Galal T. Maatooq

Antioxidant and Immunomodulatory Constituents of Henna Leaves

Abstract The immunomodulatory bioassay-guided fractionation of the methanolic extract of henna (Lawsonia inermis L.; syn. Lawsonia alba L.) leaves resulted in the isolation of seven compounds; three have been isolated for the first time from the genus, namely p-coumaric acid, 2-methoxy-3-methyl-1,4-naphthoquinone and apiin, along with the previously isolated compounds: lawsone, apigenin, luteolin, and cosmosiin. Structural elucidation of the isolated compounds was based upon their physical, chemical as well as spectroscopic characters. Their immuomodulatory profile was studied using an in vitro immunoassay, the lymphocyte transformation assay. The ABTS [2,2′-azino-bis (3-ethyl benzthiazoline-6-sulfonic acid)], free radical scavenging assay depicted that all isolated compounds exhibited antioxidant activity comparable to that of ascorbic acid.

Chemistry and immunomodulatory activity of frankincense oil.

The yield of steam distillation of frankincense essential oil (3%); and its physicochemical constants were determined. Capillary GC/MS technique was used for the analysis of the oil. Several oil components were identified based upon comparison of their mass spectral data with those of reference compounds published in literature or stored in a computer library. The oil was found to contain monoterpenes (13.1%), sesquiterpenes (1%), and diterpenes (42.5%). The major components of the oil were duva-3,9,13-trien-1,5α-diol-1-acetate (21.4%), octyl acetate (13.4%), o-methyl anisole (7.6%), naphthalene decahydro-1,1,4a-trimethyl- 6-methylene-5-(3-methyl-2-pentenyl) (5.7%), thunbergol (4.1%), phenanthrene-7- ethenyl-1,2,3,4,4a,5,6,7,8,9,10,10a-dodecahydro-1,1,4a,7-tetramethyl (4.1%), α-pinene (3.1%), sclarene (2.9%), 9-cis-retinal (2.8%), octyl formate (1.4%), verticiol (1.2%) decyl acetate (1.2%), n-octanol (1.1%). The chemical profile of the oil is considered as a chemotaxonomical marker that confirmed the botanical and geographical source of the resin. Biologically, the oil exhibited a strong immunostimulant activity (90% lymphocyte transformation) when assessed by a lymphocyte proliferation assay.

Immunomodulatory Triterpenoids from the Oleogum Resin of Boswellia carterii Birdwood

Abstract The immunomodulatory bioassay-guided fractionation of the oleogum resin of frankincense (Boswellia carterii Bird wood) resulted in the isolation and identification of 9 compounds; palmitic acid and eight triterpenoids belonging to lupane, ursane, oleanane, and tirucallane skeleta were isolated form the resin. These triterpenoids are lupeol, β-boswellic acid, 11-keto-β-boswellic acid, acetyl β-boswellic acid, acetyl 11-keto-β-boswellic acid, acetyl- α-boswellic acid, 3-oxo-tirucallic acid, and 3-hydroxy-tirucallic acid. The structures of the isolated compounds were deduced based on spectroscopic evidences. The lymphocyte transformation assay of the isolated compounds proved that the total extract retained more activity than that of any of the purified compounds.

C-p-hydroxybenzoylglycoflavones from Citrullus colocynthis

Abstract In a flavonoid investigation of the fruits and aerial parts of Citrullus colocynthis six flavone C -glycosides were identified. The fruits contained isovitexin, iso-orientin and iso-orientin 3′-methyl ether, while the aerial parts contained three new C - p -hydroxybenzyl derivatives, viz. 8- C - p -hydroxybenzoylisovitexin, 6- C - p -hydroxybenzoylvitexin, and 8- C - p -hydroxybenzoylisovitexin 4′- O -glucoside. Their chemical identity was established by NMR spectroscopic methods including 2D-NMR, as well as UV and MS analyses.

