Isobutyl Amides from Pepper (Piper nigrum L.)

Four isobutyl amides were isolated from the fruits of white pepper (Piper nigrum L.) and identified to be N-isobutyl-13-(3,4-methylenedioxyphenyl)-2E,4E,12E-tridecatrienamide (3, guineensine), N-isobutyl-2E,4E,8Z-eicosatrienamide (5), N-isobutyl-2E,4E-octadecadienamide (6) and N-isobutyl-2E,4E-decadienamide (7, pellitorine).     

Sequencing of Coat Protein Gene of an isolate of Cucumber mosaic virus Infecting Black Pepper (Piper nigrum L) in India

The coat protein gene of an isolate of Cucumber mosaic virus (CMV) associated with stunted disease affecting black pepper plant was cloned and sequenced. The coat protein gene comprised of 657 nucleotides encoding a protein of 218 amino acids. Sequence analysis showed that the gene was most closely related to CMV infecting Egyptian henbane plant in India, the member of subgroup I of CMV. The amino acid sequence identity with members of subgroup I was 92-99% while that with members of subgroup II was 77–79%. On the basis of sequence homology, it is concluded that CMV infecting black pepper in India is a strain of CMV belonging to subgroup I.     

Structures and Syntheses of Two Phenolic Amides from Piper nigrum L.

Two phenolic amides were isolated from the fruits of white pepper (Piper nigrum L.) and identified to be N-trans-feruloyl tyramine (2a) and N-5-(4-hydroxyphenyl)-2E, 4E-pentadienoyl piperidine (6a) on the basis of chemical and specrtal evidence. Both compounds were synthesized.     

In silico analyses of superoxide dismutases (SODs) of rice (Oryza sativa L.)

Superoxide dismutases (SODs), members of the metalloenzymes family are most effective intracellular enzymatic antioxidant in aerobic organisms. These enzymes provide the first line of defense in plants against the toxic effects of elevated levels of reactive oxygen species (ROS) generated during various environmental stresses. The availability of high-throughput computational tools has provided better opportunities to characterize the protein features and determine their function. In the present study an attempt was made to gain an insight into the structure and evolution of subunits of SODs (Cu-Zn, Mn and Fe SODs) of rice. The 3-Dimensional structures of SODs were modeled based on available X-ray crystal structures and further validated. The primary sequence, secondary and tertiary structure analysis revealed Mn and Fe SOD to be structurally homologous while Cu-Zn SOD is un-related to either of them. Comparative structural study also revealed former two were dominated by α-helices followed by β-strands in contrast; Cu-Zn SOD dominated by β-strands. Molecular phylogeny indicated a common evolutionary origin of Mn and Fe SOD while Cu-Zn SOD may have evolved separately.     

The isolation of genomic DNA from blackcurrant (ribes nigrum L.)

A method is described for isolating DNA of high molecular mass (M_r) from blackcurrant and other soft-fruit species. Following a hexacethylytimethyl ammonium bromide (CTAB)-based extraction procedure, samples are treated with a glycosidic hydrolase mixture and RNase, and then purified. The suitability of this DNA for Southern analysis and genomic-library construction is demonstrated.     

Antioxidant efficacy of black pepper (Piper nigrum L.) and piperine in rats with high fat diet induced oxidative stress

The present study was aimed to explore the effect of black pepper (Piper nigrum L.) on tissue lipid peroxidation, enzymic and non-enzymic antioxidants in rats fed a high-fat diet. Thirty male Wistar rats (95-115 g) were divided into 5 groups. They were fed standard pellet diet, high-fat diet (20% coconut oil, 2% cholesterol and 0.125% bile salts), high-fat diet plus black pepper (0.25 g or 0.5 g/kg body weight), high-fat diet plus piperine (0.02 g/kg body weight) for a period of 10 weeks. Significantly elevated levels of thiobarbituric acid reactive substances (TBARS), conjugated dienes (CD) and significantly lowered activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and reduced glutathione (GSH) in the liver, heart, kidney, intestine and aorta were observed in rats fed the high fat diet as compared to the control rats. Simultaneous supplementation with black pepper or piperine lowered TBARS and CD levels and maintained SOD, CAT, GPx, GST, and GSH levels to near those of control rats. The data indicate that supplementation with black pepper or the active principle of black pepper, piperine, can reduce high-fat diet induced oxidative stress to the cells.     

