Lacinilene

Small airway constriction and recruitment of leukocytes on pulmonary surfaces are prominent, documented responses to the inhalation of cotton dust. Currently, one or both of these effects are generally ascribed to endotoxin (8-10), to antigen-antibody reactions (11), to lacinilene C-7 methyl ether (1, 13), to a low molecular weight ( 1000 daltons), neutral, highly water soluble substance that is stable in boiling water and found in cotton bracts (14), to chemotaxins present in cotton mill dust extracts (15, 16) or to histamine releasing substances (17). 

Intermediate for the 58 total synthesis of lacinilene C-7 methyl ether... 

Hernandezine (=Thalicsimine Thaliximine) (bisbenzylisoquinoline) Lacinilene C 7-methyl ether (sesquiterpene)... 

Lacinilene C 7-methyl Gossypium hirsutum (cotton) t Ca2+ influx per V-Cai+ CH... 

A new synthesis of torreyol (183) based on an intramolecular Diels-Alder reaction has been reported (Scheme 30).A second synthesis of lacinilene C methyl ether (184), a constituent of cotton, has been published. This compound is thought to be responsible for byssinosis, a disease prevalent in the textile industry. 

In the laboratory of K. Krohn, the total synthesis of phytoalexine (+)-lacinilene C methyl ether was completed. In order to prepare the core of the natural product, an intermolecular Friedel-Crafts acylation was carried out between succinic anhydride and an aromatic substrate, followed by an intramolecular acylation. After the first acylation, the 4-keto arylbutyric acid was reduced under Clemmensen reduction conditions (to activate the aromatic ring for the intramolecular acylation). 

Krohn, K., Zimmermann, G. Transition-Metal-Catalyzed Oxidations. 11. Total Synthesis of ( )-Lacinilene C Methyl Ether by P-Naphthol to a-... 

Fig. 2. Structures and biochemical relationships of 2,7-dihydroxycadalene, 2-hydroxy-7-methoxycadalene, lacinilene C, and lacinilene C methyl ether.

Resistant, compared to susceptible, cultivars exhibit more rapid synthesis of terpenoid aldehyde phytoalexins in xylem vessels (16), and cadalene and lacinilene phytoalexins in cotyledonary tissue Q7), in response to X. campestris infection. Of the various compounds tested, 2,7-dihyciroxycadalene, followed by lacinilene C, had the greatest antibiotic activity against the bacterium. Lacinilene C exists as two optical isomers, which occur in different proportions in two different resistant cultivars. The (+)-lacinilene C is more than three times as toxic as (-)-lacinilene C (17). The toxicity of terpenoid aldehydes and their precursors have not been tested against the bacterium. 

Aflatoxin Bj is the most potent carcinogenic known substance occurring naturally. Interestingly enough 3-methyl-2-butanol is one of the main characteristic odors of living colonies of A. flavus. As an illustration of the complexity of these interactions it may be mentioned that treating cotton leaves with cell-free extracts of A. flavus induces five phytoalexins (lacinilene C, lacinilene C 7-methyl ether, scopoletin, 2-hydroxy-7-methoxycadalene, and 2,7-dihydroxycadalene) in the leaves (135). 

Scheme 7. Five phytoalexins, lacinilene C [1], lacinilene C 7-methyl ether [2], scopoletin [3], 2-hydroxy-7-methoxycadalene [4], and 2,7 dihydroxycadalene [5]) induced by A. flavus in cotton leaves. The antibiotic cortalcerone [6] is induced in the fungus Corticium caeruleum by various stimuli.

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