Bioactive microbial metabolites from glycyrrhetinic acid

Biotransformation of 18beta-glycyrrhetinic acid, using Absidia pseudocylinderospora ATCC 24169, Gliocladium viride ATCC 10097 and Cunninghamella echinulata ATCC 8688a afforded seven metabolites, which were identified by different spectroscopic techniques (1H, 13C NMR, DEPT, 1H-1H COSY, HMBC and HMQC). Three of these metabolites, viz. 15alpha-hydroxy-18alpha-glycyrrhetinic acid, 13beta-hydroxy-7alpha,27-oxy-12-dihydro-18beta-glycyrrhetinic acid and 1alpha-hydroxy-18beta-glycyrrhetinic acid are new. The 13C NMR data and full assignment for the known metabolite 7beta, 15alpha-dihydroxy-18beta-glycyrrhetinic acid are described here for the first time. The major metabolites were evaluated for their hepatoprotective activity using different in vitro and in vivo models. These included protection against FeCl3/ascorbic acid-induced lipid peroxidation of normal mice liver homogenate, induction of nitric oxide (NO) production in rat macrophages and in vivo hepatoprotection against CCl4-induced hepatotoxicity in albino mice.

Two flavonoid glycosides from Chenopodium murale

Two new triglycosides, kaempferol-3-O-[(4-beta-D-apiofuranosyl)-alpha-L- rhamnopyranoside]-7-O-alpha-L-rhamnopyranoside and kaempferol-3-O-[(4-beta-D-xylopyranosyl)-alpha-L-rhamnopyranoside]-7-O- alpha-L-rhamnopyranoside were isolated from the methanol extract of Chenopodium murale, together with a known diglycoside, kaempferol-3-O-beta-D-glucopyranoside-7-O-alpha-L-rhamnopyranoside. The characterization of the three compounds was achieved by various spectroscopic methods.

A novel antioxidant phenanthrenoid dimer from Juncus acutus L.

A novel phenanthrenoid symmetrical dimer 8,8′-bidehydrojuncusol [1,1′,6,6′-tetramethyl-5,5′-divinyl-8,8′-biphenanthrene-2,2′,7,7′-tetraol], a related phenanthrenoid monomer, a phenolic chromone, and five flavonoids derivatives have been isolated from the halophyte Juncus acutus L., Juncaceae. The structure of the dimeric phenanthrenoid was determined on the basis of spectroscopic analyses, including 2D NMR spectroscopy, and by spectral correlations. The new dimer and the other isolated compounds bearing four phenolic hydroxy groups showed the significant in vitro antioxidant activity comparable with that of ascorbic acid using 2,2′-azino-bis[3-ethylbenzothiazoline-6-sulphonate] (ABTS) radical cation decolourisation assay. On the basis of the results from an in vitro anti-inflammatory assay using lipopolysaccharide-stimulated RAW264.7 macrophage cells linked with immunoblot analysis, it was found that dimerisation of dehydrojuncusol [1,6-dimethyl-5-vinyl-8-phenanthrene-2,7-diol] molecule nearly nullified its inhibitory effect on the expression of the pro-inflammatory inducible nitric oxide synthase (iNOS) protein.

Limonoids from Citrus reticulata

The seeds of Citrus reticulata afforded the new limonoid derivative, isolimonexic acid methyl ether, in addition to the the previously isolated limonin, deacetylnomilin, obacunone and ichangin. The structure elucidation was achieved primarily through 1D and 2-D-NMR analyses. The marginal antimalarial activity of isolimonexic acid methyl ether is reported.

A New Triterpene Saponin from Chenopodium ficifolium

The new triterpene saponin 3-O-β-ᴅ-glucopyranoside, 28-β-ᴅ-glucopyranosyl-(1→2)-β-d-glucopyranosiduronic acid oleanolate was isolated from the roots of Chenopodium ficifolium. The known compounds stigmasterol-3-O-glucoside and 3-O-β-ᴅ-glucopyranosiduronic acid, 28-β-ᴅ-glucopyranosyl oleanolate were also isolated. The latter compound, oleanolic acid, β-sitosterol and its glucoside were isolated from the aerial parts. The identity of these compounds was verified through different chemical and physico-chemical evidences including different 1D and 2D NMR experiments.

Microbial metabolism of partheniol by Mucor circinelloides

Six new partheniol metabolites were isolated from the biotransformation reaction with Mucor circinelloides ATCC 15242. These metabolites are: humula-1(10), 4, 7-trien-6alpha-ol 2, maali-3-en-8alpha-ol 3, aromadendrane-4alpha, 8alpha, 10alpha-triol 4, maaliane-4alpha, 8alpha, 9alpha-triol 5, maaliane-5alpha, 8alpha, 9alpha-triol 6, 5(9), 6-tricyclohumulane-4alpha, 8alpha, 10alpha-triol 7. The structural assignments of these metabolites were made possible by different spectroscopic means.