Isolation of antibacterial diterpenoids fromCryptomeria japonicabark

Rosin: A comprehensive review on traditional uses, phytochemistry, and pharmacology

Rosin, a natural resin obtained from conifer trees, has a long history of use in traditional folk medicine for treating abscesses, wounds, carbuncles, and burns, etc. It has been employed in ancient Egypt, China, Nordic countries, and Turkey as a therapeutic remedy. This comprehensive review examines the traditional uses, phytochemistry, and pharmacology of rosin, and it provides a critical update on current knowledge of rosin and identifies potential therapeutic opportunities. The chemical composition of rosin is known to vary depending on factors such as botanical sources, geographical locations, and processing methods. Rosin acids, which account for over 90% of its primary chemical constituents, have been identified as the predominant compounds in rosin. Researchers have isolated approximately 50 compounds from rosin, with terpenoid rosin acids being the most prevalent. Furthermore, the review highlights the potential pharmacological activities of rosin and its constituents. Crude extracts and isolated rosin acids have demonstrated promising properties, including antimicrobial, anti-inflammatory, anti-tumor, insecticidal, wound healing, and anti-obesity effects. However, the review emphasizes that further research is needed, as existing studies are predominantly preliminary. Many of the reported bioactivities require further verification, and the underlying mechanisms of action remain largely unexplored. In conclusion, rosin has been extensively used in traditional medicine across different cultures, and its chemical composition has been confirmed to a significant extent. The pharmacological activities observed in crude extracts and isolated rosin acids support its traditional uses. Nevertheless, additional research is necessary to deepen our understanding of the pharmacological mechanisms underlying its effects.

Two New Compounds from the Endophytic Fungi of Dryopteris crassirhizoma and Their Antimicrobial Activities

Two endophytic fungi Trichoderma afroharzianum (HP-3) and Alternaria alstroemeriae (HP-7) were isolated and purified from the fresh root of Dryopteris crassirhizoma. Chemical investigation of the two fungi resulted in the isolation of two new phenols 2,4-dihydroxy-3-farnesyl-5-methoxy benzoic acid (1) and 2-hydroxyphenethyl 2-phenylacetate (2), together with 22 known compounds. Their structures were elucidated by NMR, UV, IR, HRESIMS, and comparison to the literature data. Compounds 15 and 16 showed significant antibacterial activity against Micrococcus lysodeikticus with MIC value of 6.25 μg/mL, while 8 and 14 displayed moderate inhibitory activities against several plant pathogenic fungi and clinically important bacterial strains. This is the first study to report the isolation, identification, and antimicrobial properties of metabolites from endophytic fungi of D. crassirhizoma. Our findings may provide lead compounds for the development of new antibacterial agents.

A new abietane diterpene tuurgan a from caryopteris mongholica

Five abietane diterpenes compounds were separated from petroleum ether extraction sites of ethanol extract of Caryopteris Mongholica, and Compound 1 was identified as a new abietane diterpenes compound by NMR and mass spectrometry, named as Tuurgan A of Caryopteris Mongholica; and Compounds 2-5 separated from Caryopteris Mongholica for the first time were identified as Ferruginol (2), Taxodione (3), Caryopterisoid Q (4), and Huperphlegmarin B (5). The anti-lung cancer activity of the Compounds 1-5 were determined, which results showed that they all had high A549 cytotoxicity.

Diverse diterpenoids from Callicarpa rubella Lindl. As natural inhibitors of macrophage foam cell formation

Ten undescribed diterpenoids namely rubellawus E-N of structural types pimarane (1, 3-4), nor-abietane (2), nor-pimarane (5-6), isopimarane (7-9), and nor-isopimarane (10), along with eleven known compounds, were isolated and identified from the aerial parts of Callicarpa rubella Lindl. The structures of the isolated compounds were confirmed by comprehensive spectroscopic analyses and quantum chemical computations. Pharmacologically, almost all the compounds exhibited a potential inhibitory effect on oxidized low-density lipoprotein-induced macrophage foam cell formation, which suggests that these compounds may be promising candidates in the treatment of atherosclerosis.

