Physicochemical and biological properties of 6(1),6(3),6(5)-tri-O-alpha-maltosyl-cyclomaltoheptaose (6(1),6(3),6(5)-tri-O-alpha-maltosyl-beta-cyclodextrin)

A unique multibranched cyclomaltooligosaccharide (cyclodextrin, CD) of 6(1),6(3),6(5)-tri-O-alpha-maltosyl-cyclomaltoheptaose [6(1),6(3),6(5)-tri-O-alpha-maltosyl-beta-cyclodextrin, (G(2))(3)-betaCD] was prepared. The physicochemical and biological properties of (G(2))(3)-betaCD were determined together with those of monobranched CDs (6-O-alpha-D-glucopyranosyl-alpha-cyclodextrin (G(1)-alphaCD), 6-O-alpha-D-glucopyranosyl-beta-cyclodextrin (G(1)-betaCD), and 6-O-alpha-maltosyl-beta-cyclodextrin (G(2)-betaCD)). NMR spectra of (G(2))(3)-betaCD were measured using various 2D NMR techniques. The solubility of (G(2))(3)-betaCD in water and MeOH-water solutions was extremely high in comparison with nonbranched betaCD and was about the same as that of the other monobranched betaCDs. The formation of an inclusion complex of (G(2))(3)-betaCD with stereoisomers (estradiol, retinoic acid, quinine, citral, and glycyrrhetinic acid) depends on the cis-trans isomers of guest compounds. The cis isomers of estradiol, retinoic acid, and glycyrrhetinic acid were included more than their trans isomers, while the trans isomers of citral and quinine fit more tightly than their cis isomers. (G(2))(3)-betaCD was the most effective host compound in the cis-trans resolution of glycyrrhetinic acid. Among the branched betaCDs, (G(2))(3)-betaCD exhibited the weakest hemolytic activity in human erythrocytes and showed negligible cytotoxicity in Caco-2 cells up to 200 microM. These results indicate unique characteristics of (G(2))(3)-betaCD in some biological responses of cultured cells.     

Spectral and thermodynamic properties of Ag(I), Au(III), Cd(II), Co(II), Fe(III), Hg(II), Mn(II), Ni(II), Pb(II), U(IV), and Zn(II) binding by methanobactin from Methylosinus trichosporium OB3b

Methanobactin (mb) is a novel chromopeptide that appears to function as the extracellular component of a copper acquisition system in methanotrophic bacteria. To examine this potential physiological role, and to distinguish it from iron binding siderophores, the spectral (UV–visible absorption, circular dichroism, fluorescence, and X-ray photoelectron) and thermodynamic properties of metal binding by mb were examined. In the absence of Cu(II) or Cu(I), mb will bind Ag(I), Au(III), Co(II), Cd(II), Fe(III), Hg(II), Mn(II), Ni(II), Pb(II), U(VI), or Zn(II), but not Ba(II), Ca(II), La(II), Mg(II), and Sr(II). The results suggest metals such as Ag(I), Au(III), Hg(II), Pb(II) and possibly U(VI) are bound by a mechanism similar to Cu, whereas the coordination of Co(II), Cd(II), Fe(III), Mn(II), Ni(II) and Zn(II) by mb differs from Cu(II). Consistent with its role as a copper-binding compound or chalkophore, the binding constants of all the metals examined were less than those observed with Cu(II) and copper displaced other metals except Ag(I) and Au(III) bound to mb. However, the binding of different metals by mb suggests that methanotrophic activity also may play a role in either the solubilization or immobilization of many metals in situ.     

Circular dichroism spectra of DNA quadruplexes [d(G(5)T(5))](4) as formed with G(4) and T(4) tetrads and [d(G(5)T(5)). d(A(5)C(5))]2 as formed with Watson-Crick-like (G-C)(2) and (T-A)(2) tetrads

