Maclura Pomifera Research Articles

Use of a biosensor to determine the binding kinetics of five lectins for Galactosyl-N-acetylgalactosamine.

The dietary lectins, edible mushroom (ABL) and Jacalin (JAC) inhibit the proliferation of colonic cancer cells, whereas Amaranth (ACL) and peanut (PNA) stimulate their proliferation. All these lectins share as their preferred ligand the Thomsen-Friedenreich (TF) antigen galactosyl beta1,3 N-Acetylgalactosamine (Galbeta1,3GalNAc), but differ in their finer specificities for modifications of this determinant and in their specificities for cancerous epithelia. We have investigated, using a resonant mirror biosensor, the kinetics of binding of these lectins, and Maclura pomifera lectin (MPL), which is similar to JAC, to two different Gal-GalNac bearing glycoproteins, antarctic fish antifreeze glycoprotein (AFG) and asialofetuin. JAC had the highest affinity for AFG [K(d) 0.027 microM] due to a fast association rate constant [k(ass) 610,000 (Ms)(-1)]. The other lectins had considerably lower affinities, with K(d) ranging from 0.16 microM (ABL) to 5.7 microM (PNA), largely due to slower k(ass) [ABL 74,000 (Ms)(-1) to PNA 2700 (Ms)(-1)]. Similarly, JAC had a much higher affinity for asialofetuin [K(d) 0.083 microM] than the other lectins [K(d) 1.0 microM-4.5 microM]. Affinities were also calculated from the extent of binding at equlibrium and were generally similar to those calculated from the kinetic parameters indicating the true nature of these values.

Osajin and Pomiferin, Two Isoflavones Purified from Osage Orange Fruits, Tested for Repellency to the Maize Weevil (Coleoptera: Curculionidae)

The fruit of the osage orange tree, Maclura pomifera (Raf.) Schneid (Moraceae), has long been thought to be repellent to insects. A preliminary study reported here confirmed repellency of fruit extracts to the maize weevil, Sitophilus zeamais Motschulsky. Two isoflavones, osajin and pomiferin, were isolated from the mature fruit of M. pomifera in high purity (≥95%). Testing of purified osajin and pomiferin failed to show repellency. Repellency is likely caused by factors other than isoflavones in the fruit.

The Conformation of the T-antigen Disaccharide Bound toMaclura pomifera Agglutinin in Aqueous Solution

The complex of Maclura pomifera agglutinin with the T-antigen disaccharide (beta-d-Gal-(1-->3)-alpha-d-GalNAc-(1-->O)-Me) was investigated by NMR spectroscopy in aqueous solution. Intramolecular transferred nuclear Overhauser enhancement (NOE) effects between the monosaccharide moieties were used to derive the ligand conformation in the lectin-bound state. Ligand protons in contact with the protein were identified by saturation transfer difference experiments and intermolecular transferred NOE effects. It is demonstrated that structural differences exist for the ligand-lectin complex in aqueous solution as compared with the previously published crystal structure (Lee, X., Thompson, A., Zhiming, Z., Ton-that, H., Biesterfeldt, J., Ogata, C., Xu, L., Johnston, R. A. Z. , and Young, N. M. (1998) J. Biol. Chem. 273, 6312-6318). In order to accommodate the O-methyl group of the disaccharide, the amino acid side chain of Tyr-122 has to rotate from its position in the crystal. The NMR data are in accord with two conformational families at the beta-(1-->3)glycosidic linkage in the solution complex with interglycosidic angles phi/psi = 45/-65 degrees and -65/-18 degrees. These differ from the bound conformation of the ligand in the crystal (phi/psi = 39/-8 degrees ) and are not highly populated by the ligand in the free state. The reason for the structural differences at the beta-(1-->3)glycosidic linkage are hydrogen bonds that stabilize the relative orientation of the monosaccharide units in the crystal. Our results demonstrate that the crystallization of a protein-carbohydrate complex can interfere with the delicate process of carbohydrate recognition in solution.

The distribution of the phenolic metabolites barbaloin, aloeresin and aloenin as a peripheral defense strategy in the succulent leaf parts of Aloe arborescens.

