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Two galactomannans, GALMAN-A and GALMAN-B, were isolated from seeds of Mimosa scabrella (bracatinga), with deactivation and exposure to native enzymes, respectively. They were treated with oxovanadium(IV) and oxovanadium(V), designated (VO(2+)/VO(3+)) to form GALMAN-A:VO(2+)/VO(3+) and GALMAN-B:VO(2+)/VO(3+) complexes, respectively. The potentiometric studies provided the binding constants for the complexes and the resulting complexed species were a function of pH. (51)V NMR spectra of GALMAN-A:VO(2+)/VO(3+) and GALMAN-B:VO(2+)/VO(3+) at pH 7.8 and at 30 degrees C indicated the occurrence of two types of complexes formed by oxovanadium ions and galactomannans. GALMAN-A:VO(2+)/VO(3+) and GALMAN-B:VO(2+)/VO(3+) caused loss of HeLa cells viability at concentrations of 50-200microg/mL. GALMAN-A:VO(2+)/VO(3+) exhibited low toxicity for 24h, although GALMAN-B:VO(2+)/VO(3+) was extremely toxic, since 50microg/mL was sufficient to decrease HeLa cell viability after 48h by 60%. GALMAN-A gave rise to a slight increase in cell proliferation after 48h at 100microg/mL, whereas GALMAN-B promoted a slight decrease at concentrations of 50-100microg/mL. GALMAN-A:VO(2+)/VO(3+) and GALMAN-B:VO(2+)/VO(3+) exhibited a significant decrease in cell proliferation after 48h, each reaching 60% inhibition at 5-10microg/mL. The complexes which caused this effect were at concentrations 10 times lower than the uncomplexed polymers.

The rheological properties of a physically linked hydroalcoholic gel obtained from a binary system consisting of xanthan and of galactomannan from the seeds of Mimosa scabrella (X:GB) with a low Man:Gal ratio of 1.1:1 were compared to those of guar gum (Man:Gal ratio 1.5:1, X:GG). The rheological analysis demonstrated an improvement of strength of X:GB and X:GG hydrogels after dispersion of the polysaccharides in buffer with 1,2-propanediol. The addition of ascorbic acid to these hydrogel formulations resulted in a slight decrease of gel strength. Both hydrogels presented rheological stability over 12 weeks at ambient temperature.

A Brazilian source of galactoxyloglucan was obtained from seeds of Hymenaea courbaril and investigated before (JN) and after the hydrolytic removal of galactose (JH). The native polysaccharide contained glucose, xylose and galactose in a ~ 4.0:2.7:1 molar ratio. Gelation occurred when ~ 51% of the galactose residues was removed from the xyloglucan by fungal β-galactosidase. The rheological properties of JN and JH were analyzed. Dynamic oscillatory measurements characterized JN as a viscoelastic solution and JH as a true gel. JH achieved the maximum storage modulus G′ at temperatures above 40 °C and was found to increase with the increasing concentration. The gel point temperatures of JH fraction were determined at the cross-over point of G′ and G″ and by calculating the inflexion point of the G′ plot.

In higher plants, mannans are found as dominant reserve material in the endosperm of Arecaceae seeds and also in some species from Apiaceae, Rubiaceae and Asteraceae. A linear β(1 → 4)- d -mannan was now isolated from the endosperm of Schizolobium parahybae , family Caesalpiniaceae, a native of Southern Brazil. Its seeds were germinated and the consumption of polysaccharides from the endosperm, namely galactomannans and β(1 → 4)- d -mannan, was analysed at differents stages of germination. At the 6th day after germination no residual 3:1 Man:Gal galactomannan was found, indicating that complete degradation of galactomannan had been reached. However, after 12 days of germination, the mannan was recovered from the remaining endosperm. Its presence in the endosperm after germination demonstrated that it is not a reserve material as described for seeds of other species.

Successive aqueous (10 ºC, 25 ºC and 80 ºC) and alkaline (1M NaOH; 25 ºC) extractions of milled Parkinsonia aculeata endosperms gave rise to four galactomannan fractions. These extractions furnished viscous galactomannans with Man:Gal ratios ranging from 3.1:1; 3.7:1; 4.9:1 and 6.1:1 (P1, P2, P3 and P4, respectively). Fraction P1 was used for structural studies by using methylation analysis, periodate oxidation and 13C-NMR. It showed a linear backbone of beta(1->4) linked D-mannose units, to which single alpha(1->6)-linked D-galactose are attached. This galactomannan has Mw 775700 g/mol and intrinsic viscosity of 558 mL/g. The four fractions and the crude endosperm were treated with epichlorydrin and used as matrix for affinity chromatography. All columns tested showed ability to bind lectin samples. The efficiency is related to the degree and pattern of substitution of galactosyl units on the D-mannan backbone.

