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R. S. Bhakuni

Bio: R. S. Bhakuni is an academic researcher from Central Institute of Medicinal and Aromatic Plants. The author has contributed to research in topics: Essential oil & Nerolidol. The author has an hindex of 2, co-authored 2 publications receiving 46 citations.
Topics: Essential oil, Nerolidol, Pyrethrum, Guaiol

Papers
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Journal Article
TL;DR: The present review summarizes information available on the secondary metabolites isolated from Chrysanthemum genus and some of the biologically active secondary metabolites and pyrethroids are responsible for the insecticidal activity of the well known plant species Chrysanthesis cinerariaefolium.
Abstract: Chrysanthemum genus synthesizes and accumulates a variety of secondary metabolites. Some of the biologically active secondary metabolites and pyrethroids are responsible for the insecticidal activity of the well known plant species Chrysanthemum cinerariaefolium. The present review summarizes information available on the secondary metabolites isolated from Chrysanthemum genus.

47 citations

Journal ArticleDOI
TL;DR: The hydrodistilled oil obtained from the dried pyrethrum flowers was subjected to high resolution GC and GC-MS, leading to the quantification and identification of twenty two compounds representing (85.27%) of the total oil.
Abstract: The hydrodistilled oil obtained from the dried pyrethrum flowers (Chrysanthemum cinerariaefolium) was subjected to high resolution GC and GC-MS, leading to the quantification and identification of twenty two compounds representing (85.27%) of the total oil. trans-chrysanthemumic acid (19.61%), decanoic acid (7.63%), nerolidol (9.63%), spathulenol (4.58%), guaiol (5.93%), β-eudesmol (9.81%) and α-eudesmol (7.07%) were the major compounds. The oil of Indian species is uniquely different from the oil obtained from pyrethrum of Kenya’s origin.

2 citations


Cited by
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Journal ArticleDOI
TL;DR: An overview of current status of research on sesame lignans with respect to the analytical methods employed, the biological activities and biosynthesis of sesamol is presented.

140 citations

Journal ArticleDOI
31 May 2013-PLOS ONE
TL;DR: It is shown that germacratrien-12-oic acid is most likely the central precursor for all sesquiterpene lactones present in pyrethrum, and candidate genes implicated in three committed steps leading from farnesyl diphosphate to STL and other oxygenated derivatives of germacRatrien- 12-Oic acid were retrieved from a pyrethum trichome EST library, cloned, and characterized in yeast and in planta.
Abstract: The daisy-like flowers of pyrethrum (Tanacetum cinerariifolium) are used to extract pyrethrins, a botanical insecticide with a long history of safe and effective use. Pyrethrum flowers also contain other potential defense compounds, particularly sesquiterpene lactones (STLs), which represent problematic allergenic residues in the extracts that are removed by the pyrethrum industry. The STLs are stored in glandular trichomes present on the pyrethrum achenes, and have been shown to be active against herbivores, micro-organisms and in the below-ground competition with other plants. Despite these reported bioactivities and industrial significance, the biosynthetic origin of pyrethrum sesquiterpene lactones remains unknown. In the present study, we show that germacratrien-12-oic acid is most likely the central precursor for all sesquiterpene lactones present in pyrethrum. The formation of the lactone ring depends on the regio- (C6 or C8) and stereo-selective (α or β) hydroxylation of germacratrien-12-oic acid. Candidate genes implicated in three committed steps leading from farnesyl diphosphate to STL and other oxygenated derivatives of germacratrien-12-oic acid were retrieved from a pyrethrum trichome EST library, cloned, and characterized in yeast and in planta. The diversity and distribution of sesquiterpene lactones in different tissues and the correlation with the expression of these genes are shown and discussed.

59 citations

Journal ArticleDOI
TL;DR: The results suggest that the synthesized Ag NPs have the potential to be used as an ideal eco-friendly approach for the control of A. stephensi mosquito species from the geographical location of India.
Abstract: Mosquitoes transmit serious human diseases, causing millions of deaths every year. The use of synthetic insecticides to control vector mosquitoes has caused physiological resistance and adverse environmental effects in addition to high operational cost. Insecticides synthesized of natural products for vector con- trol have been a priority in this area. In the present study, silver nanoparticles (Ag NPs) were green-synthesized using a floral extract of Chrysanthemum indicum screened for larvicidal and pupicidal activity against the first to fourth instar larvae and pupae of the malaria vector Anopheles stephensi mosquitoes. The synthesized Ag NPs were characterized by using UV-vis absorption, X-ray diffraction, transmission electron microscopy, and energy-dispersive X-ray spectroscopy techniques. The tex- tures of the yielded Ag NPs were found to be spherical and polydispersed with a mean size in the range of 25-59 nm. Larvae and pupae were exposed to various concentrations of aqueous extract of C. indicum and synthesized Ag NPs for 24 h, and the maximum mortality was observed from the synthesized Ag NPs against the vector A. stephensi (LC50=5.07, 10.35, 14.19, 22.81, and 35.05 ppm; LC90=29.18, 47.15, 65.53, 87.96, and

58 citations

Journal ArticleDOI
TL;DR: The findings demonstrate that plant glandular trichomes can selectively secrete in a basipetal direction monoterpenoids, which can reach distant tissues, participate in chemical conversions, and immunize seedlings against insects and fungi.
Abstract: Glandular trichomes are currently known only to store mono- and sesquiterpene compounds in the subcuticular cavity just above the apical cells of trichomes or emit them into the headspace. We demonstrate that basipetal secretions can also occur, by addressing the organization of the biosynthesis and storage of pyrethrins in pyrethrum (Tanacetum cinerariifolium) flowers. Pyrethrum produces a diverse array of pyrethrins and sesquiterpene lactones for plant defense. The highest concentrations accumulate in the flower achenes, which are densely covered by glandular trichomes. The trichomes of mature achenes contain sesquiterpene lactones and other secondary metabolites, but no pyrethrins. However, during achene maturation, the key pyrethrin biosynthetic pathway enzyme chrysanthemyl diphosphate synthase is expressed only in glandular trichomes. We show evidence that chrysanthemic acid is translocated from trichomes to pericarp, where it is esterified into pyrethrins that accumulate in intercellular spaces. During seed maturation, pyrethrins are then absorbed by the embryo, and during seed germination, the embryo-stored pyrethrins are recruited by seedling tissues, which, for lack of trichomes, cannot produce pyrethrins themselves. The findings demonstrate that plant glandular trichomes can selectively secrete in a basipetal direction monoterpenoids, which can reach distant tissues, participate in chemical conversions, and immunize seedlings against insects and fungi.

57 citations

Journal ArticleDOI
TL;DR: A new endoperoxysesquiterpene lactone, 10α-hydroxy-1α,4α-endoperoxy-guaia-2-en-12,6α-olide (1 ), together with a flavanone, eriodictyol (2 ), and two flavone glycosides, acacetin-7- O -β- d -glucopyranoside (3 ) and acacetIN-7 O -α- l -rhamopyranoide (4 ), were isolated from the

44 citations