Terpenoids isolated from Azadirachta indica roots and biological activities

Abstract The chemical study of roots from Azadirachta indica A. Juss., Meliaceae, led to the isolation of two new terpenoids, limonoid morenolide and diterpene 17-hydroxy-sandaracopimar-8,15-dien-11-one, in addition to the four well-known limonoids nimbinene, nimbinal, nimbandiol and salannin, and three diterpenoids nimbidiol, ferruginol, and 6,7-dehydroferruginol. Their structural elucidations were based on one and bidimensional Nuclear Magnetic Resonance and Electrospray ionization mass spectrometry spectra data which was compared to the data found in literature. The anti-inflammatory, cytotoxic and antimycobacterial activities of the identified terpenoids were evaluated.

Chemical Constituents of Trichilia hirta (Meliaceae).

A novel oleanane-type triterpene, 15-chloro-ß-amyrone (1), was isolated from Trichilia hirta, together with the known compounds taraxer-3-one (2) and ß-taraxerol (3), along with two novel esters, 3-(isobutyryloxy)-2,2,4-trimethylpenty palmitate (4) and 3-(isobutyryloxy)-2,2,3-trimethylpenty stearate (5), and the known 3-hydroxy-2,2,4-trimethylpentyl isobutyrate (6). These compounds were characterized on the basis of their spectroscopic and HRSEIMS data and by comparison with literature data.

A Novel Alkaloid Isolated from Spiranthera atlantica (Rutaceae).

A novel alkaloid 3-hydroxy-4-(2-hydroxyethyl)-4'-methoxy-7'H-quinolino[2,1-b]quinazolin-7'-one, named atlanticol (1), was isolated from Spiranthera atlantica (Rutaceae), along with five known compounds: lupeol (3), γ-fagarine (4), skimmianine (5), 7-methoxy-1-methyl-2-phenyl-4-quinolone (6) and 8-methoxy-1-methyl-2-phenyl-4-quinolone (7). Compound 6 was isolated from the Spiranthera genus for the first time. These compounds were characterized based on their spectral data, mainly through one and two-dimensional NMR and mass spectra, but also involving comparison with literature data.

Application of preparative high-speed counter-current chromatography for the separation of two alkaloids from the roots of Tabernaemontana catharinensis (Apocynaceae).

The methanolic extract of Tabernaemontana catharinensis (Apocynaceae) roots, which contains alkaloids with several biological activities, was separated on a preparative scale using high-speed counter-current chromatography. The optimum solvent system was found to be a mixture of CHCl(3)-MeOH-H(2)O [5:10:6 (v/v/v)] and led to a successful separation of two monoterpenic indole alkaloids, voachalotine (1) and 12-methoxy-N(b)-methylvoachalotine (2) in approximately 4.0 hours. The alkaloids were all isolated at purities over 95%, and their structures were established on the basis of spectroscopic methods, including 1D and 2D NMR and EI/MS.

Two new terpenoids from Trichilia quadrijuga (Meliaceae).

Two new terpenoids, ambrosanoli-10(14)-en-11,12-diol (1), a sesquiterpene named quadrijugol, and a pregnane steroid, 3beta,4beta-dihydroxypregnan-16-one (2), were isolated from the stem and leaves of Trichilia quadrijuga, along with eleven known compounds, spathulenol, kudtdiol, 2beta,3beta,4beta-trihydroxypregnan-16-one, bourjotinolone B, piscidinol, niloticin, dihydroniloticin, beta-sitosterol, 3-O-beta-D-glucopyranosyl-sitosterol, itesmol and stigmasterol. Structures were elucidated by spectral data analysis, mainly afforded by 1H and 3C NMR (1D and 2D NMR HMQC, HMBC, NOESY and COSY) and mass spectra.

Cytotoxic pyranonaphthoquinones from Melloa quadrival vis (Bignoniaceae).

Three new pyranonaphthoquinones: 5-hydroxy-6-methoxy-alpha-lapachone, 5,6-dihydroxy-a-lapachone and 4',5-dihydroxy-6-methoxy-alpha-lapachone, and two known compounds: lapachol and 5,5'-dihydroxy-3',4',7-trimethoxyflavanone, were isolated from the stem bark of Melloa quadrivalvis. Their structures were established by spectrometric data, mainly 1D- and 2D-NMR and mass spectra. The methylazoetetrazolium (MTT) method using viable cells of the strain Hep2 and the strain NCIH-292 demonstrated cytotoxic activity. The CI50 was also calculated. The chloroform extract and 5-hydroxy-6-methoxy-alpha-lapachone inhibited cell growth.