Azadirachtin

Source: Wikipedia, the free encyclopedia.
Azadirachtin
Names
Preferred IUPAC name
Dimethyl (2aR,2a1R,3S,4S,4aR,5S,7aS,8S,10R,10aS)-10-(acetyloxy)-3,5-dihydroxy-4-[(1aR,2S,3aS,6aS,7S,7aS)-6a-hydroxy-7a-methyl-3a,6a,7,7a-tetrahydro-2,7-methanofuro[2,3-b]oxireno[2,3-e]oxepin-1a(2H)-yl]-4-methyl-8-{[(2E)-2-methylbut-2-enoyl]oxy}octahydro-1H,7H-naphtho[1,8-bc:4,4a-c′]difuran-5,10a(8H)-dicarboxylate
Identifiers
3D model (
JSmol
)
ChEBI
ChemSpider
ECHA InfoCard
 100.115.924 Edit this at Wikidata
KEGG
UNII
  • InChI=1S/C35H44O16/c1-8-15(2)24(38)49-18-12-19(48-16(3)36)32(26(39)43-6)13-46-21-22(32)31(18)14-47-34(42,27(40)44-7)25(31)29(4,23(21)37)35-20-11-17(30(35,5)51-35)33(41)9-10-45-28(33)50-20/h8-10,17-23,25,28,37,41-42H,11-14H2,1-7H3/b15-8+/t17-,18+,19-,20+,21-,22-,23-,25+,28+,29-,30+,31+,32+,33+,34+,35+/m1/s1 checkY
    Key: FTNJWQUOZFUQQJ-NDAWSKJSSA-N checkY
  • O=C(OC)[C@@]1(O)OC[C@]82[C@@H](OC(=O)/C(=C/C)C)C[C@@H](OC(=O)C)[C@@]7(C(=O)OC)CO[C@@H]([C@@H](O)[C@](C)([C@H]12)[C@]64O[C@]6([C@@H]3[C@@]5(O)/C=C\O[C@H]5O[C@H]4C3)C)[C@@H]78
Properties
C35H44O16
Molar mass 720.721 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

Azadirachtin, a

carboxylic esters
.

Chemical synthesis

Azadirachtin has a complex molecular structure; it presents both secondary and tertiary hydroxyl groups and a

molecular structure, alongside 16 stereogenic centres, 7 of which are tetrasubstituted. These characteristics explain the great difficulty encountered when trying to prepare this compound from simple precursors, using methods of synthetic organic chemistry
.

Hence, the first total synthesis was published over 22 years after the compound's discovery: this first synthesis was completed by the research group of

Steven Ley at the University of Cambridge in 2007.[1][2] The described synthesis was a relay approach, with the required, heavily functionalized decalin
intermediate being made by total synthesis on a small scale, but being derived from the natural product itself for the gram-scale operations required to complete the synthesis.

Occurrence and use

Initially found to be active as a feeding inhibitor towards the

mammals (the LD50
in rats is > 3,540 mg/kg making it practically non-toxic).

This compound is found in the seeds (0.2 to 0.8 percent by weight) of the

neem tree, Azadirachta indica (hence the prefix aza does not imply an aza compound, but refers to the scientific species name). Many more compounds, related to azadirachtin, are present in the seeds as well as in the leaves and the bark of the neem tree which also show strong biological activities among various pest insects [4][5] Effects of these preparations on beneficial arthropods are generally considered to be minimal [citation needed
]. Some laboratory and field studies have found neem extracts to be compatible with biological control. Because pure neem oil contains other insecticidal and fungicidal compounds in addition to azadirachtin, it is generally mixed at a rate of 1 US fluid ounce per US gallon (7.8 mL/L) of water when used as a pesticide.

Azadirachtin is the active ingredient in many pesticides including TreeAzin,[6] AzaMax,[7] BioNEEM,[8] AzaGuard,[9] and AzaSol,[10] Terramera Proof [11] and Terramera Cirkil.[12]

Azadirachtin has a synergistic effect with the

biocontrol agent Beauveria.[13]

Nimbecidine is a natural product insecticide mix which is mostly azadirachtin, with some other limonoids.[14]

Mechanism of action

Azadirachtin interferes with a wide variety of insect pathways.[15]

Biosynthesis

Azadirachtin is formed via an elaborate biosynthetic pathway, but is believed that the steroid

Wagner-Meerwein 1,2-methyl shift to form apotirucallol
.

Apotirucallol becomes a tetranortriterpenoid when the four terminal carbons from the side chain are cleaved off. The remaining carbons on the side chain cyclize to form a

esterified with a molecule of tiglic acid, which is derived from L-isoleucine
. It is currently proposed that the target molecule is arrived at by biosynthetically converting azadirone into salanin, which is then heavily oxidized and cyclized to reach azadirachtin.

See also

References

  1. PMID 17665403
    .
  2. PMID 17687288
    .
  3. doi:10.1039/C19680000023
    .
  4. doi:10.1016/j.pestbp.2004.10.004
    .
  5. PMID 16112073
    .
  6. ^ "TreeAzin Systemic Insecticide". BioForest Technologies. Retrieved 2014-06-03.
  7. ^ "Our Products". ParryAmerica, Inc. Archived from the original on 2015-02-19. Retrieved 2015-02-18.
  8. ^ "Insecticide With Neem Oil Concentrate 16oz | Safer® Brand 5612". www.saferbrand.com. Archived from the original on 2016-10-02. Retrieved 2016-09-28.
  9. ^ "AzaGuard Botanical Insecticide Nematacide Specimen Label" (PDF). Biosafe Systems, LLC. Archived from the original (PDF) on 2016-03-04. Retrieved 2015-02-18.
  10. ^ "AzaSol – Arborjet". arborjet.com. Retrieved 2017-06-16.
  11. ^ "Terramera – Proof". terramera.com. Retrieved 2018-09-20.
  12. ^ "Terramera – Cirkil". terramera.com. Retrieved 2018-09-20.
  13. S2CID 29326838
    .
  14. PMID 15355236
    .
  15. ^
    doi:10.3389/fagro.2021.676208
    .

External links
Retrieved from "https://en.wikipedia.org/w/index.php?title=Azadirachtin&oldid=1209371081"