Aloe arborescens is a large, multi-stemmed shrub. It is used as hedge plants to protect agricultural fields or stock and as horticultural plants in gardens. In natural habitats it is one of the very common Aloe species along the Indian Ocean coast of southern Africa, from the Cape, in the south, to Zimbabwe and Malawi in the north. Secondary phenolic metabolites such as barbaloin (Rf 0.31-0.35), aloeresin (Rf 0.25-0.3) and aloenin (Rf 0.51-0.55) have been found to be distributed in the succulent leaves of Aloe arborescens in a peripheral defense strategy. The youngest leaves have the highest content. The terminal third of each leaf has the highest content and the basal third, the lowest. Along the leaf margins, on the top third and adaxial side, the content is the highest and in the base third, the lowest along the leaf center on the abaxial side. Similar relative amounts of these three secondary phenolic metabolites were found in the different leaf locations. The leaf orientation may affect the total content of these three phenols but not their relative amounts in the different parts of the leaves. It is possible that the more often the plant parts are damaged by consumption by animals such as elephants, kudu or insects, the greater the increase of their phenolic metabolites. This increase may reduce or prevent further consumption when the content of the metabolites reaches a certain level. The plants then have a chance to renew themselves.

Comparison of growth and development of Maclura pomifera (Raf.) Schneid. in the M.M. Grishko National Botanical Gardens and Synitsa Dendrological Park using the method of modeling

Comparison of growth and development of Maclura pomifera (Raf.) Schneid. in the M.M. Grishko National Botanical Gardens and Synitsa Dendrological Park using the method of modeling

600 Maintaining Yields In Hedgerow Almond Production

Four tree training methods have been evaluated since 1979 in California for their affect on yield of “Nonpareil” ctv. almond [Prunus dulcis (Mill.) D.A.Webb] in a tightly spaced “Nonpareil”/”Price” ctvs 1:1 hedgerow planting. Four variations of open center training began at the first dormant pruning in a 2.2 × 6.7-m spacing (667 trees/ha): 1) Temporary Hedge—trees trained to three primary scaffolds, standard pruned with alternate trees gradually whisked back to allow space for permanent trees and then removed at 8th year leaving 4.4 × 6.7-m spacing(333 trees/ha); 2) Permanent Hedge—trees trained to three scaffolds, standard pruned at 2.2-m spacing; 3) Two-Scaffold Hedge—Trees trained into “perpendicular V” two scaffold configuration, standard pruned at 2.2-m spacing; 4) Unpruned Hedge—Trained to three scaffolds then left essentially unpruned at 2.2-m spacing. Replicated yield data accumulated over 15 years shows no difference in production between the three permanent 2.2-m hedgerow methods. Yield for the Temporary Hedge, however, declined 30% the year following alternate tree removal. Adequate canopy expansion resulted in some regained nut production, but yields never recovered and remain 20% below the permanent hedge treatments 13 years post-removal. Observations indicate considerable loss of fruitwood has occurred in the lower canopy of all three 2.2-m hedge treatments, especially in the Unpruned but good commercial production has been maintained at 2400 to 3000 kg/ha The size of almond kernels was not affected by training method. Trunk circumference was affected by treatment. Trees in Temporary Hedge plots grew sustantially larger after alternate tree removal than trees in all 2.2-m hedge treatments that were equal in size.

Nitrogen recovery by alley-cropped maize and trees from 15 N-labeled tree biomass in the subhumid highlands of Kenya

The effectiveness of tree-leaf biomass as a source of N to crops in agroforestry systems depends on the rate at which crops can obtain N from the biomass. A study was conducted to determine the fate of 15N labeled, soil-applied biomass of two hedgerow species, Calliandra calothyrsus Meissner (calliandra) and Leucaena leucocephala (Lam.) de Wit (leucaena), in the subhumid highlands of Kenya. Labeled biomass obtained from 15N fertilized trees was applied to microplots in an alley cropping field and maize planted. N uptake and recovery by maize and hedgerow trees was periodically determined over a 20-week period during the short rain (1995) and the long rain (1996) growing seasons. In maize crop from treatments that received leucaena biomass, higher N uptake and recovery were recorded than in maize from the plots that received calliandra biomass. However, N uptake and recovery were higher in calliandra tree hedges than in leucaena hedges, indicating differences in N uptake by the two tree species. The largest fraction (55–69%) of N in the applied tree biomass was left in the soil N pool, 8–13% recovered by maize, 2–3% by tree hedges, and 20–30% could not be accounted for. Some of the unaccounted for N may have been left in the wood and root portions of the tree hedges and in the bulk soil below the 20-cm depth. The study shows that only a small fraction of the N contained in the N-rich biomass that is applied to the soil is taken up by the current season's crop, suggesting that a major benefit may be in the build-up of the soil N store.

