Aromatic acid derivatives from the lateral roots of Aconitum carmichaelii

Two aromatic acid derivatives and a xanthone from Hypericum hengshanense

Three previously undescribed compounds including two aromatic acid derivatives (1-2), and one xanthone (3), together with ten known compounds (4-13) were isolated from the aerial part of Hypericum hengshanense. The planar structures of three new compounds were established by 1 D and 2 D NMR and MS data. And the absolute configurations of compounds 1-2 were determined by the quantum chemical ECD calculations. Compounds 1-2 showed weak cytotoxicity against Hep-2 human cancer cell lines with IC50 values of 65.1 ± 2.7 and 78.0 ± 1.0 μg/mL, respectively.

Chemical Constituents from the Roots and Rhizomes of Sophora tonkinensis and Their Effects on Proprotein Convertase Substilisin/Kexin Type 9 Expression

This study was conducted to further investigate bioactive molecules from Sophora tonkinensis that can inhibit proprotein convertase substilisin/kexin type 9 (PCSK9) expression. After interpreting NMR spectroscopic data and MS spectral data of all isolates, a new naturally occurring compound, 6-hydroxy-vitexin-2″-O-rhamnoside (7), was identified along with 30 known compounds. The calculation of the gauge-including atomic orbital (GAIO) and electronic circular dichroism (ECD) proposed the absolute configuration of 17 as (2S,3R)-methyl-2-(4-hydroxybenzyl)tartrate by comparing the calculated ECD with experimental data. All isolates were tested for their inhibitory effects on PCSK9 mRNA expression. Of the tested compounds, (+)-isolariciresinol (12) inhibited PCSK9 expression via downregulation of HNF1α and SREBPs.

Aconitum carmichaelii Debeaux: A systematic review on traditional use, and the chemical structures and pharmacological properties of polysaccharides and phenolic compounds in the roots

ETHNOPHARMACOLOGICAL RELEVANCE

Aconitum carmichaelii, belonging to the Ranunculaceae family, is a widely used traditional herbal plant in Asian countries, especially in China. The lateral ("Fuzi") and mother ("Chuanwu") roots are the two main plant parts used in Traditional Chinese Medicine (TCM), where they are used in the treatment of acute myocardial infarction, heart failure, rheumatoid arthritis, and as analgesics.

AIM OF THE STUDY

In order to further guide the research direction and application of A. carmichaelii, this study aims to give a systematic and in-depth overview on the phytochemical and pharmacological studies of non-alkaloid natural products with focus on polysaccharides and phenolic compounds.

MATERIALS AND METHODS

A comprehensive search in the literature was conducted based on the databases Google Scholar, SciFinder (American Chemical Society), Springer Link, PubMed Science, Science Direct and China National Knowledge Internet, Wanfang Data, in addition to books, doctoral and master's dissertations, and official website. The main keywords were: "Aconitum carmichaelii", "Aconiti Lateralis Radix Praeparata", "Fuzi", "Chuanwu", "Aconiti Radix", "monkshood" and "Bushi".

RESULTS

A. carmichaelii is known for the use of its different root parts, including "Fuzi" and "Chuanwu". Different types of polysaccharides, both neutral and acidic, and 39 phenolic compounds like flavonoids, phenylpropanoids, lignans, neolignans, and benzoic acid derivatives have been isolated and identified from the roots. Pharmacological studies of the isolated polysaccharides have demonstrated various biological effects such as hypoglycemic, hypolipidemic, cardiovascular, immunomodulatory, anti-tumor, and neuropharmacological activities. Studies on pharmacological effects of the phenolic compounds isolated from the roots are however limited.

CONCLUSIONS

This review shows that polysaccharides could be one of the active components in the roots of A. carmichaelii, and they are promising for future applications due to their pharmacological properties. In addition, polysaccharides are generally non-toxic, biocompatible, and biodegradable. This review also sheds light on new research directions for A. carmichaelii. A more detailed structural characterization of polysaccharides from different root parts of A. carmichaelii, and their structure-activity relationships are required. Additionally, their pharmacological properties as immunomodulators in the intestinal system should be investigated. Further, more knowledge about the pharmacological effects and molecular mechanisms of the phenolic compounds that have been identified are needed.

