Chestnutamide: a novel alkaloid from flowers of Castanea mollissima Blume

A novel alkaloid, chestnutamide, was isolated from the flowers of Castanea mollissima Blume. The structure was determined on the basis of spectral analysis.

Quinquenoside L9 from leaves and stems of Panax quinquefolium L

During additional chemical investigation on the saponin composition of leaves and stems of Panax quinquefolium L, a new minor dammarane saponin, quinquenoside L9 (1) has been obtained. By means of physico-chemical evidences and spectral analysis, its structure was elucidated 6-O-[alpha-L-rhamnopyranosyl-(1-2)-beta-D-glucopyranosyl]-dammara-3beta, 6beta,12beta,20(S),24zeta,25-hexaol (1).

Antimicrobial activity of the heartwood of Taxus baccata

The ethanolic extract of Taxus baccata heartwood showed significant activity against selected gram-negative bacteria and against five out of nine tested fungi.

Cassipoureamide-A and -B: new sulfur-containing amides from stem wood of Cassipourea guianensis

New sulfur-containing amides, cassipoureamide-A (1) and -B (2), have been isolated from the stem wood of Cassipourea guianensis, and their structures were determined to be cis-N-(2-hydroxyethyl)-4-hydroxy-1,2-dithiolane-3-carboxamide and cis-N-(2-hydroxyethyl)-5-hydroxy-1,2,3-trithiane-4-carboxamide, respectively, by MS and NMR studies.

Analgesic and antiinflammatory activities of an extract from Parkia biglobosa used in traditional medicine in the Ivory Coast

In the Ivory coast, Parkia biglobosa (Mimosaceae) is used in traditional medicine as an analgesic drug, especially against dental pain. Of the three extracts obtained from the plant bark, the hexane fraction was studied to determine its analgesic and/or antiinflammatory activities. The results show that this extract possesses a marked analgesic activity when evaluated with the abdominal writhing test in mice, but, like paracetamol, was ineffective with the hot-plate method, a feature suggesting a peripheral mechanism of action. This activity was accompanied by an antiinflammatory effect, somewhat weaker than the analgesic one.

[Studies on chemical constituents of Cistanche tubulosa (Schenk) R. Wight]

OBJECTIVE

To investigate the chemical constituents of Cistanche tubulosa.

METHOD

The chemical constituents were isolated by solvent extraction together with various chromatographic techniques including preparative HPLC. The structures were elucidated on the basis of chemical evidence and spectral data.

RESULTS

Four iridoid glycosides, one lignan glycoside and one monoterpenoid were isolated from the 95% ethanol extract from the stem of C. tubulosa and identified as adoxosidic acid(I), 8-epiloganic acid(II), geniposidic acid (III), mussaenosidic acid(IV), (+)-syringaresinol-O-beta-D-gluco pyranoside(V) and 8-hydroxygeraniol(VI).

CONCLUSION

Compounds I and VI were isolated from the genus of Cistanche for the first time. Compounds III, IV and V were isolated from this plant for the first time.

Two new 3-methoxy-4-quinolone alkaloids from the bark of Sarcomelicope megistophylla

Two new alkaloids, megistonine I (1) and megistonine II (2), were isolated from the bark of Sarcomelelicope megistophylla. Their structures, which are derived from the 3-methoxy-4-quinolone basic skeleton, were elucidated on the basis of MS and extensive NMR studies.

Constituents and cytotoxicity of Zanthoxylum rhesta stem bark

3,5-Dimethoxy-4-geranyloxycinnamyl alcohol (1), 8-methoxy-N-methylflindersine (2), xanthyletin and sesamin have been isolated from petroleum ether extract of the stem bark of Zanthoxylum rhesta. The petroleum ether extract and 8-methoxy-N-methylflindersine showed cytotoxicity on brine shrimp nauplii.

Four new stilbenoid C-glucosides isolated from the stem bark of Shorea hemsleyana

Four new C-glucopyranosides of resveratrol oligomers, hemsleyanosides A-D, were isolated from the bark of Shorea hemsleyana. The structures were established on the basis of spectroscopic evidence, including 1H-1H and 1H-13C long-range couplings and nuclear Overhauser effect experiments in the NMR spectrum.

Determination of glycerolipid composition of rice and maize tissues using solid-phase extraction

Currently available techniques for the separation and characterization of different glycerolipids are complicated and/or time consuming. By modulating the stationary phase in a solid-phase extraction (SPE) manifold, efficient and rapid separation of plant membrane lipids was achieved. The glycerolipids from rice and maize tissues were separated into seven classes (monogalactosyldiacylglycerol, digalactosyldiacylglycerol, phosphatidylethanolamine, phosphatidylcholine, sulphoquinovosyldiacylglycerol, phosphatidylinositol and phosphatidylglycerol). The pigments present in the rice and maize leaves and rice stems were successfully removed from the total lipid extracts. Pigment-free plant tissue (rice roots) was also analysed. The fatty acid profile of each lipid class isolated by SPE agreed well with those obtained by other separation techniques. The recovery of glycerolipids was at least 87%.