A general structural characterization and an investigation on the dynamics of formation of cell wall polysaccharides was performed, using plantlets stem samples from a typical gymnosperm from southern Brazil, Araucaria angustifolia, as experimental model. Microscopic examination and monosaccharide composition of plantlet segments at different heights were carried out to show the representative portions of stem cell wall development. The plantlets were divided in portions (tip, middle and base) which were submitted to sequential extractions. The extraction with water gave rise to large amounts of pectic material in the three portions and more highly substituted pectins occurred in the tip portion of the stems. Increase in alkali concentration extracted, respectively, higher amounts of xyloglucan structurally similar to those from dicotyledons. However, oligosaccharides containing galactose and fucose where found in higher amounts in base than tip portion. The changes in cell wall composition suggest that the development in gymnosperm cell walls follow the same key events as found in dicotyledon walls (type I).

A xyloglucan (XG) was extracted from the seeds of Hymenaea courbaril (Jatoba) harvested from trees growing at different locations in Brazil. They were from Foz do Chopin Forest Reserve, State of Parana (HC-I), Cuiaba (HC-II) and Sinope/State of Mato Grosso (HC-III), Natal/State of Rio Grande do Norte (HC-IV), Fortaleza/State of Ceara (HC-V) and Tamarindus indica (TM) from Conceicao de Almeida/State of Bahia, Brazil. It was submitted to SEC-MALLS analysis and its intrinsic viscosity determined. When a solution of XG was heated to 85 °C for 2 h, there was a reduction of aggregation and the XG from the seeds of H. courbaril had a higher value of C∞ when compared with that of from T. indica, probably due to the presence of an unique oligossacharide series present in the H. courbaril samples (XXXXG). This gives rise to a more rigid molecule when compared with the XG from T. indica.

The rheological properties of composite gels of starch extracted from Yam roots (Discorea sp) and hectorite (a mineral clay belonging to the smectite group) were studied in aqueous solutions as a function of hectorite concentration. The elastic (G′) and viscous (G″) moduli of the composite gels were dependent on the clay content, and for all samples G′ was greater than G″. Composite gels with clay contents of

Carbohydrates containing galactopyranosyl and mannopyranosyl units with vicinal cis-diols were treated with NaVO(3) in D(2)O, and complexation was determined by (51)V NMR spectroscopy. Me alpha-Galp, Me beta-Galp (3,4-cis-diols), and Me alpha-Manp (2,3-cis-diol) complexed, but Me beta-Manp barely did so. This low degree of complexation also occurred with a beta-mannan containing alternate (1--3)- and (1--4)-linkages and an alginate having beta-ManpA blocks. In contrast, branched alpha-mannans complexed readily, although the (51)V resonances for one with side chains terminated with alpha-Manp-(1--3)-alpha-Manp-(1--differed from another with only alpha-Manp-(1--2)-alpha-Manp-(1--groups. The anomeric configuration of Me alpha-Galp and Me beta-Galp, each with 3,4-cis-diols remote from C-1, gave rise to three (51)V signals of complexes with similar shifts and proportions. The shifts of a galactomannan with terminal alpha-Galp-(1--2)-alpha-Manp- were the same as those with alpha-Galp-(1--6)-beta-Manp- groups, but fewer complexes were formed with the former structure, probably due to greater steric crowding of the vanadate esters. Most of the complexes gave rise to a signal in the delta515 region, consistent with the dimeric trigonal-bipyramidal structure.

Podocarpus lambertii, a Podocarpaceae, is a member of the most diverse family of conifers and Araucaria angustifolia, which belongs to the Araucariaceae family, is a typical gymnosperm from Southern Brazil. A structural characterisation of their hemicelluloses was carried out. The hemicelluloses were obtained by sequential and selective extraction with aqueous alkaline solvents, which resulted in the preparation of arabinoxylans (AGX) with different Xyl:Ara ratios, indicating the existence of distinct polysaccharides. Some are more exposed in the extraction process (higher arabinose content) and others which interact strongly with cellulose, had molecular mass differences, confirmed by HPSEC analysis. Isolated arabinoxylans and galactoglucomannans (GGM) had, by chemical and spectroscopic analysis, structural features similar to those found in other coniferous species. The hemicelluloses of P. lambertii and A. angustifolia had GGM:AGX ratios of 1.0:1 and 2.3:1, respectively. This proportion found in A. angustifolia is common to other gymnosperms. However, the content of AGX in P. lambertii is higher than expected, since that coniferous plants contain mainly GGM with a lower proportion of acidic arabinoglucuronoxylans. This discrepancy, added to the peculiar morphologic characteristics from the Podocarpus genus should probably be significant in the evolutionary process.

