Glechomenes A-G, diterpenoids with anti-inflammatory activities from the aerial part of Glechoma longituba.

Ten diterpenoids including six unreported abietane-type diterpenoids Glecholmenes A-F (1-6) and an undescribed labdane-type diterpenoid Glecholmene G (9), together with three known diterpenoids (7,8,10), were firstly isolated from the aerial part of G. longituba. Their structures were established mainly by nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS) methods. Electronic circular dichroism (ECD) calculations and X-ray crystallographic analyses were used for the determination of their absolute configurations. The anti-inflammatory activity of all compounds was evaluated using the classical LPS-induced NO release model in RAW264.7 cells. Compound 2 displayed significant anti-inflammatory activities with IC50 values of 29.08 ± 1.40 µM (Aminoguanidine hydrochloride as the positive control, IC50 = 21.84 ± 0.48 µM).

Novel glycosidase from Paenibacillus lactis 154 hydrolyzing the 28-O-ß-D-glucopyranosyl ester bond of oleanane-type saponins.

Oleanane-type ginsenosides are a class of compounds with remarkable pharmacological activities. However, the lack of effective preparation methods for specific rare ginsenosides has hindered the exploration of their pharmacological properties. In this study, a novel glycoside hydrolase PlGH3 was cloned from Paenibacillus lactis 154 and heterologous expressed in Escherichia coli. Sequence analysis revealed that PlGH3 consists of 749 amino acids with a molecular weight of 89.5 kDa, exhibiting the characteristic features of the glycoside hydrolase 3 family. The enzymatic characterization results of PlGH3 showed that the optimal reaction pH and temperature was 8 and 50 °C by using p-nitrophenyl-ß-D-glucopyranoside as a substrate, respectively. The Km and kcat values towards ginsenoside Ro were 79.59 ± 3.42 µM and 18.52 s-1, respectively. PlGH3 exhibits a highly specific activity on hydrolyzing the 28-O-ß-D-glucopyranosyl ester bond of oleanane-type saponins. The mechanism of hydrolysis specificity was then presumably elucidated through molecular docking. Eventually, four kinds of rare oleanane-type ginsenosides (calenduloside E, pseudoginsenoside RP1, zingibroside R1, and tarasaponin VI) were successfully prepared by biotransforming total saponins extracted from Panax japonicus. This study contributes to understanding the mechanism of enzymatic hydrolysis of the GH3 family and provides a practical route for the preparation of rare oleanane-type ginsenosides through biotransformation. KEY POINTS: • The glucose at C-28 in oleanane-type saponins can be directionally hydrolyzed. • Mechanisms to interpret PlGH3 substrate specificity by molecular docking. • Case of preparation of low-sugar alternative saponins by directed hydrolysis.

[Research progress on chemical constituents and pharmacological effects of Glechomae Herba and prediction of its Q-markers].

Glechomae Herba, the dried aerial part of Glechoma longituba(Labiatae), has the effects of promoting urination, draining dampness, and relieving stranguria. It has received wide attention in recent years owing to the satisfactory efficacy on lithiasis. Amid the in-depth chemical and pharmacological research, it has been found that Glechomae Herba has antibacterial, anti-inflammatory, antioxidant, antithrombotic, hepatoprotective, cholagogic, antitumor, hypoglycemic, and lipid-lowering effects. The main chemical constituents are volatile oils, flavonoids, terpenoids, phenylpropanoids, and organic acids. This paper summarized the chemical constituents and pharmacological effects of Glechomae Herba. Based on genetic relationship of plants, the characteristics, efficacy, and pharmacokinetics of the chemical constituents, and the potential of these constituents as quality markers(Q-markers), it was summed up that ursolic acid, caffeic acid, rosmarinic acid, luteolin-7-O-diglucuronide, apigenin, apigenin-7-O-diglucuronide, apigetrin, and glechone can be the candidate Q-markers of Glechomae Herba.

Six polyacetylenes from Atractylodes macrocephala Koidz and their anti-colon cancer activity.

