1- Mahanimbine

Dineshkumar B, Mitra A, Mahadevappa M. (2010) Antidiabetic and hypolipidemic effects of mahanimbine (carbazole alkaloid) from Murraya koenigii (rutaceae) leaves. Int J Phytomed 2 22-30. 

In 1966, Chakraborty et al. described the isolation of (+)-mahanimbine (139a) from M. koenigii (132). Two years later, Narasimhan et al. corrected the structural assignment of Chakraborty. Although alkaloid 139a was obtained in optically active form ([a]o +52), the absolute configuration is still unknown (111,133). Later, the racemic alkaloid, (+ )-mahanimbine (139b), was isolated independently from two different Murraya species, M. euchrestifolia (29) and M. siamensis (85). 

Hydroxy-3-methylcarbazole (52) could also function as a precursor for the formation of carbazole alkaloids with a C23 skeleton as depicted in Scheme 3.6 (370). Insertion of a Cio unit, viz., geraniol at C-1 of 2-hydroxy-3-methylcarbazole (52) would yield mahanimbinol (mahanimbilol) (56). The geranyl monoterpene unit could undergo various transformations, thus giving rise to isomeric carbazole alkaloids with a C23 skeleton, such as mahanimbine (139), cyclomahanimbine (murrayazolidine, curryanin) (151), and bicyclomahanimbine (160). Therefore, mahanimbinol (mahanimbilol) could be considered as the representative member of the carbazoles with a C23 skeleton. The occurrence of 2-hydroxy-3-methylcarbazole (52),... 

Macarpine 203 Macralstonine 16, 37 Macrocarpamine 16, 37 Maculasine 24 Maculosine 9, 40 Magiioflorine 200 Mahanimbine 25 Malaxine 102... 

From the stem bark, a new carbazole derivative, named murrayanine, has been isolated. It has been formulated as l-methoxy-3-formylcarbazole (I) (Chakraborty et al., 1965). Roy and Chakraborty (1974) reported the isolation of mahanimbine. The structure of a new hexacyclic carbazole alkaloid, isomur-rayazoline, from stem bark has been shown to be 9a,10,11,12,13,13a-hexahydro-5,9,9,12-... 

Five carbazole alkaloids isolated from the CH2C12 extract and their structures, namely, euchrestine B (compound 1), bismurraya-foline E (compound 2), mahanine (compound 3), mahanimbicine (compound 4) and mahanimbine (compound 5), exhibited antioxidative properties (Nakatani, 2000 Tachibana et al., 2001). The levels of antioxidant vitamins in fresh curry leaves were... 

The three bioactive carbazole alkaloids, e.g. mahanimbine, murrayanol and maha-nine, were found to be mosquitocidal and antimicrobial. The antioxidant activity of carbazoles (l,l-diphenyl-2-picryl hydrazyl DPH) from M. koenigii was found to be in order ascorbic acid > bismurraya foline E > euchestine B, mahanine and a-tocopherol... 

Joshi, B.S., Kamat, V.N. and Gawad, D.H. (1970) On the structures of girinimbine, mahanimbine, isoma-hanimbine, koenimbidine and murrayacine. Tetrahedron 26, 1475-1482. 

Roy, S. and Chakraborty, D.P. (1974) Mahanimbine from Murraya koenigii Spreng. Phytochemistry 1 3, 2893. 

Non-tryptamines.—Glycozoline (1) has been very simply synthesized by the thermal cyclization (350 °C) of 4 -methoxy-4-methyldiphenylamine in the presence of iodine.2 Details of the syntheses of girinimbine and mahanimbine have now been published,3 and the method used in the synthesis of the latter has been extended to the synthesis of ( )-isomahanimbine (2) thus, condensation of 2-hydroxy-6-methylcarbazole with citral in pyridine containing a trace of benzoic acid gave... 

At 150 °C, (+)-mahanimbine (5) undergoes racemization, presumably by opening and re-closure of the dihydropyran ring. At higher temperatures (200 °C), curryanine (cyclomahanimbine) (6) and curryangine (7) are formed 5 the structure... 

Mahanimbine Murraya koenigii (currvleaf) TOPII (AO/FRS, TOPI)... 

Mahanimbine Murraya koenigii (curry leaf) AO/FRS - scavenges DPPH... 

Nonstructure elucidation of seven pyranocarbazole alkaloids of Murraya koenigii [mahanimbine, koenimbine, (-)-mahanine, koenine, koenigine, koenidine, and ( + )-isomahanimbine] have now been published.Mur-rayacine, a minor alkaloid of the same plant, has been isolated from the roots of Clausena heptaphylla. The stems of another Clausena species, C. anisata Willd., contain atanisatin (1), and the roots contain a second new alkaloid, clausanitin (2). ... 

Mahanimbine (3a) on ozonolysis " gave the same phenolic aldehyde as had girinimbine, " establishing the common aromatic substitution pattern and D ring type. The remainder of the structure followed from a highly characteristic n.m.r. pattern for the alkenyl-methyl substituted chromene unit. 

Heptaphylline (1) has been synthesised by sequential C(3)-formylation and C(l)-isopentenylation of 2-hydroxycarbazole. l-Formyl-2-hydroxy-3-methyl-carbazole reacts with the Wittig reagent from 2-methylprop-l-en-3-yltriphenyl-phosphonium chloride-sodium hydroxide to generate girinimbine (2a) 2-hydroxy-3-methylcarbazole reacts with citral to give ( )-mahanimbine (3a). 

Non-tryptamines.—In the Murray a carbazoles area, more details2 of the structural work on murrayacine1" (la) have been given. The alkaloid isomahanimbine1" (lb) has unfortunately been given a second name, mahanimbicine, in an independent structure determination.3 The hexacyclic bicyclomahanimbicine was also isolated in this investigation 3 it is related to the tetracyclic mahanimbicine ( = isomahanimbine) as bicyclomahanimbine is1" to mahanimbine, and can likewise be obtained from the tetracyclic compound by acid treatment... 

Koenine4 6 and koenigine4b were O-methylated to give koenimbine (lg) and koenimbidine (lc) respectively. The structure of mahanimbine (lh) was established by partial synthesis7 (Scheme 1) from mahanimbine (li). 2-Hydroxy-6-methylcarbazole reacts with citral to give ( )-isomahanimbine (lb).3... 

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