A previous study on the feeding responses of tsetse flies, Glossina morsitans morsitans, implicat... more A previous study on the feeding responses of tsetse flies, Glossina morsitans morsitans, implicated the existence of allomonal barriers, both volatile and nonvolatile, on the nonpreferred host, waterbuck, Kobus defassa. In the present study, electroantennogram-active compounds in odors from waterbuck were compared with those of two preferred hosts of tsetse flies, buffalo, Syncerus caffer, and ox, Bos indicus. Odors from the three bovids were trapped on activated charcoal and/or reverse-phase (octadecyl bonded) silica and analyzed with a gas chromatography-linked electroantennographic detector (GC-EAD) and, where possible, identified by using gas chromatography-linked mass spectrometry (GC-MS) and chromatographic comparisons with authentic samples. The GC-EAD profiles (with G. m. morsitans antennae) of the odors of the two preferred hosts were comparable, comprising medium-chain, saturated or unsaturated aldehydes and phenols, with buffalo emitting a few more EAG-active aldehydes. W...
Three flavones, 5,7-dihydroxy-2′,3′,4′,5′-tetramethoxyflavone, 5,4′-dihydroxy-7,2′,3′,5′-tetramet... more Three flavones, 5,7-dihydroxy-2′,3′,4′,5′-tetramethoxyflavone, 5,4′-dihydroxy-7,2′,3′,5′-tetramethoxyflavone, and 5,7,4′-trihydroxy-2′,3′,5′ -trimethoxyflavone were isolated from the leaf exudate of Psiadia punctulata, together with the previously reported 5-hydroxy-7,2′,3′,4′,5′-pentamethoxyflavone and 5,7,3′-trihydroxy-2′,4′,5′-trimethoxyflavone. The two phenylpropenoids, Z-docosyl-p-coumarate and E-docosyl-p-coumarate were also isolated. The structures were determined on the basis of spectroscopic evidence.
Phytochemical investigation of the ethyl acetate-soluble fraction of stem bark extract of an Afri... more Phytochemical investigation of the ethyl acetate-soluble fraction of stem bark extract of an African medicinal plant Terminalia brownii led to the isolation of a new oleanane-type triterpenoid, along with seven known triterpenoids, seven ellagic acid derivatives, and 3-O-β-D-glucopyranosyl-β-sitosterol. The new compound was identified using spectroscopic methods, notably 1D- and 2D NMR, as 3β,24-O-ethylidenyl-2α,19α-dihydroxyolean-12-en-28-oic acid. The isolated compounds were evaluated for their antimicrobial and antiplasmodial activities. Two compounds with a galloyl group (4 and 6) were found to be active against chloroquine sensitive (D6) and chloroquine resistant (W2) strains of Plasmodium falciparum, whereas three ellagic acid derivatives (5-7) were found active against three species of fungi and one species of bacteria.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Seed pods of Millettia dura yielded four novel isoflavones, which have been characterized as 3-(3... more Seed pods of Millettia dura yielded four novel isoflavones, which have been characterized as 3-(3,4-dimethoxyphenyl)-6-methoxy-8,8-dimethyl-4H,8H-benzo[1,2-b: 3,4-b′]dipyran-4-one (trivial name, durallone), 6-demethyldurallone, 3-(3,4-dimethoxyphenyl)-8-(3-methylbut-2-enyl)-6-methoxy-7-hydroxybenzopyran-4-one (trivial name, predurallone) and 3-(4-3-methylbut-2-enyloxy)-8,8-dimethyl-4H,8H-benzo[1,2-b: 3,4-b′]dipyran-4-one (trivial name, isoerythrinin-A 4′-(3-methylbut-2-enyl) ether. Structures of these compounds were determined on the basis of their spectroscopic data.
The ethyl acetate extract of the stem bark of Erythrina abyssinica showed anti-plasmodial activit... more The ethyl acetate extract of the stem bark of Erythrina abyssinica showed anti-plasmodial activity against the chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum with IC(50) values of 7.9+/-1.1 and 5.3+/-0.7 microg/ml, respectively. From this extract, a new chalcone, 2',3,4,4'-tetrahydroxy-5-prenylchalcone (trivial name 5-prenylbutein) and a new flavanone, 4',7-dihydroxy-3'-methoxy-5'-prenylflavanone (trivial name, 5-deoxyabyssinin II) along with known flavonoids have been isolated as the anti-plasmodial principles. The structures were determined on the basis of spectroscopic evidence.