Six undescribed polyacetylenes Atracetylenes A-F (1-6) and three known ones (7-9) were isolated from the rhizomes of Atractylodes macrocephala Koidz.. The comprehensive interpretation of NMR, HR-ESI-MS, DP4+ calculations, and electronic circular dichroism (ECD) calculations resulted in the elucidation of their structures and absolute configurations. The anti-colon cancer activities of (1-9) were evaluated by assaying the cytotoxicity and apoptosis on CT-26 cell lines. Notably, 5 (IC50 17.51 ± 1.41 µM) and 7 (IC50 18.58 ± 1.37 µM) exhibited significant cytotoxicity, and polyacetylenes 3-6 showed excellent abilities to promote apoptosis of CT-26 cell lines by Annexin V-FITC/PI assay. The results demonstrated that the polyacetylenes in A. macrocephala may be prospective for the treatment of colorectal cancer.

Chemical constituents from aerial parts of Scoparia dulcis.

Objective: To study the chemical constituents from the aerial parts of Scoparia dulcis. Methods: Various chromatographic techniques were used to separate the constituents and their structures were elucidated using spectroscopic methods and by comparing their data to those reported in the literatures. The α-glucosidase inhibitory activity assay was used to identify potential α-glucosidase inhibitors. Results: Nine compounds were isolated from the aerial parts of S. dulcis. Their structures were identified as Scoparic zolone (1), (2S)-2,7-dihydroxy-2H-1,4-benzoxazin-3(4H)-one (2), (2R)-7-hydroxy-2H-1,4-benzoxazin-3(4H)-one-2-O-ß-d-glucopyranoside (3), (2R)-7-methoxy-2H-1,4-benzoxazin-3(4H)-one-2-O-ß-d-glucopyranoside (4), (2S)-7-hydroxy-2H-1,4-benzoxazin-3(4H)-one-2-O-ß-d-glucopyranoside (5), 6-methoxy-benzoxazolin-2(3H)-one (6), 4-acetonyl-3,5-dimethoxy-p-quinol (7), zizyvoside I (8), and 3,4-dihydroxy benzeneacetic acid (9). Compound 2 showed the potent α-glucosidase inhibitory activity with an IC50 value of (132.8 ± 11.5) µmol/L, which is 28-fold higher than the positive control acarbose. Conclusion: Compound 1 is a new natural product. Compounds 2 and 9 have not been reported in Scoparia before. Compounds 3, 5, 7, 8 are isolated from Scrophulariaceae for the first time.

New alkaloids from Polygonatum zanlanscianense Pamp.

Sixteen alkaloid compounds were isolated from the dried rhizomes of P. zanlanscianense, including a pair of new enantiomers (R/S)-7'-ethoxy-trans-p-couma-royltyramine (1a/1b) and 14 known compounds (2-14) isolated from this plant for the first time. The structures of new compounds were identified by IR, NMR and MS spectroscopic analysis, and their absolute configurations were determined by comparison of the experimental and calculated ECD data.

Pentacyclic triterpenoids from spikes of Prunella vulgaris L. with thyroid tumour cell cytostatic bioactivities.

Five new triterpenoids, including four ursane types (1-4) and one oleanane type (5), together with 15 known ursane types pentacyclic triterpenoids (6-20) were isolated from the fruit spikes of Prunella vulgaris L., a traditional Chinese herbal medicine. Their structures were elucidated based on IR, HR-ESI-MS, and NMR spectroscopic data. The SW579 cell line was used to evaluate anti-thyroid cancer activities of (1-20). The results indicated that (7-9), (16), and (19) exhibited apparent inhibitory activity with IC50 values of 25.73-71.41 µM (cisplatin as positive control, IC50 14.49 ± 0.97 µM). Network pharmacology and molecular docking were also used for the prediction of the synergistic actions and the underlying mechanisms. Accordingly, four potential targets have been characterized.

Molecular mechanism of acceptor selection in cyclodextrin glycosyltransferases catalyzed ginsenoside transglycosylation.

