Divergent Synthesis of Methylene Lactone- and Methylene Lactam-Based Spiro Compounds: Utility of Amido-Functionalized γ-Hydroxylactam as a Precursor for Cytotoxic ,- and ,-Spiro Compounds.

Pharmaceutically attractive methylene lactone- and methylene lactam-based spiro compounds have been synthesized by employing amido-functionalized γ-hydroxylactam as a common intermediate. Development of a new route for bifurcated synthesis of two types of ,-spiro compounds was accomplished by treatment of the intermediate under acidic conditions, leading to potent cytotoxic methylene lactone-based spiro compounds. New methylene lactam-based ,-spiro compounds could be delivered via --butyloxycarbonyl protection of the terminal amide moiety of the intermediate followed by lactam cyclization under basic conditions.

Detection of Thermospermine and Spermine by HPLC in Plants.

Thermospermine, a structural isomer of spermine, is widely spread in the plant kingdom and has recently been shown to play a key role in the repression of xylem differentiation in vascular plants. However, a standard high-performance liquid chromatography (HPLC) protocol for detecting polyamines as their dansyl derivative cannot distinguish themospermine from spermine. These isomers become separated from each other after benzoylation.

Thermospermine is not a minor polyamine in the plant kingdom.

Thermospermine is a structural isomer of spermine, which is one of the polyamines studied extensively in the past, and is produced from spermidine by the action of thermospermine synthase encoded by a gene named ACAULIS5 (ACL5) in plants. According to recent genome sequencing analyses, ACL5-like genes are widely distributed throughout the plant kingdom. In Arabidopsis, ACL5 is expressed specifically during xylem formation from procambial cells to differentiating xylem vessels.