Male-Produced Sex Pheromone of Tibraca limbativentris Revisited: Absolute Configurations of Zingiberenol Stereoisomers and their Influence on Chemotaxis Behavior of Conspecific Females.

The rice stalk stink bug, Tibraca limbativentris, is an important rice pest in Brazil with a high invasive potential for Mexico and the USA. The sex pheromone of this species was previously identified as a combination of two stereoisomers of 1,10-bisaboladien-3-ol (zingiberenol), but the absolute configurations of these sesquiterpenes were not determined, neither were their effect(s) on T. limbativentris behavior evaluated. In this study, using two chiral columns, we compared retention times of the two natural 1,10-bisaboladien-3-ol stereoisomers from air-entrainment samples of male T. limbativentris with those of synthetic stereoisomers of 1,10-bisaboladien-3-ol. The results showed that T. limbativentris males produce (3S,6S,7R)-1,10-bisaboladien-3-ol (1) and (3R,6S,7R)-1,10-bisaboladien-3-ol (5) as their sex pheromone. Two new minor, male-specific components were also identified as cis and trans isomers of 2,10-bisaboladien-1-ol (sesquipiperitol). Y-tube olfactometer bioassays showed that the major (3S,6S,7R) isomer 1 was essential for attraction of T. limbativentris females, but the minor (3R,6S,7R) isomer 2 was not, nor did it show synergistic/antagonistic effects when added to the major isomer. The (1S,6S,7R) and (1R,6S,7R) stereoisomers of sesquipepiritol also attracted T. limbativentris females.

Field Responses of Rice Stalk Stink Bug, Tibraca limbativentris, to Synthetic Sex Pheromone and Isomers of 1,10-Bisaboladien-3-ol.

The rice stalk stink bug, Tibraca limbativentris Stål, is an important rice pest in Brazil, causing significant damage to rice plants and consequently yield losses, with a high invasive potential in Mexico and USA. The male-produced sex pheromone of this species was recently identified as a 7:3 mixture of (3S,6S,7R)-1,10-bisaboladien-3-ol (1) and (3R,6S,7R)-1,10-bisaboladien-3-ol (5) (a.k.a. zingiberenols). The aim of this study was to evaluate field responses of T. limbativentris females to the racemic mixture and stereoisomers of 1,10-bisaboladien-3-ol, including the male-produced sex pheromone. The results obtained in two rice-producing areas of Brazil (Rio Grande do Sul and Santa Catarina) showed that traps baited with the main component 1 alone, the racemic mixture, and a mixture of 1 and 5 were attractive to females of T. limbativentris. The minor component 5 was unable to attract females when used alone. The results indicate that the sex pheromone of T. limbativentris and racemic mixture of 1,10-bisaboladien-3-ol were equally attractive to co-specific females in rice fields, and they could be a tool to incorporate in rice stalk stink bug management programs.

The influence of Prussian drug legislation on the first German Pharmacopoeia 1872.

When the new Kaiserreich was proclaimed (1871) new rules were stated to organize all the 20 states. A unified Pharmacopoeia was also created. A committee was constituted by the Federal Parliament and the first edition was published in 1872, and in the revised form (editio altera) in 1882, the first one was the continuation of the series of Prussian Pharmacopoeia editions (1799-1862) which resolved many problems concerning the uniformity of weights and measurements, language, analytical assays and prescriptions.

The emergence of clinical chemistry in the 19th century: presuppositions and consequences.

The practice of clinical chemistry began in Germany during the years 1831--42; the institutionalization of the subject started immediately afterwards in the period 1842--1846. These developments arose from: 1) a concern with 'Naturphilosophie' in the romantic era, 2) the influence of the so-called school of natural history in the clinic, 3) sporadic state support for a science-based higher education and 4) the scientific reductionism in Medicine during the 'Vormärz'-era in the German countries. After 1848, the new field did not expand until the late 1860's, but it stimulated developments in different scientific disciplines like animal, pharmaceutical and hygienic chemistry.