New constituents from Gliricidia sepium

The heart wood of Gliricidia sepium stem yielded stigmastanol glucoside (1) and 3',4'-dihydroxy-trans-cinnamic acid octacosylester 2, along with three other known constituents.

Seasonal variations in the harpagoside content of Scrophularia scorodonia L

Seasonal variations on the content of harpagoside in Scrophularia scorodonia L. (Scrophulariaceae) were investigated using plants collected monthly from January to December in 1995. During growth of this species the percentage of harpagoside was the highest during the maximum development of the plant, specially in July. Harpagoside levels differed among leaves, stems and flowers of S. scorodonia. Leaves were distinguished from other plant parts by higher levels of harpagoside. Drying at ambient temperature influenced the yield of harpagoside compared with the results of plant drying by microwave.

[Studies on chemical constituents of aerial parts of Verbena officinalis L]

OBJECTIVE

To search for new effective ant-early-pregnancy components from the aerial part of Verbena officinalis.

METHOD

Compounds were isolated from the methanol extract of the herb by chromatography on silica gel column, and the structures were determined by physical and chemical evidences and spectroscopic analysis.

RESULT

Two compounds were obtained and identified as 3,4-dihydroverbenalin and daucosterol.

CONCLUSION

The two compounds were obtained from this the herb for the first time and 3,4-didydroverbenalin is a new product.

Alkylresorcinols in fruit pulp and leaves of Ginkgo biloba L

These studies were undertaken to characterise resorcinolic lipids (5-n-alk(en)ylresorcinols) composition and to determine their seasonal fluctuations in fruit pulp and leaves of Ginkgo biloba L. Resorcinolic lipid concentrations were consistently higher in fruit pulp than in leaves. In pulp, several mono- and di-unsaturated homologs of alkylresorcinols were the predominant group of analysed lipids. Contrary to the fruit pulp, only 5-n-pentadecylresorcinol was demonstrated in leaves. Initially, the alkylresorcinol's content both in pulp and leaves increased until June-July and decreased following seeds ripening. This trend continued until senescence of leaves in late September and October.

New skeletal sesquiterpenoids, caprariolides A-D, from Capraria biflora and their insecticidal activity

Four structurally novel isomeric sesquiterpenes have been isolated from the aerial parts of Capraria biflora. Caprariolides A (1), B (2), C (3), and D (4) have been determined by NMR spectroscopy experiments to be the (3S,5S,9R), (3R,5S,9R), (3R,5R,9R), and (3S,5R, 9R) isomers of 7-(furan-3'-yl)-3,9-dimethyl-1-oxaspiro[4. 5]dec-6-en-2-one, respectively. Both 1 and 2 were found to exhibit insecticidal activity against adult Cylas formicarius elegantulus, one of the most destructive insect pests of the sweet potato, Ipomoea sp.

Two isoflavanones from the stem bark of Erythrina sacleuxii

From the stem bark of Erythrina sacleuxii two new isoflavanones, (R)-5,7-dihydroxy-2',4',5'-trimethoxyisoflavanone (trivial name, (R)-2,3-dihydro-7-demethylrobustigenin) and (R)-5-hydroxy-2',4',5'-trimethoxy-2",2"-dimethylpyrano[5",6":6,7]isoflavanone (trivial name, (R)-saclenone) were isolated. In addition the known compounds shinpterocarpin, 2,3-dehydrokievitone, abyssinone V, abyssinone V-4'-methyl ether, erythrinasinate and 4'-O-methylsigmoidin B were isolated. The structures were determined on the basis of spectroscopic evidence.

Induction of apoptosis by Acanthopanax senticosus HARMS and its component, sesamin in human stomach cancer KATO III cells

Antitumor effect of the stem bark of Acanthopanax senticosus HARMS (ASH) from Hokkaido (Japanese name: Ezoukogi) on human stomach cancer KATO III cells was investigated. The extract of the stem bark of ASH prepared with hot water was dissolved in distilled water and used for the assay of antitumor effect on the KATO III cells. The exposure of KATO III cells to ASH led to both growth inhibition and induction of apoptosis. Morphological change showing apoptotic bodies was observed in the cells treated with ASH. The fragmentation by ASH of DNA to oligonucleosomal-sized fragments that are characteristics of apoptosis was observed to be concentration- and time-dependent. We have investigated which component in ASH is effective on the induction of apoptosis. Among chlorogenic acid, syringaresinol di-o-beta-D glucoside, syringin, and sesamin, components of the n-butanol extract prepared from ASH, sesamin suppressed the growth and induced apoptosis in the cells. These findings suggest that growth inhibition by ASH results from the apoptosis induced by sesamin, a component of ASH.

