Inhibition of plasma extravasation by abruquinone A, a natural isoflavanquinone isolated from Abrus precatorius

Polymyxin B-induced hind-paw edema was suppressed by abruquinone A, an isoflavanquinone isolated from Abrus precatorius, in normal as well in adrenalectomized mice. Unlike dexamethasone, abruquinone A did not increase the liver glycogen content in fasting adrenalectomized mice. The volume of exuded plasma was significantly reduced by abruquinone A in neurogenic inflammation, passive cutaneous anaphylactic reaction and compound 48/80-induced ear edema. Histamine-, serotonin-, bradykinin- and substance P-induced plasma extravasation in ear edema was also suppressed by abruquinone A. Abruquinone A, like isoproterenol, significantly reduced the bradykinin- and substance P-induced plasma extravasation in normal as well as in compound 48/80-pretreated mice. In addition, abruquinone A suppressed the bradykinin- and substance P-induced ear edema to a significantly greater extent than diphenhydramine/methysergide did. In the in vitro experiments, abruquinone A suppressed the compound 48/80-induced histamine and beta-glucuronidase released from isolated rat peritoneal mast cell preparations. These results suggest that the anti-inflammatory effect of abruquinone A is mediated partly via the suppression of the release of chemical mediators from mast cells and partly via the prevention of vascular permeability changes caused by mediators. The glucocorticoid activity and the release of glucocorticoid hormones from the adrenal gland are probably not involved.

Antibodies to the tonoplast from the storage parenchyma cells of beetroot recognize a major intrinsic protein related to TIPs

A vacuole membrane (= tonoplast) subfraction was purified by sedimentation in a discontinuous sucrose gradient (0.6 M/0.3 M) from a crude vacuole fraction isolated from red beetroot storage cells. The vacuole membrane-enriched fraction was injected into the popliteal lymph nodes of rabbits to raise polyclonal antibodies. The resultant serum was tested by indirect immunofluorescence microscopy on cryosections of shoot meristem. Antibodies specifically bound to the tonoplast but not the cytoplasm or the nucleus. By immunogold microscopy of ultrathin frozen sections, the anti-tonoplast antibodies were shown to label the luminal (exoplasmic) surface of the vacuole membrane and vesicular elements of the Golgi complex. Almost all of the antibodies were directed against a polypeptide with an M(r) of 27,000 as determined by Western blotting. A 30,000 M(r) polypeptide was occasionally detected in tonoplast-enriched fractions. It was weakly labeled by the crude immune serum, but not by the serum purified by affinity on the M(r) 27,000 band. The 27 kDa polypeptide which accounted for 10 to 15% of the total membrane proteins was partially characterized. The M(r) 27,000, but not the M(r) 30,000 polypeptide, had Triton X-114 binding properties and was extracted by chloroform:methanol, indicating its high hydrophobicity. On the basis of their partitioning in detergent/aqueous phases it is suggested that the 27 kDa and the 30 kDa polypeptides belong to the tonoplast and to the vacuolar sap, respectively. Neither polypeptide binds to Con A or is sensitive to Endo F digestion, suggesting that they are either unglycosylated polypeptides or glycopeptides with modified oligosaccharides. When separated by SDS-PAGE under non-reducing conditions, the 27 kDa antigen displays a small increase in apparent relative mobility. Its NH2-terminal amino acid sequence shares homology with plant members of the MIP channel family. As suggested by its relative molecular mass, its high hydrophobicity and its NH2-terminal amino acid sequence, the M(r) 27,000 polypeptide from the tonoplast of beetroot may be a new member of the TIP family. It appears to represent a useful specific marker for the vacuole membrane at all developmental stages of the storage parenchyma cells.

[Antidepressant active constituents in the roots of Morinda officinalis How]

Five compounds having antidepressant activities have been isolated from the roots of Morinda officinalis, a Chinese traditional Yang-tonic drug. These compounds were identified as succinic acid (1), nystose (2), 1F-fructofuranosylnystose (3), inulin-type hexasaccharide (4) and heptasaccharide (5) by chemical and spectroscopic methods. All of the compounds are isolated from the species of genus Morinda for the first time.

Characterization, chromosomal mapping, and expression of different polyubiquitin genes in tissues from control and heat-shocked maize seedlings

Polyubiquitin transcripts accumulate in plant and animal cells following a heat shock. Most species have a few to several polyubiquitin genes; within a species, the genes may differ in nucleotide (nt) sequence and (or) the number of 228-nt repeats encoding the ubiquitin monomer. This study examines three maize (inbred Oh43) polyubiquitin genes. Two of the genes, MubG9 and MubG5, possess five repeats; the third, MubG1 possesses seven repeats. Sequence analyses of the genomic clones, MubG9 and MubG1 and a cDNA clone, MubG5, reveal that they differ primarily from each other in their nt sequences 5' and 3' to their open reading frames. MubG1 contains a 1004-base pair (bp) intron in its 5' untranslated region. Using gene-specific probes, we show that the amount of polyribosome-associated mRNA transcripts from MubG9 isolated from 2- and 5-day old plumules and radicles is unchanged by heat shock. While the amount of transcript from MubG1 and MubG5 on the polyribosomes in plumules and radicles of 2-day-old seedlings is also unchanged by heat shock, the levels of these transcripts are elevated considerably in similar tissues from heat-shocked 5-day-old seedlings. Similar or identical gene-specific probes were employed to map the genes using the recombinant inbred method. MubG9 maps to chromosome 4L position 186; MubG1 maps to 5L104 and MubG5 to 4L188. The opportunity to use gene-specific probes extends the evidence for distinct modulation (time and tissue) of polyubiquitin gene expression in maize and provides the basis for locus assignment within the genome.