Denudatine-type diterpenoid alkaloids from an aqueous extract of the lateral root of Aconitum carmichaelii

Five new denudatine-type diterpenoid alkaloids (1-5), along with the known analogue aconicarmine (6), were isolated from an aqueous decoction of the lateral roots of Aconitum carmichaelii (fu-zi). Their structures were determined by spectroscopic data analysis and electronic circular dichroism (ECD) calculations. Compound 5 is the first denudatine-type diterpenoid alcohol iminium alkaloid, which could be partially transformed into the aza acetal form in pyridine-d₅. Compound 5 inhibited mice writhing in an acetic acid-induced writhing assay.

Rapid identification model based on decision tree algorithm coupling with 1H NMR and feature analysis by UHPLC-QTOFMS spectrometry for sandalwood

Sandalwood is one of the most valuable woods in the world. However, today's counterfeits are widespread, it is difficult to distinguish authenticity. In this paper, similar genus (Dalbergia and Pterocarpus) and confused species (Gluta sp.) of sandalwood were quickly and efficiently identified. Rapid identification model based on ¹H NMR and decision tree (DT) algorithm was firstly developed for the identification of sandalwood, and the accuracy was improved by introducing the AdaBoost algorithm. The accuracy of the final model was above 95%. And the feature components between different species of sandalwood were further explored using UHPLC-QTOFMS and NMR spectrometry. The results showed that 183 compounds were identified, among which 99 were known components, 84 were unknown components. The ¹H NMR and ¹³C NMR signals of 505 samples were assigned, among them, 14 compounds were attributed, characteristic chemical shift intervals with great differences in the model were analysed. Furthermore, the fragmentation pattern of different compounds from sandalwood, in both positive and negative ion ESI modes, was summarized. The results showed a potential and rapid tool based on DT, NMR spectroscopy and UHPLC-QTOFMS, which had performed great potential for rapid identification and feature analysis of sandalwood.

Structure, property, biogenesis, and activity of diterpenoid alkaloids containing a sulfonic acid group from Aconitum carmichaelii

Three new C20-diterpenoid alkaloids with a sulfonic acid unit, named aconicarmisulfonines B and C (1 and 2) and chuanfusulfonine A (3), respectively, were isolated from the Aconitum carmichaelii lateral roots ("fu zi" in Chinese). Structures of 1-3 were determined by spectroscopic data analysis. Intriguing chemical properties and reactions were observed for the C20-diterpenoid alkaloids: (a) specific selective nucleophilic addition of the carbonyl (C-12) in 1 with CD3OD; (b) interconversion between 1 and 2 in D2O; (c) stereo- and/or regioselective deuterations of H-11α in 1-3 and both H-11α and H-11β in aconicarmisulfonine A (4); (d) TMSP-2,2,3,3-d 4 promoted cleavage of the C-12-C-13 bond of 4 in D2O; (e) dehydrogenation of 4 in pyridine-d 5, and (f) Na2SO3-assisted dehydrogenation and N-deethylation of songorine (5, a putative precursor of 1-4). Biogenetically, 1 and 2 are correlated with 4, for which the same novel carbon skeleton is proposed to be derived from semipinacol rearrangements via migrations of C-13-C-16 and C-15-C-16 bonds of the napelline-type skeleton, respectively. Meanwhile, 3 is a highly possible precursor or a concurrent product in the biosynthetic pathways of 1, 2, and 4. In the acetic acid-induced mice writhing assay, at 1.0 mg/kg (i.p.), compounds 1, 2, 5, 5a, and 5b exhibited analgesic effects against mice writhing.

