The biosynthesis of the “pyrethrins”

Crowley, M.P.; Godin, Paul; Inglis, H. S.; Snarey, M.; Thain, E. M.

doi:10.1016/0006-3002(62)90406-7

Cited by 29 publications

(5 citation statements)

References 6 publications

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“…6 Tlc on silica gel plate (Merk GF254, 0.5 mm) with benzene-ether mixture (30:1) gave a yellow spot of the hydrazone, which was scraped, eluted with methanol, and measured spectrophotometrically at 382 m i (log e=4.46) with Shimadzu Spectrophotometer QV-50.…”

Section: Methodsmentioning

confidence: 99%

Preparation, Stabilization, and Insecticidal Activity of Cyclodextrin-Inclusion Compounds of Pyrethroids

et al. 1976

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Section: Methodsmentioning

confidence: 99%

Preparation, Stabilization, and Insecticidal Activity of Cyclodextrin-Inclusion Compounds of Pyrethroids

et al. 1976

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“…A Spectrophotometer method has been used to measure the concentration of Pyrethrins in flowers. (Crowley, 1962). The economics of the crop were calculated under different treatments.…”

Section: Methodsmentioning

confidence: 99%

Flower yield potential of Pyrethrum (<em>Chrysanthemum cinerariaefolium</em> L.) under various NPK Levels in the Lower Hills of Uttarakhand, India

Verma,

Kumar,

Kumar

et al. 2023

J Agric Sciences

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Purpose: A favorable environment is available for the cultivation of Pyrethrum in the hilly regions of India, as well as in some mountainous areas of India. In view of the demand for Pyrethrin, it is very necessary to promote the huge cultivation of Pyrethrum. There is no misconception that research work has not been done to promote Pyrethrum, but the data related to the assessment of the right amount of nutrients required for the crop is not available in research related to agrotechnology. If the crop is to be taken as a ratoon crop, then it is very important to estimate the amount of nutrients for single recommendation of crop cultivation. Research Method: A research experiment was conducted in the year 2021 at the CSIR-Central Institute of Medicinal and Aromatic Plant Research, Centre Purara, Bageshwar (Uttarakhand) to study the flower yield potential of Pyrethrum under various NPK levels in the lower hills of Uttarakhand. The experiment was carried out in Complete Randomized Block Design. The six different levels of NPK (kg ha-1) were taken as treatments, i.e., control, 60:60:20, 80:70:30, 100:80:40, 120:90:50, and 150:100:60. Various plant growth and yield parameters considered in the study include plant height (cm), plant diameter (cm), number of flower heads, fresh flower weight plant-1 (g), dry flower weight plant-1(g), fresh flower yield (kg ha-1), dry flower yield (kg ha-1), Pyrethrin concentration (%) and yield (kg ha-1). Findings: Based on the research findings, it seems that the NPK level of 120:90:50 is the best combination to obtain the highest dry flower yield (310.49 kg ha-1) in the lower hills of Uttarakhand. However, the fresh flower weight obtained was the highest under the NPK level of 100:80:40 i.e., 840.47 kg ha-1, but it’s dry flower yield estimated was 301.93 kg ha-1 which was the second highest yield after 310.49 kg ha-1. This could be due to the difference in moisture levels in fresh flowers at the time of harvesting.Research Limitation: Considering the climate of the hilly regions of Uttarakhand, not much work has been done to assess and standardize the proper amount of nutrients required for Pyrethrum crop cultivation, which needs to be done.Originality/ Value: In the hilly areas of Uttarakhand, farmers are interested in the cultivation of Pyrethrum, but if farmers will adopt this crop cultivation as a ratoon crop, then in such a situation it is absolutely necessary to assess the proper amount of nutrients. This research will prove helpful in promoting the cultivation of Pyrethrum in the hilly areas of Uttarakhand.

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“…Although there has been little experimental verification of any biosynthetic pathway, the available data2 coupled with biogenetic analogies to presqualene alcohol and the known chemical3 interconversions of the chrysanthemyl carbon skeleton with other non-headto-tail monoterpene carbon skeletons have led to a unified hypothesis for the biosynthesis of these compounds.4 This hypothesis requires (17?,37? )-chrysanthemyl pyrophosphate (1, R = pyrophosphate) as a key intermediate in the formation of the chrysanthemyl (2), artemesyl (3), and santolinyl (4) types of irregular monoterpenes. With the ubiquitous occurrence of phosphatases in plants, it might be expected that any plants producing 1 (R = pyrophosphate) would also have the corresponding alcohol, (17?,37?…”

Section: References and Notesmentioning

confidence: 99%

Reaction of singlet oxygen with conformationally fixed cyclohexylidenecyclohexanes. Failure of an all suprafacial mechanism

Kellogg¹,

Kaiser²

1975

J. Org. Chem.

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The biosynthesis of the “pyrethrins”

Cited by 29 publications

References 6 publications

Preparation, Stabilization, and Insecticidal Activity of Cyclodextrin-Inclusion Compounds of Pyrethroids

Preparation, Stabilization, and Insecticidal Activity of Cyclodextrin-Inclusion Compounds of Pyrethroids

Flower yield potential of Pyrethrum (<em>Chrysanthemum cinerariaefolium</em> L.) under various NPK Levels in the Lower Hills of Uttarakhand, India

Reaction of singlet oxygen with conformationally fixed cyclohexylidenecyclohexanes. Failure of an all suprafacial mechanism

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