Changes in apolar metabolites during in vitro organogenesis of Pancratium maritimum

Metabolite Profiling of Gardenia jasminoides Ellis In Vitro Cultures with Different Levels of Differentiation

Gardenia jasminoides Ellis is an aromatic and medicinal plant of high economic value. Much research has focused on the phytochemistry and biological activities of Gardenia fruit extracts; however, the potential of the Gardenia plant in vitro cultures used as mass production systems of valuable secondary metabolites has been understudied. This paper presents data on metabolite profiling (GC/MS and HPLC), antioxidant activities (DPPH, TEAC, FRAP, and CUPRAC), and SSR profiles of G. jasminoides plant leaves and in vitro cultures with different levels of differentiation (shoots, callus, and cell suspension). The data show strong correlations (r = 0.9777 to r = 0.9908) between antioxidant activity and the concentrations of chlorogenic acid, salicylic acid, rutin, and hesperidin. Eleven co-dominant microsatellite simple sequence repeats (SSRs) markers were used to evaluate genetic variations (average PIC = 0.738 ± 0.153). All of the investigated Gardenia in vitro cultures showed high genetic variabilities (average Na = 5.636 ± 2.157, average Ne = 3.0 ± 1.095). This is the first report on a study on metabolite profiles, antioxidant activities, and genetic variations of G. jasminoides in vitro cultures with different levels of differentiation.

Dimethylamination of Primary Alcohols Using a Homogeneous Iridium Catalyst: A Synthetic Method for N,N-Dimethylamine Derivatives

A new catalytic system for N,N-dimethylamination of primary alcohols using aqueous dimethylamine in the absence of additional organic solvents has been developed. The reaction proceeds via borrowing hydrogen processes, which are atom-efficient and environmentally benign. An iridium catalyst bearing an N-heterocyclic carbene (NHC) ligand exhibited high performance, without showing any deactivation under aqueous conditions. In addition, valuable N,N-dimethylamine derivatives, including biologically active and pharmaceutical molecules, were synthesized. The practical application of this methodology was demonstrated by a gram-scale reaction.

Recent Progress in Amaryllidaceae Biotechnology

Plants belonging to the monocotyledonous Amaryllidaceae family include about 1100 species divided among 75 genera. They are well known as medicinal and ornamental plants, producing pharmaceutically important alkaloids, the most intensively investigated of which are galanthamine and lycorine. Amaryllidaceae alkaloids possess various biological activities, the most important one being their anti-acetylcholinesterase activity, used for the treatment of Alzheimer's disease. Due to increased demand for Amaryllidaceae alkaloids (mainly galanthamine) and the limited availability of plant sources, in vitro culture technology has attracted the attention of researchers as a prospective alternative for their sustainable production. Plant in vitro systems have been extensively used for continuous, sustainable, and economically viable production of bioactive plant secondary metabolites. Over the past two decades, a significant success has been demonstrated in the development of in vitro systems synthesizing Amaryllidaceae alkaloids. The present review discusses the state of the art of in vitro Amaryllidaceae alkaloids production, summarizing recently documented plant in vitro systems producing them, as well as the authors' point of view on the development of biotechnological production processes with a focus on the future prospects of in vitro culture technology for the commercial production of these valuable alkaloids.

Application of in vivo solid phase microextraction (SPME) in capturing metabolome of apple (Malus ×domestica Borkh.) fruit

An in vivo direct-immersion SPME sampling coupled to comprehensive two-dimensional gas chromatography – time-of-flight mass spectrometry (GCxGC-ToFMS) was employed to capture real-time changes in the metabolome of ‘Honeycrisp’ apples during ripening on the tree. This novel sampling approach was successful in acquiring a broad metabolic fingerprint, capturing unique metabolites and detecting changes in metabolic profiles associated with fruit maturation. Several metabolites and chemical classes, including volatile esters, phenylpropanoid metabolites, 1-octen-3-ol, hexanal, and (2E,4E)-2,4-hexadienal were found to be up-regulated in response to fruit maturation. For the first time, Amaryllidaceae alkaloids, metabolites with important biological activities, including anti-cancer, anti-viral, anti-parasitic, and acetylcholinesterase (AChE) inhibitory activity, were detected in apples. Considering the elimination of oxidative degradation mechanisms that adversely impact the representativeness of metabolome obtained ex vivo, and further evidence that lipoxygenase (LOX) pathway contributes to volatile production in intact fruit, in vivo DI-SPME represents an attractive approach for global plant metabolite studies.

