Self-organized interconnect method for molecular devices

Lack of an appropriate method for wiring molecules that have controlled functions and structures has been a barrier for the development of molecular devices. We developed an interconnect method to program three kinds of component molecules with their own functions and to wire a molecular device in a self-organized manner. By using the interconnect method we developed, we produced conductive wires and optical switching devices and have demonstrated their device functions. Our interconnect method allows us to control various molecular device characteristics by combining the three molecules.     

Steroidal glycosides from the underground parts of Solanum sodomaeum

A new steroidal glycoside has been isolated from the underground parts of Solanum sodomaeum L., along with seven known steroidal glycosides. Their chemical structures were determined on the basis of spectroscopic data and chemical evidence, and the structure of one known pregnane type glycoside was corrected. In addition, their antiproliferative activity against human promyelocytic leukemia (HL-60) cells was investigated, and five compounds exhibited stronger activity than cisplatin.     

Iridoid glucosides from the fruit of Genipa americana

Four new iridoid glucosides, called genamesides A-D, have been isolated from the fruit of Genipa americana L. (Rubiaceae), along with four known iridoid glucosides, geniposidic acid, geniposide, gardenoside and genipin-gentiobioside. Their chemical structures were determined on the basis of spectroscopic data.     

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

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.     

Steroids from the underground parts of Trillium kamtschaticum

Two 18-norspirostanol glycosides and an 18-norspirostanol, which were new compounds as natural products, have been isolated from the underground parts of Trillium kamtschaticum PALL. along with eight known steroidal glycosides. Their chemical structures were determined on the basis of spectroscopic data.     

New megastigmane glycoside and aromadendrane derivative from the aerial part of Piper elongatum

A new megastigmane glycoside, called pipeloside A, and a new aromadendrane type sesquiterpenoid, pipelol A, were isolated from the MeOH extract of the aerial part of Piper elongatum VAHL. along with a known megastigmane glycoside, byzantionoside B. The structures of these compounds were elucidated on the basis of spectroscopic data and chemical evidence.