ABSTRACT
Phytoalexins are common in all the natural product groups, e.g., isoflavonoids, furanoterpenoids, sesquiterpenoids, polyacetylenes, and dihydrophenanthrenes (Tomiyama, 1971; Grisebach and Abel, 1978). They were defined in 1940 as defensive substances possessing antimicrobial properties which were produced by host plants after infection (Müller and Borger, 1940), but now they are recognized to be induced by products of microbial origin or stress treatment (injury, heat, UV light, etc.) as well as living microorganisms (Masamune et al., 1978). For example, representative sesquiterpene phytoalexins isolated from the Solanaceae family (potato, tobacco, etc.) are listed in Fig. 1 (1–7) (Stoessl et al., 1976). These compounds involve unique structures. In particular, phytoalexins (4–7) belong to spirovetivane sesquiterpenes bearing a spiro[4.5]decane skeleton. Sesquiterpene phytoalexins isolated from Solanaceae. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780203752647/a1a27a5a-cb92-45e1-8d4d-c3cf86d40c11/content/fig19_1_OB.tif"/>
