(+)-Bulbocapnine-beta-N-oxide from glaucium fimbrilligerum

Corydecusines A-H, new phthalideisoquinoline hemicetal alkaloids from the bulbs of Corydalis decumbens inhibit Tau pathology by activating autophagy mediated by AMPK-ULK1 pathway

Twelve phthalideisoquinoline hemiacetal alkaloids including eight new ones (1-8) and one natural alkaloid characterized by an aziridine moiety with unassigned NMR data (9), were isolated and identified from the bulbs of Corydalis decumbens. Their structures were established by comprehensive analyses of HRESIMS, NMR, X-ray crystallography, and ECD analyses. The unambiguously established structures of the phthalideisoquinoline hemiacetal alkaloids indicated that the absolute configurations of C-1, C-9, and C-7' were confusable only relied on coupling constants. A summary of their ECD spectra was concluded and provided an insight for C-1, C-9, and C-7' absolute configuration assignment. These new compounds were evaluated to induce autophagy flux through flow cytometry analysis. Moreover, compounds 2 and 6 could significantly induce autophagy and inhibit Tau pathology by AMPK-ULK1 pathway activation, which provided an avenue for anti-AD lead compounds discovery.

Four new alkaloids from the roots of Dactylicapnos scandens

Four new alkaloids (1 - 4), together with five known ones (5 - 9), were isolated from the bulbs of Dactylicapnos scandens. The structures were determined by analysis of their spectroscopic data and quantum-chemical calculations. All the isolates were tested for their ability to modulate neuronal Ca2+ mobilization in primary cultured neocortical neurons. Compound 8 inhibited spontaneous Ca2+ oscillations at low micromolar concentrations.

Phytochemistry and pharmacology of alkaloids from Glaucium spp

Glaucium Mill. comprising 28 species with 78 synonyms, 3 subspecies, and 3 varieties worldwide belongs to the Papaveraceae family. The plants are well known for their different types of alkaloids. In the present study, we attempted to review the chemistry and pharmacology of the alkaloids from the genus Glaucium. For this purpose, the relevant data were collected from different scientific databases including, "Google Scholar", "ISI Web of Knowledge", "PubMed", "Scopus", and available books and e-books. Our results showed that aporphine alkaloids are dominated in the species; however, other types of alkaloids including protopines, benzophenanthridines, benzylisoquinolines, protoberberines, and morphinanes have also been reported from the genus. The pharmacological studies have shown that the alkaloids from Glaucium species have several biological activities of which anti-cancer and anti-cholinesterase effects have been highly reported. Besides, the data indicated that most of the species have been investigated neither phytochemically nor pharmacologically. Glaucium flavum, known as yellow horn poppy, is the most studied species. According to the reports, the plants from this genus have anti-cancer and anti-cholinesterase potentials and can be used as a source for aporphine alkaloids.

Aporphine Alkaloids from Ocotea puberula with Anti-Trypanosoma Cruzi Potential - Activity of Dicentrine-β-N-Oxide in the Plasma Membrane Electric Potentials

One new aporphine, dicentrine-β-N-oxide (1), together with five related known alkaloids dehydrodicentrine (2), predicentrine (3), N-methyllaurotetanine (4), cassythicine (5), and dicentrine (6) were isolated from the leaves of Ocotea puberula (Lauraceae). Antiprotozoal activity of the isolated compounds was evaluated in vitro against trypomastigote forms of Trypanosoma cruzi. Among the tested compounds, alkaloid 1 exhibited higher potential with EC₅₀ value of 18.2 μM and reduced toxicity against NCTC cells (CC₅₀ >200 μM - SI>11.0), similar to positive control benznidazole (EC₅₀ of 17.7 μM and SI=10.7). Considering the promising results of dicentrine-β-N-oxide (1) against trypomastigotes, the mechanism of parasite death caused by this alkaloid was investigated. As observed, this compound reached the plasma membrane electric potential directly after 2 h of incubation and triggered mitochondrial depolarization, which probably leads to trypomastigote death. Therefore, dicentrine-β-N-oxide (1), reported for the first time in this work, can contribute to future works for the development of new trypanocidal agents.

