Antimicrobial activity of Centaurea diffusa

The methanol soluble fraction of the aqueous extract obtained from the dry heads of Centaurea diffusa demonstrated antimicrobial activity in twelve evaluated microorganisms.     

Antimicrobial activity of the essential oil of Centaurea aladagensis

Composition of the water-distilled oil of the aerial parts of Centaurea aladagensis, endemic in Turkey, was analysed by GC-MS. Hexadecanoic acid (39.3%), caryophyllene oxide (6.6%) and hexahydrofarnesyl acetone (4.3%) were found as main constituents in the oil. The oil was tested against 7 human pathogenic microorganisms.     

Antimicrobial activity of clerodane diterpenoids from Polyalthia longifolia seeds

The diterpenoids 16alpha-hydroxy-cleroda-3,13 (14)-Z-diene-15,16-olide (1) and 16-oxo-cleroda-3, 13(14)-E-diene-15-oic acid (2), isolated from the hexane extract of the seeds of Polyalthia longifolia, demonstrated significant antibacterial and antifungal activities.     

Antitrypsin activity of extracts from Ecballium elaterium seeds.

The antitrypsin activity of extracts obtained from two different seed types of Ecballium elaterium, was tested in vitro. The presence of trypsin inhibitors in three chromatographed samples for each extract, showed a strong and specific antitrypsin activity.     

紫竹开花生物学特性观察及花粉生活力测定

以开花紫竹为研究对象,采用野外实地观测的方法,掌握了其开花预兆、开花竹株类型、小穗形态及结构、竹花开放顺序及竹花开放时间等开花生物学特性.由TTC染色法得出紫竹花粉生活力约90%.液体培养基法得出不同发育阶段的花粉萌发率以花药刚露头为最高,不同质量浓度的蔗糖溶液培养基以150 g/L的萌发率为最高,不同浓度的硼酸溶液培养基以100 mg/L的萌发率为最高.     

Biological activity of phenolic compounds from Alchornea glandulosa

From the isopropyl acetate fraction obtained by partition of the leaves ethanolic extract of Alchornea glandulosa, six phenolic compounds were isolated and identified. General lethality of the extract, fractions and compounds were assayed with Brine Shrimp Test (BST) and with Antifeedant Activity Bioassay (AAB) against neonate larvae of Spodoptera frugiperda. Aqueous fraction and ethyl gallate, one of the major constituents of the polar fraction, have shown the highest toxicity in BST. Ethanolic extract, isopropyl acetate fraction and gallic acid reduced significantly larval growth of S. frugiperda neonates.     

9种野生花卉种子生物学特性研究

该文研究了9种野生花卉的千粒重、含水量、种子形态及种子萌发特性。试验结果表明,在设定的温度范围15～25℃内,种子萌发难易度有明显不同。大花剪秋萝（Lychnis fulgens）和狭苞橐吾（Ligularia intermedia）较易萌发,发芽历程短,萌发的最适温度分别为25℃和20℃,发芽率分别达到97．3％和100％;芹叶铁线莲（Clematis aethusifolia）、短尾铁线莲（Clematis brevicaudata）和棉团铁线莲（Clematis hexapetala）发芽历程长,种子始发芽晚,在20℃条件下发芽率均达到最高,分别为88％,84％和57．3％。野罂粟（Papaver nudicaule）、牛扁（Aeonitum barbatumvar puberlum）、草本威灵仙（Veronicastrum sibiricum）和金莲花（Trollius chinensis）发芽率低,在试验条件下种子最高萌发率分别为29％,20％,17％和4．0％。     

Bioactivity-guided isolation of antiproliferative compounds from Centaurea jacea L

Bioassay-guided fractionation of the chloroform extract of Centaurea jacea L. afforded the isolation of cirsiliol, apigenin, hispidulin, eupatorin, isokaempferide, axillarin, centaureidin, 6-methoxykaempferol 3-methyl ether, trachelogenin, cnicin, 4'-acetylcnicin and three aliphatic glucose diesters, including the new natural product 1β-isobutanoyl-2-angeloyl-glucose. The structures of the compounds were established on the basis of spectroscopic analyses (UV, MS and NMR). All compounds were isolated for the first time from this species. The compounds were evaluated for their tumour cell growth inhibitory activities on HeLa, MCF-7 and A431 cells. Different types of secondary metabolites (flavonoids, sesquiterpenes) were found to be responsible for the antitumour effects of the extracts; the highest activity was exerted by centaureidin, in addition to moderately active compounds (cirsiliol, isokaempferide, apigenin, hispidulin, cnicin and 4'-acetylcnicin).     

Antibacterial activity of Caesalpinia bonducella seeds.

The methanol extract and four triterpenoids isolated from the seeds of Caesalpinia bonducella showed a wide range of inhibiting activity against both gram-positive and gram-negative bacteria.     

Antimicrobial activity of the leaves and seeds of Bixa orellana

The ethanolic extracts of the leaves and seeds of Bixa orellana showed a broad spectrum of antimicrobial activity. The activity of the leaf extract was more pronounced.     

Biological activity of Euonymus europaeus

The n-hexane, dichloromethane and methanol extracts of the seeds of Euonymus europaeus have been screened for antibacterial and free radical scavenging activity. General toxicity (brine shrimp lethality assay) of these extracts has also been assessed.     

Triterpenoid p-aminobenzoates from the seeds of zucchini

An investigation of the triterpenoid fraction of zucchini seeds afforded two novel multiflorane p-aminobenzoates, identified as 7-epi zucchini factor A and debenzoyl zucchini factor B. Multiflorane p-aminobenzoates could not be detected in zucchini sprouts, which contained bryonolic acid as the only multiflorane constituent. No compound of this type could be obtained from adult plant parts (roots, stems, leaves).     

