Labdane-type diterpenes

Li WX, Cui CB, Cai B, Yao XS. Labdane-type diterpenes as new cell cycle inhibitors and apoptosis inducers from Vitex trifolia L. J Asian Nat Prod Res 2005 7 95-105. 

LABDANE -TYPE DITERPENES CHEMISTRY AND BIOLOGICAL ACTIVITY... 

In addition to the (antimicrobial, enzyme and endocrine related) properties mentioned above, it is interesting that many labdane type diterpenes also exhibit significant properties against cancer cells. A number of labdane type diterpenes tested exhibited remarkable antiproliferative and cytotoxic activities. Itokawa et al. [193] found that extracts from the rhizomes of Hedychium coronarium (Zingiberacae), cause growth inhibition of Chinese hamster V-79 cells and sarcoma 180 ascites in mice. Chemical analysis led to the isolation of 8 (17), 12 (E)-labdadiene-15, 16-dial along with four new coronarins (A-D). All of the compounds exhibited... 

As noted, the labdanes display a broad spectrum of biochemical and pharmacological activities, suggesting that they may significantly affect the function of the immune system and inflammatory cells. The labdanes may affect critical enzymes such as adenylate cyclase, protein kinases and phospholipase A2, which are intimately involved in signal transduction and cell activation processes. Much of the information on labdane-type diterpene effects has been provided by forskolin and mainly in in vitro systems. 

Labdane type diterpenes obviously exhibit a wide spectrum of actions. Primarily forskolin exhibits (a) antihypertensive properties, lowering blood pressure in different animal species through a vasodilatory effect (b) positive inotropic effects in cardiac muscle and (c) bronchodilatory effects [155] and (d) pressure-lowering properties [244]. 

Konishi T, Konoshima T, Fujiwara Y, Kiyosawa S, Miyahara K, Nishi M (1999) Stereostructures of New Labdane-Type Diterpenes, Excoecarins F, Gl, and G2 from the Wood of Excoecaria agallocha. Chem Pharm Bull 47 456... 

Munesada, K., Siddiqui, H. L., and Suga, T., 1992. Biologically active labdane-type diterpene glycosides from the root-stalks of Gleichenia japonica. Phytochemistry 31, 1533-1536... 

A subsequent analysis of specimens of A. kurodai collected in 1985 from the Mei Prefecture in Japan yielded a new labdane-type diterpene, cpi-aplysin-20 [21], which is a diastereomer of aplysin-20 [2 2](36), together with the enantiomer of isoconcinndiol [2 3](37). 

New labdane-type diterpenes were also reported from B. boliviensis [33], Baccharis medullosa D. C. [42], B. paniculata [43] and Baccharis stembergiana Stend. [44], As we can see from the data reported in the literature, in one species clerodanre diterpenes and in the other labdanes were present, indicating that there are chemically different groups in the large genus Baccharis. 

From the chloroform soluble fraction of the methanolic extract of the seeds of A. zerumbet, two labdane-type diterpenes, named zerumin A (73) and B (74) were isolated along with two known compounds coronarin E and ( )-15,16-bisnorlabda-8(17),l 1-diene-13-one [59]. 

Terpenoids. Mono- and sesquiterpenoids are the common constituents of all nine genera. Labdane-type diterpenes are found mainly in Aframomum, Alpinia and Hedychium. Only plants in the genus Kaempferia are able to produce pimarane diterpenes. Steroidal compounds and steroidal saponins are found only in plants of the genus Costus. 

Physalis. A new labdane-type diterpene, physacoztomatin (Fig. 7.9), has been discovered as a constituent of the aerial parts of Physalis coztomatl Moc. SESsfi ex Dun. whose fruits are used in Mexican cuisine ( tomate agrio or tomate amarillo ) (Perez-Castorena et al. 2006). 

Correlations within a stereochemically homogeneous series of compounds, such as monosaccharides and steroids, which are well documented elsewhere in the literature are considered in outline only. Series of compounds which are essentially dimeric or polymeric types built up from chiral monomeric units are not covered in detail, since their configurations follow readily from those of the monomeric unit. Examples of such polymeric-type compounds are di-, oligo- and polysaccharides bis (benzylisoquinoline) and other dimeric alkaloids biflavonoids and polypeptides. Series of natural products having essentially the same carbon skeleton but known in a variety of stereochemical types due to epimerism at one or more chiral centres are frequently covered by general notes rather than by large numbers of examples. This treatment is given, for example, to the labdane-type diterpenes and the yohimbane-type alkaloids. 

A combination of spectroscopic evidence and chemical degradation has been used to determine the structure and absolute configuration of a new labdane-type diterpene, trans-(5 R, 7iS, 85,9S, 105)-labda-12,14-dien-7,8-diol (516) isolated from Porella species (62). The positions and configurations of the tertiary and the secondary hydroxyl groups were established by formation of (521) from (516), the facile dehydration of (521) to give (522), and by the appearance of the H-7 signal in the H-NMR spectrum as a (W = l Hz). The negative CD curve of (522) further... 

Recently some highly oxygenated labdane-type diterpenes (517—520) have been isolated from Ptychanthus species (Jungermanniales). The structure proposals rest on H-NMR and C-NMR spectral analysis (321, 322). 

Sholichin, M., K. Yamasaki, R. Miyama, R. Yahara, and O. Tanaka Labdane-type diterpenes from Stevia rebaudiana, Phytochem. 19, 326 (1980). 

Matsingou, C., Hatziantoniou, S., Georgopoulos, A., Dimas, K., Terzis, A., and Demetzos, C. (2005) Labdane-type diterpenes thermalefiects on phospholipid bilayers, incorporation into liposomes and biological activity. Chcm. Phys. Lipids, 138, 1-11. 

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