Sesquiterpenoids and phenylpropanoids from pericarps of Illicium oligandrum

Anti-diabetic and anti-inflammatory bioactive hits from Coriaria intermedia Matsum. stem and Dracontomelon dao (Blanco) Merr. & Rolfe bark through bioassay-guided fractionation and liquid chromatography-tandem mass spectrometry

Women have been found to be at a higher risk of morbidity and mortality from type 2 diabetes mellitus (T2DM) and asthma. α-Glucosidase inhibitors have been used to treat T2DM, and arachidonic acid 15-lipoxygenase (ALOX15) inhibitors have been suggested to be used as treatments for asthma and T2DM. Compounds that inhibit both enzymes may be studied as potential treatments for people with both T2DM and asthma. This study aimed to determine potential anti-diabetic and anti-inflammatory bioactive hits from Coriaria intermedia Matsum. stem and Dracontomelon dao (Blanco) Merr. & Rolfe bark. A bioassay-guided fractionation framework was used to generate bioactive fractions from C. intermedia stem and D. dao bark. Subsequently, dereplication through ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) and database searching was performed to putatively identify the components of one bioactive fraction from each plant. Seven compounds were putatively identified from the C. intermedia stem active fraction, and six of these compounds were putatively identified from this plant for the first time. Nine compounds were putatively identified from the D. dao bark active fraction, and seven of these compounds were putatively identified from this plant for the first time. One putative compound from the C. intermedia stem active fraction (corilagin) has been previously reported to have inhibitory activity against both α-glucosidase and 15-lipoxygenase-1. It is suggested that further studies on the potential of corilagin as an anti-diabetic and anti-inflammatory treatment should be pursued based on its several beneficial pharmacological activities and its low reported toxicity.

Chemical composition and pharmacological activity of seco-prezizaane-type sesquiterpenes

The seco-prezizaane-type sesquiterpenes (SPS), as a special class of sesquiterpenes with a highly oxidative five-ring cage structure and seven consecutive chiral centers, are isolated from the genus Illicium, which have a variety of biological activities, including neurotoxicity and neurotrophic effects, etc. This review summarizes the chemical constituents and pharmacological effects of SPS, and discusses the potential trend and scope of future research.

A new coumarin glucoside from Angelica pubescens

A new coumarin glucoside named angelol A-3'-β-D-glucoside and four known compounds (2-5) were isolated from the root of Angelica pubescens. Their chemical structures were elucidated by extensive spectroscopic methods involving HR-ESI-MS, 1D and 2D NMR. The absolute configuration of compound 1 was confirmed by the CD experiment. All compounds were tested for nitric oxide (NO) inhibitory activity in vitro. The results showed that all compounds exhibited weak to moderate inhibition activities of NO production except compound 5.

Bergamotane-type sesquiterpenes from the leaves and twigs of Illicium oligandrum and their anti-inflammatory activities

Eight undescribed β-bergamotene-type sesquiterpene oliganins A-H (1-8) and one known α-bergamotene-type sesquiterpene (9) were isolated from the leaves and twigs of Illicium oligandrum Merr. & Chun. The structures of compounds 1-8 were elucidated by extensive spectroscopic data, and the absolute configurations were determined by using a modified Mosher's method and electronic circular dichroism calculations. The isolates were further evaluated in terms of their anti-inflammatory potential on nitric oxide (NO) generation in lipopolysaccharide-stimulated RAW264.7 and BV2 cells. Compounds 2 and 8 exhibited potent inhibitory effects on the production of NO with IC₅₀ values ranging from 21.65 to 49.28 μM, which were greater than or comparable to those of dexamethasone (positive control).

Plants-Derived Biomolecules as Potent Antiviral Phytomedicines: New Insights on Ethnobotanical Evidences against Coronaviruses

SARS-CoV-2 infection (COVID-19) is in focus over all known human diseases, because it is destroying the world economy and social life, with increased mortality rate each day. To date, there is no specific medicine or vaccine available against this pandemic disease. However, the presence of medicinal plants and their bioactive molecules with antiviral properties might also be a successful strategy in order to develop therapeutic agents against SARS-CoV-2 infection. Thus, this review will summarize the available literature and other information/data sources related to antiviral medicinal plants, with possible ethnobotanical evidence in correlation with coronaviruses. The identification of novel antiviral compounds is of critical significance, and medicinal plant based natural compounds are a good source for such discoveries. In depth search and analysis revealed several medicinal plants with excellent efficacy against SARS-CoV-1 and MERS-CoV, which are well-known to act on ACE-2 receptor, 3CLpro and other viral protein targets. In this review, we have consolidated the data of several medicinal plants and their natural bioactive metabolites, which have promising antiviral activities against coronaviruses with detailed modes of action/mechanism. It is concluded that this review will be useful for researchers worldwide and highly recommended for the development of naturally safe and effective therapeutic drugs/agents against SARS-CoV-2 infection, which might be used in therapeutic protocols alone or in combination with chemically synthetized drugs.