An antimicrobial abietane from the root of Plectranthus hereroensis

A new abietane diterpene, 16-acetoxy-7 alpha, 12-dihydroxy-8,12-abietadiene-11,14-dione, has been isolated from the acetone extract of the root of Plectranthus hereroensis and its structure established by spectroscopic means. This compound showed antibacterial activity against Staphylococcus aureus and Vibrio cholerae, and antiviral activity against Herpes simplex type II.

Characterization of a rice gene family encoding root-specific proteins

Two cDNA clones (RCc2 and RCc3) corresponding to mRNAs highly expressed only in root tissues of rice (Oryza sativa L.) seedlings were characterized. Respectively, they encode polypeptides of 146 (14.5 kDa) and 133 amino acids (13.4 kDa) that share high (> 70%) sequence similarity with a polypeptide encoded by a cDNA (ZRP3) encoding an mRNA preferentially expressed in young maize roots. Genomic DNA blot analysis revealed that they are members of a small gene family and RCg2, the gene corresponding to RCc2, was isolated. A 1656 bp 5'-upstream sequence of RCg2 was translationally fused to a beta-glucuronidase (GUS) reporter gene and stable introduction of the chimeric construct into rice was confirmed by PCR and genomic DNA blot analyses. Histochemical analysis of transgenic rice plants containing the full-length chimeric gene showed high levels of GUS activity in mature cells and the elongation and maturation zones of primary and secondary roots, and in the root caps, but no GUS activity was detected in root meristematic regions. Surprisingly, high GUS activity was also detected in leaves of the same plants. This raises the possibility that the RCg2 5'-upstream element may not be sufficient for the proper spatial control of root specificity in transgenic rice.

Mode of action of the anti-influenza virus activity of plant flavonoid, 5,7,4'-trihydroxy-8-methoxyflavone, from the roots of Scutellaria baicalensis

When mouse-adapted influenza virus A/PR/8/34 (A/PR8) (10 PFU/cell) was adsorbed to Madin-Darby canine kidney (MDCK) cells at 4 degrees C for 1 h and incubated at 37 degrees C, release of the virus from the cells was detected in the medium from 4 h after incubation and reached to plateau at 8 h. However, 5,7,4'-trihydroxy-8-methoxyflavone (F36) from the roots of Scutellaria baicalensis significantly reduced this single-cycle replication of A/PR8 from 4 h to 12 h after incubation by dose-dependent manner and the dose which decrease the virus titer one tenth was 11 microM. F36 (50 microM) did not inhibit the adsorption of A/PR8 to MDCK cells, but reduced release of the virus in the medium, when it was added at 0 or 2 h after the incubation. The cell-associated virus determined by sialidase activity was also reduced by F36 treatment at 0 or 2 h. F36 also inhibited the fusion of A/PR8 with liposomes containing bovine brain mixed gangliosides at pH 5.0. However, F36 little affected on the elongation activity of the viral RNA-dependent RNA polymerase in vitro. These results suggest that F36 reduces the replication of A/PR8 by inhibiting the fusion of the virus with endosome/lysosome membrane which occurs at early stage of virus infection cycle. Whereas, when F36 was added to the MDCK cells infected with A/PR8 at 3 or 4 h after incubation, release of the virus in the medium was reduced but the cell-associated virus was increased in comparison with control.(ABSTRACT TRUNCATED AT 250 WORDS)

Polar distribution of annexin-like proteins during phytochrome-mediated initiation and growth of rhizoids in the ferns Dryopteris and Anemia

Although the calcium requirement of phytochrome-mediated fern spore germination and early rhizoid growth is well established, the calcium-binding proteins that serve as transducers for these responses are not known. Here we report the presence of annexin-like proteins in germinating spores of Dryopteris filix-mas (L.) Schott and Anemia phyllitidis (L.) Sw. and evidence that they may be important participants in early photomorphogenic changes in gametophytes. Immunolocalization and immunoblot assays of these proteins were carried out using polyclonal antibodies raised either against a 35-kDa annexin-like protein from pea or against anchorin CII from chicken. Western-blot analysis showed that crude protein extracts obtained from both species after red-light treatment contained two cross-reactive protein bands with molecular weights around 70 kDa. These proteins were annexin-like in that they bound to a phosphatidylserine affinity column in a calcium-dependent fashion. Using this column, two protein bands around 70 kDa, i.e. 67 and 73 kDa, were partially purified together with proteins at 36 kDa and a doublet at 54 kDa. Proteins of these latter molecular weights are suggested to be members of the annexin family, but no cross-reactivity could be found between these and the two antibodies used in our investigations. Immunodetectable levels of these proteins were observed only after light-mediated induction of spore germination. Imaging of the immuno-localization patterns observed with both antibodies showed that the annexin-like proteins are concentrated at the extreme tips of the rhizoids in D. filix-mas and A. phyllitidis during rhizoid initiation and all stages of elongation. We suggest that these proteins may play a major role in the tip-oriented exocytosis events that are critical for the initiation and growth of fern rhizoids.

Expression of the betaine aldehyde dehydrogenase gene in barley in response to osmotic stress and abscisic acid

When subjected to salt stress or drought, some vascular plants such as barley respond with an increased accumulation of the osmoprotectant glycine betaine (betaine), being the last step of betaine synthesis catalyzed by betaine aldehyde dehydrogenase (BADH). We report here cloning and characterization of BADH cDNA from barley, a monocot, and the expression pattern of a BADH transcript. An open reading frame of 1515 bp encoded a protein which showed high homology to BADH enzymes present in other plants (spinach and sugar-beet) and in Escherichia coli. Transgenic tobacco plants harboring the clone expressed high levels of both BADH protein and its enzymatic activity. Northern blot analyses indicated that BADH mRNA levels increased almost 8-fold and 2-fold, respectively, in leaves and roots of barley plants grown in high-salt conditions, and that these levels decreased upon release of the stress, whereas they did not decrease under continuous salt stress. BADH transcripts also accumulate in response to water stress or drought, indicating a common response of the plant to osmotic changes that affect its water status. The addition of abscisic acid (ABA) to plants during growth also increased the levels of BADH transcripts dramatically, although the response was delayed when compared to that found for salt-stressed plants. Removal of plant roots before transferring the plants to high-salt conditions reduced only slightly the accumulation of BADH transcripts in the leaves.