Non-alkaloidal constituents from the genus Aconitum: a review

Species of the genus Aconitum are widely distributed in the north temperate region and have been used in traditional medicine since antiquity due to their biological activities. Phytochemical investigations of Aconitum species have revealed the presence of multiple active ingredients, including flavonoids, phenylpropanoids, phenolics and acids, terpenoids, and polysaccharides in addition to their diterpenoid alkaloids. These non-alkaloidal constituents show great research significance for their novel structures, broad bioactivities, and chemotaxonomical significance. This review addresses, for the first time, the non-alkaloidal constituents and their biological properties and their taxonomic significance for Aconitum plants to facilitate future research.

Sulfur-enriched alkaloids from the root of Isatis indigotica

Five new sulfur-enriched alkaloids isatithioetherins A-E (1-5), and two pairs of scalemic enantiomers (+)- and (-)-isatithiopyrin B (6a and 6b) and isoepigoitrin and isogoitrin (7a and 7b), along with the known scalemic enantiomers epigoitrin and goitrin (8a and 8b), were isolated and characterized from an aqueous extract of the Isatis indigotica roots. Their structures were determined by extensive spectroscopic data analysis, including 2D NMR and theoretical calculations of electronic circular dichroism (ECD) spectra based on the quantum-mechanical time-dependent density functional theory (TDDFT). Compounds 1-5 represent a novel group of sulfur-enriched alkaloids, biogenetically originating from stereoselective assemblies of epigoitrin-derived units. Isolation and structure characterization of 6a and 6b support the postulated biosynthetic pathways for the diastereomers 9a and 9b via a rare thio-Diels-Alder reaction. Compounds 2 and 4 showed antiviral activity against the influenza virus A/Hanfang/359/95 (H3N2, IC50 0.60 and 1.92 μmol/L) and the herpes simplex virus 1 (HSV-1, IC50 3.70 and 2.87 μmol/L), and 2 also inhibited Coxsackie virus B3 (IC50 0.71 μmol/L).

Cytotoxic Compounds from the Seeds of Sophora alopecuroides

Chemical purification of the ethyl acetate extract from the seeds of Sophora alopecuroides yielded a new natural product, ethyl 2-(4-hydroxybenzyl) malic acid (1), along with 7 known compounds, methyl eucomate (2), eucomic acid (3), piscidic acid (4) and ethyl 2-(4-hydroxybenzyl) tartrate (5), butein-4'-O-β-D-glucopyranoside (6), iso-liquiritigenin (7), and butein (8). The structure of 1 was determined by spectroscopic analyses including extensive 1D (1H NMR, 13C NMR) and 2D NMR spectra (COSY, HSQC and HMBC) as well as MS data. All compounds were evaluated for their cytotoxic activities against hepato-cellular carcinoma (HCC) cell lines, HepG2 andHep3B. Compound 8 significantly inhibited the cancer cell growth in a concentration-dependent manner.

C19-Diterpenoid alkaloid arabinosides from an aqueous extract of the lateral root of Aconitum carmichaelii and their analgesic activities

Eight new C₁₉-diterpenoid alkaloid arabinosides, named aconicarmichosides E–L (1–8), were isolated from an aqueous extract of the lateral roots of Aconitum carmichaelii (Fu Zi). Their structures were determined by spectroscopic and chemical methods including 2D NMR experiments and acid hydrolysis. Compounds 1–8, together with the previously reported four neoline 14-O-arabinosides from the same plant, represent the only examples of glycosidic diterpenoid alkaloids so far. At a dose of 1.0 mg/kg (i.p.), as compared with the black control, compounds 1, 2, and 4–6 exhibited analgesic effects with >65.6% inhibitions against acetic acid-induced writhing of mice. Structure–activity relationship was also discussed.

8,4'-Oxyneolignane glucosides from an aqueous extract of "ban lan gen" (Isatis indigotica root) and their absolute configurations

Three pairs of glycosidic 8,4'-oxyneolignane diastereoisomers, named isatioxyneolignosides A-F (1-6), were isolated from an aqueous extract of Isatis indigotica roots. Their structures and absolute configurations were elucidated by comprehensive spectroscopic data analysis and enzyme hydrolysis. The validity of ΔδC8-C7 values to distinguish threo and erythro aryl glycerol units and Cotton effects at 235±5 nm to determine absolute configurations at C-8 in 1-6 and their aglycones (1a-6a) are discussed.