Neofusicoccum cryptomeriae sp. nov. and N. parvum Cause Stem Basal Canker of Cryptomeria japonica in China

Cryptomeria japonica D. Don is a coniferous tree species widely grown in southern China for its high ornamental value. Recently, during disease surveys in China, a symptom of dieback occurred on C. japonica in Nanjing, Jiangsu Province, China. A total of 130 trees were surveyed and more than 90% showed the same symptom. The crowns of affected trees were brown when viewing from a distance, and the bark showed no difference from the healthy ones. In this study, 157 isolates were isolated from the 3 affected plants of C. japonica, and based on the living culture on PDA, the fungal isolates were preliminarily divided into 6 groups. Thirteen representative isolates were selected for the pathogenicity test, and seven of them showed obvious pathogenicity on C. japonica, causing stem basal canker. These isolates were identified based on comparisons of the DNA sequences of the internal transcribed spacer regions (ITS), partial translation elongation factor 1-alpha (tef1), β-tubulin (tub2), and DNA-directed RNA polymerase II subunit (rpb2) and combined with their morphological characteristics. Results showed that these seven isolates belong to two taxa in Neofusicoccum, including a species new to science. The new species, Neofusicoccum cryptomeriae, was hereby described and illustrated. The other species was N. parvum. Both species were pathogens of stem basal canker of Cryptomeria japonica.

Biological activities of organic extracts and specialized metabolites from different parts of Cryptomeria japonica (Cupressaceae) - A critical review

Forest operations and wood industry generate large amounts of residues that are discarded in the field and cause environmental pollution. However, these biomass residues are still raw materials to obtain value-added products, such as essential oils, organic/aqueous extracts and resins that are among the great natural sources of bioactive metabolites. Thus, in recent years, the scientific community is giving special attention to their valorization. To date, different uses of biomass residues have been proposed, such as a source of renewable energy, fertilizers, animal feed and bioactive molecules. In this context, Cryptomeria japonica biomass residues (e.g., bark and its exudate, heartwood, sapwood, leaves, cones and roots) represent a source of diverse specialized metabolites (e.g., sesqui-, di-, tri- and sesquarterpenes, flavonoids, lignans and norlignans) with potential application in different fields, particularly in the agrochemical, food, cosmeceutical, pharmaceutical, phytomedicine and esthetic, due to their valuable multi-bioactivities determined over the last decades. Thus, this review provides an overview of the reported biological activities of organic extracts/fractions and their specialized metabolites obtained from different parts of C. japonica, in order to encourage the alternative uses of C. japonica wastes/byproducts, and implement a sustainable and circular bioeconomy.

Triterpenoids, steroids and other constituents from Euphorbia kansui and their anti-inflammatory and anti-tumor properties

Six undescribed triterpenoids (euphokanols A-F), two undescribed C21-steroidal glycosides (euphokanosides A and B), together with fifty-four known compounds were isolated from the roots of Euphorbia kansui. Their structures were demonstrated by extensive spectroscopic data (1D, 2D NMR and HR-ESI-MS), and the absolute configuration of euphokanol A was elucidated based on electronic circular dichroism (ECD) calculation. Among them, euphokanol A was a tetracyclic triterpenoid with a 5,10-epoxy moiety and concurrent rearrangement of Me-19(10 → 9) and Me-30 (14 → 8), while euphokanols B and C were rare 19(10 → 9) abeo-tirucallane-type triterpenoids with Δ5(10) double bonds and 7,8-epoxy moieties. In addition, ten C21-steroidal glycosides were isolated from Euphorbia plants for the first time. Moreover, cynotophylloside B, caudatin, 5α,8α-epidioxy-22E-ergosta-6,22-diene-3β-ol, 6β,7β-epoxy-3β,4β,5β-trihydroxyl-20-deoxyingenol, 13-hydroxyingenol-3-(2,3- dimethylbutanoate)-13-dodecanoate, ingenol, 3-O-benzoyl-13-O-dodecanoateingenol, 3-O-(2'E,4'Z-decadienoyl)-20-O-acetylingenol, 20-O-acetylingenol and 20- deoxyingenol exhibited significant inhibition on NO production with IC50 values of 9.10, 17.38, 1.71, 0.55, 0.57, 12.22, 0.56, 0.30, 11.21 and 2.98 μM, respectively. Furthermore, wilfoside KIN, cynsaccatol L, kanesulone A, and 3β,7β,15β-triacetyloxy-5α-benzoyloxy-2α,8α-dihydroxyjatropha-6(17),11E-diene-9, 14-dione showed cytotoxicity against HepG2 cell line, with IC50 values of 12.55, 12.61, 18.24 and 18.26 μM, respectively. 13-Hydroxyingenol-3-(2,3-dimethylbutanoate)-13- dodecanoate exhibited anti-proliferation activity on MCF-7 cell line with an IC50 value of 17.12 μM. Specifically, euphol selectively inhibited the growth of human glioma stem cells (GSC-3# and GSC-12#), with IC50 values of 8.89 and 13.00 μM, respectively.

