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PubMed1992

Study of the gastrointestinal diffusion system (GDS): influence of acacia gum on mechanical and chemical properties in free cellulose acetate films.

In this work a study of free cellulose acetate films was carried out in the presence and absence of acacia gum at high concentrations (50 and 75%). The mechanical toughness and the aspect were influenced by operatory conditions and by the relative air humidity. The increase of relative humidity from about 0% to 75% decreased the mechanical toughness and the color film changed from a clear to opaque white. The presence of acacia gum decreased the mechanical toughness and the water vapour transmission rate and increased the film water solubility.

Cellulose↗
PubMed1965

FLUORIDE METABOLISM IN ACACIA GEORGINAE GIDYEA.

1. The metabolism of fluoride in seedlings and small plants of Acacia georginae has been studied with the idea of finding the conditions under which the plant makes fluoroacetate in the laboratory. 2. Individual seedlings vary in the extent to which they take up fluoride and convert it into a form other than inorganic which is here called ;organic' fluoride, F(org.). The differences between the toxicity of A. georginae Gidyea trees may therefore be genetic in origin. 3. The uptake of fluoride from solutions 0.525-1.05mm (10-20p.p.m.) was not large. In 1-4 days it reached 8 p.p.m. in the aerial parts and 16 p.p.m. in the roots. Unlike the distribution of the halogen in grass, total fluoride was greater than inorganic fluoride. It was almost a rule that more ;organic' fluoride was present in the roots than in the aerial parts. 4. With higher concentrations of fluoride 10.5-15.75mm (200-300p.p.m.) much larger amounts of fluoride were taken up, especially by the roots, and much more apparent organic fluoride was formed. 5. pH had a large influence upon the intake, this being lowest at an initial pH8.4 and highest at pH4.0. The pH outside this range was not investigated. Some observations have been made with a view to clarifying the biochemical paths for the synthesis of the C-F bond. 6. There is no evidence that chloride is an intermediary in synthesis. 7. Succinate is not accumulated in fluoride-stressed plants, suggesting that succinate dehydrogenase is not inhibited. 8. Enolase does not appear to be inhibited in vivo.

Acacia↗
PubMed1999

Antiplasmodial activity of selected sudanese medicinal plants with emphasis on Acacia nilotica.

Twenty-two plant organs from eleven plants comprising five families were extracted and screened for antiplasmodial activity in vitro against Plasmodium falciparum 3D7 (chloroquine sensitive) and Dd2 (chloroquine resistant and pyrimethamine sensitive). Fifty nine percent of plant extracts from 22 extracts exerted activity on P. falciparum strain 3D7 with an IC(50) less than 50 microg/mL, whereas 43% of plant extracts showed an IC(50) value within 50 microg/mL on Dd2 strains. Plant extracts from Gardenia lutea, Haplophyllum tuberculatum, Cassia tora, Acacia nilotica and Aristolochia bracteolata possessed IC(50) values less than 5 microg/mL on both tested strains. Bioassay guided fractionation of A. nilotica revealed that the ethyl acetate extract possessed the highest activity (IC(50) = 1.5 microg/mL). Fraction 2 (R(f) = 0.75) prepared by preparative chromatography showed the highest activity on P. falciparum (IC(50) = 1.7 microg/mL). Phytochemical analysis indicated that the most active phase contained terpenoids and tannins and was devoid of alkaloids and saponins. The effect of plant extracts on lymphocyte proliferation showed low toxicity to the human cells. This plant has been subjected to long term clinical trials in folk medicine and is a promising plant.

Acacia↗
PubMed1999

Studies on antihypertensive and antispasmodic activities of methanol extract of Acacia nilotica pods.

A methanol extract of Acacia nilotica pods (AN) caused a dose-dependent (3-30 mg/kg) fall in arterial blood pressure. Treatment of animals with atropine abolished the vasodilator response of acetylcholine (ACh), whereas the antihypertensive effect of the plant extract remained unaltered. Phentolamine (an alpha-adrenergic blocker) abolished the vasoconstrictor effect of norepinephrine (NE), whereas pretreatment of the animal with AN, did not modify the NE response. These results indicate that the antihypertensive effect of plant extract is independent of muscarinic receptor stimulation or adrenoceptor blockade. In the in vitro studies, AN produced a dose-dependent (0.3-3.0 mg/mL) inhibitory effect on force and rate of spontaneous contractions in guinea-pig paired atria. Similarly, it inhibited the spontaneous contraction of rabbit jejunum in a concentration-dependent (0.1-3.0 mg/mL) manner. AN also inhibited K(+)-induced contractions in rabbit jejunum at a similar concentration range, which suggests that the antispasmodic action of AN is mediated through calcium channel blockade, and this may also be responsible for the blood pressure lowering effect of AN, observed in the in vivo studies.