Highly oxidized sesquiterpenes from the fruits of Illicium lanceolatum A. C. Smith

Ten undescribed highly oxidized sesquiterpenes and six known sesquiterpenes were isolated from H₂O-soluble part of the fruits of Illicium lanceolatum A. C. Smith. The structures of undescribed compounds were elucidated by interpretation of spectroscopic data, and the absolute configurations of 2α-hydroxyneoanisatinic acid, (1R,5R,6S,7R,9R,10R)-3,4-dehydro-12-hydroxy-floridanolide, and (1R,4S,5R,6S,7S,9S)-1-deoxy-13-hydroxymerrilactone B were determined by the single-crystal X-ray diffraction analysis. Illilanceolatin A was the first example of a seco-prezizaane type sesquiterpene with a hemiacetal moiety located at C-10. 2α-Hydroxyneoanisatinic acid and anisatinic acid were two naturally occurring undescribed seco-prezizaane type sesquiterpenes with a 5/5/6 tricyclic carbon skeleton. Plausible biosynthetic pathways of the isolated polycyclic and highly oxidized sesquiterpenes derived from the intermediate allo-cedrane were proposed. (1R,5R,6S,7R,9R,10R)-3,4-dehydro-12-hydroxy-floridanolide, 1,3-dihydroxyneoanisatin, and 2α-hydroxyneoanisatin displayed neuroprotective effects with protection rates of 19.9, 22.7 and 24.3% at 10 μM, respectively. Additionally, the preliminary acute toxicity of anisatinic acid was also evaluated.

DNA Topoisomerase Inhibitory Activity of Constituents from the Fruits of Illicium verum

Three new compounds, a sesquilignan (1) and two glucosylated phenylpropanoids (2, 3), and seven known compounds (4-10), were isolated from the fruits of Illicium verum HOOK. FIL. (Illiciaceae). The structures of 1-3 were determined based on one and two dimensional (1D- and 2D-) NMR data and electronic circular dichroism (ECD) spectra analyses. Compounds 3, 5, 6, and 8-10 exhibited potent inhibitory activities against topoisomerase II with IC₅₀ values of 54.6, 25.5, 17.9, 12.1, 0.3 and 1.0 µM, respectively, compared to etoposide, the positive control, with an IC₅₀ of 43.8 µM.

Rhobupcyanoside B, A new cyanoside from Rhodiola bupleuroides

One new cyanoside, rhobupcyanoside B (1), together with 7 known ones, was isolated from the 70% ethanol extract of the roots and rhizomes of Rhodiola bupleuroides. Their structures were determined by spectroscopic methods, including 2D NMR techniques. Compound 1 was evaluated for its inhibitory activity against α-glucosidase with IC50 value of 278.28 ± 0.55 μM by comparing with the positive control (acarbose) at 210.40 ± 0.32 μM.

Sesquiterpenes from the roots of Illicium oligandrum

Two new sesquiterpenes, oligandrin (1) and oligandric acid (2), together with three analogues, tashironin A (3), tashironin (4), and oplodiol (5), were isolated from the roots of Illicium oligandrum. The structures of new compounds were determined based on 1D and 2D NMR experiments and X-ray diffraction. Compound 1 represents a presumed biosynthetic precursor of seco-prezizaane sesquiterpenes which consists of a novel 6/6/5 tricarbocyclic skeleton. Compound 2 is the first example of chamipinene-type sesquiterpene possessing a 6/4/6 tricyclic system from the genus Illicium. Compounds 1-5 were evaluated in vitro for their activity against coxsackie virus B3 (CVB3), influenza virus A/Hanfang/359/95 (H3N2), and influenza virus A/FM/1/47 (H1N1). Compound 1 showed selective antiviral activity against CVB3 with IC50 value of 11.11 μM.