Xylem conduits of a resurrection plant contain a unique lipid lining and refill following a distinct pattern after desiccation

The axial and radial refilling with water of cut dry branches (up to 80 cm tall) of the resurrection plant Myrothamnus flabellifolia was studied in both acro- and basipetal directions by using 1H-NMR imaging. NMR measurements showed that the conducting elements were not filled simultaneously. Axial water ascent occurred initially only in a cluster of a very few conducting elements. Refilling of the other conducting elements and of the living cells was mainly achieved by radial extraction of water from these initial conducting elements. With time, xylem elements in a few further regions were apparently refilled axially. Radial water spread through the tissue occurred almost linearly with time, but much faster in the acropetal than in the basipetal direction. Application of hydrostatic pressure (up to 16 kPa) produced similar temporal and spatial radial refilling patterns, except that more conducting elements were refilled axially during the first phase of water rise. The addition of raffinose to the water considerably reduced axial and radial spreading rates. The polarity of water climbing was supported by measurements of the water rise in dry branches using the 'light refraction'(and, sometimes, the 'leaf recurving') method. Basipetal refilling of the xylem conduit exhibited biphasic kinetics; the final rise height did not exceed 20-30 cm. Three-cm-long branch pieces also showed a directionality of water climbing, ruling out the possibility that changes in the conducting area from the base to the apex of the branches were responsible for this effect. The polarity of water ascent was independent of gravity and also did not change when the ambient temperature was raised to c. 40 degrees C. At external pressures of 50-100 kPa the polarity disappeared, with basipetal and acropetal refill times of the xylem conduit of tall branches becoming comparable. Refilling of branches dried horizontally (with a clinostat) or inverted (in the direction of gravity) showed a pronounced reduction of the acropetal water rise to or below basipetal water climbing level (which was unaffected by this treatment). Unlike water, benzene and acetone climbing showed no polarity. In the case of benzene, the rise kinetics (including the final heights) were comparable with those measured acropetally for water, whereas with acetone the rise height was less. Transmission electron microscopy of dry branches demonstrated that the inner surfaces of the conducting tracheids and vessels were lined with a continuous osmiophilic (lipid) layer, as postulated by the kinetic analysis and light microscopy studies. The thickness of the layer varied between 20 and 80 nm. The parenchymal and intervessel pits as well as numerous tracheid corners contained opaque inclusions, presumably also consisting of lipids. Electron microscopy of rehydrated plants showed that the lipid layer was either thinned or had disintegrated and that numerous vesicle-like structures and lipid bodies were formed (together with various intermediate structural elements). These, many other data and the physical-chemical literature imply that several (radial) driving forces (such as capillary condensation, Marangoni forces, capillary, osmotic and turgor pressure forces) operate when a few conducting elements become axially refilled with water. These forces apparently lead to an avalanche-like radial refilling of most of the conducting elements and living cells, and thus to the removal of the 'internal cuticle' and of the hydrophobic inclusions in the pits. The polarity of water movement presumably results from high resistances in the basipetal direction, which are created by local gradients in the thickness of the lipid film as a result of draining under gravity in response to drought. There are striking similarities in morphology and function between the xylem-lining lipid film and the lung surfactant film lining the pulmonary air spaces of mammals.

Novel antihyperglycemic terpenoid-quinones from Pycnanthus angolensis

Two new compounds, pycnanthuquinone A (1) and pycnanthuquinone B (2), were isolated from leaves and stems of the African plant, Pycnanthus angolensis (Welw.) Warb (Myristicaceae), by bioassay-guided fractionation of an ethanolic extract using a diabetic mouse model. Pycnanthuquinones A and B are the first representatives of a novel terpenoid-type quinone skeleton, and both compounds possess significant antihyperglycemic activity.

Flavanone, triterpene and chromene derivatives from the stems of Paramignya griffithii

Five compounds, including three that are novel, were isolated from the stems of Paramignya grifithii (Rutaceae). Two new and one known prenylated flavanones were characterized as 3',4'-dihydroxy-7-methoxy-8-(3-methylbut-2-enyl)-furano(4",5":6,5)-flava-adicin. In addition, a triterpene, 3-oxo-tirucalla-7,24-diene-21-al, and a novel chromene, 6-(2-hydroxyethyl)-2,2-dimethyl-2H-1-benzopyran, were identified.