Triterpenoid saponins from the root of Sideroxylon foetidissimum

Two novel triterpenoid saponins named sideroxyloside B and sideroxyloside C were isolated from the root of Sideroxylon foetidissimum. On the basis of spectroscopic and chemical methods, their structures were established as 3-O-beta-D-glucopyranosyl-28-O([beta-D-apiofuranosyl-(1-->3)-beta- D- xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->4)] [beta-D-apiofuranosyl(1-->3)]-alpha-L-rhamnopyranosyl-(1-->2)-alph a-L- arabinopyranosyl) protobassic acid and 28-O([beta-D-xylopyranosyl-(1-->4)- alpha-L-rhamnopyranosyl-(1-->4)] [beta-D-apiofuranosyl-(1-->3)]-alpha-L- rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl) protobassic acid, respectively.

Studies on hypoxoside and rooperol analogues from Hypoxis rooperi and Hypoxis latifolia and their biotransformation in man by using high-performance liquid chromatography with in-line sorption enrichment and diode-array detection

Methanol extracts of the corms of Hypoxis rooperi and H. latifolia were studied for their hypoxoside content by an in-line sorption enrichment HPLC technique [Kruger et al., J. Chromatogr., 612 (1993) 191]. Hypoxoside is the trivial name for (E)-1,5-bis(3'-hydroxy-4'-O-beta-D-glucopyranosyl-phenyl) pent-1-en-4-yne and rooperol the aglucone obtained from beta-glucosidase treatment. Hypoxoside and rooperol analogues containing 4, 3 and 2 hydroxyl groups resolved as separate peaks with the proportion of the latter two markedly higher in H. latifolia than in H. rooperi. After oral ingestion of hypoxoside by humans, no hypoxoside or rooperol appeared in the serum. Only rooperol was present in the faeces. The serum and urine contained at least three phase II metabolite peaks. Selective enzyme hydrolysis showed that they represent the diglucuronide, disulfate and glucuronide-sulfate conjugates of all three rooperol analogues.

Plasmodesmata of maize root tips: structure and composition

A procedure is described for obtaining clean maize cell wall preparations that contain embedded plasmodesmata. Negative staining and rotary shadowing have been used with transmission electron microscopy to visualise the plasmodesmata in these isolated walls, and to assess the effects of simple biochemical treatments on plasmodesmal components. Light protease treatment removes material from the exposed ends of plasmodesmata but does not extract the plasmodesmal core, which lies within the cell wall. However, heavy proteolysis occasionally removes the complete plasmodesma, including its enclosing collar structure, from the wall. Extraction with urea has a similar effect. The collar itself appears not to be proteinaceous in composition, although protein may bind it into the wall. Callose is localised in the wall around plasmodesmata, but does not appear to be a constituent of the collar. The membrane components of the plasmodesma (plasma membrane and desmotubule) can be extracted with membrane-solubilising detergents. This treatment releases from the wall a small number of proteins that are regarded as being potentially of plasmodesmal origin. These results show that plasmodesmata from maize can be dissected biochemically and suggest a strategy for the characterisation of individual molecular components.

[Chemical constituents of roots, rhizomes and stems of Amomum villosum Lour]

Ethyl octacosate, docosyl hexylate, a new compound stigmast-4-ene-1,3-dione, beta-sitosterol and daucosterol were isolated and identified from the roots and rhizomes of Amomum villosum cultivated in Xishuangbanna, Yunnan. Two compounds daucosterol and emodin monoglycoside were isolated and identified from the stems of A. villosum.

Characterization of an acidic polysaccharide with immunological activities from the tuber of Pinellia ternata

An acidic polysaccharide, called pinellian PA, was isolated from the tuber of Pinellia ternata Breit. It was homogeneous on electrophoresis and gel chromatography, and its molecular mass was estimated to be 11.8 x 10(4). Pinellian PA is composed of L-arabinose: D-galactose: L-rhamnose: D-galacturonic acid: D-glucuronic acid in the molar ratio of 5:15:1:3:3, in addition to small amounts of O-acetyl groups and peptide moieties. Reduction of carboxyl groups, methylation analysis and nuclear magnetic resonance studies show that the core structural features include a backbone chain composed of beta-1,3-linked D-galactose units. Some of the galactose units in the backbone carry beta-1,6-linked D-galactosyl side-chains at position 6. Pinellian PA produces significant potentiation of the reticuloendothelial system, as shown by a carbon clearance test, and also exhibits potent anti-complementary activity.

A glucan with immunological activities from the tuber of Alisma orientale

A glucan, called alisman SI, was isolated from the tuber of Alisma orientale Juzepcz. It was homogeneous on electrophoresis and gel chromatography, and its molecular mass was 1.1 x 10(4). It is composed solely of D-glucose. Methylation analysis, nuclear magnetic resonance and enzymic degradation studies indicated that it has a high-branched glucan type structure mainly composed of alpha-1,4-linked D-glucopyranosyl residues with partially alpha-1,6-linked units and both 3,4- and 4,6-branching points. The polysaccharide exhibited significant reticuloendothelial system-potentiating activity in a carbon clearance test, as well as a pronounced anti-complementary activity.

Promotion of neuronal differentiation of PC12h cells by natural lignans and iridoids

We studied the effect of (+)- and (-)-syringaresinol, (+)-syringaresinol glucosides, syringin, aucubin and catalpol on neurite outgrowth of a cultured cell line of paraneuron, PC12h cells. Of these compounds, (+)-syringaresinol diglucoside and partly glucosidase-hydrolyzed aucubin were found to be the most potent in promotion of the neurite outgrowth and stimulated responses to a high concentration of KCl and to carbachol in the cells, as observed by increase of the concentration of cytosolic free calcium. It is suggested that some of these herb-derived compounds can induce neuronal differentiation in PC12h cells.