The structure and rheological properties of water-soluble polysaccharides from industrialized mango pulp were investigated. Soluble fraction (SF) 2 was heterogeneous on high performance size exclusion chromatography, giving two peaks as determined by multi-angle laser light scattering and refractive index detectors. The presence of starch in SF2 was demonstrated by a positive iodine reaction and by 13C nuclear magnetic resonance (NMR) spectroscopy. The presence of pectic polysaccharides was shown by a calorimetric method, 13C-NMR spectroscopy and carboxyl reduction. The main pectic polysaccharide was polygalacturonic acid; type I rhamnogalacturonan was also detected. Analysis of the rheological properties of SF2 showed a pseudoplastic behavior up to 3 g x l(-1). 'Creep and recovery' tests and analysis performed under a dynamic state revealed a weak gel character for solutions at concentrations of 15, 20 and 30 g x l(-1).

A fucosylated xyloglucan was isolated from the leaves of Hymenaea courbaril by alkaline extraction, followed by ethanol precipitation and ion-exchange chromatography. The isolated polysaccharide showed Glc:Xyl:Gal:Fuc in molar ratio of 8:5:2.5:1 and (D)(25) +40.5 degrees. Composition and linkage analyses, supported by NMR spectroscopic measurements, showed that the polysaccharide has a glucan backbone which is highly substituted at O-6 with D-xylopyranose residues, about a half of which are substituted at O-2 by D-galactopyranosyl units. Some of the galactose residues are further substituted by L-fucopyranose at O-2. The M(r), as determined by HPSEC, was 49,500.

A galactomannan was isolated from the endosperm of seeds of Senna macranthera . It contained mannose and galactose in a 3.0:1 ratio and consisted mainly of a (1→4)-linked β- d -Man p main-chain partially substituted at O-6 with α- d -Gal p side-chains. Sulphation with SO 3 -pyridine gave a product with DS 0.40. According to 13 C NMR analysis, the OH-6 groups of galactopyranosyl and mannopyranosyl units were preferentially substituted. The product had 45 IU/mg of anticoagulant activity, as shown by the in vitro activated partial thromboplastin time (APTT), compared with 183 IU/mg for a porcine intestinal mucosa heparin. Two fractions of the sulphated derivative were obtained differing in their affinity to AT III in gel. Only that with a high affinity (DS 1.4) showed a strong anticoagulant activity, as measured by APTT (321 IU/mg) and Heptest. By analogy with heparin, the anticoagulant activity of the derivative could be expressed through binding of the polysaccharide to AT III.

The seed endosperm from the Leguminosae Schizolobium amazonicum was shown to consist of three different parts: (i) the embryo side or interior section; (ii) the seed coat side or exterior section; and (iii) an intermediate zone rich in galactomannan with a 3:1 Man/Gal ratio located between the two sides of the seeds. The exterior section was submitted to a series of hot water and alkaline extractions and the remaining product investigated by monosaccharide analysis, 13 C NMR, X-ray and electron diffraction, together with electron microscopy. After an extraction with 16% NaOH, a linear β(1→4) microfibrillar mannan could be isolated in this portion of the seeds. This is the first time that a pure mannan fraction has been found in the seed of a Leguminosae.

