Two New Diterpenoid Glucosides from Clerodendrathus spicatus

Asymmetric synthesis of the fully functionalized six-membered A-ring of siphonol A

A synthetic study toward the construction of the fully functionalized six-membered A-ring of siphonol A is described. The salient features include the introduction of a six-membered ring system through a HWE reaction, the construction of a stereocenter at C5 via a hetero-Diels-Alder reaction, and the installation of the fully functionalized six-membered A-ring of siphonol A through photolytic decarboxylation.

The complete chloroplast genome sequence of Clerodendranthus spicatus, a medicinal plant for preventing and treating kidney diseases from Lamiaceae family

BACKGROUND

Clerodendranthus spicatus (Thunb.) C. Y. Wu ex H. W. Li is one of the most important medicines for the treatment of nephrology in the southeast regions of China. To understand the taxonomic classification of Clerodendranthus species and identify species discrimination markers, we sequenced and characterized its chloroplast genome in the current study.

METHODS AND RESULTS

Total genomic DNA were isolated from dried leaves of C. spicatus and sequenced using an Illumina sequencing platform. The data were assembled and annotated by the NOVOPlasty software and CpGAVAS2 web service. The complete chloroplast genome of C. spicatus was 152,155 bp, including a large single-copy region of 83,098 bp, a small single-copy region of 17,665 bp, and a pair of inverted repeat regions of 25,696 bp. The Isoleucine codons are the most abundant, accounting for 4.17% of all codons. The codons of AUG, UUA, and AGA demonstrated a high degree of usage bias. Twenty-eight simple sequence repeats, thirty-six tandem repeats, and forty interspersed repeats were identified. The distribution of the specific rps19, ycf1, rpl2, trnH, psbA genes were analyzed. Analysis of the genetic distance of the intergenic spacer regions shows that ndhG-ndhI, accD-psaI, rps15-ycf1, rpl20-clpP, ccsA-ndhD regions have high K2p values. Phylogenetic analysis showed that C. spicatu is closely related to two Lamiaceae species, Tectona grandis, and Glechoma longituba.

CONCLUSIONS

In this study, we sequenced and characterized the chloroplast genome of C. spicatus. Phylogenomic analysis has identified species closely related to C. spicatus, which represent potential candidates for the development of drugs improving renal functions.

New Diterpenoids from Clerodendranthus spicatus

Two new diterpenoids, neoorthosiphonones B and C (1 and 2), and one known diterpenoid, were isolated from the aerial parts of Clerodendranthus spicatus. Their structures including absolute configurations were determined by comprehensive spectroscopic analyses and X-ray crystallographic methods. No compound was found to inhibit fibronectin production at the concentration of 20 μM.

Clerodendranoic acid, a new phenolic acid from Clerodendranthus spicatus

Phenolic acid derivatives are typical constituents of Clerodendranthus spicatus which were considered to the active principles of this medicinal plant. These chemical constituents with their interesting frameworks and biological significance attracted our attention. As part of our ongoing chemical investigation of C. spicatus using various column chromatography techniques, a new phenolic compound, named clerodendranoic acid (1), was isolated from the aerial parts of C. spicatus together with five known ones, including rosmarinic acid (2), methyl rosmarinate (3), caffeic acid (4), methyl caffeate (5), ethyl caffeate (6). Their structures, including stereochemical configurations, were completely established by extensive spectroscopic methods, mainly inclvolving 1D, 2D NMR, as well as HRESIMS.