Double electrophoretic separation and lectin analyses of the component chains of secretory immunoglobulin A from human saliva.

A new method is presented for the separation of secretory immunoglobulin A (SIgA) from salivary samples. Salivary proteins (from parotid or stimulated whole mouth saliva) were precipitated with methanol to concentrate SIgA from salivary samples whilst removing other salivary proteins. SIgA purified from breast milk and salivary proteins was separated by 10% sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) under nonreducing conditions. Following completion of electrophoresis the top strip of gel was removed and the proteins present reduced with dithiothreitol. The gel strip was then applied to the top of a second 10% SDS gel, and the proteins were electrophoresed and then stained by Coomassie Brilliant Blue R-250. Three major protein bands were stained in all samples corresponding in molecular mass to secretory component, alpha-heavy chain and light chains of SIgA. Separated proteins were also electroblotted onto nitrocellulose and stained by fluorescein isothiocyanate (FITC). Lectin analysis was then used to detect the O-glycans present on IgA1. Lectins from Helix aspersa and Arachis hypogaea were used to determine the amount of terminal N-acetyl galactosamine and nonsialylated O-glycans, respectively. Maclura pomifera lectin was used to determine the total amount of IgA1 present on the blots. The results indicate that SlgA in stimulated whole mouth saliva, stimulated parotid saliva and purified from breast milk contain similar O-glycans.

Environmental Interactions between Different Tree Species and Mung Bean (Vigna radiata (L.) Wilczek) in Hedgerow Intercropping Systems in Sri Lanka

Annual crops grown in association with contour hedgerows often show yield reductions. This paper quantifies the variation of above- and below-ground environmental factors in hedgerow intercrops involving six different tree species (Calliandra calothyrus, Desmodium ransonii, Flemingia c ongesta, Gliricidia sepium, Cassia spectabilis and Tithonia diversifolia) and thereby shows the effects of tree hedges on mung bean (Vigna radiata). Compared to a sole crop of mung bean, most hedgerow intercrops removed greater soil nitrogen, whereas all removed lower soil phosphorus. Mung bean closer to the hedgerows had lower N and P, indicating competitive capture of nutrients by hedges. Most hedgerow intercrops had greater top-soil water because of their shading effect, especially near hedgerows. However, greater absorption by tree root systems decreased subsoil water near hedgerows late in the season. Soil temperature was lower in most hedgerow intercrops than in the control and increased with increasing distance from hedges. During initial stages of mung bean growth, radiation interception of intercrops was greater than that of the control, especially closer to hedgerows. However, after the first month, radiation interception of the sole crop was either equal to or greater than that of hedgerow intercrops. There was significant variation between tree species in all these environmental factors. Gliricidia, which allowed greater mung bean yields, also allowed greater nutrient capture by mung bean, greater top-soil water availability, lower extraction of subsoil water and lower soil temperatures.

Characterization of prenylated xanthones and flavanones by liquid chromatography/atmospheric pressure chemical ionization mass spectrometry.

Reversed-phase liquid chromatography with atmospheric pressure chemical ionization mass spectrometry (LC/APCI-MS) in the positive-ion mode was utilized to analyze crude ether extracts from the root bark of Maclura pomifera, a tree known to have a high content of prenylated xanthones and flavanones. Identification of three xanthones and two flavanones was based on their unique mass spectra. Under optimum conditions peaks corresponding to the [MH](+) ion and characteristic fragments for each compound were observed. (1)H NMR data were used to confirm the identities of two xanthones that had the same molecular mass and similar fragmentation patterns. Fragmentation of the analytes was achieved by application of an electrostatic potential at the entrance of the single quadrupole mass spectrometer. The optimum voltage for fragmentation was found to be related to the class of compounds analyzed and, within each class, to be dependent on the structure of the prenyl moiety. Collision-induced pathways consistent with precedent literature describing the MS characterization of similar compounds and with the observed fragmentation patterns are tentatively proposed.

