For centuries, 'khat sessions' have played a key role in the social and cultural traditions among several communities around Saudi Arabia and most East African countries. The identification of cathinone as the main psychoactive compound of khat leaves, exhibiting amphetamine-like pharmacological properties, resulted in the synthesis of several derivatives structurally similar to this so-called natural amphetamine. Synthetic cathinones were primarily developed for therapeutic purposes, but promptly started being misused and extensively abused for their euphoric effects. In the mid-2000's, synthetic cathinones emerged in the recreational drug markets as legal alternatives ('legal highs') to amphetamine, 'ecstasy', or cocaine. Currently, they are sold as 'bath salts' or 'plant food', under ambiguous labels lacking information about their true contents. Cathinone derivatives are conveniently available online or at 'smartshops' and are much more affordable than the traditional illicit drugs. Despite the scarcity of scientific data on these 'legal highs', synthetic cathinones use became an increasingly popular practice worldwide. Additionally, criminalization of these derivatives is often useless since for each specific substance that gets legally controlled, one or more structurally modified analogs are introduced into the legal market. Chemically, these substances are structurally related to amphetamine. For this reason, cathinone derivatives share with this drug both central nervous system stimulating and sympathomimetic features. Reports of intoxication and deaths related to the use of 'bath salts' have been frequently described over the last years, and several attempts to apply a legislative control on synthetic cathinones have been made. However, further research on their pharmacological and toxicological properties is fully required in order to access the actual potential harm of synthetic cathinones to general public health. The present work provides a review on khat and synthetic cathinones, concerning their historical background, prevalence, patterns of use, legal status, chemistry, pharmacokinetics, pharmacodynamics, and their physiological and toxicological effects on animals and humans.

In the area of psychotropic drugs, tryptamines are known to be a broad class of classical or serotonergic hallucinogens. These drugs are capable of producing profound changes in sensory perception, mood and thought in humans and act primarily as agonists of the 5-HT2A receptor. Well-known tryptamines such as psilocybin contained in Aztec sacred mushrooms and N,N-dimethyltryptamine (DMT), present in South American psychoactive beverage ayahuasca, have been restrictedly used since ancient times in sociocultural and ritual contexts. However, with the discovery of hallucinogenic properties of lysergic acid diethylamide (LSD) in mid-1900s, tryptamines began to be used recreationally among young people. More recently, new synthetically produced tryptamine hallucinogens, such as alpha-methyltryptamine (AMT), 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT) and 5-methoxy-N,N-diisopropyltryptamine (5-MeO-DIPT), emerged in the recreational drug market, which have been claimed as the next-generation designer drugs to replace LSD ('legal' alternatives to LSD). Tryptamine derivatives are widely accessible over the Internet through companies selling them as 'research chemicals', but can also be sold in 'headshops' and street dealers. Reports of intoxication and deaths related to the use of new tryptamines have been described over the last years, raising international concern over tryptamines. However, the lack of literature pertaining to pharmacological and toxicological properties of new tryptamine hallucinogens hampers the assessment of their actual potential harm to general public health. This review provides a comprehensive update on tryptamine hallucinogens, concerning their historical background, prevalence, patterns of use and legal status, chemistry, toxicokinetics, toxicodynamics and their physiological and toxicological effects on animals and humans.

The oxidative degradation of white wines rapidly leads to a loss of their sensorial qualities. The identification of the most important descriptors related with oxidation-spoiled wine was performed by a trained sensory panel. The terms selected were "honey-like", "farm-feed", "hay", and "woody-like". By gas chromatography-olfactometry analysis three aromatic zones related to these descriptors in the oxidation-spoiled white wines could be determined. Comparison of the aroma extract dilution analysis aromagrams of oxidation-spoiled white wines and a nonspoiled wine showed the highest values of dilution factors were attributed to 3-(methylthio)propionaldehyde, phenylacetaldehyde, 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN), and 4,5-dimethyl-3-hydroxy-2(5H)-furanone (sotolon). A "forced aging" experiment was implemented to simulate the typical oxidation-spoiled aroma. Samples rated with the highest score in the ranking test were also those that presented the highest concentration of these four molecules. To test the sensory impact of these substances, a normal wine (unspoiled) was spiked with these molecules (with the exception of TDN) singly and in combination, and the similarity value (SV) between samples and the oxidation-spoiled white wines was then determined. The highest value from the similarity tests was 5.4 when the three compounds were added simultaneously; 3-(methylthio)propionaldehyde alone was found to be responsible for 3.6, suggesting that, among the molecules studied, it is the most important contributor to the typical aroma of an oxidation-spoiled white wine.