Diterpenes from Coleus forskohlii (WILLD.) BRIQ. (Labiatae).
Three new minor labdane diterpene glycosides, forskoditerpenoside C, D, and E (1-3), and a novel labdane diterpene forskoditerpene A (4) were isolated from the ethanol extract of the whole plant of Coleus forskohlii. Their structures and relative stereochemistry were elucidated on the basis of extensive spectroscopic analyses including 1D-, 2D-NMR, and HR-ESI-MS experiments. Compounds 1-3 showed an unusual 8,13-epoxy-labd-14-en-11-one glycoside pattern. They showed relaxative effects on isolated guinea pig tracheal spirals in vitro. Compound 4 with a cyclopropyl, confirmed by a single-crystal X-ray diffraction determination, is the first known labdane derivative with a spiro element.
Isoforskolin from Native Plant Coleus forskohlii of Yunnan, China Plays Multiple Biological Roles
Isoforskolin (ISOF) was isolated from Coleus forskohlii native to Yunnan in China. It is identified as 
one analog of diterpene forskolin (FSK) which comes from the Indian plant Coleus forskohlii. Researches 
found that the Yunnan native plant Coleus forskohlii contained rich ISOF but not FSK. ISOF 
was reported to activate adenylyl cyclase (AC) isoforms. The ophthalmologic and cardiovascular 
effects of ISOF were firstly reported in the 1990s. The researchers in Kunming, China, found ISOF 
could lower blood pressure and intraocular pressure. Recent researches found the respiratory 
tract effects of ISOF, and showed that ISOF significantly elevated cyclic adenosine monophosphate 
(cAMP) levels in rat lung homogenate, and relaxed the histamine-induced contraction of isolated 
guinea pig trachea and lung smooth muscle, isoforskolin pretreatment attenuates acute lung injury 
induced by lipopolysaccharide (LPS) in several models, lowered LPS-induced secretion of the 
inflammatory cytokine in human monocytes.
Novel 1,9-dideoxyforskolin analogues through microbial transformations
Abstract Microbial transformations of 1,9-dideoxyforskolin ( 1 ) and 7-deacetyl-1,9-dideoxyforskolin ( 2 ) were carried out. Various mono- and di-hydroxylated derivatives were isolated and identified.