Understanding the mechanisms of enzyme specificity is increasingly important from a fundamental viewpoint and for practical applications. Transglycosylation has attracted many attentions due to its importance in improving the functional properties of acceptor substrates both in vivo and in vitro. Cyclodextrin glucanotransferase (CGTase) is one of the key enzymes in transglycosylation, it has a broad substrate spectrum and utilizes sugar as the donor. However, little is known about the acceptor selectivity of CGTase, which greatly hampers efforts toward the rational design of desirable transglycosylated derivatives. In this study, we found that the CGTase from Bacillus circulans, BcCGTase, was able to form glycosylated products with diverse ginsenosides. In particular, it not only carries out diverse mono-, di-, and even higher-order glycosylations via the transfer of glucose moieties to the COGlc positions, but also can glycosylate the C3-OH position of ginsenosides. In contrast, another CGTase from Bacillus licheniformis (BlCGTase) showed relatively specific acceptor preference with only several ginsenosides. Structural comparison between BcCGTase and BlCGTase revealed that the Arg74/K81 position within the acceptor-binding sites of BcCGTase/BlCGTase was responsible for the differences in catalytic specificity for ginsenoside F1. Further mutagenesis confirmed their roles in the acceptor selection. In conclusion, our study not only demonstrates the acceptor selectivity of CGTases, but also provides insight into the catalytic mechanism of CGTases, which will potentially increase the utility of CGTase for biosynthesis of new, rationally designed transglycosylated derivatives.

Two new stilbenoid diglycosides from the stems of Dendrobium 'Sonia'.

Two undescribed stilbenoid diglycosides, dendrosonside A and dendrosonside B (1 and 2), were isolated from the stems of Dendrobium 'Sonia'. Their structures were elucidated based on 1 D/2D NMR and HRESIMS. The glycosyls contained in the two isolates were determined as D-glucose by acid hydrolysis and GC-MS analyses. In addition, 1 and 2 were further tested for the inhibition of nitric oxide production.

Seven new 2-(2-phenylethyl) chromone derivatives from agarwood of Aquilaria agallocha with inhibitory effects on nitric oxide production.

Seven new 2-(2-Phenethyl) chromone derivatives (1-7), including four 2-(2-Phenethyl) chromones (1-4), one 6, 7, 8 trihydroxy-2-(2-Phenethyl) chromone (5), one acetylated 5, 6, 7, 8-tetrahydroxy-2-(2-Phenethyl) chromone (6), and one chlorine-containing 5, 6, 7, 8-tetrahydro-2-(2-Phenethyl) chromone (7), along with eight known compounds (8-15), were isolated from agarwood originating from Aquilaria agallocha Roxb.. Their structures were determined mainly by high-resolution electrospray ionization mass spectrometry (HR-ESI-MS) and nuclear magnetic resonance (NMR) analysis. The absolute configurations of 3-7 were resolved by electronic circular dichroism (ECD) calculations. Nearly all compounds were evaluated for their anti-inflammatory activities in RAW264.7 cells. Compounds 1 and 7-11 displayed significant anti-inflammatory activities with IC50 values ranging from 3.71 to 32.04 µM.

Eudesmane-type and agarospirane-type sesquiterpenes from agarwood of Aquilaria agallocha.

Eleven previously unreported sesquiterpenes, including nine eudesmane-type (agalleudesmanol A-I) and two agarospirane-type sesquiterpenes (agarospiranic aldehyde A-B), together with eight known sesquiterpenes, were isolated from the agarwood of Aquilaria agallocha Roxb. The structures were established based on extensive spectroscopic analyses, including infrared (IR), high-resolution electrospray ionisation mass spectrometry (HRESIMS), nuclear magnetic resonance (NMR), X-ray diffraction, quantum chemical calculations based on empirical electronic circular dichroism (ECD) data, and DP4+ probability analysis. The bioactivity of these undescribed compounds against lipopolysaccharide (LPS)-induced NO production in RAW 264.7 cells was evaluated. Compounds 1 and 2 exhibited significant anti-inflammatory activities, with IC50 values of 5.46-14.07 µM (aminoguanidine as positive control, IC50 20.33 ± 1.08 µM).

Rapid screening for natural lipase inhibitors from Alisma orientale combining high-performance thin-layer chromatography-bioautography with mass spectrometry.

