Exudate Flavonoids from Aerial Parts of Five Ambrosia Species

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E ck h a rd W ollenw eber, Y oshinori A sakaw a*, D etlef Schillo, U lrich L eh m an n , and H eid ru n W eigelThe bud exudates of Populus nigra, P. trichocarpa, and P. grandidentata x tremuloides were analyzed for the presence of phenolics and flavonoids. A novel natural product, caffeic acid y.ydimethylallyl ester, was identified from P. nigra, along with further phenolics such as /?-hydroxyacetophenone, dimethyl caffeic acid, cinnamoyl cinnamata and vanillin. The flavonoid aglycones correspond to those reported earlier. Propolis samples from the Sonoran Desert were shown to exhibit the flavonoid pattern that is typical for poplar bud exudates, thus confirming this material as the major source for bee-glue. Only a single flavonoid might originate from the leaf exudate of a desert shrub.

“…o f tw o Baccharis species (c.f. [2]) and of A m b ro sia deltoidea [20] and its p res ence in propolis m ight, th e re fo re, point to such a source.…”

Section: Discussionmentioning

confidence: 93%

A Novel Caffeic Acid Derivative and Other Constituents of Populus Bud Excretion and Propolis (Bee-Glue)

Wollenweber

Asakawa

Schillo

et al. 1987

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“…The characteristic exudate flavonoids of this plant are the major products, 3'-desmethoxysudachitin (5,7,4'-trihydroxy-6,8-dimethoxy flavone) and xanthomicrol (5,4'-dihydroxy-6,7,8-trimethoxy flavone), and the minor components, scutellarein-6-methyl ether (hispidulin), luteolin-7-methyl ether, 6-methoxy luteolin (nepetin), sideritiflavone (5,3',4'-trihydroxy-6,7,8-trimethoxy flavone), kaempferol, quercetin, rhamnetin (quercetin-7-me), rhamnazin (quercetin-7,3'-diMe) and ombuin (quercetin-7,4'-diMe). The presence of two coumarins, scopoletin and ayapin, is also typi cal for the "fingerprint" of Am brosia deltoidea on TLC, where they appear as light blue fluorescent spots (Wollenweber et al, 1987b). Thus, their pres ence in these propolis samples confirms this plant source.…”

Section: Resultsmentioning

confidence: 65%

“…The "fingerprint" of these propolis samples matches with bud exudate of P. fremontii, although this poplar is extremely rare in the Tucson area where it grows only spo radically in watercourse beds . Only one flavonoid was detected (xanthomicrol, 5,4'-dihydroxy-6,7,8-trimethoxy flavone) that cannot be derived from Populus, but might originate from the leaf exudate of an asteraceous desert shrub such as an Ambrosia species (Wollenweber et al, 1987b; or a Baccharis species (Wollenweber et al, 1986;1989). Finally, propolis samples were obtained from colonies of feral bees found in rock outcrops beyond the flight range of any poplar trees.…”

Section: Introductionmentioning

confidence: 99%

Feral Honey Bees in the Sonoran Desert: Propolis Sources other than Poplars (Populus spp.)

Wollenweber

Buchmann

1997

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In Central Europe and other temperate regions the lipophilic bee hive product propolis normally originates from the bud exudate of poplar trees that is collected by the bees. Based on bee observations, various other sources have been discussed in particular for tropical regions, but in only few cases the origin has been proved by analytical methods. We have analyzed propolis samples from managed honey-bees as well as from feral bee colonies in the Sonoran Desert. Propolis collected in hives out of flight reach of poplars contained flavonoid aglycones and other phenolics that point to specific plants as the source of propolis in this area, namely Ambrosia deltoidea and Encelia farinosa.

“…Analysis of bulk material has now permitted the identification of three additional products: scutellellarein-7-Me, 6-OH-luteolin-6,3'-diMe and quercetin-3'-Me. The exudate flavonoid patterns of other A m brosia spe cies have been discussed previously (see Wollenweber et al, 1995), but a number of species remain to be studied.…”

Section: Resultsmentioning

confidence: 97%

Exudate Flavonoids in Asteraceae from Arizona, California and Mexico

Wollenweber¹,

Dörr²,

Fritz³

et al. 1997

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A steraceae, A stereae, Eupatorieae, Helenieae, Heliantheae, Exudate Flavonoids A series of A steraceae, belonging to the tribes Astereae, Eupatorieae, Helenieae and Heli antheae, have been analyzed for the presence of flavonoid aglycones accumulated on leaf and stem surfaces. Methyl ethers of apigenin, luteolin, kaempferol, and quercetin as well as methyl ethers of their relevant 6 -hydroxy derivatives were abundant, whereas 8 -O-substituted derivatives and flavanones were encountered only occasionally; 6 ,8 -di-O-substituted flavonols were found in only one species.