Laxmi N. Misra

Cuauthemone derivatives from Tessaria integrifolia and Pluchea symphytifolia

Abstract The aerial parts of Tessaria integrifolia afforded in addition to known compounds nine further cuauthemone derivatives and those from Pluchea symphytifolia also a further sesquiterpene of this type. The structures of two pairs of similar compounds are revised from 11-hydroxy to 11-peroxy derivatives.

Eremophilane derivatives and other constituents from Senecio species

Abstract The investigation and reinvestigation respectively of 23 Senecio species afforded 11 further cacalol derivatives, a furoeremophilone, 17 eremophilanes, 4 bisabolene derivatives, a shikimic acid derivative, a bis -prenylated p -hydroxybenzaldehyde, menth-2-en- 1,7-diol and a cumol derivative. The configuration of some eremophilanes have been revised. Structures were elucidated by spectroscopic methods. The results are summarized in a table. The chemotaxonomic aspects agree with those of previous investigations.

Clerodane and labdane diterpenoids from Baccharis species

Abstract The investigation of eight Baccharis species afforded, in addition to known compounds, five new clerodanes, three labdane derivatives and a nor-diterpene as well as one hydroperoxide derived from 4α-hydroxygermacra-1(10), 5-diene. The structures were elucidated by spectroscopic methods. The structures of esters isolated previously from B. cassinaefolia have to be revised. Chemotaxonomic aspects are discussed briefly.

Guaianolides, heliangolides, diterpenes and cycloartenol derivatives from Balsamorhiza sagittata

Abstract Investigation of the aerial parts of Balsamorhiza sagittata afforded 12 new sesquiterpene lactones, five guaianolides, three heliangolides, three germacranolides and two geranylnerol derivatives. From the roots eight cycloartane derivatives, a hydroxylanosterone and hexacos-1-ene were isolated. Structures were elucidated mainly by spectroscopic methods, especially high field NMR. The chemotaxonomic situation is discussed briefly.

Isodaucane derivatives, norsesquiterpenes and clerodanes from chromolaena laevigata

Abstract The aerial parts of Chromolaena laevigata gave four new compounds derived from chromolaenin, four clerodane derivatives and a new type of norsesquiterpenes as well as two sesquiterpenes with a new carbon skeleton.

Pseudoguaianolides carabrone derivatives from Loxothysanus sinuatus

Abstract The aerial parts of Loxothysanus sinuatus afforded in addition to known compounds nine new pseudoguaianolides, three guaianolides and five carabrone derivatives. The structures were elucidated by spectroscopic methods. The chemotaxonomy is discussed briefly. The configurations of two guaianolides were corrected.

Further glaucolides from south african Vernonia species

Abstract The investigation of three South African Vernonia species afforded minute amounts of five new glaucolides, two monoepoxides and three diepoxides. The structures were elucidated by 1 H NMR spectroscopy. The roots of Vernonia sutherlandii contain, in addition to vernonataloide, bergamotene and santalene, minute amounts of the corresponding acetoxy derivatives.

Guaianolide α-arabinopyranosides from Helenium amarum

Abstract The aerial parts of Helenium amarum afforded, in addition to compounds reported previously, several known sesquiterpene lactones as well as some new ones, two pseudoguaianolides and a complex mixture of guaianolide α-arabinopyranosides, which differed in the position of the double bond, the configuration at C-8 and the position of an acetate group in the sugar moiety. Furthermore seco-caryophyllenes and phenylpropane derivatives were isolated. The structures were elucidated by spectroscopic methods and few chemical transformations.

Structure and synthesis of chlorophenol derivatives from helichrysum species

Abstract The isolation of a further chlorophenol acetylene from Helichrysum coriaceum as well as the synthesis of three naturally occurring chlorophenols are described.

Seco-helenanolides from Dugaldia integrifolia

Abstract The aerial parts of Dugaldia integrifolia afforded, in addition to acetylhymenograndin, floribundin, hymenoxon and isotelekin, three new seco -helenanolides and two derivatives of silphinene, one being isolated previously from Dugaldia hoopesii