Autofluorescence-Based Investigation of Spatial Distribution of Phenolic Compounds in Soybeans Using Confocal Laser Microscopy and a High-Resolution Mass Spectrometric Approach

In this research, we present a detailed comparative analysis of the bioactive substances of soybean varieties k-11538 (Russia), k-11559 (Russia), k-569 (China), k-5367 (China), k-5373 (China), k-5586 (Sweden), and Primorskaya-86 (Russia) using an LSM 800 confocal laser microscope and an amaZon ion trap SL mass spectrometer. Laser microscopy made it possible to clarify in detail the spatial arrangement of the polyphenolic content of soybeans. Our results revealed that the phenolics of soybean are spatially located mainly in the seed coat and the outer layer of the cotyledon. High-performance liquid chromatography (HPLC) was used in combination with an amaZon SL BRUKER DALTONIKS ion trap (tandem mass spectrometry) to identify target analytes in soybean extracts. The results of initial studies revealed the presence of 63 compounds, and 45 of the target analytes were identified as polyphenolic compounds.

Several natural phytochemicals from Chinese traditional fermented food-pickled Raphanus sativus L.: Purification and characterization

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β-Sitosterol, β-sitosterol-3-o-glucose glycosides, α-linolenic acid, 1-monopalmitin and chaenomic acid A were identified from 5-year-old pickled radish.

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Production of the merad product 5-hydroxymethylfurfural in fresh white radish after salting and fermentation.

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β-Sitosterol, β-sitosterol-3-O-glucose glycosides have good affinity with antioxidant enzymes.

In this study, we aimed to isolate and identify the bioactive compounds from 5-year pickled radish. The pickled radish was extracted with methanol or ethyl acetate. Sephadex LH-20, normal phase and reverse phase silica gel column chromatography were used for separation and purification, combined with thin layer chromatography (TLC), high performance liquid chromatography (HPLC), electrospray mass spectrometry (ESI-MS), nuclear magnetic resonance spectroscopy (NMR) technology for structural identification. The results showed that 6 compounds were separated and purified from methanol and ethyl acetate extracts of 5-year-old pickled radish. The structures were identified as 5-hydroxymethylfurfural, β-sitosterol, β-sitosterol-3-O-glucose glycosides, α-linolenic acid, 1-monopalmitin and chaenomic acid A. Using molecular docking, it was determined that β-sitosterol and its derivative β-sitosterol-3-O-glucose glycosides have high affinity for five antioxidant enzymes, and there were multiple hydrogen bonds between them. These results indicated that pickled radishes might be used as an important source of natural chemical substances.

Structurally Diverse Metabolites from the Ophiorrhiza japonica Bl. and Their Antioxidant Activities In Vitro and PPARα Agonistic Activities In Silico

Ophiorrhiza japonica Bl. is a traditional Chinese materia medica widely used to treat several diseases. Chemical and pharmacological studies on O. japonica have been carried out; however, neither of them has been fully explored. In this study, an array of compounds was isolated from the title plant, including a new anthraquinone, ophiorrhizaquinone A (1), three alkaloids 2–4 and seven other compounds 5–11 with diverse structural types. Additionally, compounds 2, 5, 7, 8, 10 and 11 were isolated from the genus of Ophiorrhiza for the first time. Antioxidant bioassays in vitro using DPPH and ABTS were performed, and the results showed that compound 3 exhibited modest antioxidant activity with IC₅₀ values of 0.0321 mg/mL and 0.0319 mg/mL, respectively. An in silico study of PPARα agonistic activities of compounds 2 and 3 was conducted by molecular docking experiments, revealing that both of them occupied the active site of PPARα via hydrogen bonds and hydrophobic interactions effectively. This study enriched both the phytochemical and pharmacological profiles of O. japonica.

