of the methanolic extracts were much higher than those of the ethyl acetate extracts. The different varieties that were studied did not show any major difference in their phenolic profile. Indeed, all the varieties contained mainly catechin or epi catechin derivatives, sinapic, cinnamic, and coumaric acid derivatives. However, it should be noted that, unexpectedly, a glycosylated aurone was tentatively identified in the Tazizaout variety. Further investigations are required to characterise the non-identified flavonoids.

ABC Transporter Genes and Methotrexate Response in Rheumatoid Arthritis

Background/Aim: The anticancer potential of indomethacin and diclofenac has been reported against several types of cancer cells. In this study, we investigated the enhancement effect of a coumaric acid derivative found in some Piper plants, N-trans-p-coumaroyltyramine (TCT) on indomethacin and diclofenac cytotoxicity in breast cancer cells. Materials and Methods: MCF-7 and mitoxantrone-resistant MCF-7 (MCF-7/MX) cancer cells were treated with indomethacin or diclofenac in the presence of TCT for 48 h. Cell viability, apoptosis, mitochondrial function and signaling proteins were assayed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, Hoechst 33342, tetramethyl-rhodamine-ethyl-ester and western blot analysis, respectively. Results: Combination treatment resulted in significant reduction of cell viability and mitochondrial membrane potential, whereas the ratio of BCL2-associated X, apoptosis regulator to BCL2 apoptosis regulator, and apoptosis increased. The enhancing effect of TCT was related to reduced nuclear factor-erythroid factor 2-related factor 2/heme oxygenase-1 expression, and increased activation of the protein kinase RNA-like endoplasmic reticulum kinase/eukaryotic initiation factor 2 alpha/activating transcription factor 4/C/EBP homologous protein signaling pathways. Conclusion: TCT in combination with indomethacin or diclofenac promoted endoplasmic reticulum stress-dependent apoptosis in breast cancer cells.

Correlated accumulation of anthocyanins and rosmarinic acid in mechanically stressed red cell suspensions of basil ( Ocimum basilicum)

A red basil cell line (T2b) rich in rosmarinic acid (RA) was selected for the stable production of anthocyanins (ACs) in the dark. Cell suspension cultures were subjected to mechanical stress through increased agitation (switch from 90 to 150 rpm) to determine the relationship between AC and RA accumulation. Cell extracts were analyzed by HPLC and LC–MS, and the resulting data were processed with multivariate statistical analysis. MS and MS/MS spectra facilitated the putative annotation of several complex cyanidin-based ACs, which were esterified with coumaric acid and, in some cases, also with malonic acid. It was also possible to identify various RA-related molecules, some caffeic and coumaric acid derivatives and some flavanones. Mechanical stress increased the total AC and RA contents, but reduced biomass accumulation. Many metabolites were induced by mechanical stress, including RA and some of its derivatives, most ACs, hydroxycinnamic acids and flavonoids, whereas the abundance of some RA dimers was reduced. Although AC and RA share a common early biosynthetic pathway (from phenylalanine to 4-coumaroyl-CoA) and could have similar or overlapping functions providing antioxidant activity against stress-generated reactive oxygen species, there appeared to be no competition between their individual pathways.

Influence of pre-harvest UV-B irradiation and normal or controlled atmosphere storage on flavonoid and hydroxycinnamic acid contents of pak choi ( Brassica campestris L. ssp. chinensis var. communis)

