Salannin(p)

• CAS: 992-20-1
• Catalog Number: ACM992201
• Category: Main Products
• Molecular Weight: 596.713
• Molecular Formula: C₃₄H₄₄O₉
• Synonyms: SALANNIN(P);2H,3H-Cyclopenta(D)naphtho(1,8-bc:2,3-B)difuran-6-acetic acid, 3-(acetyloxy)-8-(3-furanyl)-2A,4,5,5A,6,6A,8,9,9A,10A,10B,10C-dodecahydro-2A,5A,6A,7-tetramethyl-5-(((2E)-2-methyl-1-oxo-2-butenyl)oxy)-, methyl ester, (2ar,3R,5S,5ar,6R,6ar,8R,9ar,10as,10br,10cr)-;2H,3H-Cyclopenta(D)naphtho(1,8-bc:2,3-B)difuran-6-acetic acid, 3-(acetyloxy)-8-(3-furanyl)-2A,4,5,5A,6,6A,8,9,9A,10A,10B,10C-dodecahydro-2A,5A,6A,7-tetramethyl-5-((2-methyl-1-oxo-2-butenyl)oxy)-, methyl ester, (2aalpha,3beta,5beta(E), 5aalpha,6alpha,6aalpha,8beta,9abeta,10aalpha,10balpha,10cbeta)-(+)-;Azadirachtin, neem;Azadriactin;Caswell no. 594a;Margosan-o-concentrate
• IUPAC Name: salannin
• Exact Mass: 596.29900

Case Study

Salannin as a Substrate for Fungal Biotransformation to Generate Novel Limonoid Derivatives

Haldar, Saikat, et al. RSC advances 4.53 (2014): 27661-27664.

Salannin, a C-seco limonoid from the Meliaceae family, exhibits potent insecticidal and growth-inhibiting properties. However, its complex molecular architecture limits chemical modifications for structure-activity relationship studies. Biocatalysis offers a regio- and stereoselective alternative for functionalizing such natural products under mild conditions. This study investigated the biotransformation of salannin using the fungal strain Cunninghamella echinulata.
Methods: Salannin (400 mg) was incubated with C. echinulata (NCIM 691) for 8 days. Two metabolites were isolated by column chromatography and characterized by HRMS, IR, 1D/2D NMR, and X-ray crystallography.
Key Results:
· C. echinulata efficiently transformed salannin (95% conversion over 7 days) into two major metabolites: salanninolide (2, 78 mg, 19.5% yield) and a novel N-(2-hydroxyethyl)-α,β-unsaturated-γ-lactam analogue named salanninactam (3, 11 mg, 2.75% yield).
· Salanninolide (2) resulted from oxidation of the C-17 furan ring to a γ-hydroxybutenolide (C20-C23), confirmed by X-ray crystallography. The compound existed as an inseparable 86:14 diastereomeric mixture at C-23.
· Salanninactam (3) represented an unprecedented transformation: the furan ring was converted to an N-(2-hydroxyethyl)-substituted α,β-unsaturated-γ-lactam, as elucidated by 2D NMR (COSY, HSQC, HMBC). HRMS showed [M+Na]+ at m/z 678.3251, corresponding to C34H49O10N.
· The biotransformation proceeded with high selectivity: only the furan moiety was modified while the intact limonoid skeleton (rings A-D) remained unchanged, demonstrating the exquisite specificity of fungal enzymes.