We utilize electrophoresis and find that a thermally treated equimolar mixture of the oligonucleotide d(G(5)T(5)) and its complementary oligonucleotide d(A(5)C(5)) exhibits either two bands or a single band in one lane, depending on the conditions of the incubation solutions. The thermally treated d(G(5)T(5)) solution loaded in a different lane exhibits a single band of the parallel quadruplex [d(G(5)T(5))](4), which is composed of homocyclic hydrogen-bonded G(4) and T(4) tetrads previously proposed. For the thermally treated equimolar mixture of d(G(5)T(5)) and d(A(5)C(5)), the fast band is assigned to a Watson-Crick d(G(5)T(5)). d(A(5)C(5)) duplex, so that the slow band with the same low mobility as that of [d(G(5)T(5))](4) may be assigned to either [d(G(5)T(5))](4) itself or a [d(G(5)T(5)). d(A(5)C(5))](2) quadruplex. If the latter compound is true, this may be the antiparallel quadruplex composed of the heterocyclic hydrogen-bonded G-C-G-C and T-A-T-A tetrads proposed previously. After removing these three bands for the duplex and two kinds of hypothetical quadruplexes, we electrophoretically elute the corresponding compounds in the same electrophoresis buffer using an electroeluter. The eluted compounds are ascertained to be stable by electrophoresis. The circular dichroism (CD) and UV absorption spectra measured for the three isolated compounds are found to be clearly different. For the electrophoretic elution of the hypothetical [d(G(5)T(5))](4) quadruplex, the result of the molecularity of n = 4 obtained from the CD melting curve analysis provides further support for the formation of the parallel [d(G(5)T(5))](4) quadruplex already proposed. For the thermally treated equimolar mixture of d(G(5)T(5)) and d(C(5)A(5)), the fast band with a molecularity of n = 2 corresponds to the Watson-Crick duplex, d(G(5)T(5)). d(A(5)C(5)). The slow band with a molecularity of n = 4 indicates the antiparallel quadruplex [d(G(5)T(5)). d(A(5)C(5))](2), whose observed CD and UV spectra are different from those of [d(G(5)T(5))](4). By electrophoresis, after reannealing the eluted compound [d(G(5)T(5)). d(A(5)C(5))](2), a distinct photograph showing the band splitting of this quadruplex band into the lower duplex and upper quadruplex bands is not possible; but by a transilluminator, we occasionally observe this band splitting with the naked eye. The linear response polarizability tensor calculations for the thus determined structures of the [d(G(5)T(5))](4) quadruplex, the McGavin-like [d(G(5)T(5)). d(A(5)C(5))](2) quadruplex, and the Watson-Crick d(G(5)T(5)). d(A(5)C(5)) duplex are found to qualitatively predict the observed CD and UV spectra.     

New complexes of La(III), Ce(III), Pr(III), Nd(III), Sm(III), Eu(III) and Gd(III) ions with morin

New solid complex compounds of La(III), Ce(III), Pr(III), Nd(III), Sm(III), Eu(III) and Gd(III) ions with morin were synthesized. The molecular formula of the complexes is Ln(C₁₅H₉O₇)₃ · nH₂O, where Ln is the cation of lanthanide and n = 6 for La(III), Sm(III), Gd(III) or n = 8 for Ce(III), Pr(III), Nd(III) and Eu(III). Thermogravimetric studies and the values of dehydration enthalpy indicate that water occurring in the compounds is not present in the inner coordination sphere of the complex. The structure of the complexes was determined on the basis of UV-visible, IR, MS, ¹H NMR and ¹³C NMR analyses. It was found that in binding the lanthanide ions the following groups of morin take part: 3OH and 4CO in the case of complexes of La, Pr, Nd, Sm and Eu, or 5OH and 4CO in the case of complexes of Ce and Gd. The complexes are five- and six-membered chelate compounds.     

The frequencies of Gm(1), Gm(2), Gm(4), Gm(12), and Inv(1) in Hessen (Germany)

Summary The serum groups Gm(1) [Gm(a)], Gm(2) [Gm(x)], Gm(4) [Gm(f)]. Gm(12) [Gm(b)] and Inv(1) [Inv(1)] of 2000 sera of healthy blood donors from the land Hesse were examined. The results obtained were compared with those known until now. Three persons, not related to each other, possessed the extremely rare phenotype Gm(-1, 2, 4, 12) [Gm (a-x+b+f+)]. In 0.75% of the cases we found a discordant behaviour of the factors Gm(4) and Gm(12) [Gm(f) and Gm(b)].

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Zusammenfassung 2000 Seren von gesunden Blutspendern aus Hessen wurden bezüglich der Gamma-Globulin-Serumgruppen Gm(1) [Gm(a)], Gm(2) [Gm(x)], Gm(4) [Gm(f)]. Gm(12) [Gm(b)] und Inv(1) [Inv(1)] untersucht. Die gefundenen Resultate wurden mit den bisher bekannten verglichen. Drei miteinander nicht verwandte Personen wiesen den äußerst seltenen Phänotyp Gm(-1, 2, 4, 12) [Gm(a-x+b+f+)] auf. In 0.75% der Fälle fanden wir ein diskordantes Verhalten der Faktoren Gm(4) und Gm(12) [Gm(f) und Gm(b)].