Acacia↗
PubMed1999

The pharmacological effects of an aqueous extract from Acacia nilotica seeds.

An aqueous extract of the seed of Acacia nilotica was investigated for its pharmacological profile. On the isolated guinea-pig ileum, the extract displayed sustained dose-related contractile activity. The contractions which were reduced by hexamethonium, promethazine or atropine were completely abolished by nifedipine. The intravenous (i.v.) administration of the extract (11, 22, 44, 55 microg/kg) to anaesthetized cats produced a dose-related significant elevation of blood pressure. The mechanisms of the spasmogenic and vasoconstrictor actions of the extract have not been determined, however, the results suggest the involvement of calcium.

Acacia↗
PubMed2005

Larvicidal activity of Acacia nilotica extracts and isolation of D-pinitol--a bioactive carbohydrate.

A low-molecular-weight, sugar-like compound other than glucose, fructose, sucrose, or myo-inositol showing lipophilic nature was isolated from the EtOH extract of Acacia nilotica. The structure of the compound was determined by spectral methods. This alicyclic polyalcohol was found to be D-pinitol (= 3-O-methyl-D-chiro-inositol; 1). The configuration of the compound was confirmed by single-crystal X-ray analysis. The compound 1 is known from Soybean, Australian mangroves, Fagonia indica, Arachis hypogaea, etc., but we have isolated this compound for the first time from the aerial parts of A. nilotica. Very few references have been cited for compound 1 for its entomological activity, and there are no reports on mosquitoes. Therefore, the crude extracts of A. nilotica were tested for its biological activity against mosquito larvae. Acetone extract at 500-ppm concentration showed chronic toxicity against Aedes aegypti and Culex quinquefasciatus IVth instar mosquito larvae. Such a biological activity has been observed for the first time for this plant. This study could be a stepping stone to a solution for destroying larval species as well as consumption of such a widely grown, problem weed, A. nilotica. This larvicidal agent, since it is derived from plant, is eco-friendly, cost effective, non-hazardous to non-target organisms and would be safe unlike commercially available insecticides.

Acacia↗
PubMed1977

Characteristics of medicated and unmedicated microglobules recovered from complex coacervates of gelatin-acacia.

Medicated and unmedicated microglobules prepared from complex coacervates of Type A gelatin and acacia were recovered as water-insoluble powders consisting of discrete units, which were spontaneously revertible to highly disperse systems when suspended in water or physiological electrolyte solutions. Spherical microglobules containing up to 15% (w/w) sulfamerazine had a nominal diameter of 30 micron in aqueous suspension. Larger but irregularly shaped products containing up to 45% (w/w) sulfamerazine were also recovered. The relationships of the weight of sulfamerazine added per coacervate batch to weight yield and percent (w/w) included sulfamerazine of the microglobules were both linear.

Acacia↗
PubMed1980

Micromeritic properties of sulfamethoxazole microcapsules prepared by gelatin-acacia coacervation.

Micronized sulfamethoxazole particles were microencapsulated using the gelatin-acacia complex conacervation method. The effects of the coacervation pH and the amount of formaldehyde used on the micromeritic parameters of the microcapsules were investigated. The particle-size and the wall thickness distributions were log-normal forms. As the pH was increased, the particle size decreased (8.5-28.5 micrometers). The porosity of various pH-adjusted microcapsules was between 0.158 and 0.277. The particle size of formalized microcapsules was larger than that of the unformalized microcapsules because formalization prevents shrinking of microcapsules during the dehydration and drying process. A smooth surface appeared on the unformalized microcapsule, but a net-like wrinkled structure was observed upon scanning the formalized one. Moreover, folding and invaginating structures were found on the spray-dried microcapsules. The optimum coacervation pH value was 3.5, at which the highest core content was obtained (77.5% w/w). Approximately 6.73 microgram of formaldehyde remained in 1 g of the microcapsules formalized with 50 ml of formaldehyde. The crystalline sulfamethoxazole in the microcapsules prepared by spray drying the coacervate slurries was changed into the amorphous form, while the microcapsules dried in the conventional manner showed the same sulfamethoxazole form as the starting substance.

Acacia↗
PubMed1981

Electrophoretic properties of sulfamethoxazole microcapsules and gelatin-acacia coacervates.