The influence of different initial phenolic contents in pak choi ( Brassica campestris L. ssp. chinensis var. communis) leaves, obtained by pre-harvest treatment with and without UV-B, on storage behaviour was investigated. The storage conditions were controlled (1.5–2.5% O 2 and 5–6% CO 2) or normal air atmospheres at 2 °C and 99% relative humidity. A complementary pre-harvest experiment was conducted to investigate the effect of temperature and UV-B irradiation on the level of phenolic compounds. Both UV-B treatment and temperature showed significant effects regarding polyphenolic contents determined by HPLC-DAD; total polyphenolic content increased under low temperature even without UV-B. UV-B irradiation resulted in a distinct increase in hydroxycinnamic acid derivatives at low temperature (9 °C) and of flavonoids at ambient temperature (22 °C), which might be related to the enhanced level of flavonoid precursors, i.e. hydroxycinnamic acids, which are not utilized for flavonoids in the biosynthesis pathway at low temperature. This hypothesis is supported by the strong increase in the concentration of coumaric acid derivatives under UV-B treatment and low temperature. The epidermal UV-A absorption by PAM fluorometry (pulse amplitude modulation) increased after cultivation under UV-B irradiation and this effect was more pronounced at 22 °C than at 9 °C due to the increases of flavonoid contents and their good correlation with epidermal absorption. Polyphenols are responsible for the epidermal absorption of leaves in the UV range of irradiation. The non-destructive PAM fluorometry of epidermal screening and HPLC-DAD analysis for flavonoids of leaf extracts correlated well and both methods were also applied in the postharvest storage experiment. Plants with a higher initial polyphenolic content showed an increasing effect in epidermal UV-A absorption data and a significantly increasing concentration for flavonoids over the storage period, which is assumed to be due to ongoing biosynthesis induced by the pre-harvest UV-B treatment. The level of flavonoids increased more in controlled atmospheres than in normal air, but hydroxycinnamic acids were unaffected. Fresh weight and chlorophyll content of the plants as markers of postharvest senescence changed only marginally during storage, but UV-B treated plants lost significantly more weight than plants without this treatment.

Effects of Date (Phoenix dactylifera L., Medjool or Hallawi Variety) Consumption by Healthy Subjects on Serum Glucose and Lipid Levels and on Serum Oxidative Status: A Pilot Study

The present pilot study analyzed, for the first time, the in vivo effect of Medjool or Hallawi date consumption by healthy subjects on serum glucose, lipids, and oxidative stress. Total phenolics concentration in the Hallawi versus Medjool dates was greater by 20-31%. The major proportion of the soluble phenolics in both date varieties consisted of phenolic acids, mainly ferulic acid and coumaric acid derivatives, and also chlorogenic and caffeic acid derivatives. Unlike the Medjool dates, Hallawi dates contained a significant proportion of catechins as well. In addition, both varieties contained a quercetin derivative. Both date varieties possess antioxidative properties in vitro, but the ferric ion reducing antioxidant power of Hallawi versus Medjool dates was higher by 24%. Ten healthy subjects consumed, for a period of 4 weeks 100 g/day of either Medjool or Hallawi dates. The date consumption did not significantly affect the subjects' body mass index (BMI), their serum total cholesterol, or their cholesterol levels in the VLDL, LDL, or HDL fractions. Most important, fasting serum glucose and triacylglycerol levels were not increased after consumption of either date variety, and serum triacylglycerol levels even significantly (p < 0.05) decreased, by 8 or 15% after Medjool or Hallawi date consumption, respectively. Basal serum oxidative status was significantly (p < 0.01) decreased by 33%, as compared to the levels observed before consumption, after Hallawi (but not Medjool) date consumption. Similarly, the susceptibility of serum to AAPH-induced lipid peroxidation decreased by 12%, but only after Hallawi date consumption. In agreement with the above results, serum activity of the HDL-associated antioxidant enzyme paraoxonase 1 (PON1) significantly increased, by 8%, after Hallawi date consumption. It is concluded that date consumption (and mainly the Hallawi variety) by healthy subjects, despite their high sugar content, demonstrates beneficial effects on serum triacylglycerol and oxidative stress and does not worsen serum glucose and lipid/lipoprotein patterns, and thus can be considered an antiatherogenic nutrient .

