@article {42999, title = {Comparative functional characterization of eugenol synthase from four different ocimum species: implications on eugenol accumulation}, journal = {Biochimica Et Biophysica Acta-Proteins and Proteomics}, volume = {1864}, year = {2016}, month = {NOV}, pages = {1539-1547}, abstract = {

Isoprenoids and phenylpropanoids are the major secondary metabolite constituents in Ocimum genus. Though enzymes from phenylpropanoid pathway have been characterized from few plants, limited information exists on how they modulate levels of secondary metabolites. Here, we performed phenylpropanoid profiling in different tissues from five Ocimum species, which revealed significant variations in secondary metabolites including eugenol, eugenol methyl ether, estragole and methyl cinnamate levels. Expression analysis of eugenol synthase (EGS) gene showed higher transcript levels especially in young leaves and inflorescence; and were positively correlated with eugenol contents. Additionally, transcript levels of coniferyl alcohol acyl transferase, a key enzyme diverting pool of substrate to phenylpropanoids, were in accordance with their abundance in respective species. In particular, eugenol methyl transferase expression positively correlated with higher levels of eugenol methyl ether in Ocimum tenuiflorum. Further, EGSs were functionally characterized from four Ocimum species varying in their eugenol contents. Kinetic and expression analyses indicated, higher enzyme turnover and transcripts levels, in species accumulating more eugenol. Moreover, biochemical and bioinformatics studies demonstrated that coniferyl acetate was the preferred substrate over coumaryl acetate when used, individually or together, in the enzyme assay. Overall, this study revealed the preliminary evidence for varied accumulation of eugenol and its abundance over chavicol in these Ocimum species. Current findings could potentially provide novel insights for metabolic modulations in medicinal and aromatic plants. (C) 2016 Elsevier B.V. All rights reserved.

}, doi = {10.1016/j.bbapap.2016.08.004}, author = {Anand, Atul and Jayaramaiah, Ramesha H. and Beedkar, Supriya D. and Singh, Priyanka A. and Joshi, Rakesh S. and Mulani, Fayaj A. and Dholakia, Bhushan B. and Punekar, Sachin A. and Gade, Wasudeo N. and Thulasiram, Hirekodathakallu V. and Giri, Ashok P.} } @article { ISI:000374800700041, title = {Functional characterization and transient expression manipulation of a new sesquiterpene synthase involved in beta-caryophyllene accumulation in Ocimum}, journal = {Biochemical And Biophysical Research Communications}, volume = {473}, number = {1}, year = {2016}, month = {APR}, pages = {265-271}, publisher = {ACADEMIC PRESS INC ELSEVIER SCIENCE}, address = {525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA}, abstract = {

The genus Ocimum has a unique blend of diverse secondary metabolites, with major proportion of terpenoids including mono- and sesquiterpenes. Although, beta-Caryophyllene, bicyclic sesquiterpene, is one of the major terpene found in Ocimum species and known to possess several biological activities, not much is known about its biosynthesis in Ocimum. Here, we describe isolation and characterization of beta-caryophyllene synthase gene from Ocimum kilimandscharicum Gurke (OkBCS- GenBank accession no. KP226502). The open reading frame of 1629 bp encoded a protein of 542 amino acids with molecular mass of 63.6 kDa and pl value of 5.66. The deduced amino acid sequence revealed 50-70\% similarity with known sesquiterpene synthases from angiosperms. Recombinant OkBCS converted farnesyl diphosphate to beta-caryophyllene as a major product (94\%) and 6\% alpha-humulene. Expression variation of OkBCS well corroborated with beta-caryophyllene levels in different tissues from five Ocimum species. OkBCS transcript revealed higher expression in leaves and flowers. Further, agro-infiltration based transient expression manipulation with OkBCS over-expression and silencing confirmed its role in beta-caryophyllene biosynthesis. These findings may potentially be further utilized to improve plant defense against insect pests. (C) 2016 Elsevier Inc. All rights reserved.

