Propolis samples from a geographical part of northwest Greece (Prespa National Park, PNP), which is characterized as a plant endemism center and biodiversity hotspot, were characterized through pollen analysis, chemically analyzed, and biologically evaluated. The majority of the studied propolis showed typical chemical constituents (phenolic acids, flavonoids, and chalcones) of European type, while a sample of Mediterranean-type propolis (rich in diterpenes) was also identified. The palynological characterization was implemented to determine the botanical origin and to explain the chemical composition. The total phenolic content and the DPPH assay showed that the European-type propolis samples possessed strong antioxidant activity (86-91% inhibition at 200 μg/mL). Moreover, promising antibacterial activity of the extracts (MIC values 0.56-1.95 mg/mL) and moderate antifungal activity (MIC values 1.13-2.40 mg/mL) were noticed, while the sample with the highest activity had a significant content in terpenes (Mediterranean type). Propolis samples from the PNP area represent a rich source of antibacterial and antioxidant compounds and confirm the fact that propolis is a significant natural product with potential use for improving human health and stimulating the body's defense. Finally, it is noteworthy that a significant chemical diversity was demonstrated, even in samples from a limited geographical area as this of PNP.

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Pruni Cortex is a herbal drug from the bark of the Japanese flowering cherries, Prunus jamasakura or Prunus verecunda, and is included in the traditional Japanese herbal (Kampo) formula Jumihaidokuto, which is administered orally to patients suffering from inflammatory skin diseases. The flavanones contained in Pruni Cortex (e.g., sakuranetin and naringenin) have potent anti-inflammatory, anti-allergic, and anti-microbial activities. Although the effects of Pruni Cortex on skin disease have been well studied, reports regarding its pharmacological effects on the liver are limited. In this study, we extracted the bark of Prunus jamasakura and purified it to isolate the pharmacologically active constituents by monitoring nitric oxide (NO) production in rat hepatocytes that were treated with the pro-inflammatory cytokine, interleukin (IL)-1β. Sakuranetin and (-)-naringenin, which were present in an ethyl acetate-soluble fraction of the bark extract, significantly inhibited NO induction and inducible nitric oxide synthase (iNOS) expression. These two flavanones decreased the expression of type 1 IL-1 receptor gene and phosphorylation of Akt, also known as protein kinase B, which is regulated by phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K). Furthermore, sakuranetin decreased the phosphorylation of the activator isoforms of CCAAT/enhancer-binding protein β (C/EBPβ), which synergistically activates the transcription of the iNOS gene with nuclear factor κB (NF-κB). Therefore, sakuranetin inhibited the co-activating activity of C/EBPβ with NF-κB, leading to the suppression of iNOS gene expression in hepatocytes. Taken together, sakuranetin in Pruni Cortex downregulated the iNOS gene by inhibiting PI3K/Akt signal transduction and the phosphorylation of C/EBPβ. These results imply that sakuranetin may be primarily responsible for the anti-inflammatory effects of Pruni Cortex in the liver.

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Vertical seed dispersal, which plays a key role in plant escape and/or expansion under climate change, was recently evaluated for the first time using negative correlation between altitudes and oxygen isotope ratio of seeds. Although this method is innovative, its applicability to other plants is unknown. To explore the applicability of the method, we regressed altitudes on δ 18 O of seeds of five woody species constituting three families in temperate forests in central Japan. Because climatic factors, including temperature and precipitation that influence δ 18 O of plant materials, demonstrate intensive seasonal fluctuation in the temperate zone, we also evaluated the effect of fruiting season of each species on δ 18 O of seeds using generalized linear mixed models (GLMM). Negative correlation between altitudes and δ 18 O of seeds was found in four of five species tested. The slope of regression lines tended to be lower in late-fruiting species. The GLMM analysis revealed that altitudes and date of fruiting peak negatively affected δ 18 O of seeds. These results indicate that the estimation of vertical seed dispersal using δ 18 O of seeds can be applicable for various species, not just confined to specific taxa, by identifying the altitudes of plants that produced seeds. The results also suggest that the regression line between altitudes and δ 18 O of seeds is rather species specific and that vertical seed dispersal in late-fruiting species is estimated at a low resolution due to their small regression slopes. A future study on the identification of environmental factors and plant traits that cause a difference in δ 18 O of seeds, combined with an improvement of analysis, will lead to effective evaluation of vertical seed dispersal in various species and thereby promote our understanding about the mechanism and ecological functions of vertical seed dispersal.

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Numerous cultivars of Japanese flowering cherry (Prunus subgenus Cerasus) are recognized, but in many cases they are difficult to distinguish morphologically. Therefore, we evaluated the clonal status of 215 designated cultivars using 17 SSR markers. More than half the cultivars were morphologically distinct and had unique genotypes. However, 22 cultivars were found to consist of multiple clones, which probably originate from the chance seedlings, suggesting that their unique characteristics have not been maintained through propagation by grafting alone. We also identified 23 groups consisting of two or more cultivars with identical genotypes. Most members of these groups were putatively synonymously related and morphologically identical. However, some of them were probably derived from bud sport mutants and had distinct morphologies. SSR marker analysis provided useful insights into the clonal status of the examined Japanese flowering cherry cultivars and proved to be a useful tool for cultivar characterization.

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Peptide-N4-(N-acetyl-beta-glucosaminyl)asparagine amidase A (PNGase A) was purified from almonds (Prunus amygdalus var. dulcis). Contrary to previous results in the literature, the enzyme appeared to be a heterodimer with subunits of 55 and 27 kDa when analysed by SDS/PAGE and two-dimensional electrophoresis. Peaks corresponding to molecular masses of 54.2, 21.2 and 75.5 kDa were observed with matrix-assisted laser-desorption/ionization mass spectrometry. The N-terminal sequences of the larger and the smaller chain were determined to be LASGYHSWAD and EPTPLHDFPP, respectively. Both polypeptides reacted with concanavalin A, indicating their glycoprotein nature. Upon digestion of PNGase with pepsin, the N-linked oligosaccharides were released with active PNGase and analysed as their 2-aminopyridine derivatives by two-dimensional HPLC and by matrix-assisted laser-desorption mass spectrometry. The most abundant N-glycan of the four species found exhibited the well known vacuole type structure, i.e. the pentasaccharide core with xylose and alpha1,3-linked fucose. The other structures either had an additional mannose residue and/or lacked the fucose. PNGase A was largely but not absolutely resistant to self-deglycosylation. However, only at an extremely high enzyme/substrate ratio, N-glycans released from PNGase A itself caused a detectable contamination of a PNGase digest of a glycopeptide.

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