Indole alkaloid sulfonic acids from an aqueous extract of Isatis indigotica roots and their antiviral activity

Six new indole alkaloid sulfonic acids (1-6), together with two analogues (7 and 8) that were previously reported as synthetic products, were isolated from an aqueous extract of the Isatis indigotica root. Their structures including the absolute configurations were determined by spectroscopic data analysis, combined with enzyme hydrolysis and comparison of experimental circular dichroism and calculated electronic circular dichroism spectra. In the preliminary assay, compounds 2 and 4 showed antiviral activity against Coxsackie virus B3 and influenza virus A/Hanfang/359/95 (H3N2), respectively.

Aromatic compounds from an aqueous extract of "ban lan gen" and their antiviral activities

A pair of new diphenyl glycerol ether enantiomers (−)-1 and (+)-1 and two new methyl benzamidobenzoates 2 and 3, named (−)-(R)- and (+)-(S)-isatindigotrioic acid [(−)-1 and (+)-1] and isatindigoticamides A (2) and B (3), respectively, were isolated from an aqueous decoction of the roots of Isatis indigotica (ban lan gen). Their structures were elucidated by spectroscopic data analysis including 2D NMR experiments. The absolute configurations of (−)-1 and (+)-1 were assigned based on the CD exciton chirality method. Compounds 2 and 3 exhibited antiviral activities against HSV-1 with IC₅₀ values of 4.87 and 25.87 μmol/L, respectively. Compound 2 was also found active against Coxsackie virus B3 and LPS-induced NO production.

Three pairs of alkaloid enantiomers from the root of Isatis indigotica

Three pairs of enantiomerically pure alkaloids with diverse structure features, named isatindigoticoic acid A and epiisatindigoticoic acid A [(−)-1 and (+)-1], phaitanthrin A and epiphaitanthrin A [(−)-2 and (+)-2], and isatindopyrromizol A and epiisatindopyrromizol A [(−)-3 and (+)-3], respectively, were isolated from an aqueous extract of the roots of Isatis indigotica. Racemic and scalemic mixtures of these enantiomers were separated by HPLC on a chiral semi-preparative column. Their structures including absolute configurations were determined by extensive spectroscopic analysis in conjunction with the calculation of electronic circular dichroism (ECD) spectra. The enantiomer pairs possess parent structures of 2-oxo-1,2,3,4-tetrahydroquinoline-4-carboxylic acid, indolo[2,1-b]quinazolinone, and 3-thioxohexahydro-1H-pyrrolo[1,2-c]imidazol-1-one, respectively. Except for phaitanthrin A [(−)-2] which the configuration was previously undetermined, these compounds are new enantiomeric natural products.

Indole alkaloid glucosides from the roots of Isatis indigotica

Five new indole alkaloid glucosides named isatindigotindolosides A-E (1-5), along with three known analogs (6-8), were isolated from an aqueous extract of the Isatis indigotica roots. Their structures including the absolute configurations were determined based on comprehensive spectroscopic data analysis, combined with chemical methods and electronic circular dichroism spectra calculations. In the preliminary assays, compounds 1, 6 and 7 showed antiviral activity against influenza virus A/Hanfang/359/95 (H3N2) with IC50 values of 14.6-33.3 μM. Compound 1 also exhibited inhibitory effect against nitric oxide (NO) production in microglial cell BV2 with an inhibition ratio of 93.0% at 10 μM.