Peripheral defence strategy: variation of barbaloin content in the succulent leaf parts of Aloe arborescens Miller (Liliaceae)

Aloe arborescens is a large, multi-stemmed shrub and is one of the very common Aloe species along the Indian Ocean coast of southern Africa, from the Cape, in the south, to Zimbabwe and Malawi in the north. It is used as a hedge plant to protect agricultural fields or stock and as a horticultural plant in gardens. Barbaloin, a secondary phenolic metabolite, is distributed in the plants as part of a peripheral defence strategy. Barbaloin content was found to be highest in the youngest leaves. Within these, concentration varied: at its highest in the terminal third of the leaf, at its lowest in the basal third; higher in the terminal, adaxial, leaf margin and lower in the basal, abaxial, leaf centre. The more times a leaf is cut, the higher the barbaloin content of the new growth from the leaf base that remains on the plant. This may deter animals such as elephants and kudu from eating the new growths. They may prefer to eat other plants that have not been damaged by consumption for longer periods. This phenomenon may give damaged plants the chance to renew themselves before their leaves are consumed again.

Peripheral defence strategy: variation of barbaloin content in the succulent leaf parts of Aloe arborescens Miller (Liliaceae)

Abstract Aloe arborescens is a large, multi-stemmed shrub and is one of the very common Aloe species along the Indian Ocean coast of southern Africa, from the Cape, in the south, to Zimbabwe and Malawi in the north. It is used as a hedge plant to protect agricultural fields or stock and as a horticultural plant in gardens. Barbaloin, a secondary phenolic metabolite, is distributed in the plants as part of a peripheral defence strategy. Barbaloin content was found to be highest in the youngest leaves. Within these, concentration varied: at its highest in the terminal third of the leaf, at its lowest in the basal third; higher in the terminal, adaxial, leaf margin and lower in the basal, abaxial, leaf centre. The more times a leaf is cut, the higher the barbaloin content of the new growth from the leaf base that remains on the plant. This may deter animals such as elephants and kudu from eating the new growths. They may prefer to eat other plants that have not been damaged by consumption for longer periods. This phenomenon may give damaged plants the chance to renew themselves before their leaves are consumed again.

Effects of Different Tree Species on Growth and Yield of Mung Bean (Vigna radiata (L.) Wilczek) Grown in Hedgerow Intercropping Systems in Sri Lanka

Reduction of crop yields due to resource competition from tree hedges is a serious drawback of hedgerow intercropping. This work quantified the competition of six potential hedgerow tree species (Calliandra calothyrus, Desmodium ransonii, Flemingia congesta, Gliricidia sepium, Cassia spectabilis and Tithonia diversifolia) on mung bean (Vigna radiata) grown as hedgerow intercrops at Pallekelle in the mid-elevational (367 m above sea level), subhumid (rainfall of 1400 mm year−1) zone of Sri Lanka. Leaf area, total biomass and yield of mung bean in hedgerow intercrops showed a clear reduction closer to the hedgerows, whereas no such reduction was observed in a sole crop of mung bean. At 30 cm from the hedgerow, growth and yield of mung bean were significantly lower than in the sole crop, indicating significant competition from hedgerows. However, growth and yield of mung bean increased with increasing distance from hedgerows so that, at 150 cm, mung bean under Gliricidia and Desmodium showed significantly greater growth and yields than the control. In contrast, even the maximum mung bean yields under the rest of the species did not reach that of the control. The differences in competition with different hedgerow species are discussed in terms of variations between tree species in biomass production, quality of prunings and the possibility of root competition.

Characterisation of lectin binding patterns of mouse bronchiolar and rat alveolar epithelial cells in culture.

Lung epithelial cell differentiation pathways remain unclear. This is due in part to the plasticity of these cells and the lack of markers which accurately reflect their differentiation status. The aim of this study was to determine if lectin binding properties are useful determinants of functional differentiation status in vitro. Mouse Clara cells were cultured for 5 days. During this time, no alteration in differentiation was evident by electron microscopy. No significant alteration in binding reactivity of Bauhinia purpurea (BPA), Maclura pomifera (MPA), Concanavalin A, Wheat germ or Helix pomatia lectins occurred in cultures compared with Clara cells in mouse lung tissue. In contrast, nitrotetrazolium blue reductase activity and CC10 expression declined in culture. Rat type II cells were cultured for 8 days. Between days 0 and 4, the number of type II cells identified by electron microscopy was constant at 70-80%, decreasing to 8% by day 6. In contrast, by day 4, only 42% cells retained alkaline phosphatase activity. BPA and MPA reactivity was altered at day 0 and day 4 respectively, compared with cells in situ. Therefore, the reactivity of lectins analysed here does not reflect functional differentiation status of cultured mouse Clara cells. However, BPA and MPA reactivity may be a sensitive indicator of alterations in rat type II cell differentiation in vitro.