水稻线粒体丝氨酸羟甲基转移酶基因的电子克隆

采用基于EST的电子克隆方法得到了一段长1611bp的cDNA序列,以此为信息探针搜索HTGs数据库,找到一个与之高度匹配的基因组DNA序列——OSJNBa0057G07克隆。用FGENESH分析该克隆中的联配区域得到一个包含14个外显子和13个内含子的基因。该基因位于水稻第3染色体物理图谱的136．0～137．6cM区域。推导的ORF编码498个氨基酸,经BLASTP搜索SWISS-PROT数据库和蛋白序列的亚细胞定位显示,该基因编码水稻的线粒体丝氨酸羟甲基转移酶(mSHMT)。该基因受到EST序列的完全支持,其中不乏来自盐胁迫、稻瘟病菌侵染等逆境处理的EST序列,推测该基因与水稻对逆境的应答反应有关。     

Characterisation of novel S-alleles from cherry (Prunus avium L.)

In plant populations exhibiting gametophytic self-incompatibility, individuals harbouring rare S alleles are likely to have a reproductive advantage over individuals having more common alleles. Consequently, determination of the self-incompatibility haplotype of individuals is essential for genetic studies and the development of informed management strategies. This study characterises six new S alleles identified in wild cherry (Prunus avium L.). Investigations to determine the S genotype of individuals in recently planted woodland through length polymorphisms of introns associated with the stylar S-RNase gene and the pollen SFB gene revealed six S intron profiles which did not correspond to those of known S alleles. These are now attributed to S ₂₇ to S ₃₂ . Consensus primers, annealing in the S-RNase sequence coding for the signal peptide and C5 regions, were used to isolate the S-RNase alleles associated with the novel S intron profiles. The proteins corresponding to the new alleles were separated by isoelectric focusing from stylar extracts and their pI values determined. Similarities between the deduced amino acid sequence for the new alleles isolated and other cherry S-RNase sequences available on the databases ranged from 40% to 86%. Amplification products for SFB introns ranged from 172 to 208bp. New sequence regions exposed to positive selection were identified and the significance of the PS3 region reinforced. A phylogenetic relationship between P. avium S-RNases for S ₁₀ and S ₁₃ and between corresponding SFB alleles may indicate co-evolution of allele specificities of these two genes. The nucleotide sequences reported in this paper have been submitted to the EMBL/GenBank database under the following accession numbers: S ₂₇ (DQ266439), S ₂₈ (DQ266440), S ₂₉ (DQ266441), S ₃₀ (DQ266442), S ₃₁ (DQ266443), S ₃₂ (DQ266444).     

Spectroscopic methods and in silico analyses using density functional theory to characterize and identify piperine alkaloid crystals isolated from pepper (Piper Nigrum L.)

Communicated by Ramaswamy H. Sarma     

Muscodor albus MOW12 an Endophyte of Piper nigrum L. (Piperaceae) Collected from North East India Produces Volatile Antimicrobials

Muscodor albus MOW12, an endophytic fungus isolated from Piper nigrum in Mawlong, Meghalaya, India, resembles some cultural and hyphal characteristics of previous isolates of Muscodor sp. In addition, it possesses about 99 % similarity in its ITS rDNA with other M. albus isolates and thus is nicely centered within the genetic tree to other Muscodor spp. This xylariaceae fungus effectively inhibits and kills certain plant pathogenic fungi by virtue of a mixture of volatile compounds that it produces. The majority of these compounds were identified by gas chromatography/mass spectrometry as small molecular weight esters, alcohols, and acids. The main ester components of this isolate of M. albus in its volatile mixture are acetic acid, ethyl ester; propanoic acid, 2-methyl-, methyl ester and acetic acid, 2-methylpropyl ester. This appears to be the first report of any M. albus strain from India.     

Characterisation of cell wall polysaccharides from okra (Abelmoschus esculentus (L.) Moench)