Procyanidins from tormentil: fractionation and study of the anti-radical activity towards superoxide anion

A standardised water-soluble extract was prepared from rhizomes of Potentilla tormentilla. The procyanidins in the extract were fractionated according to their degree of polymerisation by chromatography on Sephadex LH20. The anti-radical activities of the different fractions towards superoxide anion were compared when pentamers and hexamers were found to be the most active.

Novel Ca(2+)-ATPase inhibitors from the dried root tubers of Polygonum Multiflorum

The MeOH extract of the dried root tubers of Polygonum multiflorum yielded three bioactive compounds with an inhibitory activity on calmodulin-depleted erythrocyte calcium-dependent ATPase. These compounds were identified as E-2,3,5,4'-tetrahydroxystilbene 2-O-beta-D-glucopyranoside [2] (IC50 = 240 microM) and cis- and trans-E-3-butylidene-4,5,6,7-tetrahydro-6,7-dihydroxy-1(3H)- isobenzofuranone [3 and 4](IC50 = 160 and 260 microM, respectively). E-2,4,6,4'-Tetrahydroxystilbene 2-O-beta-D-glucopyranoside [1] was also isolated but was found to have no inhibitory effect on the enzyme.

Isolation, purification and partial characterization of viper venom inhibiting factor from the root extract of the Indian medicinal plant sarsaparilla (Hemidesmus indicus R. Br.)

An organic acid, isolated and purified from the root extract of an Indian medicinal plant sarsaparilla Hemidesmus indicus R. Br, possessed viper venom inhibitory activity. The compound (designated HI-RVIF) was isolated by solvent extraction, silica gel column chromatography and thin layer chromatography, and was homogeneous in nature. The white needle-shaped crystals were soluble in water, methanol and chloroform and had a melting point of 155-158 degrees C and lambda max 260 nm. Spectral analysis confirmed the presence of a benzene ring, methoxy group, and hydroxyl group; the mol. wt of the compound was 168. HI-RVIF significantly antagonized viper venom-induced lethal, haemorrhagic, coagulant and anticoagulant activity in experimental rodents.

Field evaluation of transgenic potato plants expressing an antisense granule-bound starch synthase gene: increase of the antisense effect during tuber growth

Transgenic plants of a tetraploid potato cultivar were obtained in which the amylose content of tuber starch was reduced via antisense RNA-mediated inhibition of the expression of the gene encoding granule-bound starch synthase (GBSS). GBSS is one of the key enzymes in the biosynthesis of starch and catalyses the formation of amylose. The antisense GBSS genes, based on the full-length GBSS cDNA driven by the 35S CaMV promoter or the potato GBSS promoter, were introduced into the potato genome by Agrobacterium tumefaciens-mediated transformation. Expression of each of these genes resulted in the complete inhibition of GBSS gene expression, and thus in the production of amylose-free tuber starch, in mature field-grown plants originating from rooted in vitro plantlets of 4 out of 66 transgenic clones. Clones in which the GBSS gene expression was incompletely inhibited showed an increase of the extent of inhibition during tuber growth. This is likely to be due to the increase of starch granule size during tuber growth and the specific distribution pattern of starch components in granules of clones with reduced GBSS activity. Expression of the antisense GBSS gene from the GBSS promoter resulted in a higher stability of inhibition in tubers of field-grown plants as compared to expression from the 35S CaMV promoter. Field analysis of the transgenic clones indicated that inhibition of GBSS gene expression could be achieved without significantly affecting the starch and sugar content of transgenic tubers, the expression level of other genes involved in starch and tuber metabolism and agronomic characteristics such as yield and dry matter content.

Cycloartane triterpene glycosides from the hairy root cultures of Astragalus membranaceus

Agroastragaloside II, a new astragaloside was isolated from the hairy root culture of Astragalus membranaceus. Its structure was established as 3-O-beta-(2'-O-acetyl)-D-xylopyranosyl-6-O-beta-D-glucopyranosyl-(24S)- 3 beta,6 alpha,16 beta,24,25-pentahydroxy-9,19-cyclolanostane on the basis of spectroscopic data. Three known astragalosides, astragaloside II, isoastragaloside I and 3-O-beta-D-xylopyranosyl-cycloastragenol were also isolated.

Triterpenoid saponins from Ardisia crenata

Two novel triterpenoid saponins, ardisicrenoside A [3 beta-O-(alpha-L-rhamnopyranosyl-(1-->2)-[beta-D-glucopyranosyl- (1-->4)-[beta-D-glucopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl)- 13 beta,28-epoxy-16 alpha,30-oleananediol] and ardisicrenoside B [3 beta-O-(beta-D-xylopyranosyl-(1-->2)-[beta-D- glucopyranosyl-(1-->4)-[beta-D-glucopyranosyl-(1-->2)]- alpha-L-arabinopyranosyl)-13 beta,28-epoxy-16 alpha,30-oleananediol] were isolated from the roots of Ardisia crenata. Two known triterpenoid saponins, ardisiacrispins A and B were also isolated from this source. Their structures were determined mainly by 2D NMR (COSY, HOHAHA, HETCOR, HMBC and ROESY) experiments. The aglycones are the new 13 beta,28-epoxy-3 beta,16 alpha,30-oleananetriol for ardisicrenosides A and B.