}, keywords = {beta-Caryophyllene, Natural product biosynthesis, Ocimum, Terpene synthase, Transient expression}, issn = {0006-291X}, doi = {10.1016/j.bbrc.2016.03.090}, author = {Jayaramaiah, Ramesha H. and Anand, Atul and Beedkar, Supriya D. and Dholakia, Shushan B. and Punekar, Sachin A. and Kalunke, Raviraj M. and Gade, Wasudeo N. and Thulasiram, Hirekodathakallu V. and Giri, Ashok P.} } @article { ISI:000368189500001, title = {Potential dual role of eugenol in inhibiting advanced glycation end products in diabetes: proteomic and mechanistic insights}, journal = {Scientific Reports}, volume = {6}, year = {2016}, month = {JAN}, publisher = {NATURE PUBLISHING GROUP}, address = {MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND}, abstract = {

Medicinally important genus Ocimum harbors a vast pool of chemically diverse metabolites. Current study aims at identifying anti-diabetic candidate compounds from Ocimum species. Major metabolites in O. kilimandscharicum, O. tenuiflorum, O. gratissimum were purified, characterized and evaluated for anti-glycation activity. In vitro inhibition of advanced glycation end products (AGEs) by eugenol was found to be highest. Preliminary biophysical analysis and blind docking studies to understand eugenol-albumin interaction indicated eugenol to possess strong binding affinity for surface exposed lysines. However, binding of eugenol to bovine serum albumin (BSA) did not result in significant change in secondary structure of protein. In vivo diabetic mice model studies with eugenol showed reduction in blood glucose levels by 38\% likely due to inhibition of alpha-glucosidase while insulin and glycated hemoglobin levels remain unchanged. Western blotting using anti-AGE antibody and mass spectrometry detected notably fewer AGE modified peptides upon eugenol treatment both in vivo and in vitro. Histopathological examination revealed comparatively lesser lesions in eugenol-treated mice. Thus, we propose eugenol has dual mode of action in combating diabetes; it lowers blood glucose by inhibiting a-glucosidase and prevents AGE formation by binding to epsilon-amine group on lysine, protecting it from glycation, offering potential use in diabetic management.

}, issn = {2045-2322}, doi = {10.1038/srep18798}, author = {Singh, Priyanka and Jayaramaiah, Ramesha H. and Agawane, Sachin B. and Vannuruswamy, Garikapati and Korwar, Arvind M. and Anand, Atul and Dhaygude, Vitthal S. and Shaikh, Mahemud L. and Joshi, Rakesh S. and Boppana, Ramanamurthy and Kulkarni, Mahesh J. and Thulasiram, Hirekodathakallu V. and Giri, Ashok P.} } @article {45524, title = {Terpene profiling, transcriptome analysis and characterization of cis{\textendash}terpineol synthase from Ocimum}, journal = {Physiology and Molecular Biology of Plants}, volume = {25}, year = {2019}, month = {JAN}, pages = {47-57}, type = {Article}, abstract = {

Ocimum species produces a varied mix of different metabolites that imparts immense medicinal properties. To explore this chemo-diversity, we initially carried out metabolite profiling of different tissues of five Ocimum species and identified the major terpenes. This analysis broadly classified these five Ocimum species into two distinct chemotypes namely, phenylpropanoid-rich and terpene-rich. In particular, -caryophyllene, myrcene, limonene, camphor, borneol and selinene were major terpenes present in these Ocimum species. Subsequently, transcriptomic analysis of pooled RNA samples from different tissues of Ocimum gratissimum, O. tenuiflorum and O. kilimandscharicum identified 38 unique transcripts of terpene synthase (TPS) gene family. Full-length gene cloning, followed by sequencing and phylogenetic analysis of three TPS transcripts were carried out along with their expression in various tissues. Terpenoid metabolite and expression profiling of candidate TPS genes in various tissues of Ocimum species revealed spatial variances. Further, putative TPS contig 19414 (TPS1) was selected to corroborate its role in terpene biosynthesis. Agrobacterium-mediated transient over-expression assay of TPS1 in the leaves of O. kilimandscharicum and subsequent metabolic and gene expression analyses indicated it as a cis{\textendash}terpineol synthase. Overall, present study provided deeper understanding of terpene diversity in Ocimum species and might help in the enhancement of their terpene content through advanced biotechnological approaches.

}, keywords = {Agro-infiltration assay, Metabolite profiling, Ocimum, Terpene synthase, Terpenes, Transcriptome}, issn = {0971-5894}, doi = {10.1007/s12298-018-0612-6}, author = {Anand, Atul and Jayaramaiah, Ramesha H. and Beedkar, Supriya D. and Dholakia, Bhushan B. and Lavhale, Santosh G. and Punekar, Sachin A. and Gade, Wasudeo N. and Thulasiram, Hirekodathakallu V. and Giri, Ashok P.} }