Okra pods are commonly used in Asia as a vegetable, food ingredient, as well as a traditional medicine for many different purposes; for example, as diuretic agent, for treatment of dental diseases and to reduce/prevent gastric irritations. The healthy properties are suggested to originate from the high polysaccharide content of okra pods, resulting in a highly viscous solution with a slimy appearance when okra is extracted with water. In this study, we present a structural characterisation of all major cell wall polysaccharides originating from okra pods. The sequential extraction of okra cell wall material yielded fractions of soluble solids extractable using hot buffer (HBSS), chelating agent (CHSS), dilute alkaline (DASS) and concentrated alkaline (CASS). The HBSS fraction was shown to be rich in galactose, rhamnose and galacturonic acid in the ratio 1.3:1:1.3. The degree of acetylation is relatively high (DA = 58) while the degree of methyl esterification is relatively low (DM = 24). The CHSS fraction contained much higher levels of methyl esterified galacturonic acid residues (63% galacturonic acid; DM = 48) in addition to minor amounts of rhamnose and galactose. The ratio of galactose to rhamnose to galacturonic acid was 1.3:1.0:1.3 and 4.5:1.0:1.2 for HBSS and CHSS, respectively. These results indicated that the HBSS and CHSS fractions contain rhamnogalacturonan type I next to homogalacturonan, while the latter is more prevailing in CHSS. Also the DASS fraction is characterised by high amounts of rhamnose, galactose, galacturonic acid and some arabinose, indicating that rhamnogalacturonan I elements with longer arabinose- and galactose-rich side chains were part of this fraction. Partial digestion of HBSS and CHSS by pectin methyl esterase and polygalacturonase resulted in a fraction with a lower Mw and lower viscosity in solution. These samples were subjected to NMR analysis, which indicated that, in contrast to known RG I structure, the acetyl groups in HBSS are not located on the galacturonic acid residues, while for CHSS only part of the acetyl groups are located on the RG I galacturonic acid residues. The CASS fraction consisted of XXXG-type xyloglucan and 4-methylglucuronoxylan as shown by their sugar (linkage) composition and enzymatic digestion.     

Analysis of kavalactones from Piper methysticum (kava-kava)

The chemical analysis and quality control of both Piper methysticum G. Forster (kava-kava) and extracts obtained by aqueous acetone or aqueous methanol as well as supercritical fluid extraction are reviewed. In the last two decades various procedures concerning the separation and detection of kavalactones have been routinely carried out by gas chromatography (without previous derivatization of kavalactones) and high performance liquid chromatography but most of them are not validated or only partially validated. Recently, analyses by supercritical fluid chromatography and micellar electrokinetic chromatography have also been reported. Both gas chromatography and high performance liquid chromatography can be used for the analysis of kavalactones with some advantages and disadvantages for each method. Using gas chromatography analysis, methysticin and yangonin, which are two of the major components, are generally not separated. In addition, the high temperature of the injection port caused the decomposition of methysticin. Concerning high performance liquid chromatography analyses, the reversed-phase is generally better because highly reproducible with a very low detection limit for all compounds even if the quantitative analysis of the kavalactones by liquid chromatography needs to be carried out in the absence of light to prevent the cis/trans isomerisation of yangonin.     

Phylogenetic distribution and genetic mapping of a (GGC)n microsatellite from rice (Oryza sativa L.)

DNA microsatellites are ubiquitously present in eukaryotic genomes [30] and represent a vast source of highly informative markers [30, 33, 34, 2]. We describe in this article a (GGC)_n microsatellite which is widely distributed in eukaryotic genomes. Using polymerase chain reaction (PCR) techniques and DNA sequencing, we demonstrated for the first time in plant species that a (GGC)_n microsatellite locus is moderately polymorphic. Six alleles are present at this locus in rice and length polymorphisms are caused by variation in the number of tandem GGC repeats. By scoring a backcross mapping population, we were able to demonstrate that this locus is stably inherited and does not link to any known RFLP markers on the rice RFLP map. Our results suggest that DNA microsatellites should be useful in plants for construction of genetic linkage maps, extension of the existing genetic linkage maps, linkage analysis of disease and pest resistance genes, and the study of population genetics.     

两个棉花Rac蛋白基因的克隆与表达分析

为研究棉花纤维起始和伸长的分子机理,在棉花纤维EST序列分析的基础上,从棉花纤维中扩增并克隆了2个棉花Rac蛋白的cDNA基因,分别命名为GhRacA和GhRacB。GhRacA cDNA长959bp,推测的编码蛋白包含211个氨基酸。GhRacB cDNA长920bp,编码195个氨基酸的蛋白。GhRacA和GhRacB蛋白均含有GTP／GDP结合和激活区域、Effector区和碱性氨基酸区。GhRacB的C末端有保守的异戊烯基化位点CSIL,而GhRacA没有明显的异戊烯基化位点。序列比较分析表明,GhRacA和GhRacB是2个新的棉花Rac蛋白。RT-PCR分析表明,GhRacA和GhRacB在根、下胚轴、茎、叶和纤维中都有表达,但均在棉花纤维起始和伸长时期有优势表达,推测2个基因在棉花纤维的早期发育中可能有重要的功能。