Flavones and phenylpropenoids in the surface exudate of Psiadia punctulata

Juma, Bernard F.; Yenesew, Abiy; Midiwo, Jacob O.; Waterman, Peter G.

doi:10.1016/s0031-9422(01)00147-9

Cited by 35 publications

(21 citation statements)

References 6 publications

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“…Together with their lipophilic exudates (flavonoid aglycones, waxes, terpenes, lipids), trichomes may protect leaves against extensive light, UV-B radiation, and desiccation (Ehleringer, 1982;Karabourniotis et al, 1993;Cockell and Knowland, 1999;Tattini et al, 2000;Juma et al, 2001), or they may form the first line of defense against herbivores by entrapping, deterring, or poisoning (Harborne, 1991;Wagner, 1991;Hare, 2002;Zalucki et al, 2002). For Solanaceae, in particular, trichome exudates are responsible for the mortality of neonate larvae; the removal of exudates using an ethanol solution increase larval survival (Gurr and McGrath, 2002).…”

Section: Introductionmentioning

confidence: 99%

Defensive Effect of Surface Flavonoid Aglycones of Betula pubescens Leaves Against First Instar Epirrita autumnata Larvae

et al. 2004

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Abstract-The surface of birch leaves contains glandular trichomes that secrete exudates containing flavonoid aglycones. We investigated the biological activities of white birch (Betula pubescens) leaf surface exudates against larvae of the autumnal moth, Epirrita autumnata, a common insect pest of birch. We found that tree-specific mortality (up to 100%) of first instar larvae correlated strongly with the tree-specific contents of surface flavonoid aglycones (r s = 0.905) in emerging leaves. We also found that first instars clearly preferred birch buds from which surface exudates had been removed. In addition, the duration of the first instar was shortened by 29%, and the weights and relative growth rates of first instars improved by 8% and 52%, respectively, as a result of removal of the exudates from their leaf diet. The correlation of tree-specific foliar contents of flavonoid aglycones, especially 5-hydroxy-4 ,7-dimethoxyflavanone, with changes in larval performance, suggests that flavonoid aglycones are responsible for the changes observed in first instar larval performance. The results show that chemical characteristics of birch leaves are effective against neonate E. autumnata larvae. However, the removal of leaf surface exudates from fully expanded leaves did not affect the leaf acceptance for the voracious fifth instars. This is probably a result of reduction in contents of flavonoid aglycones compared to those of emerging leaves.

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Section: Introductionmentioning

confidence: 99%

Defensive Effect of Surface Flavonoid Aglycones of Betula pubescens Leaves Against First Instar Epirrita autumnata Larvae

et al. 2004

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“…This East African taxon is considered by some taxonomists to be synonymous with P. arabica found in Saudi Arabia and the Sudan (Beentje, 1994). We have earlier reported the presence of kaurene and trachylobane diterpenes (Midiwo et al, 1997), flavones and phenylpropanoids (Juma et al, 2001) from the leaf exudates of P. punctulata. We have also noted that the compounds isolated from P. punctulata are distinct from those reported from P. arabica (Abou-Zaid et al, 1991, El-Feraly et al, 1990, and disputed the suggested synonymy between these two taxa (Juma et al, 2001).…”

Section: Introductionmentioning

confidence: 92%

Three ent-trachylobane diterpenes from the leaf exudates of Psiadia punctulata

et al. 2006

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“…The substrates were flavonoids of Polygonum senegalense, 9,10 and Psiadia punctulata flavonoids. 11 Polygonum senegalense has been found to be rich in flavonoids, especially chalcones. 9,10 This class of compounds has been extensively employed as intermediates in the synthesis of heterocyclic and carbocyclic system.…”

Section: Introductionmentioning

confidence: 99%

“…12 This is due the presence of reactive keto-ethylenic group in their general skeleton. A natural flavone, 5, 9-dihydroxy-2´,3´,4´,5´-tetramethoxyflavone from Psiadia panctulata, 11 was reacted with hydrazine hydrate to produce the semi-synthetic pyrazole product 1 (Equation 1). The protocol followed was a modification of the procedures of Hassan et al (2010).…”

Section: Introductionmentioning

confidence: 99%

Pyrazole, Isoxazoline and Bypyrimidine Derivatives from Polygonum senegalense and Psiadia punctulata Flavonoids and their Anti-Microbial Activities

Kenanda¹,

Omosa²

2017

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Currently, researchers have given special attention to the synthesis of hetero cyclic compounds with nitrogen and oxygen five in five or sixmembered ring systems. This is mainly due to their wide range of biological activities. Hence, in this study, isoxazoline, pyrazole and bypyrimidine derivatives were synthesized from flavonoids, previously isolated from Polygonum senegalense and Psiadia panctulata, and assessed for their antifungal activity. A flavone was reacted with hydrazine hydrate to afford a pyrazole analogue 5methoxy2(5(2,3,4,5tetramethoxyphenyl)1Hpyrazol3yl)benzene1,3 diol (1) Two isoxazoline derivatives namely, 2(4,5dihydro5phenylisoxazol 3yl)5methoxybenzene1,3diol (2) and 2(4,5dihydro5phenylisoxazol 3yl)3,5dimethoxyphenol (3) were successfully synthesized by the reaction of chalcones with hydroxylamine hydrochloride. An oxime derivative (4) was also generated from a similar procedure. A reaction between a chalcone and thiourea gave a bypyrimidine derivative, 4,5dihydro6(2,4 dihydroxy3,6dimethoxyphenyl)4phenylpyrimidine2(1H)thione (5). The products were then assessed for their antibacterial and antifungal activity.All compounds showed no significant activity except compound 2 that demonstrated activity against standard antibacterial agent, Streptococcus aureus with IC 50 value of 7.56 and antifungal Candida neoformans, Candida krusei and Candida glabrata strains with IC 50 values 8.01, 8.11 and 13.74 μg/mL respectively. We, therefore, recommend synthetic optimization of com pound 2 as a potential antimicrobial agent.

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Flavones and phenylpropenoids in the surface exudate of Psiadia punctulata

Cited by 35 publications

References 6 publications

Defensive Effect of Surface Flavonoid Aglycones of Betula pubescens Leaves Against First Instar Epirrita autumnata Larvae

Defensive Effect of Surface Flavonoid Aglycones of Betula pubescens Leaves Against First Instar Epirrita autumnata Larvae

Three ent-trachylobane diterpenes from the leaf exudates of Psiadia punctulata

Pyrazole, Isoxazoline and Bypyrimidine Derivatives from Polygonum senegalense and Psiadia punctulata Flavonoids and their Anti-Microbial Activities

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