Sesquiterpene Lactams and Lactones With Antioxidant Potentials From Atractylodes macrocephala Discovered by Molecular Networking Strategy.

Atractylodes macrocephala rhizome (called Bái-zhú in China) has a long history as a functional food and herbal medicine in East Asia, especially China. Sesquiterpenoids are one of the main active compounds of Atractylodes macrocephala rhizome. This study aimed to explore the unknown sesquiterpenoids of A. macrocephala rhizome using a molecular networking strategy. Two new nitrogen-containing sesquiterpenoids, atractylenolactam A (1) and atractylenolactam B (2), and 2 new sesquiterpene lactones, 8-methoxy-atractylenolide V (6) and 15-acetoxyl atractylenolide III (7), along with 12 known analogs (3-5 and 8-16) were discovered and isolated. All the structures were assigned based on detailed spectroscopic analyses. The absolute configurations of 1, 2, 6, and 7 were established by time-dependent density functional theory ECD (TDDFT-ECD) calculations. All these compounds had different degrees of concentration-dependent activating effects on nuclear-factor-E2-related factor-2 (Nrf2).

[Iridoids of wine-processed Corni Fructus].

A new iridoid glycoside, cornushmf A(1) and nine known iridoids(2-10) were isolated from the water extract of the wine-processed Corni Fructus by various column chromatographies. Their chemical structures were identified by comprehensive spectroscopic methods as 7ß-O-(2″-formylfuran-5″-methylene)-morroniside(1), 7-dehydrologanin(2), sweroside(3), 7ß-O-methylmorroniside(4), 7α-O-methylmorroniside(5), 7ß-O-ethylmorroniside(6), 7α-O-ethylmorroniside(7), cornuside(8), sarracenin(9), and loganin(10).

[Discovery and activity verification of reniformin A as an anti-tumor leading compound].

Reverse prediction and molecular docking techniques were employed to evaluate the feasibility of reniformin A(RA) as an anti-tumor leading compound. Based on the reverse prediction, network pharmacology was used to construct a "disease-compound-target-pathway" network. Thirty-nine tumor-related targets of RA were predicted, which participated in the regulation of multiple cellular activities such as apoptosis, cell cycle, and tumor metastasis, and regulated estrogen signal transduction and inflammatory response. Discovery Studio 2020 was adopted for molecular docking and toxicity prediction(TOPKAT). As revealed by the results, the binding affinity of RA with the tumor-related targets ABL1, ESR1, SRC and BCL-XL was stronger than that of oridonin(OD), while its mutagenicity, rodent carcinogenesis, and oral LD_(50) in rats were all inferior to that of OD. Furthermore, in vitro experiments were performed to confirm the anti-tumor activity of RA, and the mechanism was preliminarily discussed. The results demonstrated that RA was superior to OD in cytotoxicity, inhibition of cell colony formation, and induction of apoptosis. RA, possessing potent anti-tumor activity, is expected to be a new anti-tumor leading compound.

Four New Gallate Derivatives from Wine-Processed Corni Fructus and Their Anti-Inflammatory Activities.

Four new gallate derivatives-ornusgallate A, ent-cornusgallate A, cornusgallate B and C (1a, 1b, 2, 3)-were isolated from the wine-processed fruit of Cornus officinalis. Among them, 1a and 1b are new natural compounds with novel skeletons. Their chemical structures were elucidated by comprehensive spectroscopy methods including NMR, IR, HRESIMS, UV, ECD spectra and single-crystal X-ray diffraction analysis. The in vitro anti-inflammatory activities of all compounds were assayed in RAW 264.7 cells by assessing LPS-induced NO production. As the result, all compounds exhibited anti-inflammatory activities at attested concentrations. Among the tested compounds, compound 2 exhibited the strongest anti- inflammatory activity.

Correction: Neuroinflammatory inhibitors from Gardneria nutans Siebold & Zuccarini.

[This corrects the article DOI: 10.1039/D1RA05204G.].

A new ent-kaurane diterpene from Isodon henryi.

One new ent-Kaurane diterpenoid (1) was isolated from the ethyl acetate fraction of Isodon henryi. Along with ten diterpenoids (2-11) were isolated from this plant for the first time, including six 7,20-epoxy diterpenoids, three enmenol-type diterpenoids and one 6,7-seco-ent-kaurene diterpenoid. Their structures were elucidated by 1 D and 2 D NMR, confirmed by HRESIMS and electronic circular dichroism analyses. Furthermore, the cytotoxicities of twelve compounds were investigated in five human cancer cell lines, including A2780, BGC-823, HCT-116, HepG2 and HeLa. And the IC50 values of these diterpenoids ranged from 2.1 to 88.8 µM in the tested cell lines. Based on the molecular structures of 12 compounds and the bioassay results, it suggests that α,ß-unsaturated pentanone is the cytotoxic active site of 7,20 epoxy ent-kaurane diterpenoid, but it does not contribute much to enmenol-type diterpenoid.Supplemental data for this article can be accessed at https://doi.org/10.1080/14786419.2019.1675067.

Neuroinflammatory inhibitors from Gardneria nutans Siebold & Zuccarini.