Constituents from the stem and root of Aristolochia kaempferi

Three new phenanthrene derivatives, aristoliukine-C, aristofolin-E and aristolochic acid-Ia methyl ester, and one new sesquiterpene, madolin-P, together with 58 known compounds were isolated from the stem and root of Aristolochia kaempferi. The structures of these compounds were determined by spectral analysis. The cytotoxicity and antiplatelet activity of the isolated compounds are also discussed.

Polysaccharides from Melittis melissophyllum L. herb and callus

For comparison of the water-soluble polysaccharides from Melittis melissophyllum L. herb with that produced by Melittis callus cultures the polymeric carbohydrates were extracted from both sources, fractionated by IEC and GPC and the respective fractions analysed concerning sugar composition and linkage characteristics. The dominant structures found in all fractions isolated from herb material and callus were type-II arabinogalactans with a (1-->3)-galactose backbone and arabinose-galactose side chains. No significant differences were found between herb and callus polysaccharides. To optimize the Melittis cell culture systems the culture media were varried systematically. A modified Murashige-Skoog (MS) medium, supplemented with GA3, NAA and BAP was found to be most suitable for large-scale production of callus material.

Relationship between carbohydrate concentration and root growth potential in coniferous seedlings from three climates during cold hardening and dehardening

Greenhouse-cultured, container-grown seedlings of Aleppo pine (Pinus halepensis Mill.), radiata pine (Pinus radiata D. Don), and interior Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) were cold acclimated and deacclimated in growth chambers over 24 weeks. Needle and root cold hardiness and root growth potential (RGP) were measured weekly. Root, needle and stem analyses for soluble sugars and starch were performed biweekly. In all tissues, there was a close correspondence between cold hardiness and the absolute concentration of soluble sugars, as well as between the increase and decrease in concentration of soluble sugars during cold hardening and dehardening, respectively, supporting the theory that soluble sugars function as cryoprotectants in plant tissues. The magnitude of starch concentration did not parallel the magnitude of the cold hardiness attained, and changes in starch concentration were related to production and consumption factors, rather than timing of changes in cold hardiness. The rise and fall of RGP paralleled the rise and fall of total carbohydrate concentration in roots. The behavior of the three species was surprisingly similar, considering the different climates to which they are adapted.

Bioactive triterpenoids from the stem bark of Picea glehni

Two new triterpenoids, 3 alpha-methoxyserrat-14-en-21 beta-yl formate (1), and 24-methylcycloartenone (2), were isolated from the stem bark of Picea glehni (Fr. Schm.) Masters together with three known triterpenoids, 3 alpha-methoxyserrat-14-en-21 beta-ol, 3 beta-methoxyserrat-14-en-21 beta-ol, and piceanonol A. Compounds 1, 2, and a synthetic sample, 3 alpha-methoxyserrat-13-en-21 beta-yl formate showed potent inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA).

Free radical scavenging activity of Lafoensia pacari

The methanolic extract of the stem bark of Lafoensia pacari (Lythraceae) showed free radical scavenging activity in the diphenyl picryl hydrazyl radical (DPPH) decoloration assay and inhibited the enzyme xanthine oxidase 'in vitro'. Bioassay-guided isolation led to ellagic acid (EA) as the main active compound of Brazilian and Paraguayan collections of the plant.

Variation in branchlet delta13C in relation to branchlet nitrogen concentration and growth in 8-year-old hoop pine families (Araucaria cunninghamii) in subtropical Australia

Carbon isotope composition (delta13C) of branchlet tissue at nine canopy positions, and nitrogen concentration (N(mass)) at four canopy positions, were assessed in 8-year-old hoop pine (Araucaria cunninghamii Ait. ex D. Don) trees from 23 half-sib families, grown in six blocks of a progeny test in southeastern Queensland, Australia. There was considerable variation among sampling positions, families and blocks in both delta13C and N(mass). The delta13C was positively related to N(mass) only for samples from the upper outer crown (P < 0.005). Phenotypic correlations existed between tree growth and canopy delta13C. Branchlet delta13C of the inner and lower outer crown was positively related (P < 0.037) to tree height, but delta13C in branchlets of the upper outer crown was not related to tree height, or was related negatively (P < 0.045). There were significant differences in delta13C between hoop pine families for six canopy positions (upper canopy positions as well as lower canopy positions on the northern side), with heritabilities greater than 0.40. The significance of these findings is discussed in relation to water and light competition within the tree canopy of hoop pine.