Lipase inhibitors are an attractive class of hypolipidemic compounds, which inhibit the activity of human pancreatic lipase, thereby preventing the absorption of triglycerides in vivo. As a library of promising lead compounds for drug development, traditional Chinese medicine (TCM) has gained growing attention in quick discovery and identification of enzyme inhibitors of natural-origin. The purpose of this work was to discover unknown lipase inhibitors from Alisma orientale by the activity oriented analysis method thin-layer chromatography-bioautography, then use electrospray ionization mass spectrometry technology via the elution based TLC-MS interface to identify their structures. As a result, eleven natural lipase inhibitors from Alisma orientale extracts were identified based on molecular mass and fragment ions obtained by HPTLC-MS, and further confirmed by a series of complementary means including UV spectra, 1H NMR characteristic proton signals and polarity of compounds, eleven lipase inhibitors were tentatively assigned as triterpenoids: alisol B (m/z 495.50 [M + Na]+), alisol B 23-acetate (m/z 537.58 [M + Na]+), 11-deoxy-alisol B (m/z 479.50 [M + Na]+), 11-deoxy-alisol B 23-acetate (m/z 521.50 [M + Na]+), alisol A/epialisol A (m/z 513.50 [M + Na]+), 16-oxo-11-deoxy-alisol A (m/z 511.50 [M + Na]+), 16-oxo-alisol A (527.50 [M + Na] +), alisol C (m/z 509.58 [M + Na]+), alisol C 23-acetate (m/z 551.50 [M + Na]+), alisol M 23-acetate (m/z 567.50 [M + Na]+), and alismanol Q/neoalisol (m/z 493.42 [M + Na]+). The integrated approach is an efficient method for rapid screening lipase inhibitors from complex plant extracts and provides a reasonable and favorable basis for the identification and separation of other enzymatic system and other important compounds with therapeutic values.

New chlorophenolic glycoside from Curculigo orchioides and their activities on 5α-reductase.

Two new chlorophenolic glucosides curculigines P (1) and Q (2), together with seven known compounds (3-9), were isolated from the dried rhizomes of Curculigo orchioides. Their structures were determined by spectroscopic methods including 1 D, 2 D NMR and MS. All the isolated compounds were evaluated on 5α-reductase activity by a HaCaT-based bioassay. Compounds 1-9 showed varying degrees of inhibiting activity against 5α-reductase, while compound 1 indicated the most potent inhibitory effect.[Formula: see text].

Structures and biological evaluation of phenylpropanoid derivatives from Dendrobium Sonia.

Two new phenylpropanoid derivatives (1-2), together with eight known compounds (3-10) were isolated from the stems of Dendrobium sonia. The structures of these compounds were elucidated on the basis of spectroscopic analyses, including HRESIMS, 1 D and 2 D NMR experiments. All of the isolated compounds were tested for their Nitric Oxide (NO) Inhibitory Activities. The results of bioactive screening showed that compounds 2, 8, 9 and 10 exerted inhibitory effects on NO production with IC50 values in the range of 26.3 to 31.6 µM. Compound 8 and 9 exhibited stronger anti-inflammatory activities with IC50 values 26.3 and 27.7 µM, comparable to that of the positive control.

Microbial Biotransformation of Iridoid Glycosides from Gentiana Rigescens by Penicillium Brasilianum.

This study aimed to investigate the metabolic effects of endophytic fungi in Gentiana rigescens. From the 100 selected morphospecies, strain 7-2 (Penicillium brasilianum) showed a remarkable biocatalytic activity for gentiopicroside and swertiamarin, yielding seven products, including one new compound, 5-ethylidene-8-hydroxy-4,5,6,8-tetrahydropyrano[3,4-c]pyran-1-one (M04), alongside six known compounds. Gentianine (M01) was the only metabolite of swertiamarin in this study, while the remaining ones were all gentiopicroside metabolites. Among these, five compounds: gentianine (M01), (5S,6S)-5-(hydroxymethyl)-6-methyl-5,6-dihydro-1H,3H-pyrano[3,4-c]pyran-1-one (M02), (5R,6S)-5-(hydroxymethyl)-6-methyl-5,6-dihydro-1H,3H-pyrano[3,4-c]pyran-1-one (M03), 2-(3-formyl-2-oxo-3,6-dihydro-2H-pyran-4-yl)but-3-enoic acid (M06), and 2-oxo-4-(1-oxobut-3-en-2-yl)-3,6-dihydro-2H-pyran-3-carboxylic acid (M07) were similar to gentiopicroside metabolites in humans. Screening the metabolic potential of endophytic fungi in Gentiana rigescens provides an outstanding source for assessing the bioactive metabolites of iridoid glycosides. The above findings suggested that the endophytic fungi of G. rigescens possess multi-enzyme systems that mimic metabolic reactions in mammalian organisms.