Diterpenoids and sesquiterpenoids from the roots of Illicium majus

Five new diterpenoids (1-5), five new sesquiterpenoids (6-10), and three known compounds (11-13) were isolated from the roots of Illicium majus. Their structures were elucidated by extensive spectroscopic analysis. The absolute configuration of 1 was assigned by X-ray crystallography, whereas those of the 1,2-diol moieties in 3 and 4 were determined using Snatzke's method. The abietane acids 1, 2, 11, 12, and 13 displayed antiviral activity against the Coxsackie B3 virus, with IC50 values of 3.3-51.7 μM/mL.

Analysis of the neurotoxin anisatin in star anise by LC-MS/MS

The aim of this work was to develop an analytical method capable of determining the presence of anisatin in star anise. This neurotoxin may induce severe side effects such as epileptic convulsions. It is therefore of prime importance to have rapid and accurate analytical methods able to detect and quantify anisatin in samples that are purportedly edible star anise. The sample preparation combined an automated accelerated solvent extraction with a solid-supported liquid-liquid purification step on EXtrelut®. Samples were analysed on a porous graphitic carbon HPLC column and quantified by tandem mass spectrometry operating in the negative ionisation mode. The quantification range of anisatin was between 0.2 and 8 mg kg⁻¹. The applicability of this validated method was demonstrated by the analysis of several Illicium species and star anise samples purchased on the Swiss market. High levels of anisatin were measured in Illicium lanceolatum, I. majus and I. anisatum, which may cause health concerns if they are misidentified or mixed with edible Illicium verum.

A new phenylpropanoid glycoside from the fruits of Illicium simonsii

AIM

To study the constituents and bioactivity of Illicium simonsii.

METHODS

The extracts of the fruits of Illicium simonsii were submitted to a combination of chromatographic materials, silica gel, ODS column chromatography and finally preparative HPLC to obtain eight compounds which were further evaluated for their cytotoxicity by MTT method.

RESULTS

A new phenylpropanoid glycolside, 2, 4-dihydroxy-allylbenzene-2-O-β-D-glucopyranoside (1), together with seven characteristic sesquiterpene lactones, oligandrumin B (2), oligandrumin D (3), anisatin (4), veranisatin D (5), pseudomajucin (6), 1α-hydroxy-3-deoxy-pseudoanisatin (7), 8α-hydroxy-10-deoxycyclomerrillianolide (8) were isolated.

CONCLUSION

Compound 1 is new. Compounds 1, 2, 3, 5-8 were isolated from this plant for the first time. None of the isolates showed inhibitory effects on the growth of non-small cell lung tumor cell line A549.

A condensed phenylpropanoid glucoside and pregnane saponins from the roots of Hemidesmus indicus

From the roots of Hemidesmus indicus, one new condensed phenylpropanoid glucoside and three new pregnenolone glycosides, named hemidesmosides A-C, were isolated along with one known related compound, plocoside A.

Dimeric prenylated C6-C3 compounds from the stem bark of Illicium oligandrum

Three new dimeric prenylated C6-C3 compounds, namely, illicidiones A (1), B (2), and C (3), were isolated from the stem bark of Illicium oligandrum. The structure and absolute configuration of these compounds were determined by extensive spectroscopic and chemical analyses, including NMR, modified Mosher method, and single-crystal X-ray study. Compounds 1-3 exhibited weak anti-inflammatory activities.

Prenylated C6-C3 compounds with molecular diversity from the roots of Illicium oligandrum

Eleven prenylated C(6)-C(3) compounds, illioliganpyranone A (1), illioliganfunone A-D (2-5), and illioliganone D-I (6-11), together with five known prenylated C(6)-C(3) compounds (12-16), were isolated from roots of Illicium oligandrum. The structures of 1-11 were elucidated by spectroscopic methods including 1D and 2D NMR, HRESIMS, and CD experiments. Possible biosynthetic pathways to compounds 1-16 derived from a common precursor of 5-allylbenzene-1,2,4-triol were postulated. All compounds were evaluated for cytotoxic activities against five human cancer cell lines (HCT-8, Bel-7402, BGC-823, A549 and A2780). Compound 15 exhibited significant cytotoxicity against HCT-8, BGC-823, A549, and A2780 cell lines with IC(50) values of 0.30-2.57 μM. Compound 16 showed moderate selective cytotoxicity against sensitive A2780 cells with IC(50) value of 1.38 μM.