Morphologic characteristic of collective fruits and seed genuination of Maclura aurantiaca Nutt.

Morphologic characteristic of collective fruits and seed genuination of Maclura aurantiaca Nutt.

O-linked glycosylation occurs on basic parotid salivary proline-rich proteins.

Interactions between salivary glycoproteins and many oral bacteria have been shown to depend on O-linked glycans on salivary glycoproteins. Basic proline-rich proteins form the largest group of proteins within human parotid saliva. In the present study human parotid salivary glycoproteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis or two-dimensional electrophoresis, electroblotted onto nitrocellulose and probed with two biotin-labelled lectins from Maclura pomifera (MPA) and Arachis hypogaea (PNA) which are specific for O-linked (galactose beta 1,3 N-Acetylgalactosamine) glycans. Lectin binding was detected with avidin-biotin complex and enhanced chemiluminescence. Two-dimensional electrophoresis in combination with lectin binding indicated that only basic parotid salivary glycoproteins bind the lectin MPA. Following removal of terminal sialic acid residues by sialidase digestion the same glycoproteins were detected by the lectin PNA. Glycosidase digestion with endo-alpha-N-acetylgalactosaminidase (O-glycanase) in conjunction with sialidase eliminated MPA binding. Taken together these results indicate that many basic parotid salivary glycoproteins contain O-glycans, all of which are sialylated.

Small Mammals in Central Kansas Windbreaks in Winter

Field windbreaks consist of trees, shrubs, or a combination of both planted adjacent to fields or farmsteads to reduce the force of wind. Kansas has about 4,900 ha of farmstead windbreaks and 118,000 ha of field windbreaks (Soil Conservation Service, 1994). Johnson and Beck (1988) reviewed the literature and identified references to 28 species of mammals using windbreaks with seven species classified as high dependence/high use. The purpose of this study was to determine which small mammal species use field windbreaks in central Kansas during winter. Twenty field windbreaks of variable size (0.28 ha-11.66 ha) were studied in Stafford and Pawnee counties, Kansas. The number of rows in the windbreaks ranged from 1 to 17, with a mean of 6.7 rows. The most frequently occurring tree species in the windbreaks were eastern cottonwood (Populus deltoides) occurring in 100% of the windbreaks, eastern redcedar (Juniperus virginiana) (85%), Siberian elm (Ulmus pumila) (55%), honey locust, (Gleditsia triacanthos) (50%) and Osage orange (Maclura pomifera) (50%). Small mammal trapping was conducted during mid-February. Twenty-five trapping stations were set at 5-meter intervals along a transect that bisected each windbreak. Each station had one Sherman live trap (3 in x 3.5 in x 12 in) and one museum special snap trap (2.75 in x 5.5 in), baited with a mixture of peanut butter and oats. Trapping was conducted for three consecutive nights in each windbreak, resulting in 150 trap-nights per windbreak and a total of 3,000 trap-nights during the course of the sampling period. One hundred and forty-nine captures of six small mammal species were made in the 20 windbreaks. The species captured were white-footed mouse (Peromyscus leucopus), deer mouse (P. maniculatus), cotton rat (Sigmodon hispidus), western harvest mouse (Reithrodontomys megalotis), Elliot's short-tailed shrew (Blarina hylophaga), and house mouse (Mus musculus). Eighteen of the 20 windbreaks (90%) contained at least one species of small mammal, and one windbreak contained five of the six species, lacking only the Elliot's short-tailed shrew. The average number of small mammal species per windbreak was 1.75. The white-footed mouse was the species most often captured (51.7% of total captures), followed by deer mouse (40.2%), western

Lectin binding studies of parotid salivary glycoproteins in Sjögren's syndrome.

