Dihydrochalcones from Uvaria angolensis

Hufford, Charles D.; Oguntimein, Babajide O.

doi:10.1016/0031-9422(80)83036-6

Cited by 58 publications

(31 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The known compounds were identified as myrigalone A (MyA) (37), myrigalone E (MyE) (3), myrigalone B (MyB) (37), uvangoletin (26), demethoxymatteucinol (64), myrigalone D (MyD) (37), and demethoxymatteucinol-7-methyl ether (31), on the basis of a comparison of their 1 H and 13 C NMR spectroscopic data with those reported previously.…”

Section: Resultsmentioning

confidence: 95%

Differential Effects of Rare Specific Flavonoids on Compatible and Incompatible Strains in the Myrica gale - Frankia Actinorhizal Symbiosis

Popovici

Comte

Bagnarol

et al. 2010

Appl Environ Microbiol

View full text Add to dashboard Cite

Plant secondary metabolites, and specifically phenolics, play important roles when plants interact with their environment and can act as weapons or positive signals during biotic interactions. One such interaction, the establishment of mutualistic nitrogen-fixing symbioses, typically involves phenolic-based recognition mechanisms between host plants and bacterial symbionts during the early stages of interaction. While these mechanisms are well studied in the rhizobia-legume symbiosis, little is known about the role of plant phenolics in the symbiosis between actinorhizal plants and Frankia genus strains. In this study, the responsiveness of Frankia strains to plant phenolics was correlated with their symbiotic compatibility. We used Myrica gale, a host species with narrow symbiont specificity, and a set of compatible and noncompatible Frankia strains. M. gale fruit exudate phenolics were extracted, and 8 dominant molecules were purified and identified as flavonoids by high-resolution spectroscopic techniques. Total fruit exudates, along with two purified dihydrochalcone molecules, induced modifications of bacterial growth and nitrogen fixation according to the symbiotic specificity of strains, enhancing compatible strains and inhibiting incompatible ones. Candidate genes involved in these effects were identified by a global transcriptomic approach using ACN14a strain whole-genome microarrays. Fruit exudates induced differential expression of 22 genes involved mostly in oxidative stress response and drug resistance, along with the overexpression of a whiB transcriptional regulator. This work provides evidence for the involvement of plant secondary metabolites in determining symbiotic specificity and expands our understanding of the mechanisms, leading to the establishment of actinorhizal symbioses.Over the course of evolution, plants have developed many strategies to adapt to their environment and manage their biotic interactions. The production of secondary metabolites is an important tool in many of these strategies. In particular, secondary metabolites are involved in plant-microbe interactions both as weapons in plant defense mechanisms and as early signals in mutualistic as well as pathogenic relationships (22). For example, sesquiterpenes and flavonoids are involved in the early steps of arbuscular mycorrhizal symbiosis (1, 62). Similarly, in the early stages of the rhizobia-legume symbiosis, recognition of host flavonoids enhances rhizospheric competitiveness and root colonization and is the basic mechanism through which rhizobia induce the transcription of nod genes, leading to root hair deformation and nodulation in the plant tissues (13,49,55).Actinorhizal symbiosis is a less well-known nitrogen-fixing interaction, resulting from the association between the actinobacterium Frankia and plants belonging to eight dicotyledonous families collectively called "actinorhizal": Betulaceae, Myricaceae, Rosaceae, Datiscaceae, Elaeagnaceae, Coriariaceae, Casuarinaceae, and Rhamnaceae (8). Due to the nitrogen-fixing...

show abstract

Section: Resultsmentioning

confidence: 95%

Differential Effects of Rare Specific Flavonoids on Compatible and Incompatible Strains in the Myrica gale - Frankia Actinorhizal Symbiosis

Popovici

Comte

Bagnarol

et al. 2010

Appl Environ Microbiol

View full text Add to dashboard Cite

show abstract

“…Hence the possibility of the structure 2a was excluded. Consequently, the new compound 10) uvaretin (4), 3,6,11) isouvaretin (5), 6,11) diuvaretin (6), 6,11) and uvangoletin (7), 12) respectively, by comparing these spectral data with values reported in the literature. Compounds 3, 5, 6, and 7 were isolated for the first time from U. acuminata.…”

mentioning

confidence: 91%

Cytotoxic C-Benzylated Dihydrochalcones from Uvaria acuminata

Ichimaru

Nakatani

Takahashi

et al. 2004

CHEMICAL & PHARMACEUTICAL BULLETIN

View full text Add to dashboard Cite

Two new C-benzylated dihydrochalcones, isochamuvaritin (1) and acumitin (2), have been isolated from the African medicinal plant Uvaria acuminata, together with the previously reported benzylbenzoate (3), uvaretin (4), isouvaretin (5), diuvaretin (6), and uvangoletin (7). The structural elucidation of compounds 1 and 2 in spectroscopic studies is described. C-Benzylated dihydrochalcones, especially 1, 2, 4, and 6, showed considerable cytotoxicity toward human promyelocytic leukemia HL-60 cells.