PHYLOGENETIC TRENDS IN PHENOLIC METABOLISM OF MILKWEEDS (ASCLEPIAS): EVIDENCE FOR ESCALATION

Although plant-defense theory has long predicted patterns of chemical defense across taxa, we know remarkably little about the evolution of defense, especially in the context of directional phylogenetic trends. Here we contrast the production of phenolics and cardenolides in 35 species of milkweeds (Asclepias and Gomphocarpus). Maximum-likelihood analyses of character evolution revealed three major patterns. First, consistent with the defense-escalation hypothesis, the diversification of the milkweeds was associated with a trend for increasing phenolic production; this pattern was reversed (a declining evolutionary trend) for cardenolides, toxins sequestered by specialist herbivores. Second, phylogenetically independent correlations existed among phenolic classes across species. For example, coumaric acid derivatives showed negatively correlated evolution with caffeic acid derivatives, and this was likely driven by the fact that the former are used as precursors for the latter. In contrast, coumaric acid derivatives were positively correlated with flavonoids, consistent with competition for the precursor p-coumaric acid. Finally, of the phenolic classes, only flavonoids showed correlated evolution (positive) with cardenolides, consistent with a physiological and evolutionary link between the two via malonate. Thus, this study presents a rigorous test of the defense-escalation hypothesis and a novel phylogenetic approach to understanding the long-term persistence of physiological constraints on secondary metabolism.

Chemical constituents of Acanthus ilicifolius L. and effect on osteoblastic MC3T3E1 cells

A new coumaric acid derivative called acancifoliuside (1) and six known compounds as acteoside (2), isoacteoside (3), acanthaminoside (4), (+)-lyoniresinol 3a-O-beta-glucopyranoside (5), (-)-lyoniresinol (6), and alpha-amyrin (7), were isolated from the methanolic extract of the leaves of Acanthus ilicifolius L. (Acanthaceae). Their structures were determined by spectroscopic methods and a comparison with the spectral data reported in the literature. The effects of the compounds on the function of osteoblastic MC3T3-E1 cells were tested. Compounds 2, 3, and 5 (30 microM) increased the growth and differentiation of osteoblasts significantly (P<0.05), indicating that A. ilicifolius leaves may help prevent osteoporosis.

Synthesis and properties of coumaric acid derivative homo-polymers

Poly(4-hydroxycinnamic acid) (P4HCA), poly(3-hydroxycinnamic acid) (P3HCA), poly(3-methoxy-4-hydroxycinnamic acid) (PMHCA) and poly(3,4-dihydroxycinnamic acid) (PDHCA) were synthesized by the thermal poly-condensation of the corresponding monomers, which are lignin precursors, coumaric acid derivatives consisting of cinnamoyl groups and different position and number of OH groups. The solubility of the homo-polymers in organic solvents decreased in the order of P3HCA > PDHCA > P4HCA > PMHCA. The wide angle X-ray diffraction (WAXD) results indicated that P4HCA or PMHCA with p-OH group had higher crystallinity, in contrast to P3HCA or PDHCA with m-OH group which had lower crystallinity. Crossed-polarizing microscopy suggested that P4HCA had the nematic liquid crystal properties at 220°C and PDHCA showed birefringence properties at 200°C. In cell-adhesion tests, PDHCA showed the highest cell adhesion (ca. 70%), whereas P3HCA, P4HCA and PMHCA had 50, 18 and 10% cell adhesion, respectively. The coumaric acid derivative homo-polymers can be useful as cell adhesion controllable thermotropic polymers for biomedical and environmental fields.

Flavonoids, Coumarins and Triterpenes from the Aerial Parts of Cnidoscolus texanus

Phytochemical investigation on Cnidoscolus texanus led to the isolation of 26 compounds, which included 15 flavonoids (1-15), three coumarins (16-18), three coumaric acid derivatives (19-21), four triterpenoids (22-25), and one phytosterol (26). Among them, aromadendrin 7-O-(4''-O-P-E-coumaroyl-beta-glucopyranoside) (1), aromadendrin 7-O-(3'',6''-di-O-P-E-coumaroyl-beta-glucopyranoside) (2), and naringenin 7-O-(4''-O-P-Z-coumaroyl-beta-glucopyranoside) (3) are new compounds. Their structures were determined by spectroscopic and chemical methods. All flavonoids were found to be inactive against DNA topoisomerase I.