The influence of the galactomannan characteristic ratios ( M / G ) on the temperature of gelation ( T g ) and the gel strength of mixtures of galactomannan with xanthan is reported. Two galactomannans were investigated: one highly substituted from the seeds of Mimosa scabrella ( M / G =11), and the other, less substituted, from the endosperm of Schizolobium parahybae , with ( M / G =30) [Ganter JLMS, Zawadzki-Baggio SF, Leitner SC, Sierakowski MR, Reicher F. J Carbohydr Chem 1993;12:753]. The xanthan:galactomannan systems (4:2 g l −1 , in 5 mM NaCl) showed a temperature of gel formation ( T g ) of 24°C for that of S. parahybae [Bresolin TMB, Milas M, Rinaudo M and Ganter JLMS. Int J Biol Macromol 1998;23:263] and 20°C for the galactomannan of M. scabrella , determined by viscoelastic measurements and microcalorimetry. A T g of 40–50°C was found by Shatwell et al. [Shatwell KP, Sutherland IW, Ross-Murphy SB, Dea ICM. Carbohydr Polym 1991;14:29] for locust bean gum-LBG ( M / G =43). Lundin and Hermansson [Lundin L, Hermansson AM. Carbohydr Polym 1995;26:129] reported a difference of 13°C for T g of two LBG samples with M / G =3 (40°C) and 5 (53°C), in mixtures with xanthan. It appears that the more substituted galactomannans have lower temperatures of gelation in the presence of xanthan. The mechanism of gelation depends also on the M / G ratio. For the lower values it involves only disordered xanthan chains in contrast to M / G ratios higher than 3. In addition, the presence of the galactomannan from M. scabrella increased slightly the temperature of the conformational change ( T m ) of xanthan probably due to the ionic strength contribution of proteins (3.9%) present in the galactomannan. On the other hand, the galactomannans from S. parahybae , with 1.5% of proteins and M. scabrella , with 2.4% of protein, did not show this effect, the T m of xanthan alone or in a mixture being practically unchanged.

Schizolobium amazonicum and S. parahybae galactomannans yielded the same pattern of oligosaccharides on partial acid hydrolysis. Seed coats of both species furnished unusual linear arabinans providing chemotyping evidence supporting the suggestion that they are not different species. Schizolobium parahybae and S. amazonicum seeds yielded galactomannans with identical 3.0:1 Man:Gal ratios and with the same d-galactose distribution along the main chain. Although the galactomannan from seeds of Cassia fastuosa showed the same Man:Gal ratio, its fine structure differed significantly from that of the two Schizolobium species as shown by the analysis of oligosaccharides (DP 2 to 6) obtained by partial acid hydrolysis. Seed coasts of S. parahybae and S. amazonicum furnished similar unusual neutral linear α-l-arabinofuranan (1 → 5) linked, as determined by methylation analysis, optical rotation and 13C NMR spectroscopy. On the other hand, C. fastuosa seed coats furnished two acidic arabinans. These results in terms of using galactomannans and arabinans in chemotyping, support the suggestion of Rizzini that S. parahybae and S. amazonicum are not different species.

Treatment of the xyloglucan isolated from the seeds of Hymenaea courbaril with Humicola insolensendo-1,4-β-d-glucanase I produced xyloglucan oligosaccharides, which were then isolated and characterized. The two most abundant compounds were the heptasaccharide (XXXG) and the octasaccharide (XXLG), which were examined by reference to the biological activity of other structurally related xyloglucan compounds. The reduced oligomer (XXLGol) was shown to promote growth of wheat (Triticum aestivum) coleoptiles independently of the presence of 2,4-dichlorophenoxyacetic acid (2,4-D). In the presence of 2,4-D, XXLGol at nanomolar concentrations increased the auxin-induced response. It was found that XXLGol is a signaling molecule, since it has the ability to induce, at nanomolar concentrations, a rapid increase in an α-l-fucosidase response in suspended cells or protoplasts of Rubus fruticosus L. and to modulate 2,4-D or gibberellic acid-induced α-l-fucosidase.

The synergistic effect obtained by mixing xanthan and galactomannans from Brazilian seeds ( Mimosa scabrella Bentham and Schizolobium parahybum (Vell) Blake), with mannose:galactose ratios of 1.1:1 and 3:1 respectively, were examined. Viscosity measurements were performed under different conditions. A strong interaction was observed with xanthan:galactomannan ( X : G ) from S. parahybum , in water at 1 and 2g/liter. For the mixture of xanthan:galactomannan from M. scabrella ( X : G 3:1 2 g/liter, in water) despite the latter high galactose content, an increase in viscosity of 32% was observed over that calculated assuming no interaction. The results showed the formation of a gel-like structure with hysteresis between increasing and decreasing shear rate. The interaction occurred mainly when the system was previously subjected to 80 °C in water, independent of the conformation of xanthan. The stronger interactions were obtained in aqueous systems. Since the main chain of the M. scabrella galactomannan is almost completely substituted, the synergistic effect must have an interaction mechanism different from that previously described by Dea and Morrison (1975), Dea et al. (1977), Morris et al. (1977), and Lundin and Hermansson (1995) in which xanthan interacts with galactomannan via the unsubstituted region of the latter.