Human parotid salivas were collected from patients with secondary Sjögren's syndrome and controls without disease or with drug-induced xerostomia. Parotid glycoproteins were separated by gradient sodium dodecyl sulphate gel electrophoresis (SDS-PAGE), electroblotted onto nitrocellulose membrane and probed with biotinylated lectins of characterised sugar specificities. The binding patterns of lectins from Maclura pomifera (MPA) and Arachis hypogaea (PNA) indicated that many parotid glycoproteins have sialylated O-linked glycans and that sialylation is not affected by disease. Binding by lectins from Ricinus communis (RCA-1), Limax flavus (LFA), Lotus tetragonolobus (LTA) and Ulex europaeus (UEA-1) appeared unaltered in secondary Sjögren's syndrome, suggesting no obvious change in N-glycosylation of parotid glycoproteins. Variations in binding patterns of most lectins was attributable to subject-to-subject variations in recognised polymorphic proteins. Dolichos biflorus agglutinin (DBA) consistently showed increased binding to a 75 kDa (Mr) protein in salivas from patients with secondary Sjögren's syndrome. The binding protein was identified as lactoferrin but found not to contain N-acetylgalactosamine, the sugar to which DBA binds. Binding of DBA to lactoferrin was dependent upon its saturation with iron, modified SDS-PAGE under nonreducing conditions resolved iron-free and iron-saturated lactoferrins and demonstrated increased levels of the iron-saturated form in secondary Sjögren's syndrome. Lectin binding studies of purified lactoferrins from saliva, milk, and polymorphonuclear neutrophils suggested that raised levels of lactoferrin in saliva originate from salivary cells and not from inflammatory cells. These results suggest that DBA binding provides greater specificity as an indicator of salivary gland disease than measurement of lactoferrin levels alone.

A lysosomal storage disease induced by Ipomoea carnea in goats in Mozambique.

A novel plant-induced lysosomal storage disease was observed in goats from a village in Mozambique. Affected animals were ataxic, with head tremors and nystagmus. Because of a lack of suitable feed, the animals consumed an exotic hedge plant growing in the village that was identified as Ipomoea carnea (shrubby morning glory, Convolvulaceae). The toxicosis was reproduced by feeding I. carnea plant material to goats. In acute cases, histologic changes in the brain and spinal cord comprised widespread cytoplasmic vacuolation of neurons and glial cells in association with axonal spheroid formation. Ultrastructurally, cytoplasmic storage vacuoles in neurons were membrane bound and consistent with lysosomes. Cytoplasmic vacuolation was also found in neurons in the submucosal and mesenteric plexuses in the small intestine, in renal tubular epithelial cells, and in macrophage-phagocytic cells in the spleen and lymph nodes in acute cases. Residual alterations in the brain in chronic cases revealed predominantly cerebellar lesions characterized by loss of Purkinje neurons and gliosis of the Purkinje cell layer. Analysis of I. carnea plant material by gas chromatography-mass spectrometry established the presence of the mannosidase inhibitor swainsonine and 2 glycosidase inhibitors, calystegine B2 and calystegine C1, consistent with a plant-induced alpha-mannosidosis in the goats. The described storage disorder is analogous to the lysosomal storage diseases induced by ingestion of locoweeds (Astragalus and Oxytropis) and poison peas (Swainsona).

Comparison of methods for extraction of flavanones and xanthones from the root bark of the osage orange tree using liquid chromatography

This study compares conventional solid–liquid extraction, supercritical fluid extraction (SFE), and pressurized fluid extraction (PFE) for their efficiency in extracting xanthones and flavanones from the root bark of the osage orange tree ( Maclura pomifera). Seven compounds were extracted from the plant material by solvent extraction at room temperature for 48 h. The same compounds were removed from the root bark by 45- and 35-min extractions using SFE and PFE, respectively, and under optimized conditions, in same or higher yields than those obtained by the conventional 48-h solvent extraction. Although all seven compounds were present in the SFE extracts when only CO 2 was used as the fluid, the addition of 20 vol.% methanol (MeOH) to the CO 2 proved essential for achieving high yields. Use of SFE with CO 2–MeOH also led to the recovery of an additional flavanone from a wet sample of root bark. This flavanone is absent from the conventional solvent extracts and appears in small amounts in the PFE extracts. An optimized LC separation for the analysis of the different extracts is presented, and it is demonstrated that the separation of xanthones and flavanones is considerably improved by the use of deactivated C 18 columns in conjunction with a mobile phase containing acetonitrile and a weak organic acid.