Discovery of the Potential Biomarkers for Discrimination between Hedyotis diffusa and Hedyotis corymbosa by UPLC-QTOF/MS Metabolome Analysis

Hedyotis diffuse Willd. (HD) and Hedyotis corymbosa (L.) Lam. (HC), two closely related species of the same genus, are both used for health benefits and disease prevention in China. HC is also indiscriminately sold as HD in the wholesale chain and food markets. This confusion has led to a growing concern about their identification and quality evaluation. In order to further understand the molecular diversification between them, we focus on the screening of chemical components and the analysis of non-targeted metabolites. In this study, UPLC-QTOF-MSE, UNIFI platform and multivariate statistical analyses were used to profile them. Firstly, a total of 113 compounds, including 80 shared chemical constituents of the two plants, were identified from HC and HD by using the UNIFI platform. Secondly, the differences between two herbs were highlighted with the comparative analysis. As a result, a total of 33 robust biomarkers enabling the differentiation were discovered by using multivariate statistical analyses. For HC, there were 18 potential biomarkers (either the contents were much greater than in HD or being detected only in HC) including three iridoids, eight flavonoids, two tannins, two ketones, one alcohol and two monoterpenes. For HD, there were15 potential biomarkers (either the contents were much greater than in HC or being detected only in HD) including two iridoids, eight flavonoids, one tannin, one ketone, and three anthraquinones. With a comprehensive consideration of the contents or the MS responses of the chemical composition, Hedycoryside A and B, detected only in HC, could be used for rapid identification of HC. The compounds 1,3-dihydroxy-2-methylanthraquinone and 2-hydroxy-3-methylanthraquinone, detected only in HD, could be used for rapid identification of that plant. The systematic comparison of similarities and differences between two confusing Chinese herbs will provide reliable characterization profiles to clarify the pharmacological fundamental substances. HC should not be used as the substitute of HD.

Sustainable production of azadirachtin from differentiated in vitro cell lines of neem (Azadirachta indica)

Neem possesses immense medicinal properties and has immediate application as ecofriendly, biodegradable biopesticide. All these properties are because of a structurally complex bioactive compound Azadirachtin, mainly present in seeds. However, it could not be exploited to its full because of heterogeneity in compound production due to out-breeding in nature of the plant. This is the first elaborate report on systematic studies on azadirachtin biosynthesis where different redifferentiated and dedifferentiated in vitro cell lines of A. indica (neem), obtained from various explants, were utilized. All cell lines were found positive for the compound with significantly higher azadirachtin yield of 2330 µg /g DW was obtained from redifferentiated cell lines established from zygotic embryo cultures. The study, demonstrates the possibility of consistent biosynthesis of azadirachtin in bulk under optimal growth conditions.

Azadirachtin has high industrial demand due to its immediate application as an ecofriendly, biodegradable biopesticide and also due to its various other significant bioactivities. To date, the only commercially feasible way to produce azadirachtin is extraction from seeds, but their availability is very limited as the tree flowers only once a year and only one-third of the fruits are collected due to operational problems. Further, due to the strict out-breeding nature of the plant, the seeds are highly heterozygous, resulting in inconsistent metabolite production. Therefore, in the present study, to achieve sustainable production of azadirachtin, dedifferentiated and redifferentiated calli derived from various explants of neem—zygotic embryo, leaf and ovary—were investigated for their potential to biosynthesize azadirachtin. High-performance liquid chromatography analysis of the in vitro cell lines showed the presence of azadirachtin in all the samples tested, the content of which in cultured cells varied with explant source and cell differentiation response. The presence of azadirachtin in samples was further confirmed by positive electrospray ionization mass spectroscopy. The zygotic embryo cultures of neem accumulated much higher amounts of azadirachtin than leaf and ovary cultures. Furthermore, organized in vitro callus cultures (redifferentiated) supported higher azadirachtin biosynthesis, while unorganized callus cultures (dedifferentiated) supported the least. The maximum azadirachtin content of 2.33 mg g⁻¹ dry weight was obtained from redifferentiated immature zygotic embryo cultures.

Towards a molecular understanding of the biosynthesis of amaryllidaceae alkaloids in support of their expanding medical use

The alkaloids characteristically produced by the subfamily Amaryllidoideae of the Amaryllidaceae, bulbous plant species that include well know genera such as Narcissus (daffodils) and Galanthus (snowdrops), are a source of new pharmaceutical compounds. Presently, only the Amaryllidaceae alkaloid galanthamine, an acetylcholinesterase inhibitor used to treat symptoms of Alzheimer's disease, is produced commercially as a drug from cultivated plants. However, several Amaryllidaceae alkaloids have shown great promise as anti-cancer drugs, but their further clinical development is restricted by their limited commercial availability. Amaryllidaceae species have a long history of cultivation and breeding as ornamental bulbs, and phytochemical research has focussed on the diversity in alkaloid content and composition. In contrast to the available pharmacological and phytochemical data, ecological, physiological and molecular aspects of the Amaryllidaceae and their alkaloids are much less explored and the identity of the alkaloid biosynthetic genes is presently unknown. An improved molecular understanding of Amaryllidaceae alkaloid biosynthesis would greatly benefit the rational design of breeding programs to produce cultivars optimised for the production of pharmaceutical compounds and enable biotechnology based approaches.