Galactomannans with Man:Gal ratios ranging from 1.1:1 to 3:1, obtained from the seeds of Mimosa scabrella, Stryphnodendron barbatiman, Schizolobium parahybum and Schizolobium amazonicum, were submitted to mild acid hydrolysis. The products were fractionated by gel permeation chromatography on BioGel P2 yielding fractions with degrees of polymerization (DP) of 1 to 6. Those with DP 2 to 6 from each species were analysed by ion-exchange high-performance liquid chromatography and characterized by 13C- and 1H-nuclear magnetic resonance (NMR) spectroscopy. The distribution of the oligosaccharides of each degree of polymerization was very similar for the products from S. parahybum and S. amazonicum, indicating the same D-galactosyl distribution on the D-mannan backbone, in agreement with the 13C-NMR splitting in the C4 region of the D-mannosyl units in the original polymers. The hydrolytic conditions adopted allowed characterization of compounds that are not generally produced by enzymatic treatments. The results show that the structures of the oligosaccharides, even if there is a preferential hydrolysis of Gal-Man linkages, reflect the composition of the parent polymer.

The seeds of Senna multijuga were extracted with water or 1% acetic acid and treated with ethanol, resulting in two insoluble fractions. After purification, the major one (FIA, 23%) was shown to be a galactomannan (Man:Gal 2.3:1; [alpha] = +54.6; [eta] = 1340 ml g-1). It consists of a main chain of (1-->4)-linked beta-D-mannopyranosyl residues substituted at O6 by single-unit alpha-D-galactopyranosyl side chains. The second fraction (FIB, 2.5%) was an O-acetyl-glucuronoarabinoxylan from the seed coats (O-acetyl 8.3 mol%; glucuronic acid 11.7%, Xyl:Ara ratio 20:1), which showed a predominance of 4-O-substituted Xylp units (84.4%), branched at O3 with non-reducing end units of Xylp, Araf and glucuronic acid. The O-acetyl positions in D-xylosyl units are at O2 (4.8%), O3 (4.4%) and O2,3 (0.9%). The ratio between O3 and O2 determined by 13C-nuclear magnetic resonance spectroscopy is 1.5:1.

Chemical structures of galactomannans from the native Brazilian species, M. scabrella, S. barbatiman and S. parahy-bum were studied. Their seeds, on aqueous extraction, furnished high yields of viscous galactomannans, whose mannose to galactose ratios were 1.1:1, 1.5:1, and 3.0:1, respectively. The polysaccharides were analysed by methylation, periodate oxidation and chromium trioxide oxidation. The results, confirmed by 13C NMR spectroscopy, indicated expected structures of legume galactomannans, namely a polymeric main chain of (l→4) -linked β-D-mannopyranosyl residues substituted at 0–6 by single unit α-D-galactopyranosyl side-chains. 13C NMR spectra showed clear splitting of the O-substituted resonances of C-4 of the β-D-mannosyl residues depending on the nearest-neighbour probabilities, indicating a random arrangement of the D-galactosyl groups in all of the three galactomannans.

Pretreatment resulting in enzymatic inactivation proved to be essential for the preparation of highly viscous solutions of the galactomannan from seeds ofS. barbatiman ([η]= 1400 mL/g). Short periods of reflux with aqueous methanol or ethanol or treatment with boiling water of the seeds was used. The target for the inactivation step is a β-d-endo-mannanase activity present in the dormant seeds.

The rheological properties of the galactomannan from the seeds of a member of the Leguminosae have been studied. The sample used had a mannose/galactose ratio close to 1 and an intrinsic viscosity of 900 ml/g. The viscosity results are characteristic of a random coil polymer with a critical concentration c∗ = 2·6/[η] which is similar to the values found for polystyrene and polystyrenesulphonate, but higher than the value obtained for more rigid polysaccharides. The slope of the logarithmic plot of the specific viscosity measured at zero shear rate against c[η] in the semi-dilute regime was 4·2, a value in agreement with the theoretical predictions for linear polymers interacting by purely topological entanglements. The viscoelastic behaviour was lower than that found for solutions of other galactomannans and this and the less severe dependence of the viscosity on the coil overlap parameter is probably due to lower interactions because of the high galactose content.

A lectin and a galactoxyloglucan were characterized from Mucuna sloanei seed cotyledons. The galactoxyloglucan, isolated by water extraction and ethanol precipitation, had Glc:Xyl:Gal proportions in a molar ratio of 1.8:1.7:1.0 and a molar mass (M(w)) of 1.6x10(6)g mol(-1). The lectin (sloanin), isolated from the same seed by affinity chromatography on cross-linked Adenanthera pavonina galactomannan, gave two protein bands by SDS-PAGE (36 and 34 kDa) and one peak by gel filtration (63.6 kDa). Its N-terminal sequence indicated approximately 69% identity with soybean agglutinin to leguminous lectins. Circular dichroism (CD) spectra established that sloanin predominantly contains beta-sheet structures. Sloanin has approximately 5.5% carbohydrate and displayed hemagglutinating activity against rabbit and enzyme treated human erythrocytes, inhibited only by D-Gal containing sugars. The interaction between sloanin and storage cell-wall galactoxyloglucan was tested by affinity chromatography and fluorescence spectroscopy.