Biological activity of Glechoma hederacea

The n-hexane, dichloromethane and methanol extracts of the aerial parts of Glechoma hederacea have been screened for antibacterial and free radical scavenging activity. General toxicity (brine shrimp lethality assay) of these extracts has also been assessed.     

Antibacterial activity of tannin constituents from Phaseolus vulgaris, Fagoypyrum esculentum, Corylus avellana and Juglans nigra

Tannins were fractionated from acetonic extract preparations of phenolic compounds from Phaseolus vulgaris, Fagoypyrum esculentum, Corylus avellana and Juglans nigra. Wide variations in antibacterial activities ranging from MICs of 62.5 to 500 microg/ml were apparent. Of particular note was a relatively high level of activity (62.5 to 125 microg/ml) for all extracts against Listeria monocytogenes.     

Antioxidant activity of Citrus paradisi seeds glyceric extract

The antioxidant activity of Citrus paradisi (grapefruit) seeds glyceric extract dissolved in ethanol and in aqueous media was evaluated using three different methods: evaluation by DPPH assay, by 5-lipoxygenase assay and by luminol/xanthine/xanthine oxidase chemiluminescence assay. The total phenolic content was determined by the Prussian Blue method opportunely modified. The grapefruit seeds glyceric extract utilized as aqueous solutions demonstrated antioxidant properties better than those displayed by alcoholic solutions.     

Characterization of proteinase activity in stratified Douglas-fir seeds

We investigated the effect of stratification on the proteinase activity involved in mobilization of the major soluble approximately 45 kDa storage protein during germination of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seeds. Complete hydrolysis of the approximately 45 kDa protein was observed approximately 7 days after exposure of stratified seeds to germination conditions. Coincident with the onset of mobilization, proteinase activity was detected primarily in microsomal extracts from stratified seeds. Microsomal-associated proteinase activity was most active at pH 8.0 and had a molecular mass > 175 kDa as determined by gelatin SDS-PAGE gels. In vitro digestion of soluble protein extracts indicated that, following stratification, there was a significant increase in proteinase activity and hydrolysis of the approximately 45 kDa storage protein. Whether this increase was a result of activation of preexisting proteinase(s) or de novo synthesis remains unknown. In vitro digestion of soluble protein extracts in the presence of various proteinase inhibitors showed that digestion of the approximately 45 kDa storage protein is mediated primarily by a metalloproteinase and to a lesser degree by a serine proteinase. The accumulation of approximately 25 kDa protein products following in vitro digestion suggests that mobilization of the approximately 45 kDa soluble storage protein is mediated by a multi-step process involving the action of different classes of proteinases.     

Purification, characterization and evaluation of insecticidal activity of trypsin inhibitor from Albizia lebbeck seeds

A Bowman-Birk inhibitor with activity against gut proteases of Helicoverpa armigera was extracted in 0.1 M sodium phosphate buffer from defatted seed flour of Albizia lebbeck. It was purified to 29.62 folds with 51.43% recovery using ammonium sulfate precipitation, gel filtration chromatography on Sephadex G-100 column and ion exchange chromatography on DEAE-Sephadex A50. The purified protein had a molecular weight of 12,303 daltons as determined by SDS-PAGE. It was found to be heat stable up to 60°C and had two pH optima of 7.5 and 9.0. The inhibitor exhibited non-competitive pattern of inhibition with a low Ki value of 0.2 μM. The inhibitor was found to be susceptible to varying concentrations of reducing agents like DTT and 2-mercaptoethanol, thereby indicating the role of disulphide bridges in maintaining its three dimensional structure and stability. The purified inhibitor caused mortality and suppressed larval growth of Pieris brassicae larvae. It was also found to be effective against gut trypsin extracted from Spodoptera littoralis. The sequence of the genes encoding for such inhibitors can be determined and the genes expressing protease inhibitors can be used in vegetable crops to confer resistance against insect pests and other plant pathogens.     

毛金竹在江西地区的生物学特性

毛金竹是江西优良的乡土笋材两用竹种,但长期处于野生状态,资源面临衰退的局面,亟需开展科学经营研究和技术推广。在江西省毛金竹林分内设立固定样地,进行了连续3年的生物学、生态学特性研究。结果表明:毛金竹笋期为4月中下旬至5月上旬、历时30~35d,笋期前25d的出笋数约占总数的75%,笋期高生长具有"慢-快-慢-停"的生长规律,幼竹高生长于6月20日左右完成,且新竹地径决定立竹全高。     

Antidiarrhoeal activity of carbazole alkaloids from Murraya koenigii Spreng (Rutaceae) seeds

The bioassay guided fractionation of the n-hexane extract of the seeds of Murraya koenigii Spreng (Rutaceae) resulted in the isolation of three bioactive carbazole alkaloids, kurryam (I), koenimbine (II) and koenine (III). The structures of the compounds were confirmed from their ¹H-, ¹³C-, and 2D-NMR spectral data. Of the three compounds (I) and (II) exhibited significant inhibitory activity against castor oil-induced diarrhoea and PGE₂-induced enteropooling in rats. The compounds also produced a significant reduction in gastrointestinal motility in the charcoal meal test in Wister rats.     

Antibacterial compounds from the seeds of Psoralea corylifolia

Psoralidin, bakuchicin, psoralin and angelicin, isolated from the seeds of Psoralea corylifolia, showed significant antibacterial activities against a number of Gram (+) and Gram (-) bacteria.