Zostera marina L.: Supercritical CO2-Extraction and Mass Spectrometric Characterization of Chemical Constituents Recovered from Seagrass

Three types of Zostera marina L. collection were extracted using the supercritical CO2-extraction method. For the purposes of supercritical CO2-extraction, old seagrass ejection on the surf edge, fresh seagrass ejection on the surf edge and seagrass collected in water were used. Several experimental conditions were investigated in the pressure range 50–350 bar, with the used volume of co-solvent ethanol in the amount of 1% in the liquid phase at a temperature in the range of 31–70 °C. The most effective extraction conditions are: pressure 250 Bar and temperature 60 °C for Z. marina collected in sea water. Z. marina contain various phenolic compounds and sulfated polyphenols with valuable biological activity. Tandem mass-spectrometry (HPLC-ESI–ion trap) was applied to detect target analytes. 77 different biologically active components have been identified in Z. marina supercritical CO2-extracts. 38 polyphenols were identified for the first time in Z. marina.

Abietane diterpenes from the twigs and leaves of Cephalotaxus oliveri Mast. with antitumor activity

Twenty one abietane diterpenes were isolated from Cephalotaxus oliveri Mast. The structures of 7 undescribed diterpenoids, named cephaloliverins A-G, were elucidated via spectroscopic data interpretation and electronic circular dichroism (ECD) analysis. The isolated diterpenoids were evaluated for their cytotoxicity against three kinds of human tumor cell lines (MCF-7, HepG2, and A549). Metaglyptin A was the most active with IC₅₀ values of 16.34, 15.63 and 21.33 μM and was further investigated for colony formation and apoptosis in HepG2 cells.

Antifungal Sesquiterpenoids from Michelia formosana Leaf Essential Oil against Wood-Rotting Fungi

Michelia formosana (Kanehira) Masamune is a broad-leaved species widespread in East Asia; the wood extract and its constituents possess antifungal activity against wood-decay fungi. Antifungal activities of leaf essential oil and its constituents from M. formosana were investigated in the present study. Bioassay-guided isolation was applied to isolate the phytochemicals from leaf essential oil. 1D and 2D NMR, FTIR, and MS spectroscopic analyses were applied to elucidate the chemical structures of isolated compounds. Leaf essential oil displayed antifungal activity against wood decay fungi and was further separated into 11 fractions by column chromatography. Four sesquiterpenoids were isolated and identified from the active fractions of leaf essential oil through bioassay-guided isolation. Among these sesquiterpenoids, guaiol, bulnesol, and β-elemol have higher antifungal activity against brown-rot fungus Laetiporus sulphureus and white-rot fungus Lenzites betulina. Leaf essential oil and active compounds showed better antifungal activity against L. sulphureus than against L. betulina. The molecular structure of active sesquiterpenoids all contain the hydroxyisopropyl group. Antifungal sesquiterpenoids from M. formosana leaf essential oil show potential as natural fungicides for decay control of lignocellulosic materials.

Chemical Constituents of the Aerial Part of Valeriana officinalis var. latifolia Miq. With COX-2 Inhibitory Activity

Twelve compounds, including a new iridoid (1) and 11 known compounds, were obtained from the aerial part of Valeriana officinalis var. latifolia Miq. Their structures were assigned by spectroscopic and mass spectrometric methods. All isolates were screened in vitro for cyclooxygenase-2 (COX-2) inhibitory activity. Two compounds (9 and 10) exhibited significant COX-2 inhibitory activity, with IC50 values ranging from 0.67 to 6.77 μM. The possible recognition mechanism between compound 9 and COX-2 was predicted by molecular docking analysis.

