Morphological and molecular characterization of Fusarium spp. associated with Fusarium wilt disease of Piper nigrum L. in Northwestern region of Sarawak

Aims@#Piper nigrum L. (black pepper) is an economically important commodity plant in Malaysia, which generated RM 200.95 million from pepper export in the year of 2018. However, the increase in pepper production is restricted by diseases. Fusarium wilt is one of the major diseases of P. nigrum L. The objectives for this study were to isolate Fusarium spp. associated with Fusarium wilt of P. nigrum L. from selected pepper farms in the northwestern region of Sarawak and to characterize the Fusarium spp. isolated morphologically and molecularly.@*Methodology and results@#Fusarium spp. were isolated from diseased root samples. The pathogen was grown on potato dextrose agar (PDA) under dark condition at circa (ca.) 25 °C for morphological characterisation. Molecular characterisation was done by using internal transcribed spacer (ITS). Phylogenetic tree was constructed to study the genetic relationship of the isolates. Fusarium solani, F. oxysporum, F. proliferatum were the three Fusarium species identified. There were variations in morphological characters observed between and among the species, including the colony form, margin, elevation, surface appearance and pigmentation. No distinctive morphological characteristic was specific to a location. In addition, growth rate, macroconidia sporulation rate, and microconidia sporulation rate of the isolates were not correlated. In molecular phylogeny, the three Fusarium species were separated into three distinct clades representing the three identified species. The genetic relatedness between isolates within each species was depicted in the tree. @*Conclusion, significance and impact of study@#Variations were observed among isolates in this study based on morphological and molecular characterization. This study would contribute information on the variations of Fusarium spp. associated with Fusarium wilt of P. nigrum L. from the northwestern region of Sarawak.

Anti-oxidative Effect of Piperine from Piper nigrum L. in Caenorhabditis elegans

Piper nigrum L. (Piperaceae), which is a well-known food seasoning, has been used as a traditional medicine for the treatment of vomiting, abdominal pain, diarrhea and anorexia in Korea, China and Japan. Methanol extract from the fruit of P. nigrum was successively partitioned as n-hexane, methylene chloride, ethyl acetate, n-butanol and H₂O soluble fractions. Among those fractions the ethyl acetate soluble fraction showed the most potent DPPH radical scavenging activity, and piperine was isolated from the ethyl acetate fraction. To know the antioxidant activity of piperine, we tested the activities of superoxide dismutase (SOD) and catalase together with oxidative stress tolerance and intracellular ROS level in Caenorhabditis elegans. To investigate whether piperine-mediated increased stress tolerance was due to regulation of stress-response gene, we quantified SOD-3 expression using transgenic strain including CF1553. Consequently, piperine enhanced SOD and catalase activities of C. elegans, and reduced intracellular ROS accumulation in a dose–dependent manner. Moreover, piperine-treated CF1553 worms exhibited significantly higher SOD-3::GFP intensity.

Quantification of total phenol, flavonoid content and pharmacognostical evaluation including HPTLC fingerprinting for the standardization of Piper nigrum Linn fruits

Objective: To carry out the physicochemical and phytochemical standardization with high performance thin layer chromatography fingerprinting of Piper nigrum L. (P. nigrum) fruits in order to ascertain the standard pharmacognostical parameters of this king of spices. Methods: Many standardization parameters like extractive values, total ash value, water soluble ash value and acid insoluble ash, moisture content, loss on drying and pH values of P. nigrum L. fruits were analyzed. The method of Harborne was adopted for the preliminary phytochemicals screening. Analysis of total phenolic and flavonoid contents, pesticides residues, aflatoxin and heavy metals were also performed. CAMAG-high performance thin layer chromatography system was used for fingerprinting of methanolic extract of P. nigrum L. fruits. Results: The results of phytochemicals testing indicated the presence of carbohydrates, phenolic compounds, flavonoids, alkaloids, proteins, saponins, lipids, sterols and tannins in various solvent extracts. Total phenolic and flavonoid contents in methanolic extract were found to be 1.728 1 mg/g and 1.087 μg/g, respectively. Heavy metals concentrations were found to be within standard limits. Aflatoxins and pesticides residues were absent. Conclusions: The outcome of this study might prove beneficial in herbal industries for identification, purification and standardization of P. nigrum L. fruits.

Biochemical studies in relation to glutamate dehydrogenase in piper nigrum (L.).

Black pepper, the king of spices, the most important and widely used spice in the world is the dried mature berries of P. nigrum L. Inorganic nitrogen is assimilated into amino acids glutamine, glutamate, asparagines and aspartate which serve as important nitrogen carriers in plants. The enzymes glutamine synthetase (GS) EC. 6.3.1.2, glutamate synthase (GOGAT) E.C. 1.4.1.14, glutamate dehydrogenase (GDH) E.C.1.4.1.4, aspartate aminotransferase and asparagine synthetase are responsible for biosynthesis of these amino acids. Although extensive studies have been carried out on the epidemiology of the diseases and agronomical aspects of P. nigrum, very few studies have been made on the enzymological aspects especially that associated with the nitrogen assimilation. A better understanding of the various properties of the enzyme will be valuable in the future studies concerned with Nitrogen metabolism in P. nigrum. Main objective of present study was to standardize the extraction and study the properties of GDH from P. nigrum L. Effect of additives and its optimum concentration were determined, standardized homogenizing medium was formulated, standardized assay system formulated, different properties like pH optimum, Substrate saturation and km value determined; it’s all in agreement with the previously reported values, result indicate NADP+/NADPH is the better substrate i.e. the enzyme activity is contributed by chloroplastic form of GDH than by the mitochondrial form.

Chemical components of essential oil of Piper nigrum L. and essential oil of Piper betle L. in Nghe An province

Chemical components of essential oil of Piper nigrum L. and essential oil of Piper betle L. were identified by GC/MS method. The main constituents in essential oil of Piper nigrum L. are D-limonene, alpha-pinene, beta-pinene and D3-carene. The main components of essential oil of Piper betle L. are eugenyl acetate or isoeugenyl acetate, alylpyrocatechol diacetate, eugenol or isoeugenol, caryophylen

Determination of Piperine in Root of Piper nigrum L.by HPLC / 中药新药与临床药理

Objective To develop a RP-HPLC method for the determination of piperine in the root of Piper nigrum L.Methods RP-HPLC was carried out on Luna C18 column(250 mm? 4.60 mm,5 ? m) with the column temperature of 35 ℃.The mobile phase consisted of a mixture of methanol-water(77 :23) at a flow rate of 1.0 mL? min-1.The determination wavelength was at 343 nm.Results The calibration curve was linear within the concentration range of 0.164 ? g～ 0.984 ? g,r=0.9996,and the average recovery was 98.09 %,RSD=2.67 %(n=9).The average content of piperine in three batches of pepper roots was in the range of 6.67～6.77mg?g-1.Conclusion Pepper root contains piperine,and this method is suitable for the quality control of the root of Piper nigrum L.