Two new monoterpene indole alkaloid glycosides nutanoside A-B (1-2), two new phenolic glycoside esters nutanester A-B (6-7), together with five known compounds (3-5, 8-9) were isolated from the ethanol extract of Gardneria nutans Siebold & Zuccarini. Their structures were established on the basis of extensive spectroscopic analysis and TDDFT/ECD calculations. Compounds 1 and 2 are two rare monoterpene indole alkaloids with the glucosyl moiety located at C-12 and represent the first two examples of enantiomer of ajmaline type monoterpene indole alkaloids. Compounds 3, 4 and 6 displayed significant inhibitory effects on NO production in over-activated BV2 microglial cells, with the IC50 values of 2.29, 6.36, and 8.78 µM, respectively. Compounds 1, 5, 7 could significantly inhibit the mRNA expression of inflammatory factors TNF-α and IL-6 induced by LPS in BV2 microglial cells at the effective concentration. Moreover, compound 3 exhibited stronger cytotoxicities against U87 and HCT116 cell lines than taxol with IC50 values of 10.58 and 14.60 µM, respectively.

Author Correction: Isolation and identification of two pairs of cytotoxic diterpene tautomers and their tautomerization mechanisms.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Isolation and identification of two pairs of cytotoxic diterpene tautomers and their tautomerization mechanisms.

Discovering anticancer drugs that do not have adverse side effects has been a developing research field worldwide in recent decades. In this work, four previously undescribed cytotoxic diterpenoids were isolated from the aerial parts of Isodon excisoides. Interestingly, these four diterpenoids were two pairs of tautomers that were first reported in plants. Their structures were further elucidated using various spectroscopic methods. The tautomerization phenomenon and mechanism for these two pairs of tautomers were emphatically described. The theoretical simulation results indicated that the diterpene tautomerization is greatly related to certain factors, including the existence of a transition state, the change of bond length and the level of conversion energy; the tautomerization for the two pairs of tautomers is mainly caused by proton transfer. For bioassays, the cytotoxicities of the tautomers against five human cancer cell lines were also investigated. The results indicated that each of the four diterpenoids showed significant cytotoxicity in at least three cell lines and could serve as potential anticancer agents for further investigation.

Isolation and identification of two new compounds from the Penicillium sp. SYPF7381.

Two new compounds, (7R, 2E, 5E)-3,5,7-trimethyl-2,5-octadienedioic-8-methyl ester (1) and neovasipyridone G (3), together with a new natural product compound (7R,2E,5E)-3,5,7-trimethyl-2,5-octadienedioic acid (2), and six known compounds (4-9) were isolated from Penicillium sp. SYPF7381. Their structures were elucidated on the basis of extensive spectroscopic analysis, and the absolute configurations of compounds 1 and 2 were determined by optical rotation. The absolute configuration of compound 3 was determined by means of electronic circular dichroism (ECD) calculation. In addition, the in vitro anti-inflammatory activities of all compounds were assayed in RAW 264.7 cells by assessing LPS-induced NO production. Furthermore, the structure-antiinflammation activity relationships for these isolated compounds were summarized based on the experimental as well as the docking results.

(±) Benzomalvins E isolated from Penicillium sp. SYPF 8411 in the rhizosphere soil of Codonopsis clematidea.

(+) Benzomalvins E (1) and (-) Benzomalvins E (2), a pair of epimeric derivatives, together with three known benzomalvins (3-5), were isolated from solid cultures of a interrhizospheric fungus Penicillium sp. SYPF 8411. The planar structure of (+) Benzomalvins E (1) has been previously reported. While, the absolute configuration of compound 1 was established by X-ray crystallographic analysis for the first time. The planar structure of the new compound 2 were elucidated by detailed interpretation of their HR ESI-TOF MS and NMR spectroscopic data. The absolute configuration of compound 2 was established by Rh2(OCOCF3)4-induced CD spectral data and the electronic circular dichroic (ECD) method. Furthermore, the epimerization induced by pH, temperature and H2O was revealed. Benzomalvins (1-3, 5), a type of indoximod, enhanced the cytotoxic capability of 5-fluorouracil against A549.

Two new triterpenes from the roots of Pfaffia glomerata.

Pfaffia paniculata is a commercialized dietary supplement used as the substitute for the Asian ginseng in Brazil. We conducted the systematic isolation of the EtOAc fraction with anti-inflammatory effect and two new triterpenoids, along with 26 known compounds were characterized by means of MS and NMR analysis. Interestingly, the new compound 1 is the first seco-ring triterpenoid reported in the Pfaffia genus. Furthermore, among the known compounds, 14 and 15 exhibited anti-inflammatory activity in Caco-2 cells, but two new compounds showed no anti-inflammatory.

A new sesquiterpene lactone glycoside and a new quinic acid methyl ester from Patrinia villosa.

A new sesquiterpene lactone glycoside (1) and a new quinic acid methyl ester (2) were isolated from Patrinia villosa, together with another two known compounds chlorogenic acid n-butyl ester (3), 3, 4-di-O-caffeoylquinic acid methyl ester (4). Their structures were established using 1D/2D-NMR spectroscopy, mass spectrometry, and comparing with spectroscopic data reported in the literature.