Stryphnodendron barbatiman (barbatimao) is a native tree that is found throughout the “Cerrados,” a region of Central Brazil. Plant seeds, on water extraction, furnished 28 g% galactomannan (dryweight basis), the monosaccharide composition of which (galactose to mannose ratio, 1.0:1.5) fits in the legume heteromannan group. This seed gum, after Sevag deproteinization, still retained 6 g% of associated protein and had a molecular weight of about 1.8 MD on gel filtration. A high intrinsic viscosity (1300 cP) was observed for the polysaccharide sample obtained after reflux of the crushed seeds in 80% aqueous methanol.

The complex polysaccharide of the leaves of Pereskia aculeata is highly branched, containing units of arabinofuranose, arabinopyranose, galactopyranose, galactopyranosyluronic acid, and rhamnopyranose. Glucopyranose units are also present. The location of 25 molar % of acetate ester groups was determined using modified Bouveng procedures, one of the changes being the use of refluxing methanolic sodium methoxide for the removal of N -methyl- N -phenylcarbamoyl groups. With the aid of g.l.c.-m.s. on a capillary column of DB-210, which separated the various isomeric mono-, di-, and tri- O -methyl arabinitol acetates, and by examination of e.i. fragmentation patterns of various derivatives deuterated at C-1, the O -acetyl groups were located. They were found mainly as monosubstituents at O-2 and O-3 of nonreducing arabinofuranosyl end-groups and at O-2 of 4- O -substituted galacto- and gluco-pyranosyl units.

Xyloglucans from seeds of Copaifera langsdorffii (XGC), Hymenaea courbaril (XGJ) and Mucuna sloanei (XGM) were obtained from milled and defatted cotyledons by aqueous extraction at 25 °C. The resulting fractions contained Glc, Xyl and Gal in molar ratios of 2.5: 1.5: 1.0 (XGC), 3.8: 2.6: 1.0 (XGJ) and 2.5: 1.6: 1.0 (XGM). HPSEC-MALLS/RI analysis showed that each polysaccharide fraction was homogeneous; Mw values were 1.6 × 105, 2.0 × 105 and 1.5 × 105 g/mol, respectively. The effect of the xyloglucans on the production of O 2 · - and NO· and on the recruitment of macrophages to the mouse peritoneum was evaluated. All polysaccharides promoted an increase in the number of peritoneal macrophages in a dose-dependent manner. The largest increase, of 576% in comparison to the control group, was elicited by XGJ at 200 mg/kg. The effect of XGC, XGJ and XGM on O 2 · - production, in the presence or absence of phorbol 12-myristate 13-acetate (PMA), was not statistically significant. For NO· production, the lowest concentration of XGC (10 μg/ml) gave rise to an increase of 262% when compared to the control group; the effect was dose-dependent, reaching 307% at 50 μg/ml. On the other hand, XGJ at a concentration of 50 μg/ml enhanced NO· production by 92%. XGM did not affect NO· production significantly. The results indicate that xyloglucans from C. langsdorffii, H. courbaril and M. sloanei have immunomodulatory activity.

Tomato pulp treated at industrial unit conditions was utilized to determine the physical and chemical changes on pectin substances properties and its correlation to the consistency of tomato pulp, hot break pretreated product, concentrated pulp at 70oC/30 min and sterilized pulp at 102oC/10 min. The assays carried out were: apparent viscosity, serum separation degree, precipitate weight ratio, insoluble solids and pectic substances as uronic acid, fractionated according to their solubility in water, 0.2% ammonium oxalate, 0.05N hydrochloric acid and 0.05N sodium hydroxide solutions. Concentration and sterilization cause reduction in the apparent viscosity, the precipitate weight ratio and increasing of the serum separation degree of the suspension compare to tomato pulp submitted only to pre-treatment and those conditions didn’t affect significantly the total uronic acid and insoluble solids in water. However, changes occurred on chemical composition, detected into fractions of pectic substances expressed as uronic acid in all samples; results for pre-treated pulp sample to sterilized pulp samples (final product) show a high water solubilization of the fractions of the pectic substances, around 31%, confirmed by an increment of 24% in the water soluble fraction. A high correlation was established between the concentration of water-insoluble fractions and apparent viscosity, precipitate weight ratio and serum separation degree.

