Milbemycins are 16-membered macrolide antibiotic insecticides, acaricides, and anthelmintics isolated from Streptomyces fermentation products. It is mainly used to control different types of pests such as mites, leafminers, aphids and whiteflies, and is effective in all growth and development stages of pests. This type of compound has the characteristics of novel structure, unique mechanism of action, broad-spectrum biological activity, low effective dose, easy degradation, and high safety.
Since the first successful commercialization of mibamycin A3/A4, mibamycins have developed rapidly as pesticides. In particular, the successful launch of Lepimectin reflects the bright future of research on mibamycin insecticides and repellents. The U.S. Environmental Protection Agency considers it a low-risk pesticide, and the Netherlands approves it as a "GNO" (natural product in crop production). It can be said that Mibamycin is one of the best acaricides in the world today. It has become a very popular insecticide and acaricide in developed countries and has been registered in 43 countries and regions including the United States and Japan.
01 Product Introduction
Product name: Milbemectin
Other name: Milbemycin A3-milbemycin A4 mixt
Chemical name: (1R,4S,5'S,6R,6'R,8R,10E,13R,14E,16E,20R,21R,24S)-21,24-dihydroxy-5',6',11,13, 22-pentamethylspiro[3,7,19-trioxacyclo[15.6.1.14,8.020,24]bipenta-10,14,16,22-tetraene-6,2'-oxacyclohexane]-2-one -(1R,4S,5'S,6R,6'R,8R,10E,13R,14E,16E,20R,21R,24S)-6'-ethyl-21,24-dihydroxy-5',11,13 ,22-tetramethylspiro[3,7,19-trioxacyclo[15.6.1.14,8.020,24]
Twenty-five-10,14,16,22-tetraene-6,2'-oxan]-2-one
Molecular formula: C63H90O14; C31H44O7(Ⅰ) · C32H46O7(Ⅱ)
Relative molecular mass: 1071.380; 528.677 (Ⅰ) · 542.703 (Ⅱ)
CAS NO.: 1799297-76-9. 51596-10-2 (Ⅰ); 51596-11-3 (Ⅱ)
Structural formula:
Physical and chemical properties: The pure product is white powder.
Melting point: A3 212~215℃, A4 212~215℃.
Relative density﹙25℃﹚: A3 1.1270, A4 1.265.
Vapor pressure (25℃): A3<1.3×10-8Pa, A4<1.3×10-8 Pa.
Partition coefficients: A3lgP = 5.3, A4lgP = 5.9.
Henry's constant <9.93×10-4Pa·m3/mol.
Solubility (20℃): A3, water 0.88mg/L,
Organic solvent (g/L): methanol 64.8, ethanol 41.9, acetone 66.1, ethyl acetate 69.5, benzene 143.1, n-hexane 1.4, A4, water 7.2 mg/L.
02 Mechanism of action
The principle of action of Mibamycin is different from the anthelmintic effects of contact and intravasation types. It does not inhibit protein synthesis, but blocks the transmission of signals from the parasite's central nervous system to motor neurons by stimulating 2-aminobutyric acid (GABA), causing paralysis and death outside the body.
The main difference between invertebrates and mammals is that in mammals GABA is only in the central nervous system, while invertebrates are in the muscles. Therefore, if it does not reach the brain through the blood, it is safe for mammals. It can replace organophosphorus, carbamate, pyrethroid and organochlorine compounds currently used in crop protection.
Mibamycin is effective against pests at all growth stages. Its mode of action is contact killing and gastric killing. Although it has poor systemic properties, it has good conductive activity. It is safe for crops, has little impact on arthropods, and has no cross-resistance with existing acaricides. It is an ideal choice for comprehensive pest control and reducing the risk of resistance.
03 Application
Applicable crops: apples, asparagus, adzuki beans, celery, cabbage, cherries, citrus, cotton, cucumbers, eggplants, currants, melons, ornamental plants, papaya, parsley, peaches, pears, strawberries, tea, tomatoes, grapes , watermelon and yam, etc.
Control objects: Cinnabar spider mite, two-spotted leaf moth, Kanzawa spider mite, citrus spider mite, apple spider mite, citrus rust tick, aphids, whitefly, whitefly, and spotted leafminer. Also effective against nematodes such as pine wood nematode.
Common dosage forms: 1% EC, 1% WP.
Application Technique: Effective against all stages of pests. Its activity is similar to that of abamectin, but its toxicity is low and it is safer than abamectin.
Instructions for use: The recommended dosage of mebamycin worldwide is 5.6~28g/hm2. 1% EC is used to control spider mites, 1kg per hectare, diluted 1000 times, applied when harmful mites occur, and stopped 6 days before harvesting. 1% EC is used to control citrus spider mites. Use 1.3kg per hectare and dilute it 1500 times. When the pest density reaches 5 per leaf, apply once and stop applying 6 days before harvesting. 1% EC is used to control two-spotted spider mites in pear. Apply 0.6 to 0.8kg per hectare and dilute 1500 times. Apply once when leaf moth occurs, and then apply again every 14 days. Stop applying 6 days before receiving. 1% EC is used to control jujube ring spot. Use 0.6 to 0.8kg per hectare, dilute 1500 times, apply once when spider mites occur, and stop applying 6 days before harvesting. 1% EC is used to control aphids in cruciferous vegetables. Use 0.5~0.7kg per hectare and dilute 1500 times. Apply once when pests occur, and then apply again every 7 days. Stop applying 6 days before receiving. 1% EC is used to control two-spotted spider mites on peach. Apply 2kg per hectare and dilute 1000 times. Apply once when the pest occurs and stop applying 15 days before receiving.
04 Synthesis situation
The specific synthesis route is as follows:
05 Market Outlook
Mibamycin has a strong effect, a small dosage, is safe to humans, non-toxic, and does not pollute the environment. It kills pests, does not kill natural enemies of pests, and is not easy to develop resistance. It can be used as a compound or rotation drug to prevent the development of resistance to this type of drug. It is currently the most promising broad-spectrum, efficient, new, insect-resistant, and non-cross-resistance biological pesticide.
Source: AgroPages
