Vegetative anatomy and micromorphology of Salvia divinorum (Lamiaceae) from Mexico, combined with chromatographic analysis of salvinorin A

Thin-Layer Chromatography (TLC) in the Screening of Botanicals-Its Versatile Potential and Selected Applications

The aim of this paper is to present a comprehensive overview of the main aims and scopes in screening of botanicals, a task of which thin-layer chromatography (TLC) is, on an everyday basis, confronted with and engaged in. Stunning omnipresence of this modest analytical technique (both in its standard format (TLC) and the high-performance one (HPTLC), either hyphenated or not) for many analysts might at a first glance appear chaotic and random, with an auxiliary rather than leading role in research, and not capable of issuing meaningful final statements. Based on these reflections, our purpose is not to present a general review paper on TLC in screening of botanicals, but a blueprint rather (illustrated with a selection of practical examples), which highlights a sovereign and important role of TLC in accomplishing the following analytical tasks: (i) solving puzzles related to chemotaxonomy of plants, (ii) screening a wide spectrum of biological properties of plants, (iii) providing quality control of herbal medicines and alimentary and cosmetic products of biological origin, and (iv) tracing psychoactive plants under forensic surveillance.

Micromorphological Traits of Balcanic Micromeria and Closely Related Clinopodium Species (Lamiaceae)

A study of the trichomes types and distribution and pollen morphology was carried out in nine Micromeria taxa (M. cristata ssp. cristata, M. cristata ssp. kosaninii, M. croatica, M. graeca ssp. graeca, M. graeca ssp. fruticulosa, M. juliana, M. kerneri, M. longipedunculata and M. microphylla) and five closely related Clinopodium species (C. dalmaticum, C. frivaldszkyanum, C. pulegium, C. serpyllifolium and C. thymifolium) from the Lamiaceae family of the Balkan Peninsula. By scanning electron microscope, non-glandular trichomes, peltate and capitate trichomes were observed on the calyx, leaves and stem of the studied species. Two subtypes of capitate trichomes were observed in Micromeria species: subtype 1 (consisting of a basal epidermal cell and an elliptically shaped head cell) and subtype 2 (consisting of a basal epidermal cell, two to three stalk cells and a round head cell). In Clinopodium species, three types of capitate trichomes were observed: subtype 1, subtype 3 (consisting of a basal epidermal cell, a short peduncle cell, and a single round head cell), and subtype 4 (consisting of a basal epidermal cell, a stalk cell, and an elongated head cell). These results support the recent transfer of Micromeria species from the section Pseudomelissa to the genus Clinopodium.

Pharmacokinetics and Pharmacodynamics of Salvinorin A and Salvia divinorum: Clinical and Forensic Aspects

Salvia divinorum Epling and Játiva is a perennial mint from the Lamiaceae family, endemic to Mexico, predominantly from the state of Oaxaca. Due to its psychoactive properties, S. divinorum had been used for centuries by Mazatecans for divinatory, religious, and medicinal purposes. In recent years, its use for recreational purposes, especially among adolescents and young adults, has progressively increased. The main bioactive compound underlying the hallucinogenic effects, salvinorin A, is a non-nitrogenous diterpenoid with high affinity and selectivity for the κ-opioid receptor. The aim of this work is to comprehensively review and discuss the toxicokinetics and toxicodynamics of S. divinorum and salvinorin A, highlighting their psychological, physiological, and toxic effects. Potential therapeutic applications and forensic aspects are also covered in this review. The leaves of S. divinorum can be chewed, drunk as an infusion, smoked, or vaporised. Absorption of salvinorin A occurs through the oral mucosa or the respiratory tract, being rapidly broken down in the gastrointestinal system to its major inactive metabolite, salvinorin B, when swallowed. Salvinorin A is rapidly distributed, with accumulation in the brain, and quickly eliminated. Its pharmacokinetic parameters parallel well with the short-lived psychoactive and physiological effects. No reports on toxicity or serious adverse outcomes were found. A variety of therapeutic applications have been proposed for S. divinorum which includes the treatment of chronic pain, gastrointestinal and mood disorders, neurological diseases, and treatment of drug dependence. Notwithstanding, there is still limited knowledge regarding the pharmacology and toxicology features of S. divinorum and salvinorin A, and this is needed due to its widespread use. Additionally, the clinical acceptance of salvinorin A has been hampered, especially due to the psychotropic side effects and misuse, turning the scientific community to the development of analogues with better pharmacological profiles.

