Kaurenic acid

Usubillaga, A., Morales, A. 1972. Kaurenic acids in Espeletia species. Phytochemistry 11 1856-1857. 

From the kaurane-type diterpenoids, ent-kaurenic acid, Fig. (13) and ent-kaurenol, Fig. (14) were reported from the roots of Baccharis ramoisissima Gardn. [391, Baccharis minutiflora Mart. [451 and Baccharis intermixta Gardn. [25],... 

Although referred to as kaurenic acid, the published structure of this compound from Melampodium perfoliatum contained a C-4p-oriented carboxyl group.]... 

Bohlmann, F., and P.K. Mahanta Kaurenic acid derivatives from Adenos-temma caffrum. Phytochem. 17, 814, (1978). 

Bohlmann, F., C. Zdero, H. Robinson, and R.M. King 15a-Methylacryl-oyloxy-e/2/-kaurenic acid from Ichthyothere species. Phytochem. 20, 522 (1981). 

Bohlmann, F., J. Ziesche, R.M. King, and H. Robinson Eudesmanolides and diterpenes from Wedelia trilobata and an ewZ-kaurenic acid derivative from Aspilia parvifolia. Phytochem. 20, 751 (1981). 

Ortega, A., F.J. Morales, and M. Salmon Kaurenic acid derivatives from Stevia eupatoria, Phytochem. 24, 1850 (1985). 

Most of the GA-synthesis inhibitors characterized so far affect two segments of the compHcated pathway from MVA to the many different GAs identified. The cycHzation reactions that produce / Akaurene are inhibited by the onium growth retardants, and the oxidations of /-kaurene to /-kaurenoic acid are sensitive to heterocycHc triazoles such as paclobutrazol and similar compounds. Other enzymes in the pathway are points for pathway dismption by as yet undeveloped GA biosynthesis inhibitors (236). 

Obermann, H. andG. Spiteller. 16,17-dihydroxy-9-kauren-l8-oic acid. A compound of roasted coffee. Chem Ber 1975 108 1093. 

Naturally Occurring Substances.—Beyeria (Euphorbiaceae) species have been the source of a number of tetracyclic diterpenoids. Some of these were new or poorly defined species and their classification has now been clarified. " The presence of enf-kaurenal has again been recorded in Fusarium monoliforme, whilst ent-kaur-16-en-19-oic acid (72) has been isolated from Mikania hirsutissima (Composi-tae). Microbiological hydro xylation of ent-kaur-16-en-19-oic acid by... 

Varieties of sunflower (Helianthus annums, Asteraceae) that are resistant to attack by larvae of the sunflower moth (Homeosoma electellum) contain high concentrations of trachyloban-19-oic acid and (-)-16-kauren-19-oic acid in their florets (84,132). 

Aralia chinensis L. A. cordata Thunb. var. continentalis (Kitag.) Y. C. Chu A. elata (Miq.) Seem. A. elata (Miq.) Seem. F. subinermis Y. C. Chu Jia Mu, Du Huo (Aralia) (root) Diterpenoids such as (-) pimaradene, (-) kaurene derivatives, l-pimara-8, 15-dien-19-oic acid, aralosides, araligenin, oleanolic acid, beta-taralin, alpha-taralin.20 48 50 Carminative, for arthralgia, gastroenteritis, headache, diuretic, antidiabetic, antiseptic. 

Podocarpus macrophyllus (Thunb.) D. Don Luo Han Song (Southern yew) (stem bark, leaf, root, fruit) Pinene, camphene, cadinene, podocarpene, neocryuptomerin, kaurene, ecdysterone, ponasterone, makisterones, hinokiflavone, sciadopitysin, podocarpus flavones, macrephyllic acid, podototarin, totarol.54 For ringworms, blood disorders, tonic for heart, kidneys, lungs, stomach. 

The alternative stereochemistry typified by labdadienyl PP can be seen in the structure of abi-etic acid (Figure 5.48), the major component of the rosin fraction of turpentine from pines and other conifers (Table 5.1). Initially, the tricyclic system is built up as in the pathway to /-kaurene (Figure 5.47), via the same mechanism, but generating the enantiomeric series of compounds. The cation loses a proton to give sandaracopimara-diene (Figure 5.48), which undergoes a methyl... 

Microbiological Methods. The low substrate specificity of many of the enzymes involved in GA biosynthesis in Gibberella fujikuroi has been utilized for the preparation of higher plant GAs. Suitable analogs of the natural GA-precursors are converted by the fungus to the corresponding GA analogs. It is usual to prevent the synthesis of the natural GAs in order to facilitate purification of the unnatural products. A mutant strain, Bl- la, in which GA biosynthesis is blocked early in the pathway (67) (between ent-kaurenal and ent-kaurenoic acid) has been used. 

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