Arsenic uptake in orchard trees: implications for dendroanalysis

The distribution of arsenic in the stems of fruit trees grown in soils exposed to arsenical pesticides has been studied using neutron activation analysis. The results show arsenic to be confined mainly to heartwood near the pith and active xylem tissue in the most recent annual growth rings. These results suggest that dendroanalysis for arsenic in fruit trees will not yield a reliable chronology of arsenic exposure.

Hypoglycemic effect of Equisetum myriochaetum aerial parts on streptozotocin diabetic rats

The hypoglycemic effect of water as well as butanolic extracts prepared from aerial parts of Equisetum myriochaetum (Equisetaceae) was examined in streptozotocin induced diabetic rats. A single oral administration of the water extract (WE) at doses of 7 and 13 mg/kg and of the butanol extract (BE) at doses of 8 and 16 mg/kg significantly (P<0.001) lowered the plasma glucose levels in diabetic rats after three hours of the administration. As a reference drug glibenclamide was used and showed, at a dose of 3 mg/kg, similar hypoglycemic effect like the tested extracts. Three kaempferol glucosides and one caffeoyl glucoside were isolated from the drug and were shown to be the main constituents in both extracts.

Extraction of total RNA from a high pigment content plant. Marigold (Tagetes erecta)

The Mexican marigold (Tagetes erecta) produces inflorescences of intense yellow color that contain high levels of xanthophylls, particularly lutein, which makes it a suitable model for the study of carotenoid biosynthesis and regulation throughout the development of the inflorescences. However, these studies require the recovery of total RNA from floral buds and inflorescences at different developmental stages, each of which presents specific extraction problems. Four protocols were tested, but only through the modification of one of them was it possible to obtain total RNA of sufficient quality and quantity to perform RT-PCR and Northern blots and to construct a cDNA library. This article presents the modified protocol for the recovery of total RNA from carotenoid-rich plant tissues.

Aristolactams and dioxoaporphines from Fissistigma balansae and Fissistigma oldhamii

Investigation of extracts of Fissistigma balansae and Fissistigma oldhamii resulted in the isolation of 11 aristolactams-stigmalactam (1), piperolactam A (2), piperolactam C (3), aristolactam AII (4), aristolactam AIIIa (5), aristolactam BII (6), aristolactam BIII (7), aristolactam FII (8), goniothalactam (9), enterocarpam I (10), and velutinam (11)-as well as two dioxoaporphines, noraristolodione (12) and norcepharadione B (13). The new compound 1 was identified by spectral data interpretation. Compounds 1-13 were subjected to antiplatelet aggregation testing.

Phenolic compounds from Eucalyptus maculata

From the chloroformic extract of the resinous exudate of the stems of Eucalyptus maculata, four phenolic constituents have been isolated. A new di-cinnamic acid glucose ester was isolated, in addition to cinnamic acid, 7-methyl aromadendrin and sakuranetin. The isolated compounds were elucidated using UV, IR, 1D and 2D NMR and MS.

[Studies on constituents in Uncaria macrophylla Wall]

OBJECTIVE

To study the chemical constituents of Uncaria macrophylla.

METHOD

Compounds were isolated by Columu Chromatography, and the structures were identified by NMR spectral data and other methods.

RESULT AND CONCLUSION

Six compounds were isolated and identified as ursolic acid, 3 beta-6 beta-23-trihydroxyurs-12-en-28-oic acid, 3 beta, 6 beta, 19 alpha-trihydroxyurs-12-en-28-oic acid, epicatechin, beta-sitosterol and daucosterin. All the compounds were isolated for the first time from the plant.

Antifeedant activity of withanolides from Salpichroa origanifolia on Musca domestica

The antifeedant effect of several salpichrolides on larvae of Musca domestica was investigated. Three naturally occurring compounds, salpichrolide A (1), salpichrolide C (2), and salpichrolide G (3), previously isolated from Salpichroa origanifolia, and two known (4, 6) and three new (5, 7, 8) synthetic analogues were tested. The maximal effect on development was observed for salpichrolide A (1), while salpichrolide G (3) was the most toxic. The content of the salpichrolides in S. origanifolia was monitored by HPLC during plant development, reaching a maximum during summer.

