Chemical Constituents of the Flowers of Azadirachta indica.

Abstract

Studies on the chemical constituents of the flowers of Azadirachta indica have led to the isolation of two new flavanones, flowerine ( 5-hydroxy-7,4'-dimethoxy-8-(3-methylbut-2-enyl)flavan-4-one; 1) and flowerone ( 5,7,8,4'-tetrahydroxy-3'-(3-methylbut-3-enyl)flavan-4-one; 2), and two new triterpenoids, O-methylazadironolide ( 7a-(acetoxy)-23x-methoxy-21,23-epoxy-24,25,26,27-tetranorapotirucalla-1,14,20(22)-trien-3,21-dione; 3) and diepoxyazadirol ( (20S,23S,24R)-7-a-(acetoxy)-25-hydroxy-21,24 : 23,24-diepoxyapotirucalla-1,14-dien-3-one; 4) along with the known triterpenoid trichilenone acetate ( 7a-(acetoxy)-14,15 : 21,23-diepoxy-24,25,26,27-tetranorapotirucalla-1,20,22-trien-3-one; 5), two known flavanones, nimbaflavone ( 5,7-dihydroxy-4'-methoxy-8,3'-bis(3-methylbut-2-enyl)-flavan-4-one; 6) and 3'-prenylnaringenin ( 5,7,4'-trihydroxy-3'-(3-methylbut-2-enyl) flavan-4-one; 7), and 4-(2-hydroxyethyl)phenol (8). Their structures have been elucidated through spectral studies, including 2D-NMR experiments, and chemical transformation. Compounds 5, 7 and 8 are heretofore unreported from any part of tree, while 6 has been isolated earlier from leaves.

A comprehensive review of phytochemical profile, bioactives for pharmaceuticals, and pharmacological attributes of Azadirachta indica

“…Therefore, it can be effectively used as anti-malarial agent in treatment of malaria. GC-EIMS analysis of flower's extract revealed thepresence of five sesquiterpenes, three aromatics, seventeen fatty acids, five fatty acid esters, three steroids and eight hydrocarbons (Siddiqui et al, 2009).…”

“…Resins of shoot apex and young leaves contained isoprenylated flavanone (8-prenyl-5,7-dihydroxy-3′-(3hydroxy-3,3-dimethylbutyl)-4′-methoxyflavanone; Balasubramanian, Mohan, Arumugasamy, & Udaiyan, 1993). Fresh flowers also showed significant larvicidal activity against Anopheles stephensi owing to the presence of sesquiterpenes, aromatic compounds, fatty acids, fatty acid esters, steroids, few hydrocarbons, azharone, azadirone, and isoazadironolide (Siddiqui et al, 2006(Siddiqui et al, , 2009.…”

Prenylated flavanones and flavanonols as chemical markers in Glycosmis species (Rutaceae)

“…However, this flavanonol was shown to predominate in a sample collected at Ton Tae waterfall near Trang co-occurring with only small amounts of mundulea-flavanon B (4). An unifoliolate species from Thale Ban National Park, most probably belonging to the G. chlorosperma group, differed by the accumulation of the known 4 0 -O-methyl-8-prenylnaringenin (5) (Bohm et al, 1989;Parsons et al, 1993;Auzi et al, 1997;Narvaez-Mastache et al, 2006) together with small amounts of the known flowerin (6) (Jain et al, 1978;Siddiqui et al, 2003;Cano et al, 2006). Morphologically this collection could be clearly distinguished from the rare unifoliolate G. chlorosperma (Bl.)…”

GC-based analysis of insecticidal constituents of the flowers ofAzadirachta indicaA. Juss

“…Although its different parts have been studied extensively for its chemical constituents (Ali, Rhaman, Ahamed, Hossain, & Uddin, 1996;Jarvis, Morgan, & Edward, 1999;Kaushik & Vir, 2000;Luo, Ma, & Wu, 2000;Sharma, Bali, & Singh, 1998;Siddiqui, Ali, Rasheed, & Kardar, 2003;Siddiqui, Faizi, Siddiqui, & Ghiasuddin, 1992;Siddiqui, Mahmood, Siddiqui, & Faizi, 1988;Siddiqui et al, 2004), the systematic studies on flowers were lacking. Hence, studies on the fresh flowers of A. indica were undertaken (Siddiqui et al, 2003).…”

“…Hence, studies on the fresh flowers of A. indica were undertaken (Siddiqui et al, 2003). An extension of these studies on the n-hexane soluble fraction and essential oil of the flowers, showing larvicidal activity against Anopheles stephensi Liston, a vector of malarial parasite, forms the basis of this communication.…”