First synthesis of (±)-halichonadins A-D.

Described herein is the first total synthesis of a marine isocyanide terpene, (±)-halichonadin C. Our synthetic strategy features nitrile-to-isocyanide interconversion utilizing hypervalent iodine-promoted Hofmann rearrangement. This approach led to successful construction of an isocyanide group at the stereochemically encumbered C-6 position in (±)-halichonadin C. Furthermore, in accord with a scenario we propose for the biosynthesis of halichonadins A-D, (±)-halichonadin C was transformed to halichonadins A and B via the missing link intermediate, halichonadin isocyanate.

Comparison of anthocyanin distribution in berries of Haskap (Lonicera caerulea subsp. edulis (Turcz. ex. Herder) Hultén), Miyama-uguisukagura (Lonicera gracilipes Miq.), and their interspecific hybrid using imaging mass spectrometry.

Haskap (Lonicera caerulea subsp. edulis), a shrub with violet-blue fruits, is distributed mainly in Hokkaido, Japan. Miyama-uguisukagura (Lonicera gracilipes), a species related to Haskap, produces red fruits. Interspecific hybridization of Miyama-uguisukagura and Haskap was performed to introduce novel characteristics in the resulting hybrids. The shape and color of the interspecific hybrid fruits differed from those of the parent fruits. A comparison of anthocyanin distribution among these three fruit types by imaging mass spectrometry (IMS) revealed the presence of five different anthocyanins. The average cyanidin 3,5-diglucoside and peonidin 3,5-diglucoside intensities in the interspecific hybrid fruit were higher than those of the parent fruits, whereas the average pelargonidin 3-glucoside, cyanidin 3-glucoside, and peonidin 3-glucoside intensities were the highest in Haskap. All anthocyanins were mainly accumulated in the inner and outer skins of Haskap and interspecific hybrid fruits, and in the skin of Miyama-uguisukagura fruits. The order of signal intensities of all anthocyanins among the three fruits was unchanged in different regions. Additionally, a comparison of IMS and LC/MS data from our previous study confirmed the possibility of comparing multiple fruits in the same plate by IMS. Thus, we elucidated anthocyanin distribution patterns of the interspecific hybrid and parent fruits by IMS.

Induction of potato variants with enhanced resistance to common scab disease via cell culture is applicable to a cultivar developed in Japan, but the effect of using the phytotoxin thaxtomin A is restrictive.

To induce potato variants with enhanced resistance to common scab disease that retain the desirable agronomic traits of the original cultivars, we used a cell culture technique that employs thaxtomin A, the primary phytotoxin that induces scab symptoms. We induced 24 variants from the potato cultivar 'Saya-akane', developed in Japan, and selected two with enhanced resistance to the disease by growing them in planters with bacteriainoculated soil and in a field infested with the disease. We also examined toxin tolerance in micro-tubers of variants that showed a lower degree or percentage of infection in the glasshouse screening, and found no significant difference relative to the original cultivar. To clarify the effect of using thaxtomin A, we examined the efficiency of induction of the potential enhanced resistance by comparing the degree of infection among variants grown in planters with inoculated soil. We observed no significant difference between variants induced on culture medium with and without the toxin. These results suggest that the effect of using the toxin as a positive selection agent is restrictive and that most resistance-enhancing mutations are induced by the cell culture procedure itself.