Photodegradation of avermectin B1a thin films on glass

Crouch, Louis S.; Feely, William F.; Arison, Byron H.; Vandenheuvel, W.J.A.; Colwell, Lawrence F.; Stearns, Ralph A.; Kline, Walter F.; Wislocki, Peter G.

doi:10.1021/jf00007a024

Cited by 52 publications

(36 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Most of these unknown abamectin residues in crops are quite polar relative to B1A when assayed by reverse-phase HPLC (Moye et al, 1990;Crouch, unpublished results). In addition, avermectin BI, is entirely degraded to polar residues after photolysis of thin films for 1 day or longer (Crouch et al, 1991). Since these unknown polar abamectin degradates in crops have not been identified, the present studies describe the isolation and toxicological testing of these residues en masse from citrus.…”

Section: Introductionmentioning

confidence: 93%

Nontoxicity of polar abamectin degradates from citrus fruit and thin film photolysis

Crouch¹,

Gordon²,

Feely³

et al. 1992

J. Agric. Food Chem.

Self Cite

View full text Add to dashboard Cite

After application to crops, abamectin (avermectin BI, plus avermectin Bib) degrades largely to a polar residue of unknown identity. Such polar degradates are also formed after photolysis of abamectin as a thin film on glass for approximately 1 day. To establish the safety of these residues, polar abamectin degradates were isolated from oranges treated with abamectin in the field and after photolysis of thin films on glass. These degradates were tested and found to have no adverse maternal or developmental effects in the CF1 mouse, the laboratory speciedstrain most sensitive to abamectin toxicity. In addition, the degradates from photolysis of thin films were negative in the microbial mutagenesis assay.

show abstract

Section: Introductionmentioning

confidence: 93%

Nontoxicity of polar abamectin degradates from citrus fruit and thin film photolysis

Crouch¹,

Gordon²,

Feely³

et al. 1992

J. Agric. Food Chem.

Self Cite

View full text Add to dashboard Cite

show abstract

“…The photolytic behavior of avermectin in Av-MAC-SDS was evaluated by the thin-film method described in reference [14], with free avermectin as a control. Ten mL of the methanol suspension of Av-MAC-SDS was placed in several uncovered glass Petri dishes and dried in air at room temperature to form thin films.…”

Section: Photolysis Experiments Of Avermectin In Av-mac-sdsmentioning

confidence: 99%

Properties of Avermectin Delivery System Using Surfactant-Modified Mesoporous Activated Carbon as a Carrier

Sun

Wang

Zhao

et al. 2018

Journal of Nanomaterials

View full text Add to dashboard Cite

The sensitivity of avermectin to several environmental factors, especially light, causes low pesticidal activity and environmental pollution. In this study, surfactant-modified mesoporous activated carbon (MAC) was employed to absorb avermectin (Av) in order to improve its photostability and allow for sustained release of avermectin. The results suggest that sodium dodecyl sulfate (SDS) modified MAC has excellent absorption of avermectin, and the absorption can be represented by the Langmuir isotherm model. The Av-MAC-SDS delivery system significantly improves sustained release of avermectin and also effectively inhibits the photodegradation of avermectin. These results indicate that SDS-modified MAC can be used as a carrier for avermectin to improve its pesticidal activity and reduce pesticide residues.

show abstract

“…56) A thin film of ABM B1a degrades with half-life of 4-6 h in sunlight, producing two optical isomers (mainly 8,9-Z) and several de-alkylated derivatives. 57) Therefore, use of light resistant container for storage of avermectin drugs and drug products, as well as utilizing low actinic glassware during the analysis, are considered as the best approach to avoid the photo-degradation.…”

Section: )mentioning

confidence: 99%

An Overview on Chemical Derivatization and Stability Aspects of Selected Avermectin Derivatives

Awasthi

Razzak

Al‐Kassas

et al. 2012

CHEMICAL & PHARMACEUTICAL BULLETIN

View full text Add to dashboard Cite

Naturally occurring avermectins (AVMs) and its derivatives are potent endectocide compounds, wellknown for their novel mode of action against a broad range of nematode and anthropod animal parasites. In this review, chemical and pharmaceutical aspects of AVM derivatives are described including stability, synthetic and purification processes, impurities and degradation pathways, and subsequent suggestions are made to improve the chemical stability. It has been found out that unique structure of AVM molecules and presence of labile groups facilitated the derivatization of AVM into various compounds showing strong anthelmintic activity. However, the same unique structure is also responsible for labile nature related to sensitive stability profile of molecules. AVMs are found to be unstable in acidic and alkaline conditions. In addition, these compounds are sensitive to strong light, and subsequently presence of photo-isomer in animals treated topically with AVM product is well known. The pharmacoepial recommendations for addition of antioxidant into drug substance, as well as its products, arises from the fact that AVM are very sensitive to oxidation. Formations of solvates, salts, epoxides, reduction of double bonds and developing liquid formulation around pH 6.2, were some chemical approaches used to retard the degradation in AVM. This coherent review will contribute towards the better understanding of the correlation of chemical processes, stability profile and biological activity; therefore, it will help to design the shelf-life stable formulations containing AVMs.

show abstract

Photodegradation of avermectin B1a thin films on glass

Cited by 52 publications

References 12 publications

Nontoxicity of polar abamectin degradates from citrus fruit and thin film photolysis

Nontoxicity of polar abamectin degradates from citrus fruit and thin film photolysis

Properties of Avermectin Delivery System Using Surfactant-Modified Mesoporous Activated Carbon as a Carrier

An Overview on Chemical Derivatization and Stability Aspects of Selected Avermectin Derivatives

Contact Info

Product

Resources

About