The electrophoretic properties of sulfamethoxazole microcapsules and the coacervates prepared by gelatin-acacia coacervation were investigated. The effects of the parameters in the microcapsule preparation, such as the coacervation pH, amount of formaldehyde used for hardening, and drying method of the coacervates, on the zeta-potential of the resultant microcapsules were clarified. The Büchner effect was observed in coacervates in an electric field, which indicated that the coacervate wall was flexible. The zeta-potential versus pH curves of the coacervates appeared on the upper side of the plain sulfamethoxazole, while those of the microcapsules dried conventionally shifted to the lower side due to the denaturation of the gelatin in the microcapsule wall, which occurred during drying. Spray drying increased the denaturation of gelatin, which imparted a negative charge to the spray-dried microcapsules. Formalization of the coacervates refined the electrophoretic behavior of the microcapsules, depending on the amount of formaldehyde used. The zeta-potential of the plain sulfamethoxazole also was measured in the simulated coacervation solution to analyze the mechanism of coacervation electrophoretically.

Acacia↗
PubMed1988

Isolation of aflatoxin from Acacia and the incidence of Aspergillus flavus in the Sudan.

A total of 1300 seeds from 13 commodities were surveyed for Aspergillus flavus. An additional inoculum was obtained from 6 divergent sources. A. flavus isolants, randomly selected on the bases of visual cultural characteristics and inoculum source, were assayed for aflatoxin yielding capacity. Out of 97 analyzed isolates 76 (78.3%) were aflatoxin-elaborators of which 27 (27.8%) colonies were classified as very highly toxinogenic (greater than 1000 micrograms/kg). Acacia, described a new source of aflatoxin (81 to greater than 1000 micrograms/kg), is herein first described from Sudan as a substrate for A. flavus.

Acacia↗
PubMed2006

Transgenic Acacia sinuata from Agrobacterium tumefaciens-mediated transformation of hypocotyls.

Transgenic herbicide tolerant Acacia sinuata plants were produced by transformation with the bar gene conferring phosphinothricin resistance. Precultured hypocotyl explants were infected with Agrobacterium tumefaciens strain EHA105 in the presence of 100 microM acetosyringone and shoots regenerated on MS (Murashige and Skoog, 1962, Physiol Plant 15:473-497) medium with 13.3 microM benzylaminopurine, 2.6 microM indole-3-acetic acid, 1 g l(-1) activated charcoal, 1.5 mg l(-1) phosphinothricin, and 300 mg l(-1) cefotaxime. Phosphinothricin at 1.5 mg l(-1) was used for the selection. Shoots surviving selection on medium with phosphinothricin expressed GUS. Following Southern hybridization, eight independent shoots regenerated of 500 cocultivated explants were demonstrated to be transgenic, which represented transformation frequency of 1.6%. The transgenics carried one to four copies of the transgene. Transgenic shoots were propagated as microcuttings in MS medium with 6.6 microM 6-benzylaminopurine and 1.5 mg l(-1) phosphinothricin. Shoots elongated and rooted in MS medium with gibberellic acid and indole-3-butyric acid, respectively both supplemented with 1.5 mg l(-1) phosphinothricin. Micropropagation of transgenic plants by microcuttings proved to be a simple means to bulk up the material. Several transgenic plants were found to be resistant to leaf painting with the herbicide Basta.

Acacia↗
PubMed2006

Conflict resolution in an ant-plant interaction: Acacia constricta traits reduce ant costs to reproduction.

Many plant species attract ants onto their foliage with food rewards or nesting space. However, ants can interfere with plant reproduction when they visit flowers. This study tests whether Acacia constricta separates visiting ant species temporally or spatially from newly opened inflorescences and pollinators. The diurnal activity patterns of ants and A. constricta pollinators peaked at different times of day, and the activity of pollinators followed the daily dehiscence of A. constricta inflorescences. In addition to being largely temporally separated, ants rarely visited open inflorescences. A floral ant repellent contributes to the spatial separation of ants and inflorescences. In a field experiment, ants of four species were given equal access to inflorescences in different developmental stages. On average, the frequency with which ants made initial, antennal contact with the floral stages did not differ, but ants significantly avoided secondary contact with newly opened inflorescences relative to buds and old inflorescences, and old inflorescences relative to buds. Ants also avoided contact with pollen alone, indicating that pollen is at least one source of the repellent. The results suggest A. constricta has effectively resolved the potential conflict between visiting ants and plant reproduction.

Acacia↗
PubMed2005

Comparison of antifungal and antioxidant activities of Acacia mangium and A. auriculiformis heartwood extracts.