A new nucleoside and two new pyrrole alkaloid derivatives from Cordyceps militaris.

A new nucleoside, a new natural product nucleoside, and two new pyrrole alkaloids derivatives with eight known compounds were isolated from the fruiting body of Cordyceps militaris. The structures of the new compounds were elucidated through extensive analysis of spectroscopic data including 1D and 2D NMR, HRESIMS, IR and UV. All the isolated compounds were detected for their bioactivities against LPS-induced NO production in RAW 264.7 cells. Unfortunately, all the isolates have shown no obvious activity.

Antioxidative 2-(2-phenylethyl)chromones in Chinese eaglewood from Aquilaria sinensis.

Two new compounds 6,7-dimethoxy-2-[2-(2'-hydroxyphenyl)ethyl]chromone (1) and 6,7-dimethoxy-2-[2-(4'-hydroxyphenyl)ethenyl]chromone (2), together with ten known 2-(2-phenylethyl)chromones (3-12) were isolated from the resinous wood of Aquilaria sinensis (Lour.) Gilg. Their structures were elucidated by detailed IR, MS, NMR spectroscopic analyses, and comparison with reported. The absolute configuration of 3 was confirmed by Cu Kα X-ray crystallographic experiment, and the X-ray crystallographic data of 3 were firstly reported. Compounds 2, 8, 10, and 11 exhibited strong ABTS•+ radical scavenging activity, with IC50 values of 12.3, 16.5, 12.1, and 34.7 µM, respectively.[Formula: see text].

Four new sesquiterpenoids with anti-inflammatory activity from the stems of Jasminum officinale.

Four new sesquiterpenoids，including three nor-cinalbicane type sesquiterpenoids, named Jasminol A, G, H (1-3) and one eremophilene-type sesquiterpenoid, named Jasminol B (4) together with nine known compounds (5-13) were isolated from the stems of Jasminum officinale L. The structures of new compound were elucidated on the base of IR, HR-ESI-MS, 1D NMR, 2D NMR and DEPT analysis, and the absolute configurations were determined by single-crystal X-ray diffraction analysis. In addition, the anti-inflammatory activity of isolated compounds was evaluated using lipopolysaccharide (LPS)-induced murine macrophage RAW264.7, and compounds 1-4 exhibited a moderate inhibition of LPS-induced nitric oxide (NO) production in RAW264.7 cells with IC50 values of 20.56 ±â€¯1.31, 30.12 ±â€¯0.89, 30.35 ±â€¯2.72 and 31.60 ±â€¯1.69 µM, respectively, and CC50 values >200 uM.

A new ionone derivative from the leaves of Picrasma quassioides.

Nigakialcohol A (1), as unusual cyclization ionone derivative, together with eight known ones (2-9), were isolated from the leaves of Picrasma quassioides (D. Don) Benn (Simaroubaceae). Their structures were elucidated by extensive spectroscopic analyses and comparison with literature data. Compound 2 showed a weak inhibitory effect on NO production at non-cytotoxic concentration (100 µM) with inhibitory rate of 59%, and thus it should be regarded as potential anti-inflammatory agents.

Abietane Diterpenoids from the Roots of Clerodendrum trichotomum and Their Nitric Oxide Inhibitory Activities.

Twelve new abietane diterpenoids (1-12) and 31 known analogues (13-43) were isolated from a medicinal Chinese herb, Clerodendrum trichotomum Thunberg. The absolute configurations of 1-3 were established on the basis of ECD and X-ray crystallography data, whereas that of 4 was elucidated by comparison of experimental and calculated ECD data. Eight diterpenoids, 15,16-dehydroteuvincenone G (1), trichotomin A (4), 2α-hydrocaryopincaolide F (7), villosin C (20), 15-dehydro-17-hydroxycyrtophyllone A (22), demethylcryptojaponol (38), 6ß-hydroxydemethylcryptojaponol (39), and trichotomone (43), exerted inhibitory effects against NO production with IC50 values of 5.6-16.1 µM. The structure-activity relationships of the isolated diterpenoids are also estimated.