Highly substituted glucuronoarabinoxylans (hsGAXs) and low-branched xylans show a distinct localization pattern in the tissues of Zea mays L

Polyclonal antibodies which recognized highly substituted glucuronoarabinoxylans (hsGAXs) and low-branched xylans and did not cross-react with each other, were raised in order to examine localization of these epitopes in internodes of maize. Immunofluorescent labeling revealed different pattern between two succeeding developmental stages. The hsGAX epitope was localized evenly in primary walls in all tissue types, and strongly in unlignified secondary walls in phloem. However, lignified secondary walls in protoxylem, parenchyma and a part of fibers were faintly labeled with this epitope. Moreover, the epitope showed limited binding in lignified parenchyma and fiber walls at ultrastructural level. Low-branched xylan epitope was localized evenly throughout lignified walls in all tissue types. This epitope was also localized only in lignified walls of other organs such as leaf, root apex and dark-grown mesocotyl. Low-branched xylans are significantly related to lignification. Localization of hsGAX epitope in their organs was similar to that in internodes. The hsGAX epitope was distributed both in unlignified walls of all tissues and in lignified walls of parenchyma and annular thickening of protoxylem. We propose that hsGAX has separate functions in lignified and unlignified tissues. In conclusion, at tissue level, hsGAX is localized mainly in unlignified walls, and low-branched xylans in lignified walls.

Interaction of nutrient limitation and elevated CO2 concentration on carbon assimilation of a tropical tree seedling (Cedrela odorata)

Carbon assimilation by Cedrela odorata L. (Meliaceae) seedlings was investigated in ambient and elevated CO2 concentrations ([CO2]) for 119 days, using small fumigation chambers. A solution containing macro- and micronutrients was supplied at two rates. The 5% rate (high rate) was designed to avoid nutrient limitation and allow a maximum rate of growth. The 1% rate (low rate) allowed examination of the effect of the nutrient limitation-elevated CO2 interaction on carbon assimilation. Root growth was stimulated by 23% in elevated [CO2] at a high rate of nutrient supply, but this did not lead to a change in the root:shoot ratio. Total biomass did not change at either rate of nutrient supply, despite an increase in relative growth rate at the low nutrient supply rate. Net assimilation rates and relative growth rates were stimulated by the high rate of nutrient addition, irrespective of [CO2]. We used a biochemical model of photosynthesis to investigate assimilation at the leaf level. Maximum rate of electron transport (Jmax) and maximum velocity of carboxylation (Vcmax) did not differ significantly with CO2 treatment, but showed a substantial reduction at the low rate of nutrient supply. Across both CO2 treatments, mean Jmax for seedlings grown at a high rate of nutrient supply was 75 micromol m(-2) s(-1) and mean Vcmax was 27 micromol m(-2) s(-1). The corresponding mean values for seedlings grown at a low rate of nutrient supply were 36 micromol m(-2) s(-1) and 15 micromol m(-2) s(-1), respectively. Concentrations of leaf nitrogen, on a mass basis, were significantly decreased by the low nutrient supply rate, in proportion to the observed decrease in photosynthetic parameters. Chlorophyll and carbohydrate concentrations of leaves were unaffected by growth [CO2]. Because there was no net increase in growth in response to elevated [CO2], despite increased assimilation of carbon at the leaf level, we hypothesize that the rate of respiration of non-photosynthetic organs was increased.

Three new toxic norditerpenoid alkaloids from the low larkspur Delphinium nuttallianum

Three new N-(methylsuccinimido)anthranoyllycoctonine norditerpenoids, given the names bearline (1), 14-acetylbearline (2), and 16-deacetylgeyerline (3), were isolated from the extract of the low larkspur Delphinium nuttallianum. The structures of the individual alkaloids were determined by (1)H and (13)C NMR spectroscopy and HRMS. These alkaloids are structurally related to the neurotoxic alkaloid methyllycaconitine (4) and may be important in establishing the toxicity of low larkspurs to cattle. A mouse bioassay was used to measure the LD(50) values for two of the new alkaloids (1 and 2), as sufficient quantities of 3 were not available for toxicity testing. A structurally related alkaloid, geyerline (7), was isolated from D. geyeri in sufficient quantities for toxicity testing. The toxicities of 1, 2, and 7 were found to be comparable to that of 4, with calculated LD(50) values in mice of 5.7, 3.3, and 6.2 mg/kg, respectively.

Evaluation of the antimicrobial property of the stem bark of Picralima nitida (Apocynaceae)

The basic fraction (BF) of the methanol extract of the stem bark of Picralima nitida (family Apocynaceae) exhibited significant antimicrobial activity against a wide range of Gram-positive bacteria and fungi, but limited activity against Gram-negative bacteria. The BF had a similar minimum inhibitory concentration (MIC) for S. aureus to the control drug ampicillin, and lower MIC values against A. flavus and A. niger than those of tiaconazole. Values of the minimum bactericidal concentration (MBC) of the BF against microorganisms tested were generally much higher than those for the control drugs ampicillin and gentamicin. The results suggest that some constituents of the stem bark could be isolated and developed into effective antimicrobial agents.