A previous study on the feeding responses of tsetse flies, Glossina morsitans morsitans, implicat... more A previous study on the feeding responses of tsetse flies, Glossina morsitans morsitans, implicated the existence of allomonal barriers, both volatile and nonvolatile, on the nonpreferred host, waterbuck, Kobus defassa. In the present study, electroantennogram-active compounds in odors from waterbuck were compared with those of two preferred hosts of tsetse flies, buffalo, Syncerus caffer, and ox, Bos indicus. Odors from the three bovids were trapped on activated charcoal and/or reverse-phase (octadecyl bonded) silica and analyzed with a gas chromatography-linked electroantennographic detector (GC-EAD) and, where possible, identified by using gas chromatography-linked mass spectrometry (GC-MS) and chromatographic comparisons with authentic samples. The GC-EAD profiles (with G. m. morsitans antennae) of the odors of the two preferred hosts were comparable, comprising medium-chain, saturated or unsaturated aldehydes and phenols, with buffalo emitting a few more EAG-active aldehydes. W...
Three flavones, 5,7-dihydroxy-2′,3′,4′,5′-tetramethoxyflavone, 5,4′-dihydroxy-7,2′,3′,5′-tetramet... more Three flavones, 5,7-dihydroxy-2′,3′,4′,5′-tetramethoxyflavone, 5,4′-dihydroxy-7,2′,3′,5′-tetramethoxyflavone, and 5,7,4′-trihydroxy-2′,3′,5′ -trimethoxyflavone were isolated from the leaf exudate of Psiadia punctulata, together with the previously reported 5-hydroxy-7,2′,3′,4′,5′-pentamethoxyflavone and 5,7,3′-trihydroxy-2′,4′,5′-trimethoxyflavone. The two phenylpropenoids, Z-docosyl-p-coumarate and E-docosyl-p-coumarate were also isolated. The structures were determined on the basis of spectroscopic evidence.
Phytochemical investigation of the ethyl acetate-soluble fraction of stem bark extract of an Afri... more Phytochemical investigation of the ethyl acetate-soluble fraction of stem bark extract of an African medicinal plant Terminalia brownii led to the isolation of a new oleanane-type triterpenoid, along with seven known triterpenoids, seven ellagic acid derivatives, and 3-O-β-D-glucopyranosyl-β-sitosterol. The new compound was identified using spectroscopic methods, notably 1D- and 2D NMR, as 3β,24-O-ethylidenyl-2α,19α-dihydroxyolean-12-en-28-oic acid. The isolated compounds were evaluated for their antimicrobial and antiplasmodial activities. Two compounds with a galloyl group (4 and 6) were found to be active against chloroquine sensitive (D6) and chloroquine resistant (W2) strains of Plasmodium falciparum, whereas three ellagic acid derivatives (5-7) were found active against three species of fungi and one species of bacteria.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Seed pods of Millettia dura yielded four novel isoflavones, which have been characterized as 3-(3... more Seed pods of Millettia dura yielded four novel isoflavones, which have been characterized as 3-(3,4-dimethoxyphenyl)-6-methoxy-8,8-dimethyl-4H,8H-benzo[1,2-b: 3,4-b′]dipyran-4-one (trivial name, durallone), 6-demethyldurallone, 3-(3,4-dimethoxyphenyl)-8-(3-methylbut-2-enyl)-6-methoxy-7-hydroxybenzopyran-4-one (trivial name, predurallone) and 3-(4-3-methylbut-2-enyloxy)-8,8-dimethyl-4H,8H-benzo[1,2-b: 3,4-b′]dipyran-4-one (trivial name, isoerythrinin-A 4′-(3-methylbut-2-enyl) ether. Structures of these compounds were determined on the basis of their spectroscopic data.
The ethyl acetate extract of the stem bark of Erythrina abyssinica showed anti-plasmodial activit... more The ethyl acetate extract of the stem bark of Erythrina abyssinica showed anti-plasmodial activity against the chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum with IC(50) values of 7.9+/-1.1 and 5.3+/-0.7 microg/ml, respectively. From this extract, a new chalcone, 2',3,4,4'-tetrahydroxy-5-prenylchalcone (trivial name 5-prenylbutein) and a new flavanone, 4',7-dihydroxy-3'-methoxy-5'-prenylflavanone (trivial name, 5-deoxyabyssinin II) along with known flavonoids have been isolated as the anti-plasmodial principles. The structures were determined on the basis of spectroscopic evidence.
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