C14-polyacetylenol glycosides from the roots of Codonopsis pilosula

Eight new C14-polyacetylenol glycosides, containing ene-diyne and ene-yn-ene chromophores named codonopilodiynosides H-M (1-6) and codonopiloenynenosides A and B (7 and 8), respectively, together with three known analogs lobetyolinin, pratialin B, and lobetyolin (9-11), were isolated from an aqueous extract of the roots of Codonopsis pilosula. Their structures were determined by spectroscopic and chemical methods including 2D NMR data analysis and enzymatic hydrolysis. The absolute configurations of aglycones in 1-10 were assigned by application of the methoxyphenylacetic acid (MPA) determination rule of Δδ(RS) values and/or the empirical rule of Mo2(OAc)4-induced circular dichroism for the vicinal diols, or by comparison of specific rotation values with those of reported compounds. Compounds 4-6 are the first polyacetylenol glycosides possessing a cis-ene-diyne chromophore from the genus Codonopsis, while 8 has a rear trans-ene-yn-cis-ene chromophore and a (6S,7S)-6,7-diol unit against a (6R,7R)-6,7-diol unit in the others. The absolute configurations of lobetyolinin (9) and pratialin B (10) were determined for the first time.

C₁₄-polyacetylene glucosides from Codonopsis pilosula

Seven new C14-polyacetylene glucosides codonopilodiynosides A-G (1-7) were isolated from an aqueous extract of the Codonopsis pilosula roots. Their structures were determined by spectroscopic and chemical methods as (-)-(5S,6E,12E)-tetradeca-6,12-dien-8,10-diyn-1,5,14-triol 5-O-β-D-glucopyranoside (1), (-)-(5S,6E,12E)-tetradeca-6,12-dien-8,10-diyn-1,5,14-triol 5-O-β-D-glucopyranosyl-(1″ → 2')-β-D-glucopyranoside (2), (-)-(5S,6E,12E)-tetradeca-6,12-dien-8,10-diyn-1,5,14-triol 5,14-di-O-β-D-glucopyranoside (3), (-)-(5S,6E)-tetradeca-6-en-8,10-diyn-1,5,14-triol 5-O-β-D-glucopyranoside (4), (-)-(5S,6E,12E)-tetradeca-6,12-dien-8,10-diyn-1,5-diol 5-O-β-D-glucopyranosyl-(1″ → 2')-β-D-glucopyranoside (5), (-)-(6S,4E,12E)-tetradeca-4,12-dien-8,10-diyn-1,6-diol 6-O-β-D-glucopyranosyl-(1″ → 2')-β-D-glucopyranoside (6), and (-)-(5S,6E)-tetradeca-6-en-1,5-epoxy-8,10-diyn-14-ol 14-O-β-D-glucopyranosyl-(1″ → 2')-β-D-glucopyranoside (7), respectively. The absolute configurations of 1-7 were assigned by enzymatic hydrolysis followed by isolation of glucose and aglycones (1a and 4a-7a), and subsequent comparison of specific rotation, TLC, and (1)H NMR data of the glucose with an authentic sugar sample and application of modified Mosher's method based on the MPA determination rule of Δδ(RS) values for 1a and 4a, and Δδ(S) values for 6a. The configuration of 7 was assigned by electronic circular dichroism calculations based on the quantum-mechanical time-dependent density functional theory.

Antiviral glycosidic bisindole alkaloids from the roots of Isatis indigotica

Seven new glycosidic bisindole alkaloids, isatindigobisindolosides A-G (1-7), were isolated from an aqueous extract of the Isatis indigotica roots. Their structures including absolute configurations were determined by spectroscopic and chemical methods, together with calculations of electronic circular dichroism (ECD) spectra based on the quantum-mechanical time-dependent density functional theory. In the NMR spectra of 1-3, it is found that integration of H-2 and intensity of C-2 are affected not only by a substitution group at C-2 but also by solvents. Influences of the glucopyranosyloxy on the calculated ECD spectra of the glycosidic bisindole alkaloids are discussed. Compounds 2, 5, and 6 showed antiviral activity against both the influenza virus A/Hanfang/359/95 (H3N2) and Coxsackie virus B3 with IC50 values of 8.4-100.0 μM.