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Director: Prof. Dr. W. Wachsmuth

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Director: Prof. Dr. W. Spielmann

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The nomenclature suggested by WHO at a round-table conference over genes, genotypes and allotypes of immunglobulins is used. The conference took place in Geneva on the 1965 31. 5. to the 5. 6. [5].

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With technical assistance of S. Mohs.     

Nature and composition of La(III), Ce(III), Pr(III), Nd(III), Sm(III), Gd(III), Dy(III) and Ho(III) complexes of embelin

The isolation and characterization of nine polymeric complexes of the general formula [M(L)_1.5S₂]_n (where M is the metal ion, L the ligand and S the solvent, C₂H₅OH) of La(III) and Ce(III), Pr(III), Nd(III), Sm(III), Gd(III), Tb(III), Dy(III), Ho(III) with.the biologically active compound embelin using elemental and thermal analysis, infrared and electronic spectral studies is reported.     

Synthesis and luminescence properties of a blue-emitting Sr(3.5) Y(6.5) O(2) (PO(4) )(1.5) (SiO(4) )(4.5) :Eu(2+) phosphor

A novel blue‐emitting Sr_3.5Y_6.5O₂(PO₄)_1.5(SiO₄)_4.5:Eu²⁺ phosphor was synthesized via a solid‐state reaction. Powder X‐ray diffraction (XRD) analysis demonstrated that the Sr_3.5Y_6.5O₂(PO₄)_1.5(SiO₄)_4.5 host had a hexagonal crystal structure in the space group P6₃/m and unit cell parameters a = 9.418 Å, c = 6.900 Å. The as‐prepared phosphor showed a blue emission and all the main emission peaks were located at around 466 nm for different excitation wavelengths of 297, 333 and 391 nm. The temperature dependence of the photoluminescence property was investigated in the range 20–250 °C, and the emission intensity decreased to 71% of the initial value at room temperature on increasing the temperature to 150 °C. According to the classical theory of fluorescent thermal quenching, the activation energy (ΔE) for the thermal quenching luminescence of the as‐prepared Sr_3.45Y_6.5O₂(PO₄)_1.5(SiO₄)_4.5:0.05Eu²⁺ phosphor was determined to be 0.20 eV. Copyright © 2011 John Wiley & Sons, Ltd.     

N-(2-Pyridyl)acetamide complexes of palladium(II), cobalt(II), nickel(II), and copper(II)

N-(2-Pyridyl)acetamide (aapH) complexes of palladium(II), cobalt(II), nickel(II), and copper(II) have been studied by means of magnetic susceptibilities, and infrared, electronic, and PMR spectra. In the octahedral complexes M(aapH)₂X₂(M = Co, Ni, Cu; X = Cl, Br, NCS, NO₃), bidentate aapH is chelated through the pyridine-N and amid-O atomes, whereas in the square-planar Pd(aapH)₂X₂ (X = Cl, Br) unidentate aapH is coordinated through the pyridine-N atom alone. Under alkaline conditions aapH is deprotonated in the presence of palladium(II) to form Pd(aap)₂·4H₂O, aap being an anionic bidentate ligand and chelating through the pyridine-N and amide-O atoms.     

Spectral and thermodynamic properties of Ag(I), Au(III), Cd(II), Co(II), Fe(III), Hg(II), Mn(II), Ni(II), Pb(II), U(IV), and Zn(II) binding by methanobactin from Methylosinus trichosporium OB3b

Methanobactin (mb) is a novel chromopeptide that appears to function as the extracellular component of a copper acquisition system in methanotrophic bacteria. To examine this potential physiological role, and to distinguish it from iron binding siderophores, the spectral (UV–visible absorption, circular dichroism, fluorescence, and X-ray photoelectron) and thermodynamic properties of metal binding by mb were examined. In the absence of Cu(II) or Cu(I), mb will bind Ag(I), Au(III), Co(II), Cd(II), Fe(III), Hg(II), Mn(II), Ni(II), Pb(II), U(VI), or Zn(II), but not Ba(II), Ca(II), La(II), Mg(II), and Sr(II). The results suggest metals such as Ag(I), Au(III), Hg(II), Pb(II) and possibly U(VI) are bound by a mechanism similar to Cu, whereas the coordination of Co(II), Cd(II), Fe(III), Mn(II), Ni(II) and Zn(II) by mb differs from Cu(II). Consistent with its role as a copper-binding compound or chalkophore, the binding constants of all the metals examined were less than those observed with Cu(II) and copper displaced other metals except Ag(I) and Au(III) bound to mb. However, the binding of different metals by mb suggests that methanotrophic activity also may play a role in either the solubilization or immobilization of many metals in situ.     