Alkaloids from Corydalis decumbens suppress neuronal excitability in primary cultures of mouse neocortical neurons

Eight previously undescribed alkaloids, named corydemine, dihydrocorydemine, corydedine, 8,13-dioxo-14-hydroxytetrahydropalmatine, egenine-α-N-oxide, egenine-β-N-oxide, 7'-O-ethylegenine-α-N-oxide, and 7'-O-ethylegenine-β-N-oxide, together with three known ones, muramine, l-tetrahydropalmatine, and (+)-egenine, were isolated from the bulbs of Corydalis decumbens. Their structures were elucidated by comprehensive spectroscopic analysis and chemical correlation. The isolated compounds were tested for their ability to modulate neuronal excitability in primary cultured neocortical neurons. Four of the compounds, corydemine, dihydrocorydemine, muramine, and l-tetrahydropalmatine, inhibited neuronal excitability with IC₅₀ values of 3.6, 16.7, 13.5 and 14.0 μM, respectively.

Naturally occurring plant isoquinoline N-oxide alkaloids: their pharmacological and SAR activities

The present review describes research on novel natural isoquinoline alkaloids and their N-oxides isolated from different plant species. More than 200 biological active compounds have shown confirmed antimicrobial, antibacterial, antitumor, and other activities. The structures, origins, and reported biological activities of a selection of isoquinoline N-oxides alkaloids are reviewed. With the computer program PASS some additional SAR (structure-activity relationship) activities are also predicted, which point toward new possible applications of these compounds. This review emphasizes the role of isoquinoline N-oxides alkaloids as an important source of leads for drug discovery.

Molecular network and chemical fragment-based characteristics of medicinal herbs with cold and hot properties from Chinese medicine

ETHNOPHARMACOLOGICAL RELEVANCE

Chinese herbal medicines (HMs) is one of the great herbal systems of the world, which play an important role in current health care system in many countries. In the view of tradition Chinese medicine (TCM) theory, Yin-yang and five-elements theory is the central theory, which is used to explain how the world and body work. Under the guidance of such philosophy, TCM considers that HMs have different properties, which are the important factors for prescribing herbal formulae; such prescriptions are based on TCM pattern classification in clinical practice. The cold and hot property are commonly defined for HM property identification; however, the biological activities that are related to the HM property remain a mystery because of a lack of appropriate methods. A bioinformatics approach was applied to identify the distinguishing biological activities of HMs that have these cold and hot properties.

MATERIAL AND METHODS

Twenty HMs with typical cold and hot properties (10 cold and 10 hot) were selected based on TCM clinical application records and Chinese pharmacopeia. The active target proteins of each HM were searched in the PubChem database and were analyzed in Ingenuity Pathway Analysis (IPA) platform to find out the HM property-related biological activities. In addition, the main compounds of the HMs were fragmented using a fragment-based approach and were analyzed for the purpose of deciphering the properties.

RESULTS

The main biological networks of HMs with cold and hot properties include cell cycle, cellular growth, proliferation and development, cancer, cytokine signaling, and intracellular and second messenger signaling; 11 specific pathways are presented to be perturbed only by HMs with the hot property, and the 27 specific target protein molecules include PRKACA, PRKCA, PRKCB, PRKCD, PRKCE, PRKCG, PRKD1, TLR4, TLR7, TLR8, TLR9, HTR4, HTR6, HTR7, HTR2A, HTR1B, HTR2B, GNAO1, GNAI1, TNF, IL8, ROCK2, AKT1, MAPK1, RPS6KA1, RPS6KA3 and JAK2, which are involved in the biological network. One specific pathway is detected to be involved in the biological network of HMs with the cold property, the specific molecules are RAN and KPNB1. Cold propertied HMs show intensive toxicity in the heart, liver and kidney compared with hot HMs, which is likely to be correlated with the specific chemical fragments constructions in the HMs with the cold property, such as long chain alkenes, Benzo heterocycle and azotic heterocycle according to the chemical fragment analysis for the HMs.

CONCLUSIONS

Inflammation and immunity regulation are more related to HMs with the hot property, and cold propertied HMs possess the tendency to impact cell growth, proliferation and development. Integrative bioinformatics analysis and chemical structure analysis are a promising methods for identifying the biological activity of HM properties.