Association between corticolous myxomycetes and tree vitality in Cryptomeria japonica

The bark of live trees provides an important microhabitat for corticolous myxomycetes. However, the association between the presence of myxomycetes and health of host trees has not been studied in detail. In this study, we aimed to investigate the relationship between tree vitality and myxomycetes on the bark of Cryptomeria japonica trees in a montane forest in western Japan. The vitality of trees was categorized into four grades based on the visual assessment of tree shape and leaf density in the upper branches. Myxomycetes on the bark surface were examined using the moist chamber culture method. A decline in tree vitality increased bark pH and decreased electrical conductivity of the bark exudates. Seventeen myxomycete species were recorded in 74 C. japonica trees. The structure of myxomycete communities varied between healthy and unhealthy trees, and species diversity increased as the vitality declined. The relative abundance of Cribraria confusa decreased as the vitality declined, while that of Paradiacheopsis solitaria increased. The results showed that acidophilic myxomycetes grew on healthy C. japonica bark, but changes in bark pH associated with vitality decline led to the weakening of acidity and shifted the community structure; thus, corticolous myxomycete diversity was enhanced as tree vitality decline.

Antimelanogenesis Effects of Leaf Extract and Phytochemicals from Ceylon Olive (Elaeocarpus serratus) in Zebrafish Model

The melanogenesis inhibition effect in zebrafish (Danio rerio) and antityrosinase activity of the ethanolic extract and its phytochemicals from Ceylon olive (Elaeocarpus serratus Linn.) leaves were investigated in this study. Among the leaf extract and four soluble fractions, the ethyl acetate soluble fraction exhibits the best antityrosinase and antimelanogenesis activities. One phenolic acid, gallic acid, and two flavonoids, myricetin and mearnsetin, are isolated from the active subfractions through the bioassay-guided isolation; their structures are elucidated based on the 1D and 2D NMR, FTIR, UV, and MS spectroscopic analyses. These compounds have significant antityrosinase activity whether using l-tyrosine or l-DOPA as the substrate; mearnsetin shows the optimal activity. In the enzyme kinetic investigation, both gallic acid and mearnsetin are the competitive-type inhibitors against mushroom tyrosinase, and myricetin acts as a mixed-type tyrosinase inhibitor. Leaf extract and an ethyl acetate soluble fraction show effective performance in the inhibition of melanin formation in zebrafish embryos. Mearnsetin also possesses a promising antimelanogenesis effect, which is superior to the positive control, arbutin. Results reveal that the Ceylon olive leaf extract and its phytochemicals, especially mearnsetin, have the potential to be used as antimelanogenesis and skin-whitening ingredients.

Metabolite pattern in root nodules of the actinorhizal plant Casuarina equisetifolia

Casuarina equisetifolia L. (Casuarinaceae), an actinorhizal plant, exhibits mutualistic symbiosis with Frankia and promotes nitrogen fixation in root nodules. While the exchange of metabolites between host plant and microsymbiont is well understood in legume symbioses, the situation in the symbiosis between nitrogen-fixing Frankia and actinorhizal plants is less clear. In this study, a metabolomic approach was applied to root nodules of mature C. equisetifolia trees, leading to the identification of an undescribed taraxerane-type triterpenoid ester, 3-O-dihydrocoumaroyl β-taraxerol, along with twelve known compounds. An abundant component was tyramine with a content of 2.76 ± 0.315 mg/g FW in mature nodules. Tyramine specifically and abundantly accumulated in mature nitrogen-fixing nodules compared to senescent nodules, stems, leaves, and seeds. In addition, the potential function of tyramine was preliminarily examined and discussed.

Isolation and Identification of Antibacterial Bioactive Compounds From Bacillus megaterium L2