The effect of heartwood extracts from Acacia mangium (heartrot-susceptible) and A. auriculiformis (heartrot-resistant) was examined on the growth of wood rotting fungi with in vitro assays. A. auriculiformis heartwood extracts had higher antifungal activity than A. mangium. The compounds 3,4',7,8-tetrahydroxyflavanone and teracacidin (the most abundant flavonoids in both species) showed antifungal activity. A. auriculiformis contained higher levels of these flavonoids (3.5- and 43-fold higher, respectively) than A. mangium. This suggests that higher levels of these compounds may contribute to heartrot resistance. Furthermore, both flavonoids had strong 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and laccase inhibition. This suggests that the antifungal mechanism of these compounds may involve inhibition of fungal growth by quenching of free radicals produced by the extracellular fungal enzyme laccase.

Acacia↗
PubMed2005

Identification of delta7 phytosterols and phytosteryl glucosides in the wood and bark of several Acacia species.

The wood and bark of four Acacia species growing in Portugal, namely, A. longifolia, A. dealbata, A. melanoxylon, and A. retinodes, were investigated for their sterol content. The lipids fractions of the different wood and bark samples were isolated, and the sterols were identified and quantified by GC-MS. Two delta7 sterols, specifically, spinasterol and dihydrospinasterol, were the main sterols found in considerable amounts, particularly in wood tissues (more than 0.5 g/kg of dry wood in the case of A. melanoxylon and A. retinodes). The corresponding unusual steryl glucosides were also identified in significant amounts in the wood and bark extracts.

Acacia↗
PubMed1991

Sperm immobilizing effect of triterpene saponins from Acacia auriculiformis.

A mixture of two partially triterpenoid saponins (Tg), isolated from Acacia auriculiformis was tested for sperm immobilizing activity by using in vitro system. The lowest concentration (ED) required for an obvious immobilization of human sperm by using a modified Sander-Cramer test was found to be 0.35 mg/ml in physiological saline. The ability of the compound as a sperm immobilizing agent was compared with that of Triton X-100 and found to be more potent. Cervical mucus penetration test was also performed and the ED successfully prevented sperm entry in human cervical mucus. Supra-vital staining with eosin-nigrosin indicated death of the treated sperm. Electron microscopic study of Tg-treated sperm showed plasma membrane disintegration and dissolution of acrosomal cap which is presumably the cause for the spermicidal effect of the saponins. No permanent lesion was observed after application of 1.25 mg/ml Tg solution in physiological saline to the eye of rabbits for ten consecutive days.

Acacia↗
PubMed1994

Inactivation of Acacia confusa trypsin inhibitor by site-specific mutagenesis.

Native Acacia confusa trypsin inhibitor (ACTI) contains two disulphide bonds; one is an intrachain disulphide bond (Cys40-Cys86), located in the A-chain, while the other is an interchain disulphide bond (Cys133-Cys141) connecting the A- and B-chain; the inhibitor consists of 175 amino acid residues, 136 residues in the A-chain and 39 residues in the B-chain. The putative reactive site of ACTI is located at Lys64, while for all other Kunitz family trypsin inhibitors it is at Arg64. When the Lys64 residue of ACTI was converted into Ile or Arg by site-specific mutagenesis, the K64I mutant completely lost its inhibitory activity but the K64R mutant retained most of its inhibitory activity. The C133G mutant lost its inhibitory activity while the C40G mutant did not. This suggests that the interchain disulphide bond (Cys133-Cys141) linking two beta-strands of the six-strand beta-barrel is essential for ACTI inhibitory activity, while the intrachain disulphide bond (Cys40-Cys86) connecting the two loops is non-essential.

Acacia↗
PubMed1990

A thorny problem: the diagnosis and treatment of acacia thorn injuries.

Immediate diagnosis and surgical treatment of acacia thorn injury results in complete cure. Delay or late presentation results in morbidity. The features of this disorder are presented in a series of 22 patients. The principles of treatment can be applied to all other types of thorn injury.

Acacia↗
PubMed1993

Cloning and expression of the gene encoding Acacia confusa trypsin inhibitor that is active without post-translational proteolysis.

A recombinant plasmid containing the coding regions for Acacia confusa trypsin inhibitor (ACTI) has been constructed and expressed in Escherichia coli cells, as a fusion protein between ACTI and glutathione S-transferase (GST). The GST-fusion was produced as a soluble protein which did not require denaturing agents such as urea to solubilize it. The recombinant ACTI (reACTI) was obtained by treating the GST-fusion protein with thrombin. Both the reACTI and fusion protein have a strong inhibitory effect on trypsin activity without post-translational proteolysis.

Acacia↗