Uracilato and 5-halouracilato complexes of Cu(II), Zn(II) and Ni(II). X-ray structures of [Cu(uracilato-N(1))(2)(NH(3))(2)].2(H(2)O), [Cu(5-chlorouracilato-N(1))(2)(NH(3))(2)](H(2)O)(2), [Ni(5-chlorouracilato-N(1))(2)(en)(2)].2H(2)O and [Zn(5-chlorouracilato-N(1))(NH(3))(3)].(5-chlorouracilato-N(1)).(H(2)O)

Four new complexes of uracilato and 5-halouracilato with the divalent metal ions Cu(II), Zn(II) and Ni(II) were obtained and structurally characterized. [Cu(uracilato- N(1))(2)(NH(3))(2)].2(H(2)O) (1) and [Cu(5-chlorouracilato-N(1))(2)(NH(3))(2)](H(2)O)(2) (2) complexes present distorted square planar co-ordination geometry around the metal ion. Although an additional axial water molecule is present [Cu(II)-OH(2)=2.89 A (for 1) and 2.52 A (for 2)] in both cases, only in the complex 2 would be considered in the limit of a bond distance. The Zn(II) in [Zn(5-chlorouracilato-N(1))(NH(3))(3)].(5-chlorouracilato-N(1)).(H(2)O) presents a tetrahedral co-ordination with three ammonia molecules and the N(1) of the corresponding uracilato moiety. A non-coordinated uracilato molecule is present as a counterion and a recognition between co-ordinated and free ligands, by means a tandem of H-bonds, should be mentioned. Finally, the complex [Ni(5-chlorouracilato-N(1))(2)(en)(2)] (H(2)O)(2) (where en is ethylenediamine) presents a typical octahedral trans co-ordination with additional hydrogen bonds between 5-chlorouracilato and the NH(2) groups of ethylenediamine units.     

Preparation, characterization and pH-metric measurements of 4-hydroxysalicylidenechitosan Schiff-base complexes of Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Ru(III), Rh(III), Pd(II) and Au(III)

The 4-hydroxysalicylidenechitosan Schiff-base (2CS-Hdhba) was prepared by the condensation of 2,4-dihydroxybenzaldehyde with chitosan, and its metal complexes, [M(2CS-dhba)Cl₂(H₂O)₂] (M(III) = Fe, Ru, Rh), [M′(2CS-dhba)(AcO)(H₂O)₂] (M′(II) = Co, Ni, Cu, Zn), [Pd(2CS-dhba)Cl(H₂O)] and [Au(2CS-dhba)Cl₂], are reported. These complexes were characterized by elemental analysis, by spectral data (FTIR, solid-phase ¹³C NMR, UV–vis and ESR spectroscopy), by morphological observations (SEM and XRD), and by magnetic and thermal measurements. The Schiff base (2CS-Hdhba) behaves as a bidentate chelate with a single negative charge. The azomethine nitrogen and the deprotonated 2-hydroxy centres with the pendant glucosamine hydroxy functionality play no role in coordination. The dissociation constants of 2CS-Hdhba and the stability constants of some of its metal complexes have been determined pH-metrically.     

Spectroscopic investigations of Er(3+) :CdO-Bi(2) O(3) -B(2) O(3) glasses

This article reports on the optical properties of Er³⁺ ions doped CdO–Bi₂O₃–B₂O₃ (CdBiB) glasses. The materials were characterized by optical absorption and emission spectra. By using Judd–Ofelt theory, the intensity parameters Ω_λ (λ = 2, 4, 6) and also oscillatory strengths were calculated from the absorption spectra. The results were used to compute the radiative properties of Er³⁺:CdBiB glasses. The concentration quenching and energy transfer from Yb³⁺–Er³⁺ were explained. The stimulated emission cross‐section, full width at half maximum (FWHM) and FWHM × values are also calculated for all the Er³⁺:CdBiB glasses. Copyright © 2011 John Wiley & Sons, Ltd.     