Flavanones with potent antibacterial activity against methicillin-resistant Staphylococcus aureus

With the therapeutic concept of using the defensive ability of plants against microbial infections, phytoalexin, an antimicrobial phytochemical was studied for its ability to inhibit the growth of methicillin-resistant Staphylococcus aureus (MRSA). Extracts from Sophora exigua (Leguminosae) were fractionated by serial chromatography and the anti-MRSA activity of each fraction was determined by the agar-plate method. Among the active isolates, 5,7,2',6'-tetrahydroxy-6-isoprenyl-8-lavandulyl-4'-methox yflavanone (exiguaflavanone D) completely inhibited the growth of all the MRSA strains examined at the concentration of 1.56-6.25 micrograms mL-1, and 5, 2',6'-trihydroxy-8-lavandulyl-7-methoxy-flavanone (exiguaflavanone B) inhibited at a concentration of 50 micrograms mL-1. This former compound is expected to be a phytotherapeutic agent for MRSA infections as an alternative to conventional antibiotics with unwanted side-effects or the appearance of antibiotic-resistant bacteria.

Triterpenoid saponins from Ardisia crenata and their inhibitory activity on cAMP phosphodiesterase

Two novel triterpenoid saponins, ardisicrenoside C (1) [3 beta-O-(alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->4)- [beta-D-glucopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl)-16 alpha, 28-dihydroxy-olean-12-en-30-oic acid 30-O-beta-D-glucopyranosyl ester] and ardisicrenoside D (2) [3 beta-O-(beta-D-xylopyranosyl-(1-->2)- beta-D-glucopyranosyl-(1-->4)-[beta-D-glucopyranosyl-(1-->2)]-alpha-L- arabinopyranosyl)-16 alpha, 28-dihydroxy-olean-12-en-30-oic acid 30-O-beta-D-glucopyranosyl ester] were isolated from the roots of Ardisia crenata. Structure assignments are based on spectroscopic data including 2D-NMR (correlation spectroscopy (COSY), homonuclear Hartmann-Hahn spectroscopy (HOHAHA), heteronuclear correlated spectroscopy (HETCOR), heteronuclear multiple bond correlation (HMBC) and rotating frame NOE spectroscopy (ROESY)) experiments and some chemical reactions. In addition, the isolated saponins along with their prosapogenins and sapogenins have been evaluated for their inhibitory activity on cAMP phosphodiesterase as a primary screening test for new medicinal compounds.

Xanthone C-glycoside and acylated sugar from Polygala tenuifolia

A new xanthone C-glycoside, polygalaxanthone III (1), and a new acylated sugar, tenuifoliside E (2) were isolated from the roots of Polygala tenuifolia. Their structures were characterized as 4-C-[beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranosyl]-1, 3,6-trihydroxy-7-methoxyxanthone (1) and beta-D-(1-O-acetyl-3-O-feruloyl-6-O-sinapoyl)-fructofuranosy l-alpha-D-(2,4,6- O-triacetyl)glucopyranoside (2), respectively, on the basis of chemical and spectral evidence including two dimensional nuclear magnetic resonance (2D-NMR) studies.

Two acidic polysaccharides having reticuloendothelial system-potentiating activity from the raw root of Rehmannia glutinosa

Two acidic polysaccharides, called rehmannan FS-I and rehmannan FS-II, were isolated from the raw root of Rehmannia glutinosa LIBOSCHITZ. They were homogeneous on electrophoresis and gel chromatography, and their molecular masses were estimated to be 5.8 x 10(4) and 6.6 x 10(4), respectively. Rehamannan FS-I is composed of L-arabinose: D-galactose: L-rhamnose: D-galacturonic acid: D-glucuronic acid in the molar ratio of 68:40:4:84:3; rehmannan FS-II is composed of L-arabinose: D-galactose: L-rhamnose: D-galacturonic acid in the molar ratio of 18:15:4:33, in addition to small amounts of O-acetyl groups. About two-thirds (rehmannan FS-I) and about one half (rehamannan FS-II) of the hexuronic acid residues exist as methyl esters. Methylation analysis of the carboxyl-reduced derivatives and nuclear magnetic resonance studies indicated that their structural features include mainly both arabino-3,6-galactan and rhamno-galacturonan type structural units. Both polysaccharides showed remarkable reticuloendothelial system-potentiating activity in a carbon clearance test.

Effect of bisbenzylisoquinoline alkaloids from Mahonia aquifolium on the isolated rat aorta

1. The extract from roots of Mahonia aquifolium as well as berbamine and oxyacanthine relaxed K(+)-precontracted rat aortal rings with IC50 values of about 20 mumol/l. 2. Relaxation was not inhibited by denudation of the endothelium or by premedication of the aortas with indomethacin, methylene blue or propranolol. 3. Berbamine and oxyacanthine inhibited contractions induced by noradrenaline, phenylephrine and serotonin in a non-competitive manner. Further, they competitively blocked calcium-induced contraction in Ca(2+)-free depolarizing PSS. 4. The blockade of calcium entry appears to be the main mechanism of the dilatory effect of the drugs tested, but their interaction with alpha-adrenoceptors could not be excluded.

Steroidal saponins from Smilax menispermoidea and S. lebrunii

Three new (25S)spirost-5-en-3 beta,17 alpha,27-triol glycosides were isolated from the rhizomes and roots of Smilax menispermoidea and S. lebrunii. Their structures were elucidated by means of spectroscopic and chemical methods. Several known saponins were also isolated and identified.

The root epidermis-specific pea gene RH2 is homologous to a pathogenesis-related gene

Two-dimensional gel electrophoresis of pea root and root hair proteins revealed the existence of at least 10 proteins present at elevated levels in root hairs. One of these, named RH2, was isolated and a partial amino acid sequence was determined from two tryptic peptides. Using this sequence information oligonucleotides were designed to isolate by PCR an RH2 cDNA clone. In situ hybridization studies with this cDNA clone showed that rh2 is not only expressed in root hairs, but also in root epidermal cells lacking these tubular outgrowths. During post-embryonic development the gene is switched on after the transition of protoderm into epidermis and since rh2 is already expressed in a globular pea embryo in the protoderm at the side attached to the suspensor, we conclude that the expression of rh2 is developmentally regulated. At the amino acid level RH2 is 95% homologous to the pea PR protein I49a. These gene encoding I49a is induced in pea pods upon inoculation with the pathogen Fusarium solani [12]. We postulate that rh2 contributes to a constitutive defence barrier in the root epidermis. A similar role has been proposed for chalcone synthase (CHS) and chitinase, pathogenesis-related protein that are also constitutively present in certain epidermal tissues.

