NEMATICIDAL EFFICACY OF SUBSTITUTED PHENOLS, PHENOXYACETIC ACID ESTERS AND HYDRAZIDES: A
STRUCTURE-ACTIVITY RELATIONSHIP STUDY BY MANGEL S. MALIK1), VIJAY PAL1), NARESH K.
SANGWAN1), KULDIP SINGH DHINDSA1), K.K. VERMA2) and D. S. BHATTI2) 1) Department of
Chemistry and Biochemistry; 2
development in adult and larval tissues (Canavoso et al., 2001; Bier, 2005; Bross et al., 2005; Birse et al., 2010; Ecker et al., 2017).
Olea europaea L. is among the plants that have medicinal value and are used as an alternative medicine. Olive phenols, which are used for many different purposes, are
. Phenolic diterpenes, flavones, and rosmarinic acid distribution during the development of leaves, flowers, stems, and roots of Rosmarinus officinalis. Antioxidant activity. J. Agr. Food Chem. 51: 4247-4253.
Dorman, H.J.D., Peltoketo, A., Hiltunen, R., Tikkanen, M.J. 2003. Characterization of the
Plants produce more than 100 000 diverse, low molecular weight, secondary metabolites (Dixon, 2001 ). Secondary metabolites play a major role in plants’ interaction with the environment, ensuring successful adaptation and survival (Verpoorte, 2000 ). Phenolic secondary metabolites such as
Dudai, D., Segev D., Havkin-Frenkel D., Eshel, A. 2006. Genetic variation of phenolic compounds content, essential oil composition and antioxidative activity in Israel-grown Mentha longifolia L. In: Proceedings of the 1 st International Symposium on Natural Preservatives in Food
. Recent changes in the climate at the Dead Sea-a preliminary study. Climatic Change 37: 513-537.
Arora, A., Sairam, R.K., Srivastava, G.C. 2002. Oxidative stress and antioxidative system in plants. Current Science 82: 1227-1238.
Balasundram, N., Sundram, K., Samman, S. 2006. Phenolic
Chemical elicitors, namely salicylic acid (SA), β-amino butyric acid (BABA), chitosan (CHT) and 2,6-dicholoroisonicotinic acid (INA), are known to play a role in the induction of plant resistance to pathogens by increasing the activity of enzymes of phenolic synthesis pathways such as peroxidase, polyphenol oxidase and phenyl alanine ammonia lyase. These chemical elicitors applied to tomato as an 8 h seed treatment, 2 h seedling treatment and seed plus seedling treatment increased the activity of peroxidase, polyphenol oxidase and phenyl alanine ammonia lyase. The highest increase in peroxidase and phenyl alanine ammonia lyase activity was induced by the seed plus seedling treatment with 15 mM β-amino butyric acid. The increase in these enzyme activities was 70.5% and 39.3% higher, respectively, over control, whereas the highest increase in polyphenol oxidase activity was induced by the seed plus seedling treatment with 1.5 mM salicylic acid. Polyphenol oxidase activity increased 137.9% compared to the non-treated control. Similarly, seed treatment as well as seedling treatment with the elicitors particularly salicylic acid, β-amino butyric acid and chitosan elicited increased activity of peroxidase, polyphenol oxidase and phenyl alanine ammonia lyase of the phenolic syntheses pathways, which are known to be the basic components of the resistance induction mechanism.
EFFECT OF PHENOLICS AND AN AROMATIC ACID ON MELOIDOGYNE JAV ANICA INFECTING TOMATO BY K. SITARAMAIAH and K. N. PATHAK Department of Plant Pathology, G. B. Pant University of Agriculture and Technology, Pantnagar-263145, India Cinnamic acid, catechol and salicylic acid when applied as soil
The present study was conducted to determine the morphogenetic and phenologic variations in the content of the main bioactive compounds in Hypericum leptophyllum Hochst., an endemic species from Turkish flora. Wild plants were harvested at five phenological stages: vegetative, floral budding, full flowering, fresh fruiting, and mature fruiting, and assayed for chemical content by HPLC. Results indicated that H. leptophyllum did not accumulate hypericin, pseudohypericin, hyperforin, and adhyperforin. The phenolic content in whole plants increased generally during plant phenology and higher accumulation levels were observed at flowering. Among the reproductive organs, amentoflavone, quercetin, avicularin, and hyperoside contents were the highest in floral buds (2.09, 2.18, 0.55, and 2.62 mg g−1 dry mass (DM), respectively). Leaves harvested at the floral budding stage produced the highest content of chlorogenic acid, neochlorogenic acid, caffeic acid, and isoquercetin (53.32, 6.25, 0.03, and 1.91 mg g−1 DM, respectively), while leaves of plants at the vegetative stage of plant development accumulated the highest content of 2,4-dihydroxybenzoic acid and quercitrin (0.29 and 0.54 mg g–1 DM, respectively). This is the first report of the presence of avicularin, rutin, (+)-catechin, (–)-epicatechin, amentoflavone, caffeic acid, neochlorogenic acid, and 2,4-dihydroxybenzoic acid in this species. Such data could be useful for the evaluation of new sources of bioactive compounds, as well as for increasing phytotaxonomic knowledge for the poorly studied Hypericum species.
Although there is considerable information on the chemistry of bordered intervessel pit membranes, little is known on the pit membrane chemistry of other pit types in hardwoods. This study investigated distribution of phenolic compounds, pectins and hemicelluloses in different mature pit membranes of English oak xylem using transmission electron microscopy coupled with cytochemistry and immunocytochemistry. Mature bordered intertracheid (vasicentric)- and tracheid-vessel pits showed presence of xyloglucan and heteromannan (hemicelluloses) epitopes across the pit membrane (except for the annulus regions) with differences in amounts of epitopes between earlywood (EW) and latewood (LW). In contrast, pectin epitopes were detected only in the annulus regions of pit membranes. Unlike bordered pits, half-bordered (tracheary-parenchyma pits) and simple (parenchyma pits) pit membranes were rich in pectin epitopes but lacked heteromannan epitopes, indicating difference in pit membrane chemistry between pit types. Distribution of phenolic compounds also differed between pit types and between EW and LW. LW also showed great variations in distribution of phenolic compounds between vessels. Together, this study demonstrates that there are great variations in pit membrane chemistry between pit types and between EW and LW in English oak xylem.