Bismuth compounds and preparations with biological or medicinal relevance.

Although the mysteries of its history and origin remain unsolved, worldwide cultivation and high-demand production for citrus fruit (genus Citrus in family Rutaceae) make it stand high among fruit crops. Growth of the citrus industry, including rapid development of the processing technology of frozen concentrated orange juice after World War II, has greatly expanded with international trade and steadily increased consumption of citrus fruits and their products during the past several decades. Characterized by the distinct aroma and delicious taste, citrus fruits have been recognized as an important food and integrated as part of our daily diet, playing key roles in supplying energy and nutrients and in health promotion. With low protein and very little fat content, citrus fruits supply mainly carbohydrates, such as sucrose, glucose, and fructose. Fresh citrus fruits are also a good source of dietary fiber, which is associated with gastrointestinal disease prevention and lowered circulating cholesterol. In addition to vitamin C, which is the most abundant nutrient, the fruits are a source of B vitamins (thiamin, pyridoxine, niacin, riboflavin, pantothenic acid, and folate), and contribute phytochemicals such as carotenoids, flavonoids, and limonoids. These biological constituents are of vital importance in human health improvement due to their antioxidant properties, ability to be converted to vitamin A (for example, β-cryptoxanthin), and purported protection from various chronic diseases.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1541-4337.2012.00201.x

History, global distribution, and nutritional importance of citrus fruits

Although a lot of work has been done on the vibrational analysis of urea, there still remain some contradictions and uncertainties, mainly due to interpretation of the vibrational spectrum of crystalline urea based on force field calculations on isolated urea instead of on urea in its crystal phase. We have shown that this approach is not allowed in the case of urea. The vibrational spectrum of urea was interpreted by measuring the solid state infrared spectra of eight isotopomers of urea at room temperature and at −196 °C, and Raman spectra at room temperature and at −120 °C, and of a urea−water solution. Force field calculations from our recently published article on isolated urea and on urea in its crystal structure, at the Hartree−Fock level with a 6-31++G** basis set, were also used. We have also shown that high-pressure measurements using a “diamond anvil cell” are not useful by performing a vibrational analysis.

Vibrational Analysis of Urea

Sunlight photodegradation is one of the most destructive pathways for pesticides after their release into the environment. Plant surfaces, especially leaf surfaces, are the first reaction environment for a pesticide molecule after application, and spray drift would indirectly present a similar situation. Photolysis on soil surfaces becomes important when a pesticide is directly applied to soil or not significantly intercepted by plants, providing that the leaf cover does not shade the ground from sunlight. Because the foliar interception of pesticides depends on plant species and usually increases with their growth stage (Linders et al. 2000), the importance of soil photolysis is considered to be lessened when plants become mature. Spray drift after pesticide application or washoff from plants by rain is the indirect route by which a pesticide reaches the soil.

https://bilder.buecher.de/zusatz/14/14812/14812358_lese_1.pdf?origin=publication_detail

Photodegradation of Pesticides on Plant and Soil Surfaces

The molecular process whereby light induces color changes in certain substances, namely photochromism, is currently a topic of active research. Many reactions—mainly monomolecular—have been reexamined in greater detail from the standpoint of photochromism. Those found to be especially suitable for such studies include cis-trans isomerizations, pericyclic reactions, tautomerizations and dissociations. The most important in this group are undoubtedly the electrocyclization reactions. In this paper we present spiro[fluorene-9,1′-[1,8a]-dihydroindolizine] and its bis- and tris-aza analogues as examples of a promising new system with a wide range of variability. Not only the classical uses, but also those in new fields such as frequency doubling of laser radiation, holography or molecular microcircuit chips can now be considered.

Anna Weizmann

Papers

Steroids and Triterpenoids of Citrus Fruit, III, The Structure of Citrostadienol,a Natural 4Alfa-Methylstetol

Steroids and Triterpenoids of Citrus Fruit. II. Isolation of Citrostadienol1

Structure and Polarity of Some Polycyclic Spirans

THE STRUCTURE OF CITROSTADIENOL, A NATURAL 4α-METHYLSTEROL

The structure of chamazulene