Cloning and characterization of a cathepsin D inhibitor gene from Solanum tuberosum L

A DNA clone encoding a cathepsin D inhibitor CathInh was isolated from a potato genomic library using a CathInh cDNA as hybridization probe. The amino acid sequence of the coding region is nearly identical with a CathInh cDNA and CathInh proteins previously isolated from a tuber-specific cDNA library and from tubers, respectively. Analysis of GUS activity resulting from expression of chimeric CathInh promoter-GUS genes in transgenic potato plants revealed expression exclusively confined to potato tubers. No GUS activity could be detected in any other organ of the transgenic plants either constitutively or after wounding or treatment with abscisic and jasmonic acid (JA). Interestingly, part of the promoter region of the CathInh gene, essential for GUS activity in tubers, shows striking similarity to promoter regions of tuber-specific class I patatin genes.

[Studies on the Nepalese crude drugs. XIX. On the flavonoid and phenylethanoid constituents of the root of Scutellaria repens Buch.-Ham. ex D. Don]

From the root of Scutellaria repens Buch.-Ham ex D. Don, two new flavonoids (10, 11) and three new phenylethanoids (12-14) were isolated, together with nine known compounds. The structures of 10-14 were shown to be 5,7,2'-trihydroxy-6,8-dimethoxyflavone, O-5-hydroxy-6,8-dimethoxyflavone-7-yl beta-D-glucuronopyranoside, O-2-(3-hydroxy-4-methoxyphenyl)ethyl O-2,3-di-O-acethyl-alpha-L-rhamnopyranosyl- (1-->3)-(4-O-trans-feruloyl)-beta-D-glucopyranoside, O-2-(3-hydroxy-4-methoxyphenyl)ethyl O-alpha-L-rhamnopyranosyl-(1-->3)-(4-O-cis-feruloyl)-beta-D-glu cop yranoside and O-2-(3-hydroxy-4-methoxyphenyl)-ethyl O-2,3-di-O-acethyl-alpha-L-rhamnopyranosyl- (1-->3)-(4-O-cis-feruloyl)-beta-D- glucopyranoside, respectively, on the basis of the chemical and spectral data.

Expression patterns of novel genes encoding homeodomain leucine-zipper proteins in Arabidopsis thaliana

A recently discovered class of genes in Arabidopsis thaliana encode putative transcription factors which contain a homeodomain closely linked to a leucine zipper motif. We have previously reported on the cloning and cDNA sequence of one gene of this class, Athb-3. In this article we show this gene to be expressed predominantly in the cortex of the root and the stem. Using the Athb-3 clone as a probe we have isolated cDNA clones corresponding to three novel homeodomain-leucine zipper proteins. These clones, Athb-5, Athb-6 and Athb-7, hybridized to transcripts that were relatively abundant in the leaf, but also present in other vegetative organs, as well as in the flower. Only weak hybridization was observed to seed pod samples. These observations indicate that these Athb genes have major functions in the mature plant, and therefore, in contrast to homeobox genes in other eukaryotes and to the kn-1 gene in maize, are unlikely to function in the primary control of developmental processes during embryogenesis or organogenesis. The deduced amino acid sequences of Athb-5, Athb-6 and Athb-7 are highly similar to the previously isolated Athb-1, Athb-2 and Athb-3 in the homeodomain and leucine-zipper parts of the proteins, whereas the similarities to homeodomain proteins from other eukaryotes are limited. The Athb proteins thus constitute a new and well defined class of homeodomain proteins, apparently unique to plants.

Comparison of soybean and pea ENOD40 cDNA clones representing genes expressed during both early and late stages of nodule development

A pea cDNA clone representing the homologue of the soybean pGmENOD40-1 was isolated and characterized. At the nucleotide level both clones share 55% homology. Strikingly, the homology between the polypeptides derived from the pea and soybean ENOD40 cDNA sequences is only 14%. Despite this low homology Southern analyses revealed that the isolated pea cDNA clone represents the single pea ENOD40. In situ hybridizations showed that at early stages of nodule development and in mature nodules the expression pattern of pea ENOD40 is comparable to that of soybean ENOD40. Although ENOD40 show similar expression patterns in these two nodules, it is questionable whether the putative polypeptides have a similar function, since the homology is very low.

A plant plasma membrane proton-ATPase gene is regulated by development and environment and shows signs of a translational regulation

A proton-pumping ATPase is present in the plasma membrane of plant cells where it sustains transport-related functions. This enzyme is encoded by a family of genes that shows signs of both transcriptional and post-transcriptional regulation. The regulation of pma1, one of the Nicotiana plumbaginifolia H+-ATPase genes, was characterized with the help of the beta-glucuronidase (gusA) receptor gene in transgenic plants. pma1 is active in the root epidermis, the stem cortex, and guard cells. This activity depends on developmental and growth conditions. For instance, pma1 activity in guard cells was strongly enhanced when the plant material (young seedlings or mature leaves) was incubated in liquid growth medium. pma1 is also expressed in several tissues of the reproductive organs where active transport is thought to occur but where scarcely any ATPase activity has been identified, namely in the tapetum, the pollen, the transmitting tissue, and the ovules. Several pma genes have a long 5'untranslated region (leader sequence) containing an upstream open reading frame (URF). Analysis of translational and transcriptional fusions with gusA in transgenic plants suggests that the pma1 leader sequence might activate translation of the main open reading frame, even though the URF is translated by a large majority of the scanning ribosomes. As confirmation, transient expression experiments showed that the pma1 leader causes a fourfold post-transcriptional increase of main open reading frame expression. Deletion of the URF by site-directed mutagenesis stimulated the main open reading frame translation 2.7-fold in an in vitro translational assay. These results are consistent with a regulatory mechanism involving translation reinitiation. Altogether, they suggest a fine, multilevel regulation of H+-ATPase activity in the plant.