A homogeneous fucogalactoxyloglucan, isolated from the leaves of Hymenaea courbaril , was analysed by methylation-GC–MS. These procedures involved derived partially O -methylated alditol acetates and acetylated aldononitriles, which demonstrated the presence of both 2- O - and 4- O -substituted Xyl p units in the side-chains. The presence of the unusual, latter structure was confirmed by 2D NMR spectroscopy with a correlated HMQC C-4/H-4 signal at δ 77.8/3.73. A similar 4- O -substituted xylosyl structure was present in a decasaccharide Glc 4 Xyl 3 Gal 2 Fuc obtained via endo -glucanase treatment of the polysaccharide, which gave rise to a molecular ion with m / z 1555 (ESI-MS, Na + form).

On aqueous extraction, Hymenaea courbaril var. stilbocarpa, known in Brazil as jatoba, furnishes a high yield of viscous xyloglucan (45%) from its seeds. The crude polysaccharide (B1) was hydrolysed and the products, analysed as alditol acetates, were glucose, xylose, galactose and arabinose in the ratio 50:35:13:2. After further fractionation on DEAE-cellulose column (chloride form), the main fraction (70% yield, B2) was obtained. The basic structure of the xyloglucan was determined as a cellulose-type (1-->4)-linked beta-D-glucan backbone partially substituted with side chains at O6 of alpha-D-xylopyranose, some of which were themselves substituted at O2 by the units of beta-D-galactopyranose. Treatment of the xyloglucan (B2) with commercial cellulase from Trichoderma sp. yielded six oligosaccharides. These oligosaccharides were isolated by preparative paper chromatography, and their structures were determined by gas-liquid chromatography-mass spectroscopy of the derived partially O-methylated alditol acetates. These results confirm the structure proposed for jatoba seed xyloglucan.

Mature fruit of Chorisia speciosa yield an exudate (E-I) following mechanical injury. The polysaccharide contains rhamnose, arabinose, xylose, mannose, glucose, galactose and glucuronic acid in molar ratios of 20:11:1:3:2:40:23. The main chain of the structure is composed by β-galactopyranosyl units linked (1→3) and (1→6) as indicated by NMR spectra and methylation data. Arabinosef and rhamnose are terminal residues. In order to compare E-I with the polysaccharides from the fruit mesocarp, the latter was submitted to different extractions. The water fraction contains rhamnose, arabinose, xylose, mannose, glucose, galactose and uronic acid in molar ratios of 18:4:1:2:3:44:28. It was treated with CTAB yielding a precipitate which was decomplexed with NaCl, giving four fractions. The fraction obtained using 0.15 M NaCl had a quantitative composition similar that of E-I.

In view of the wide industrial applications of galactomannans as a thickening agent, those of Mimosa scabrella (bracatinga), a leguminous tree abundant in Southern Brazil, are under investigation. Seeds of bracatinga were processed on a pilot plant scale in order to obtain its galactomannan. The process consisted of successive milling, enzyme inactivation, aqueous extraction, precipitation of polysaccharide, and drying and milling. The product was obtained in 20% yield, with characteristics similar to those obtained on the laboratory scale, namely mannose:galactose ratio (M:G) 1.1:1.0 and intrinsic viscosity. Considering the seed availability in the metropolitan regions of Curitiba, it should be possible to obtain 3000 ton/year of this polysaccharide.

The floss silk from Chorisia speciosa furnished a polysaccharide with a main chain of (1→4) linked β-Xyl p substituted at O -2 by 5% of uronic acid. The xylan structure also was interposed with α-Rha p units in small amounts. The defatted seeds furnished on aqueous extraction a major fraction, ( O -acetyl, 10% and protein, 45%) wich was hydrolysed and analysed by p.c. and GLC, showing Rha (20%), Ara (16%) Gal (64%) and also uronic acids (45%). Partial hydrolysis gave rise to a polysaccharide free of arabinose, with 46% of uronic acids. Methylation analysis (GLC-MS) indicated a chain of (1→4)-linked Gal p (42% of 2,3,6-Me 3 -Gal).

