Haruki Komatsu

Production of intergeneric somatic hybrids between round kumquat (Fortunella japonica Swingle) and ‘Morita navel’ orange (Citrus sinensis Osbeck)

Intergeneric somatic hybrids between embryogenic callus-derived protoplasts of round kumquat (Fortunella japonica Swingle) and ‘Morita navel’ orange (Citrus sinensis Osbeck) were produced by electrofusion. Among the eight different fusion strains obtained, six showed normal morphology, whereas the remaining two showed malformation. All the regenerated plants were intermediate in leaf morphology and had thick and round leaves, which are typical characteristics of polyploids. Ploidy analyses by flow cytometry and chromosome counting in root-tip cells revealed that these plants are amphidiploid (2n=4×=36). Hybridity of the fusion products was confirmed by random amplified polymorphic DNA and cleaved amplified polymorphic sequence (CAPS) analyses. Furthermore, analyses of chloroplast (cp) and mitochondrial (mt) DNA by CAPS showed that these somatic hybrids contained cp- and mt-DNA of round kumquat without recombination in the regions analyzed.

Gibberellins in immature seed of Prunus cerasus: Structure determination and synthesis of gibberellin, GA95 (1,2-Didehydro-GA20)

Abstract Ten C-13-hydroxylated gibberellins (GA 3 , GA 17 , GA 19 , GA 20 , GA 32 , GA 44 , GA 86 , GA 87 , GA 95 and GA 95 isolactone) and two C-13-deoxy-GAs (GA 25 and GA 30 ) were identified in immature seeds of sour cherry ( Prunus cerasus L. cv. Montmorency) by GC-mass spectrometry. GA 95 is a new GA whose structure was determined to be 1,2-didehydroGA 20 by GC-mass spectral comparison with an authentic sample, synthesized from GA 3 . In addition, six unknown GA-like compounds were detected by GC-mass spectrometry. It remains unclear whether GA 95 isolactone was an artefact. On the basis of the structures of the endogenous GAs and the absence of GA 5 , the sequence of GA 20 → GA 95 → GA 3 → GA 87 → GA 32 could be conceived of as a possible biosynthetic pathway.

Two new triterpenoids from the seeds of blackberry (Rubus fructicosus)

Abstract Two new ursane-type triterpenoids (1, 2) attached to isopropylidenedioxy group were isolated from the seeds of blackberry (Rubus fructicosus L., Rosaceae) along with two known ursane-type triterpenoids, 2,3-O-isopropylidenyl-2α,3α,19α-trihydroxyurs-12-en-28-oic acid (3) and 1β-hydroxyeuscaphic acid (4). The chemical structures of 1 and 2 were determined to be 2,3-O-isopropylidene-1β,2β,3β,19α-tetrahydroxyurs-12-en-28-oic acid and 1,2-O-isopropylidene-1β,2α,3α,19α-tetrahydroxyurs-12-en-28-oic acid, respectively, based on spectroscopic data. Additionally, their cytotoxic activity towards HL-60 human leukaemia cells was evaluated. Among them, 3 demonstrated a clear cytotoxic activity with 72.8 μM of IC50 value. Graphical abstract

Triterpenoids from the fruits and leaves of the blackberry (Rubus allegheniensis) and their inhibitory activities on foam cell formation in human monocyte-derived macrophage

From the methanol extract of the fruits of the blackberry (Rubus allegheniensis Port.), four triterpenoids – pomolic acid (1), tormentic acid (2), euscaphic acid (3) and 1β-hydroxyeuscaphic acid (4) – were isolated, while six triterpenoids – 2, 3, myrianthic acid (5), ziyu glycoside II (6), sericic acid (7) and 19-hydroxy-2,3-secours-12-ene-2,3,28-trioic acid 3-methyl ester (8) – were obtained from the methanol extract of the leaves of this plant. Their structures were determined on the basis of spectral data. Compounds 1–8 were examined for their inhibitory activities on foam cell formation in human monocyte-derived macrophages induced by acetylated low-density lipoproteins at a 50 μM concentration. Among the tested compounds, 1 showed the strongest activity, with the inhibitory effect being 90%. The inhibitory activities of 2–8 were evaluated to be 30%, 32%, 33%, 4%, 48%, 4% and 24%, respectively. Further, the structure–activity relationship of these compounds was investigated.

Antioxidant Activities and Anti-Cancer Cell Proliferation Properties of Natsuhaze (Vaccinium oldhamii Miq.), Shashanbo (V. bracteatum Thunb.) and Blueberry Cultivars

Antioxidants are abundant in blueberries, and while there are many studies concerning the bioactive compound of fruit, it is only recently that the wild Vaccinium species has attracted attention for their diverse and abundant chemical components. The aim of this study was to investigate the bioactive compounds of blueberry cultivars and wild species found in Japan. Among the five extracts of the Vaccinium species, Natsuhaze (Vaccinium oldhamii Miq.) was found to be the most effective at inhibiting the growth of HL-60 human leukemia cells in vitro. Although all ethanol extracts showed a growth inhibitory effect on HL-60 cells, the degree of the effects differed among the species. The extract of Natsuhaze induced apoptotic bodies and nucleosomal DNA fragmentation in the HL-60 cells. Of the extracts tested, that of Natsuhaze contained the largest amount of total polyphenols and showed the greatest antioxidant activity, but the anthocyanin content of Natsuhaze was similar to that of rabbiteye blueberry (V. virgatum Ait.). The results showed that total polyphenols contributed to the high antioxidant activity and growth inhibitory effect on HL-60 human leukemia cells of Natsuhaze extract.