Collagen-like triple helix formation of synthetic (Pro-Pro-Gly)10 analogues: (4(S)-hydroxyprolyl-4(R)-hydroxyprolyl-Gly)10, (4(R)-hydroxyprolyl-4(R)-hydroxyprolyl-Gly)10 and (4(S)-fluoroprolyl-4(R)-fluoroprolyl-Gly)10.

For the rational design of a stable collagen triple helix according to the conventional rule that the pyrrolidine puckerings of Pro, 4-hydroxyproline (Hyp) and 4-fluoroproline (fPro) should be down at the X-position and up at the Y-position in the X-Y-Gly repeated sequence for enhancing the triple helix propensities of collagen model peptides, a series of peptides were prepared in which X- and Y-positions were altogether occupied by Hyp(R), Hyp(S), fPro(R) or fPro(S). Contrary to our presumption that inducing the X-Y residues to adopt a down-up conformation would result in an increase in the thermal stability of peptides, the triple helices of (Hyp(S)-Hyp(R)-Gly)(10) and (fPro(S)-fPro(R)-Gly)(10) were less stable than those of (Pro-Hyp(R)-Gly)(10) and (Pro-fPro(R)-Gly)(10), respectively. As reported by B?chinger's and Zagari's groups, (Hyp(R)-Hyp(R)-Gly)(10) which could have an up-up conformation unfavorable for the triple helix, formed a triple helix that has a high thermal stability close to that of (Pro-Hyp(R)-Gly)(10). These results clearly show that the empirical rule based on the conformational preference of pyrrolidine ring at each of X and Y residues should not be regarded as still valid, at least for predicting the stability of collagen models in which both X and Y residues have electronegative groups at the 4-position.     

Role of tfdC(I)D(I)E(I)F(I) and tfdD(II)C(II)E(II)F(II) gene modules in catabolism of 3-chlorobenzoate by Ralstonia eutropha JMP134(pJP4)

The enzymes chlorocatechol-1,2-dioxygenase, chloromuconate cycloisomerase, dienelactone hydrolase, and maleylacetate reductase allow Ralstonia eutropha JMP134(pJP4) to degrade chlorocatechols formed during growth in 2,4-dichlorophenoxyacetate or 3-chlorobenzoate (3-CB). There are two gene modules located in plasmid pJP4, tfdC(I)D(I)E(I)F(I) (module I) and tfdD(II)C(II)E(II)F(II) (module II), putatively encoding these enzymes. To assess the role of both tfd modules in the degradation of chloroaromatics, each module was cloned into the medium-copy-number plasmid vector pBBR1MCS-2 under the control of the tfdR regulatory gene. These constructs were introduced into R. eutropha JMP222 (a JMP134 derivative lacking pJP4) and Pseudomonas putida KT2442, two strains able to transform 3-CB into chlorocatechols. Specific activities in cell extracts of chlorocatechol-1,2-dioxygenase (tfdC), chloromuconate cycloisomerase (tfdD), and dienelactone hydrolase (tfdE) were 2 to 50 times higher for microorganisms containing module I compared to those containing module II. In contrast, a significantly (50-fold) higher activity of maleylacetate reductase (tfdF) was observed in cell extracts of microorganisms containing module II compared to module I. The R. eutropha JMP222 derivative containing tfdR-tfdC(I)D(I)E(I)F(I) grew four times faster in liquid cultures with 3-CB as a sole carbon and energy source than in cultures containing tfdR-tfdD(II)C(II)E(II)F(II). In the case of P. putida KT2442, only the derivative containing module I was able to grow in liquid cultures of 3-CB. These results indicate that efficient degradation of 3-CB by R. eutropha JMP134(pJP4) requires the two tfd modules such that TfdCDE is likely supplied primarily by module I, while TfdF is likely supplied by module II.     