Extraction with dimethyl sulfoxide of wood-meal of the stem of bracatinga (Mimosa scabrella), a south Brazilian hardwood, that was defatted and delignified by treatment with aqueous chlorine at 0–5° followed by extraction with cold ethanol, gave a soluble O-acetylated 4-O-methyl- d -glucurono- d -xylan having (1→4)-linked β- d -xylopyranosyl residues that were unsubstituted (65%) and 2-O-(14%), 3-O- (16%), and 2,3-di-O-acetylated (5%), as determined by methylation analysis. Another preparation obtained by use of refluxing ethanol in the delignification process showed neither removal nor migration of acetyl groups. By comparison with synthetic, partly O-acetylated d -xylans of known composition, 13C-n.m.r. spectroscopy indicated that O-acetyl group migration does not occur during treatment with cold aqueous chlorine, refluxing ethanol, or water at 70°. Methyl 2-O-acetyl-4-O-methyl-β- d -xylopyranoside (6) was also unaffected by aqueous chlorine. O-Acetyl group migration took place more readily in aqueous and dimethyl sulfoxide solutions of 6 than of O-acetyl- d -xylans. The lowest temperatures at which migration was observed in monosaccharides was at 50 and 70° for solutions in D2O and (CD3)2SO, respectively.

Resumo Determinou-se a composição qualitativa e quantitativa de carboidrátos e o potencial de produção de etanol em 25 espécies de madeiras da região de Maués-Amazônia. Summary The qualitative and quantitative composition of carbohydrates of 25 wood species from Maués area, Amazonia, and their capacity for ethanol production was determined.

A homogenous water-soluble mucilaginous heteropolysaccharide containing 3.5 % protein was isolated from the leaves of Pereskia aculeata . It contains arabinose, galactose, rhamnose and galacturonic acid in a molar ratio of 5.1:8.2:1.8:1.0 and, based on conventional polysaccharide analysis techniques, has a (1→4)-linked β- D -galactopyranosyl main chain partially substituted at O-3 by β- L -arabinopyranosyl units, which are, in turn, di- O -substituted at O-2 and O-4 by non-reducing end-groups of α- L -arabinofuranose. Also present are O -substituted units of galactopyranosyluronic acid, which are also present as non-reducing end-groups. They are then linked (1→2) to rhamnopyranosyl units. Aqueous solutions of the heteropolymer had a maximum viscosity at pH 4.5 and viscosity was reduced in the presence of salts over a wide range of pHs. The 13 C NMR spectrum of the polysaccharide in DMSO indicated a great difference between the elevated segmental motion of the arabinosyl side chains and that of the core, since signals of the former were sharp and those of the latter extremely broad.

The acidic O -acetyl- d -xylan of Mimosa scabrella contains xylose, 4- O -methylglucuronic acid, and O -acetyl groups in the molar ratios of 60:7:33 and, when subjected to controlled Smith degradation, provided xylosyl-, xylobiosyl-, xylotriosyl-, and xylotetraosyl-glycerol, as well as glycerol. Their proportions differed greatly from that which would arise from xylopyranosyl units substituted regularly with O -acetyl groups. In order to avoid ambiguities arising from resistance of some of the xylosyl units by substitution with 4- O -methylglucuronic acid, the O -acetylxylan was converted into a partly O -methylated polysaccharide having O -methyl groups with similar positions of substitution. Two successive Smith degradations were carried out, and the two sets of partly O -methylated derivatives resulting were identified by f.a.b.-m.s. The highly uneven distribution of O -acetyl groups along the xylan main-chain was confirmed, with the highest number of consecutive O -acetyl and 4- O -methylglucuronic acid substituents being six, and five O -acetyl substituents alone. 4- O -Methylglucuronic acid units were not substituted.

Endosperms from seeds of different subfamilies of Leguminosae were submitted to sequential aqueous and alkaline aqueous extractions. The extractions from species belonging to the Mimosoideae and Faboideae subfamilies yielded galactomannans with constant Man:Gal ratios, whereas the extractions from Caesalpinioideae seeds gave rise to galactomannans with increasing values of the Man:Gal ratio. The presence of a family of galactomannans within the same species may be a trait found only in Caesalpinioideae subfamily. The final insoluble residues that were obtained after the removal of galactomannans from the Caesalpinioideae and Faboideae subfamilies are composed of pure mannans and do not contain cellulose, while those from the Mimosoideae subfamily are composed of cellulose. A mannan was isolated from the unripe endosperm of Caesalpinia pulcherrima, suggesting no developmental relationship between galactomannan and mannan. These results are consistent with the presence of a distinctive cell wall pattern in the endosperms of Leguminosae species.

The structures of echinocystic and cochalic acids were confirmed as 3β,16β-dihydroxyolean-12-en-28-oic acid and 3β,16α-dihydroxyolean-12-en-28-oic acid respectively, by comparing the ease of acetonide formation of the corresponding triols.