Inhibition of the growth of cariogenic bacteria in vitro by plant flavanones

Phytoalexins, defensive compounds produced by plants against microbial infections, were purified from Sophora exigua (Leguminosae) and their growth inhibitory effects on oral cariogenic bacteria were determined in vitro. Among three isolated compounds, 5,7,2',4'-tetrahydroxy-8-lavandulylflavanone completely inhibited the growth of oral bacteria including primary cariogenic mutans streptococci, other oral streptococci, actinomycetes, and lactobacilli, at concentrations of 1.56 to 6.25 micrograms/ml.

Steroidal constituents from the roots and stems of Aclepias fruticosa

Steroidal constituents from the roots and stems of Asclepias fruticosa L. were investigated separately. From the roots, twelve pregnane pentaosides and uzarigenin beta-sophoroside were isolated together with three known coroglaucigenin and corotoxigenin glycosides. Pregnane glycosides were composed of ikemagenin or kidjolanin as an aglycone, and D-digitoxose, D-cymarose, D-oleandrose and terminal D-glucose as component sugars. Among the constituents from the stems, cardenolides show a similar pattern to those from leaves. 17 alpha-Hydroxycalactin and 17 alpha-hydroxyafroside were newly obtained along with known doubly linked and normally linked glycosides. Two pregnane glycosides and uzarigenin beta-sophoroside obtained from the roots were also isolated.

Chemical and bioactive constituents from Zanthoxylum simulans

Two new benzo[c]phenanthridine alkaloids, 6-methyldihydrochelerythrine [1] and 6-methylnorchelerythrine [2], together with 23 known compounds, were isolated from the root bark of Zanthoxylum simulans. Structures were elucidated by spectral analysis. Among them, the pyranoquinoline alkaloids, zanthosimuline [3], and huajiaosimuline [4], exhibited cytotoxic activity. In addition, compound 4 showed significant antiplatelet aggregation activity and induced terminal differentiation with cultured HL-60 cells.

An acidic polysaccharide with immunological activities from the root of Paeonia lactiflora

An acidic polysaccharide, called peonan PA, was isolated from the root of Paeonia lactiflora PALLAS. It was homogeneous on electrophoresis and gel chromatography, and its molecular mass was estimated to be 6.0 x 10(4). Peonan PA is composed of L-arabinose: D-galactose: D-galacturonic acid in the molar ratio of 2:1:10, in addition to small amounts of O-acetyl groups and peptide moieties. About forty percent of the hexuronic acid residues in peonan PA exist as methyl esters. Reduction of carboxyl groups, methylation analysis, lithium degradation and nuclear magnetic resonance studies indicated that its main structural features involve both alpha-1,5-linked L-arabino-beta-3,6-branched D-galactan type and alpha-1,4-linked D-galacturonan type structural units. The polysaccharide exhibited remarkable reticuloendothelial system-potentiating activity in a carbon clearance test and considerable anti-complementary activity.

Reinioses A--J, oligosaccharide multi-esters from the roots of Polygala reinii Fr. et Sav

Ten new acylated oligosaccharides, called reinioses A--J, and seven known oligosaccharides were isolated from the roots of Polygala reinii Fr. et Sav. and their structures were elucidated by spectroscopic and chemical means. These oligosaccharides were found to be di-, tri-, tetra- and pentasaccharides having two or more acyl residues.

A monoclonal antibody to lateral element proteins in synaptonemal complexes of Lilium longiflorum

To identify synaptonemal complex (SC) proteins in Lilium longiflorum (lily), monoclonal antibodies were generated using mice immunized with isolated pachytene nuclei. While most of the resulting monoclonal antibodies recognized nucleolar or chromatin proteins, one monoclonal antibody (anti-LE) was found that binds to lateral elements. Anti-LE bound more to lateral elements of SCs digested with DNase than to lateral elements that had not been digested with DNase. The opposite pattern of labeling was observed using monoclonal antibodies to lily chromatin and nucleolar proteins. These results indicate that anti-LE is specifically recognizing lateral element proteins and not chromatin or nucleolar proteins surrounding the lateral elements. On immunoblots, anti-LE binds to three pachytene nuclear proteins (Mr 60000, 66000 and 70000), two tetrad (early microspore) nuclear proteins (Mr 60000 and 70000), and two root tip nuclear proteins (Mr 52000 and 60000). However, anti-LE does not bind to proteins from leaf nuclei. Of these four tissues, leaf is the only one that does not have actively dividing cells. This observation suggests that at least some SC proteins are related to nuclear proteins from mitotically active cells.

The core structure of ginsenan PA, a phagocytosis-activating polysaccharide from the root of Panax ginseng

Controlled Smith degradation and limited hydrolysis of ginsenan PA, the main phagocytosis-activating polysaccharide isolated from the root of Panax ginseng C. A. Meyer, were performed. The reticuloendothelial system-potentiating and anti-complementary activities of the degradation products were investigated. Methylation analysis of the primary and secondary Smith degradation products indicated that the core structural features of ginsenan PA include a backbone chain mainly composed of beta-1,3-linked D-galactose. Almost half of the galactose units in the backbone carry side-chains composed of beta-1,6-linked D-galactosyl residues at position 6. Further 3,6-branching of D-galactose units was observed in a part of the side-chains. alpha-L-Arabinose units are connected mainly to the core galactose moieties via position 6. Removal of most of the arabinose units had a considerable effect on immunological activity.