show abstract

“…Spectral data were compared with those reported in the literature. Compounds (1) to (7) were identified as chrysin-5-glucoside (1), 17) 3-hydroxyphloridzin (2), 18) phloridzin (3), 19) chrysin (4), 20) phloretin (5), 21) 3-hydroxyphloretin (6), 22) and quercetin (7). 23) The purity of all isolated constituents, determined by integration of proton resonances and by HPLC with diode array detection (HPLC-DAD) peak integration, was Ͼ98%.…”

mentioning

confidence: 99%

Phenolic Constituents of <i>Malus doumeri</i> var. <i>formosana</i> in the Field of Skin Care

Leu

Lin

et al. 2006

Biological & Pharmaceutical Bulletin

View full text Add to dashboard Cite

Reactive oxygen species (ROS), such as hydroxyl (˙OH), superoxide anion radical (O 2 Ϫ ), and hydrogen peroxide (H 2 O 2 ), are highly reactive molecules that consequently generate metabolic products that attack lipids in cell membranes or DNA. A series of free radical chain reaction processes is associated with several types of biological damage, carcinogenesis, and cellular degeneration related to aging. Cells are protected from such damage by their endogenous scavenging systems or by other compounds. 1) Thus ROS play an important role in physiological and pathological states and are constantly produced in living organisms. 2)Aging has been associated with free radical formation in many reports.3) Oxidative stresses can be generated in the connective tissues and the skin cells by photodamage and inflammatory processes. When the skin is exposed to ultraviolet (UV) or visible light, it will produce free radicals, 4) which can then induce skin damage such as occurs in phototoxicity and aging.5) Previous studies also indicated that skin exposure to UV irradiation regulates matrix-degrading enzymes, such as metalloproteinases (MMPs)-1, -2, -3, -7, -8, -9 and -12.6,7) The MMPs are a family of zinc-dependent endopeptidases that play a key role in the turnover of extracellular matrix in skin.8) Aging and exposure to environmental insults, such as UV irradiation, increase the expression of MMPs. 9,10) Excessive MMP activity, which causes the collapse of the meshwork in the extracellular matrix, produces UV irradiation-like skin damage, including wrinkling, loss of elasticity, and dilation of surface microcapillary vessels.11) MMP-1 belongs to the subfamily of collagenases, which are the key enzymes in collagen turnover required for the remodeling of the dermal matrix. Several studies have demonstrated that the decreased elasticity of skin with aging is significantly correlated with increased elastase activity. 12)Recently, the bioactivities of several natural plants and plant-derived phytochemicals have been studied. For example, previous reports on various Malus (apple) species, which are common fruit worldwide, showed that they contain antioxidative phenolics such as dihydrochalcones and flavonoids. 13,14) There are many reports in the literature describing the strong antioxidant activities of polyphenols 15) and their benefits in treating or preventing human diseases. The ingredients in apples have also been shown to be associated with lowered risk of cardiovascular diseases and various cancers. 14)Malus doumeri A. CHEV. var. formosana (KAWAK. & KOIDZ.) S. S. YING (Rosaceae) is a Taiwanese indigenous plant with horticultural use and edible fruit. Among the Taiwanese, it is sometimes used to treat heatstroke and heat-related hyperactivity and as a tonic to reinforce vital energy. 16) However, there are few reported phytochemical examinations of this species. In this study, DPPH scavenging activity was used to identify the active constituents in M. doumeri var. formosana. The isolated components were also investigated...

show abstract

Dihydrochalcones from Uvaria angolensis

Cited by 58 publications

References 9 publications

Differential Effects of Rare Specific Flavonoids on Compatible and Incompatible Strains in the Myrica gale - Frankia Actinorhizal Symbiosis

Differential Effects of Rare Specific Flavonoids on Compatible and Incompatible Strains in the Myrica gale - Frankia Actinorhizal Symbiosis

Cytotoxic C-Benzylated Dihydrochalcones from Uvaria acuminata

Phenolic Constituents of <i>Malus doumeri</i> var. <i>formosana</i> in the Field of Skin Care

Contact Info

Product

Resources

About