Controlled Biomineralization of Magnetite (Fe(inf3)O(inf4)) and Greigite (Fe(inf3)S(inf4)) in a Magnetotactic Bacterium

A slowly moving, rod-shaped magnetotactic bacterium was found in relatively large numbers at and below the oxic-anoxic transition zone of a semianaerobic estuarine basin. Unlike all magnetotactic bacteria described to date, cells of this organism produce single-magnetic-domain particles of an iron oxide, magnetite (Fe(inf3)O(inf4)), and an iron sulfide, greigite (Fe(inf3)S(inf4)), within their magnetosomes. The crystals had different morphologies, being arrowhead or tooth shaped for the magnetite particles and roughly rectangular for the greigite particles, and were coorganized within the same chain(s) in the same cell with their long axes along the chain direction. Because the two crystal types have different crystallochemical characteristics, the findings presented here suggest that the formation of the crystal types is controlled by separate biomineralization processes and that the assembly of the magnetosome chain is controlled by a third ultrastructural process. In addition, our results show that in some magnetotactic bacteria, external environmental conditions such as redox and/or oxygen or hydrogen sulfide concentrations may affect the composition of the nonmetal part of the magnetosome mineral phase.     

fra(1) (p11), fra(1) (q22) and r(1) (p11q22) in a retarded girl.

A mentally retarded girl with a 46,XX/47, XX+r(1) (p11q22q22p11)/47, XX+r(1) (p11q22) fra(1) (p31) fra(1) (p11) fra(1) (q22) karyotype who inherited the fragile sites from the normal mother was studied. The conicidence of fra(1) (p11) and fra(1) (q22) with the ring chromosome breakpoints strongly suggests a cause-effect relationship. This finding agrees with other reported associations between fragile sites and structural chromosome abnormalities and constitutes the fourth reported of a de novo structurally abnormal chromosome as a consequence of presumed in vivo fragile sites instability. Although risk figures for chromosome anomalies and cancer associated with fragile sites are lacking, carriers of fra (1) (p11) may have a higher risk for abnormalities of chromosome 1 in somatic and gonadal cells than the general population.     

Structure of Poly (U).poly (A).poly (U)

The molecular structure of poly (U).poly (A).poly (U) has been determined and refined using the continuous x-ray intensity data on layer lines in the diffraction pattern obtained from an oriented fiber of the RNA. The final R-value for the preferred structure is 0.24, far lower than that for the plausible alternatives. The polymer forms an 11-fold right-handed triple-helix of pitch 33.5A and each base triplet is stabilized by Crick-Watson-Hoogsteen hydrogen bonds. The ribose rings in the three strands have C3'-endo, C2'-endo and C2'-endo conformations, respectively. The helix derives additional stability through systematic interchain hydrogen bonds involving ribose hydroxyls and uracil bases. The relatively grooveless cylindrical shape of the triple-helix is consistent with the lack of lateral organization.     

Structure of poly (I).poly (A).poly (I)

The molecular structure of poly (I).poly (A).poly (I) has been determined and refined using the continuous intensity data on layer lines in the x-ray diffraction pattern obtained from an oriented fiber of this polymorphic RNA complex. The polymer forms a 12-fold right-handed triple-helix of pitch 39.7A and each base-triplet is stabilized by quasi Crick-Watson-Hoogsteen hydrogen bonds. The ribose rings in all the three strands have C3'-endo conformations. The final R-value for this best structure is 0.24 and the x-ray fit is significantly superior to all the alternative structures where the different chains might have different furanose conformations. This all-purine triple-helix, counter-intuitively, has a diameter roughly 3A shorter than that of DNA and RNA triple-helices containing a homopurine and two complementary homopyrimidine strands. Its compact, grooveless cylindrical shape is consistent with the lack of lateral organization.     

Bone-seed (

Bone-seed, Chrysanthemoides monilifera ssp. monilifera (L.), is an environmental weed of coastal vegetation communities scattered throughout New Zealand. To assess the long-term implications for native forest regeneration in sites where bone-seed is present, we selected four study sites around Wellington, New Zealand, where bone-seed was abundant. We compared seed bank composition in bone-seed-invaded sites with nearby native forest patches, and monitored bone-seed and native seedling recruitment with and without control of mature bone-seed plants. We also tested the potential effects of fire on bone-seed recruitment in these communities by heating seeds prior to germination. Bone-seed, gorse (Ulex europaeus), and native species emerged from seed bank samples taken from bone-seed-invaded sites, but only native species and (less) gorse emerged from seed bank samples taken from native forest patches. Gorse germination was strongly promoted by heat but bone-seed germination was less affected by heat. Bone-seed seedling abundance increased dramatically following canopy removal, whereas native seedling abundance decreased dramatically. This suggests that disturbance of any form is likely to favour recruitment of bone-seed (and gorse) over native species, although in the long term, native seedlings can establish beneath the canopy of mature bone-seed plants. It is not yet known if, in the absence of further disturbance, regenerating native vegetation will eventually replace bone-seed in New Zealand.