13C GIAO DFT calculation as a tool for configuration prediction of N-O group in saturated heterocyclic N-oxides

Tropane, tropinone, pseudopelletierine and cocaine were oxidized in situ in a nuclear magnetic resonance (NMR) tube providing mixtures of exo/endo N-oxides. Observed (13)C chemical shifts were correlated with values calculated by gauge-including atomic orbitals density functional theory (DFT) OPBE/6-31G* method using DFT B3LYP/6-31G* optimized geometries. The same method of (13)C chemical shift calculation was applied on series of methyl-substituted 1-methylpiperidines and their epimeric N-oxides described in literature. The results show that using this undemanding calculation method enables assignment of configuration of N-O group in N-epimeric saturated heterocyclic N-oxides. The approach enables assigning of the configuration with high degree of certainty even if NMR data of only one isomer are available. An improved method of in situ oxidation of starting amines in an NMR tube is also described.

The observed and calculated 1H and 13C chemical shifts of tertiary amines and their N-oxides

A series of model tertiary amines were oxidized in situ in an NMR tube to amine N-oxides and their (1)H and (13)C NMR spectra were recorded. Next, the chemical shifts induced by oxidation (Δδ) were calculated using different GIAO methods investigating the influence of the method [Hartree-Fock (HF), Moeller-Plesset perturbation, density functional theory (DFT)], the functional applied in the DFT (B3LYP, BPW, OPBE, OPW91) and the basis set used [6-31G*, 6-311G**, 6-311 + + G** and 6-311 + + G(3df,3pd)]. The best results were obtained with the HF/6-311 + + G** and OPBE/6-311 + + G** methods. The computation/experiment comparison approach was used for the configuration prediction of chiral amine N-oxides-(R) and (S)-agroclavine-6-N-oxide.

Anti-inflammatory and analgesic activity of the topical preparation of Glaucium grandiflorum

The species of Glaucium have been used in Iranian herbal medicine in the treatment of dermatitis. Due to anti-inflammatory and analgesic activity of Glaucium grandiflorum methanolic extract in i.p. administration, these effects in topical administration were studied using carrageenan-induced edema and formalin test. Several formulations were prepared and the best cream was chosen as vehicle. Piroxicam gel and methyl salicylate ointment were studied as positive control for anti-inflammatory and analgesic activity, respectively. The edema inhibition of preparations containing extract at the doses of 1-5% w/w were significantly different from control group. The anti-inflammatory effect of MS4-5% was similar to the effect of piroxicam gel at 3 h after carrageenan injection. Topical preparation containing G. grandiflorum methanolic extract showed analgesic effect in concentrations more than 4% w/w in early phase in formalin test. This activity was observed in concentrations more than 3% w/w in late phase. The topical analgesic activity of extract was less than the analgesic activity of methyl salicylate ointment.

Anti-inflammatory, analgesic activity and acute toxicity of Glaucium grandiflorum extract

The species of Glaucium have been used in Iranian herbal medicine as laxative, hypnotic, antidiabetic agents and also in the treatment of dermatitis. The anti-inflammatory and analgesic effects of the aerial parts of Glaucium grandiflorum Boiss & Huet (Papaveraceae), a native plant of Iran, were studied using carrageenan induced edema, formalin and hot plate tests. The G. grandiflorum extract at the dose of 200 mg/kg had more edema inhibition than indomethacin at the doses of 10 (P<0.01) and 8 mg/kg (P<0.001) in the carrageenan test. The ED(50) (i.p.) in the edema induced by carrageenan was 13.59 mg/kg. In formalin test, the extract (60-90 mg/kg, i.p.) caused graded inhibition of both phases of formalin-induced pain. In hot plate test, the i.p. administration of the extract at the doses of 60, 70, 80 and 90 mg/kg significantly raised the pain threshold at a observation time of 45 min in comparison with control (P<0.001). The extract, at the antinociceptive doses, did not affect motor coordination of animals when assessed in the rotarod model. The 72 h acute LD(50) value of this extract after i.p. administration in mice was 797.94 mg/kg.