Structural characterization of vegetative organs of the endangered Brazilian native species Hesperozygis ringens (Benth.) Epling

The aim of this study was to describe the structural characterization of Hesperozygis ringens (Benth.) Epling vegetative organs. For this purpose, leaves, stems and roots of the endangered Lamiaceae were collected from a population located in Santo Antão, Santa Maria municipality, Rio Grande do Sul, Brazil. Results demonstrated that the H. ringens leaf blade presents glandular and non-glandular trichomes as well as two morphs of diallelocytic stomata, which are usually found above the epidermis level. The petiole is concave on ventral face and convex on its dorsal face, containing glandular and non-glandular trichomes as well as stomata in the epidermis. These types of trichomes were also detected in the stem. In addition, the presence of intercellular spaces within the organ is highlighted. Stomata above epidermis level also occurred in the stem. Phenolic idioblasts were found in the cortical region of plant root and deposit of lipophilic substance was observed in phloem cells. Great amount of apparently two different crystals were detected in all organs. Information obtained in this study provides knowledge about the characterizationof H. ringens, which may be used to distinguish characters of taxa and can help understand the species survival in its occurrence sites.

Salvinorina A: terpeno alucinógeno presente en Salvia divinorum Epling & Játiva

Tema y alcance: el objetivo de esta revisión es presentar los estudios químicos que se han realizado sobre Salvia divinorum E&J en estos últimos años. Características: desde la década de 1990 hasta hoy se ha incrementado la distribución y el uso de Salvia divinorum E&J para “fines recreativos”, debido a sus efectos alucinógenos y a su fácil acceso. Sus efectos en el organismo se han relacionado con las de otras sustancias como: delta-9-THC en la marihuana, DMT, LSD , MDMA, PCP y ketamina. Hallazgos: las investigaciones químicas realizadas en otros países sobre Salvia divinorum E&J se enfocan en los procesos de extracción, determinación, cuantificación, análisis y biosíntesis de Salvinorina A, compuesto químico al cual se le atribuye la bioactividad de la planta. Este compuesto es considerado como uno de los alucinógenos más potentes de origen natural, además de ser química y estructuralmente único, puesto que fue el primer diterpeno conocido con actividad psicoactiva. Conclusiones: la presente revisión encontró que en los últimos años las investigaciones químicas en Salvia divinorum E&J están enfocadas a través del uso de cromatografía de gases y cromatografía líquida en diversas matrices como hojas, sangre, orina y agua, con el fin de determinar la Salvinorina A y otros metabolitos presentes en la planta. En una de las investigaciones, comprobaron por RMN y HR-ESI-MS que la biosíntesis de Salvinorina A está dada por la ruta metabólica del ácido mevalónico y la ruta del metileritritol fosfato, las cuales corresponden a las rutas metabólicas para la biosíntesis de terpenos.

Biosynthesis of the psychotropic plant diterpene salvinorin A: Discovery and characterization of the Salvia divinorum clerodienyl diphosphate synthase

Salvia divinorum commonly known as diviner's sage, is an ethnomedicinal plant of the mint family (Lamiaceae). Salvia divinorum is rich in clerodane-type diterpenoids, which accumulate predominantly in leaf glandular trichomes. The main bioactive metabolite, salvinorin A, is the first non-nitrogenous natural compound known to function as an opioid-receptor agonist, and is undergoing clinical trials for potential use in treating neuropsychiatric diseases and drug addictions. We report here the discovery and functional characterization of two S. divinorum diterpene synthases (diTPSs), the ent-copalyl diphosphate (ent-CPP) synthase SdCPS1, and the clerodienyl diphosphate (CLPP) synthase SdCPS2. Mining of leaf- and trichome-specific transcriptomes revealed five diTPSs, two of which are class II diTPSs (SdCPS1-2) and three are class I enzymes (SdKSL1-3). Of the class II diTPSs, transient expression in Nicotiana benthamiana identified SdCPS1 as an ent-CPP synthase, which is prevalent in roots and, together with SdKSL1, exhibits a possible dual role in general and specialized metabolism. In vivo co-expression and in vitro assays combined with nuclear magnetic resonance (NMR) analysis identified SdCPS2 as a CLPP synthase. A role of SdCPS2 in catalyzing the committed step in salvinorin A biosynthesis is supported by its biochemical function, trichome-specific expression and absence of additional class II diTPSs in S. divinorum. Structure-guided mutagenesis revealed four catalytic residues that enabled the re-programming of SdCPS2 activity to afford four distinct products, thus advancing our understanding of how neo-functionalization events have shaped the array of different class II diTPS functions in plants, and may promote synthetic biology platforms for a broader spectrum of diterpenoid bioproducts.