Two oleanane triterpenoids from gordonia ceylanica and their conversions to taraxarane triterpenoids

Chemical investigation of the hot hexane extract of the stem bark of Gordonia ceylanica afforded two new oleanane triterpenoids, 3beta-acetoxy-11alpha, 13beta-dihydroxyolean-12-one and 3beta,11alpha-diacetoxy-13beta-hydroxyolean-12-one (2) The attempted acid hydrolysis of these two compounds resulted the dehydration and subsequent methyl group migration to afford the taraxarane triterpenoids 3beta,11alpha-dihydroxytaraxer-14-en-12-one (4) and 3beta-hydroxy-11alpha-acetoxytaraxer-14-en-12-one (5), respectively. These taraxaranes have not been previously reported.

[A comparative study on nutrient accumulation and distribution of different generations of Chinese fir plantations]

The nutrient accumulations and distribution of different generation of Chinese fir plantations in central production areas of China were studied through the investigation of plantation with different generation(first, second and third), ages (5, 10, 15, 20 years old) and sites(site index 14, 16 and 18). The nutrient accumulations and distribution of Chinese fir plantations were greatly influenced by the number of planting generation. Nutrient accumulation and utilization efficiency in tree layer of Chinese fir plantations declined with the increasing planting generation number, with the first generation > the second > the third; while the nutrient accumulation of understory vegetation was increased with the increasing of planting generation number. Compared with the first generation plantations, nutrient accumulation of tree layer of the second and the third generations decreased by 17.56% and 36.24% respectively, and the third generation platation decreased by 22.65% than the second generation. Meanwhile, successive planting resulted in a decreasing nutrient utilization efficiency of Chinese fir plantation, and an increasing nutrient necessary for dry matter production per unit, which is disadvantageous to the maintaining of soil fertility, but beneficial to the nutrient accumulation of understory vegetation.

Labdane diterpenes from Stachys plumosa

Three new labdane diterpenoids were isolated from the aerial parts of Stachys plumosa. The first two (1, 2) were the dextrorotatory enantiomers of the known 6-deoxyandalusol and 13-epijabugodiol. Structures were determined using NMR and MS techniques. The absolute stereochemistry of the third compound (3) was not experimentally proved.

Sensitive high-performance thin-layer chromatographic method for the estimation of diospyrin, a tumour inhibitory agent from the stem bark of Diospyros montana Roxb

Diospyrin, a tumour inhibitory agent from the stem bark of Diospyros montana was isolated and characterised. A sensitive high-performance thin-layer chromatographic (HPTLC) method was developed for the estimation of diospyrin. The method was validated for precision (intra- and inter-day), repeatability and accuracy. The method was found to be precise, with the RSDs for intra-day in the range of 0.72-1.85% and RSDs for inter-day in the range of 1.06-2.95%, for different concentrations. Instrumental precision and repeatability of the method were found to be 0.086 and 0.937 (% CV), respectively. Accuracy of the method was checked by performing the recovery study at two levels and average percentage recovery was found to be 97.87%. The developed HPTLC method was adopted for the estimation of diospyrin content of the stem bark of D. montana from different regions, which varied from 0.35 to 0.47% (w/w) in the samples.

Antiplasmodial, analgesic, and anti-inflammatory activities of the aqueous extract of the stem bark of Erythrina senegalensis

The in vivo antiplasmodial, analgesic and anti-inflammatory properties of Erythrina senegalensis, an ornamental plant commonly used in Northern Nigeria for the treatment of fevers, was evaluated. Aqueous extracts of the stem bark of the plant was used for the study. The in vivo antiplasmodial activity of the aqueous extract against Plasmodium berghei was assessed using the suppressive and curative test procedures. Analgesic activity was assessed using the acetic acid (0.75%v/v) induced abdominal constriction, while the anti-inflammatory activity was evaluated on egg-albumin induced paw oedema in rats as a model of acute inflammation. The stem bark extract of E. senegalensis exhibited only slight antiplasmodial activity while significant (P<0.05) analgesic and anti-inflammatory effects were observed. Preliminary phytochemical analysis of the extract indicates the presence of alkaloids and glycosides.

The constituents of the root and stem of Aristolochia cucurbitifolia Hayata and their biological activity

Four new compounds, three phenanthrene derivatives, aristolochic acid-III methyl ester (1), cepharanone C (2), and sodium 7-hydroxyl-8-methoxyaristolate (3), and the benzoate derivative, sodium 3,4-dimethoxybenzoate (4), together with 53 known compounds were isolated and characterized from the fresh root and stem of Aristolochia cucurbitifolia. Their structures were elucidated by spectral analyses and chemical transformations. The cytotoxicity and antiplatelet activity of the isolated compounds are also discussed.

