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M H Elgamal

Publications and source records attributed to M H Elgamal.

12 recordsLinked to original sources
PubMed1999

Antifungal effects of different plant extracts and their major components of selected aloe species.

Different extracts of both fresh and dry leaves of Aloe eru A. Berger, A. vera L. Webb & Berth and A. arborescens Mill. were screened for their antifungal activity against Aspergillus niger, Cladosporium herbarum and Fusarium moniliforme. The toxicity of the isolated pure components were evaluated on the tested fungi. A comparative chromatographic study was performed to differentiate between natural components existing in various fractions and extracts of Aloe species and specific spray reagents were used for the detection of anthraquinones in the isolated components.

Aloe↗
PubMed1999

Triterpenoid saponins from Fagonia indica.

Two new triterpenoid saponins, 3-O-{[beta-D-glucopyranosyl-(1-->2)]-[alpha-L-arabinopyranosyl-(1- ->3)]- alpha-L-arabinopyranosyl}-ursolic acid-28-O-[beta-D-glucopyranosyl] ester (indicasaponin A), 3-O-{[beta-D-glucopyranosyl-(1-->2)]-[alpha-L-arabinopyranosyl-(1- ->3)]- alpha-L-arabinopyranosyl}-oleanolic acid-28-O-[beta-D-glucopyranosyl] ester (indicasaponin B) and two known triterpenoid saponins, 3-O-[beta-D-glucopyranosyl-(1-->3)-alpha-L-arabinopyranosyl]-ur solic acid-28-O-[beta-D-glucopyranosyl] ester, 3-O-[beta-D-glucopyranosyl-(1-->3)-alpha-L-arabinopyranosyl]-olean olic acid-28-O-[beta-D-glucopyranosyl] ester have been isolated from Fagonia indica. The structures were determined primarily by NMR spectroscopy. The assignment of NMR signals was performed by means of 1H-1H COSY, NOESY, ROESY, TOCSY, HMQC and HMBC experiments.

Carbohydrate Conformation↗
PubMed1998

Two triterpene saponins from Arenaria filicaulis.

Two novel triterpenoid saponins, Snatzkein C, (3beta, 20-dihydroxylupan-28-oic acid 3-O-[beta-D-galactopyranosyl-(1-->2)-beta-D-glucopyranosyl-28- O-beta-D-glucopyranoside) and Snatzkein D, (3beta, 20-dihydroxylupan-28-oic acid 3-O-[beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl]-28-O-beta-D-++ +glucopyranoside), have been isolated from Arenaria filicaulis. Their structure and conformational behaviour were elucidated by one- and two-dimensional 1H NMR and 13C NMR spectroscopy.

Carbohydrate Conformation↗
PubMed1997

Triterpenoid saponins from the roots of Zygophyllum species.

Two new triterpenoid saponins, 3-O-[beta-D-2-O-sulphonylglucopyranosyl]-quinovic acid-28-O-[beta-D-glucopyranosyl] ester (zygophyloside G), 3-O-[alpha-L-arabinopyranosyl-(1-->2)-beta-D-quinovopyranosyl++ +]-quinovic acid-28-28-O-[beta-D-glucopyranosyl] ester (zygophyloside H), and seven known saponins have been isolated. The structures were established primarily on the basis of NMR spectroscopy. The assignment of all NMR signals was performed by means of 1H-1H COSY-45, NOESY, TOCSY, 13C APT, HMQC and HMBC experiments. The determination of the glycosylation sites was possible by the HMBC experiments.

Magnetic Resonance Spectroscopy↗
PubMed1995

Isolation of triterpene saponins from Gypsophila capillaris.

Four novel triterpenoid saponins have been isolated from Gypsophila capillaris. Three were monodesmosidic: 3 beta-hydroxyolean-12-en-23,28-dioic acid 28-O-[beta-D-glucopyranosyl-(1-->3)-beta-D-glucopyranosyl-(1-->2)] [beta-D-galactopyranosyl(1-->6)]beta-D-glucopyranoside, 3 beta-hydroxyolean-12-en-23-oxo-28-oic acid 28-O-[beta-D-glucopyranosyl-(1-->2)-beta-D-galactopyranosyl-(1-->3)] [beta-D-glucopyranosyl(1-->6)]beta-D-galactopyranoside, 3 beta-hydroxyolean-12-en-23,28-dioic acid 28-O-[beta-D-glucopyranosyl-(1-->2)-beta-D-galactopyranosyl-(1-->3)] [beta-D-glucopyranosyl(1-->6)]beta-D-galactopyranoside. The fourth was bisdesmosidic: 3 beta-hydroxyolean-12-en-23,28-dioic acid 23-O-beta-D-glucopyranosyl-28-O-[beta-D-glucopyranosyl-(1-->2)-beta-D- galactopyranosyl-(1-->3)][beta-D-glucopyranosyl-(1-->6)]beta-D- galactopyranoside. The structures of the compounds were elucidated by 1D and 2D NMR techniques and from other spectroscopic evidence.

Carbohydrate Conformation↗
PubMedDate not supplied

A further contribution to the triterpenoid constituents of Glycyrrhiza glabra L.

Five pentacyclic triterpenoids have been isolated from the minor constituents of local liquorice roots, one of them has not been isolated before from liquorice root. Their structural formulae and stereochemical configuration was determined by spectroscopic methods. 13C and 1H NMR data have been compiled.

Glycyrrhiza↗
PubMedDate not supplied

Triterpenoid saponins from Astragalus trigonus.

One new, 3-O-[[[-alpha-L-rhamnopyranosyl-(1-->2)]-[beta-D-glucopyranosyl-(1-->3)]-beta-D-glucopyranosyl-(1-->2)]-beta-D-glucuronopyranosyl]-3beta,22alpha,24-trihydroxyolean-12-ene and two known triterpenoid saponins, 3-O-[[alpha-L-rhamnopyranosyl-(1-->2)]-[beta-D-glucopyranosyl-(1-->2)]-beta-D-glucuronopyranosyl]-3beta,22beta,24-trihydroxyolean-12-ene (azukisaponin V) and 3,16-di-O-beta-D-glucopyranosyl-3beta,6alpha,16beta-trihydroxycycloart-24-ene have been isolated from Astragalus trigonus. The structures were determined primarily by NMR spectroscopy. The assignment of NMR signals was performed by means of 1H-1H COSY, NOESY, ROESY, TOCSY, HMQC and HMBC experiments.

Carbohydrate Sequence↗