Two triterpenoid saponins from Heinsia crinata

Two new triterpenoid saponins isolated from the root bark of Heinsia crinata were characterized as heinsiagenin A-3 beta-O-(beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl- (1-->6)-[alpha-L-rhamnopyranosyl-(1-->2)]-beta-D-glucopyranosyl-(1-->2)- beta-D-glucopyranoside) and heinsiagenin A-3 beta-O-(alpha-L-rhamnopyranosyl-(1-->2)-beta-D- glucopyranosyl-(1-->2)-beta-D-glucopyranoside). The structures were deduced mainly from a combination of 1- and 2D NMR experiments.

Antimicrobial isoflavans from Astragalus species

Two new antimicrobial isoflavans, 1-[(3R)-7,8-dimethoxybenzopyranyl]-4- hydroxybenzoquinone (astragaluquinone) and (3S)-7,1'-dihydroxy-8,3'-dimethoxyisoflavan (8-methoxyvestitol), and the known 7-hydroxy-2',3',4'-trimethoxyisoflavan were isolated from roots of Astragalus alexandrinus and A. trigonus. The structures of the new isoflavans were established by spectroscopic methods.

Analysis of a soluble calmodulin binding protein from fava bean roots: identification of glutamate decarboxylase as a calmodulin-activated enzyme

The identity of a soluble 62-kD Ca(2+)-dependent calmodulin binding protein (CaM-BP) from fava bean seedlings was determined. Using 125I-CaM overlay assays, a class of soluble CaM-BPs was detected in extracts of tissues comprising the axis of 1.5-week-old seedlings, excluding the root tip and emergent leaves. The size of these CaM-BPs was not uniform within all parts of the plant; the apparent molecular masses were 62 kD in roots, 60 kD in stems, and 64 kD in nodules. The root 62-kD CaM-BP was purified, and internal microsequence analysis was performed on the protein. A tryptic peptide derived from the CaM-BP consisted of a 13-residue sequence corresponding to a highly conserved region of glutamate decarboxylase (GAD), an enzyme that catalyzes the alpha-decarboxylation of glutamate to form the stress-related metabolite gamma-aminobutyrate. Activity assays of partially purified, desalted, root GAD revealed a 50% stimulation by the addition of 100 microM Ca2+, a 100% stimulation by the addition of 100 microM Ca2+ plus 100 nM CaM, and no appreciable stimulation by CaM in the absence of added Ca2+. The demonstration that plant GAD is a Ca(2+)-CaM-stimulated enzyme provides a model in which stress-linked metabolism is modulated by a Ca(2+)-mediated signal transduction pathway.

Enhancement of the immunocytochemical detection of antigens by microwave irradiation. Benefits and limitations analysed in isolated plant nuclei and Drosophila embryos in toto

Performing the antibody reaction under controlled heating through microwave irradiation results in significant improvements in the immunovisualization of antigens, such as shortening the times of incubation, lowering the antibody titres used and allowing the detection of difficult, inaccessible antigens. In addition to investigate the basis of the enhancement, we have extended to more intact samples such as isolated plant nuclei and in toto Drosophila embryos the results previously reported only with tissue sections. A drop of heterologous anti-nucleolin antibody covering isolated nuclei from onion root meristems spread on a glass slide was microwave irradiated, resulting in clear immunofluorescent labelling of the nucleoli. This result was never previously obtained in the absence of microwave treatment, even using the complicated procedure previously reported for the homologous identification of this nuclear protein. Using the much larger and to some extent impermeable Drosophila embryos, we were able to show that the incubation time and concentration of the anti-myosin antibody can be strongly reduced by performing the reaction at 45 degrees C under microwave irradiation. The controlled increase in temperature is the main factor responsible for these improvements; the importance of maintaining an adequate mixing of the samples is also emphasized. The proper implementation of these two experimental conditions will require the introduction of appropriate mixing accessories and temperature measuring probes for samples of small volume in current microwave laboratory ovens.

Canthin-6-one alkaloids from Brucea mollis var. tonkinensis

Three new alkaloids were isolated from the root-wood of Brucea mollis var. tonkinensis collected in China. Their structures were determined to be 11-O-beta-D-glucopyranosyl-(1-->6)-beta- D-glucopyranosylcanthin-6-one, 5-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosylcanthin-6-o ne and 11-hydroxycanthin-6-one-N-oxide, by chemical and spectral methods. In addition, two known alkaloids, canthin-6-one and canthin-6-one-N-oxide, were isolated.

Sigmoidins J and K, two new prenylated isoflavonoids from Erythrina sigmoidea

In addition to the two known compounds neotautenol [2] and erythrinassinate B [4], two new compounds, an isoflavanone named sigmoidin J [1] and a coumestan derivative named sigmoidin K [3], have been isolated and characterized from the root bark of the Cameroonian medicinal plant Erythrina sigmoidea. Their structures have been established as 7, 4'-dihydroxy-2',5'-dimethoxy-6'(gamma, gamma-dimethylally)isoflavanone [1] and 3,9-dihydroxy-2,10-(gamma, gamma dimethylallyl) coumestan [3], respectively, by spectroscopic techniques and from chemical evidence.

Nutritional assessment of yam (Dioscorea alata) tubers

The nutrient and antinutrient components of tubers from seven cultivars of Dioscorea alata were determined. The average crude protein content of D. alata tubers was 7.4%. Starch (75.6-84.3%) was the predominant fraction of the tuber dry matter. Significant differences in crude protein and starch contents were observed among cultivars. Vitamin C content of the yam tubers ranged from 13.0 to 24.7 mg/100 g fresh weight. The results showed yams to be reasonably good sources of minerals. Phytic acid contents of the yams were low, with values ranging from 58.6 to 198.0 mg/100 g dry matter. Total oxalate levels in yam tubers were found to be in the range of 486-781 mg/100 g dry matter, but may not constitute a nutritional concern since 50-75% of the oxalates were in the water-soluble form. The overall results are suggestive of the nutritional superiority of yams compared to other tropical root crops.