Studies on the anti-inflammatory, antipyretic and analgesic properties of Alstonia boonei stem bark

The methanol extract of the stem bark of Alstonia boonei was investigated for anti-inflammatory property. The analgesic and antipyretic properties of the extract was also evaluated. The extract caused a significant (P<0.05) inhibition of the carrageenan-induced paw oedema, cotton pellet granuloma, and exhibited an anti-arthritic activity in rats. Vascular permeability induced by acetic acid in the peritoneum of mice was also inhibited. The extract also produced marked analgesic activity by reduction of writhings induced by acetic acid, as well as the early and late phases of paw licking in mice. A significant (P<0.05) reduction in hyperpyrexia in mice was also produced by the extract. This study has established anti-inflammatory, analgesic and antipyretic activities of the stem bark of A. boonei.

Role of jasmonate in the rice (Oryza sativa L.) self-defense mechanism using proteome analysis

Exogenously applied jasmonic acid (JA) was used to study changes in protein patterns in rice (Oryza sativa L.) seedling tissues, to classify these changes, and to assign a role for these changes, in order to define the role of JA in the rice self-defense mechanism. High resolution two-dimensional polyacrylamide gel electrophoretic analysis revealed induction of new proteins in both leaf and stem tissues after JA treatment, with the major protein spots further analyzed through N-terminal and internal amino acid sequencing, purification, antibody production, and immunoblot analysis. JA treatment results in necrosis in these tissues, which is accompanied by drastic reductions in ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) subunits, and was confirmed using immunoblotting. Induction of novel proteins was found particularly in the stem tissues, including a new basic 28 kDa Bowman-Birk proteinase inhibitor protein (BBPIN; jasmonate-induced stem protein, JISP 6), and acidic 17 kDa pathogenesis-related class 1 protein (PR-1, JISP 9). This induction of proteins was blocked by a protein synthesis inhibitor cycloheximide (CHX) indicating de novo protein synthesis. Kinetin (KIN), a cytokinin and free radical scavenger reversed RuBisCO decreases, but not induction of proteins. Immunoblot analysis using antibodies generated against these purified proteins revealed a tissue-specific expression pattern and time-dependent induction after JA treatment. Our results indicate that jasmonate affects defense-related gene expression in rice seedlings, as evidenced by de novo synthesis of novel proteins with potential roles in plant defense.

[Determination of total flavonoids and dihydromyricetin in Ampelopsis grossedentala (Hand-Mazz) W. T. Wang]

OBJECTIVE

To establish a method for the assay of total flavonoids and dihydromyricetin in A. grossedentala.

METHOD

The flavonoids were determined by spectrophotometry and dihydromyricetin by TCL-scanner.

RESULT

The content of flavonoids was 43.4%-44.0%, RSD 1.56%-2.62% and the content of dihydromyricetin was 37.4%-38.5%, RSD 1.85%-2.65%.

CONCLUSION

The method is rapid, simple, accurate and good for the determination of total flavonoids and dihydromyricetin in A. grossedentala.

Stilbenoids isolated from stem bark of Shorea hemsleyana

Two new stilbene glucosides [(+)-alpha-viniferin 13b-O-beta-glucopyranoside and resveratrol 12-C-beta-glucopyranoside] and two new resveratrol oligomers, hemsleyanols A and B, were isolated from the bark of Shorea hemsleyana along with four known resveratrol oligomers. The structures of the isolates, including the relative configurations, were established by spectroscopic data involving long-range coupling and nuclear Overhauser effect experiments.

[Correction by common sea buckthorn bark and sprout extracts of hormonal and metabolic disturbances during stress in rats]

Long-term administration of the common sea buckthorn bark and sprout extract improves the hormonal-metabolic organism status in rats disturbed by a stress factor (immobilization). The drug administration led to normalization of the altered functional activity indices of the neuro-endocrine system (disturbed adrenocorticotropin, 11-deoxycortisol, insulin, urea, and glucose levels) by affecting the production of glucocorticoids and increasing the hypothalamus sensitivity with respect to regulatory signals.

Lupene-type triterpenes from Periploca aphylla

Two new lupane derivatives, 3beta,6alpha-dihydroxylup-20(29)-ene (1) and 6alpha-hydroxylup-20(29)-en-3beta-octadecanoate (2), have been isolated from the stems of Periploca aphylla, in addition to beta-sitosterol and lupeol. The structures of 1 and 2 were determined by spectral and chemical methods. Compound 1 showed strong inhibition of alpha-glucosidase type VI and a moderate antibacterial activity.