Bacterial metabolites exhibit a variety of biologically active compounds including antibacterial and antifungal activities. It is well known that Bacillus is considered to be a promising source of bioactive secondary metabolites. Most plant pathogens have an incredible ability to mutate and acquire resistance, causing major economic losses in the agricultural field. Therefore, it is necessary to use the natural antibacterial compounds in microbes to control plant pathogens. This study was conducted to investigate the bio-active compounds of Bacillus megaterium L2. According to the activity guidance of Agrobacterium tumefaciens T-37, Erwinia carotovora EC-1 and Ralstonia solanacearum RS-2, five monomeric compounds, including erucamide (1), behenic acid (2), palmitic acid (3), phenylacetic acid (4), and β-sitosterol (5), were fractionated and purified from the crude ethyl acetate extract of B. megaterium. To our knowledge, all compounds were isolated from the bacterium for the first time. To understand the antimicrobial activity of these compounds, and their minimum inhibitory concentrations (MICs) (range: 0.98∼500 μg/mL) were determined by the broth microdilution method. For the three tested pathogens, palmitic acid exhibited almost no antibacterial activity (>500 μg/mL), while erucamide had moderate antibacterial activity (MIC = 500 μg/mL). Behenic acid showed MICs of 250 μg/mL against T-37 and RS-2 strains with an antibacterial activity. β-sitosterol showed significant antimicrobial activity against RS-2. β-sitosterol showed remarkable antimicrobial activity against RS-2 with an MIC of 15.6 μg/mL. In addition, with the antimicrobial activity, against T-37 (62.5 μg/mL) and against EC-1 (125 μg/mL) and RS-2 (15.6 μg/mL) strains notably, phenylacetic acid may be interesting for the prevention and control of phytopathogenic bacteria. Our findings suggest that isolated compounds such as behenic acid, β-sitosterol, and phenylacetic acid may be promising candidates for natural antimicrobial agents.

Cytotoxic constituent of Melicope latifolia (DC.) T. G. Hartley

An undescribed conjugated sesquiterpene, amelicarin (1), together with nine known compounds (2-10) were isolated for the first time from Melicope latifolia. Their structures were elucidated by extensive NMR spectroscopic and mass spectrometric methods. The conjugated sesquiterpene possesses a unique 6/6/9/4-ring fused tetracyclic skeleton. The proposed biosynthesis pathway of 1 consist of three reactions steps: (1) polyketide formation, (2) cyclisation and (3) addition to form the conjugated sesquiterpenoid as final metabolite. Out of the ten isolated metabolites, amelicarin (1) showed activity against 4 cancerous cell lines namely SK-MEL skin cancer, KB oral cancer, BT-549 breast cancer, and SK-OV-3 ovarian cancer with IC₅₀ values between 15 and 25 µg/mL.

Combination between antibacterial and antifungal antibiotics with phytocompounds of Artemisia annua L: A strategy to control drug resistance pathogens

ETHNOPHARMACOLOGICAL RELEVANCE

Artemisia annua L. is a traditional Chinese medicine used for the treatment of malaria, jaundice and intense fever.

AIM OF THE STUDY

The aim of the present study was to investigate the phytochemicals, antioxidants, antimicrobial and synergistic potential of methanolic and petroleum ether extracts of A. annua against bacterial and fungal pathogens.

METHOD

Antioxidant activity of different concentrations of methanolic and petroleum ether extracts of A. annua was determined by DPPH free radical scavenging assay. Antimicrobial activity was determined by agar well diffusion, whereas MIC and synergistic activity was done by broth dilution method.TLC and GC-MS were done to identify active phytocompounds present in methanolic and petroleum ether extracts.

RESULTS

Methanolic extract of A. annua showed higher antioxidant potential (IC50 37 0.75 ± 0.34 μg ml^-1) as compared to petroleum ether extract. In antimicrobial analysis, methanolic and petroleum ether extracts of A. annua produced potent inhibitory activity against Candida strains as compared to bacterial strains. Methanolic and petroleum ether extracts of A. annua produced synergistic potential with decrease in MIC from 4 to 264 folds against bacterial (S. aureus and E. coli) and Candida strains in combination with antibacterial and antifungal antibiotics. Sub fraction I of methanolic and petroleum ether extracts was isolated through silica TLC and showed 10-fold more antimicrobial activity as compared to crude extract. GC-MS analysis of sub-fraction I of A. annua revealed 13 major phytocompounds with area more than 1%. Interestingly, 2-Propenoic acid and ridecyl ester (25.88%) were the major phytocompounds.

CONCLUSION

Phytocompounds of A. annua can be used as bioenhancer of antibacterial and antifungal agents to control drug resistance.

Antibiotics from Extremophilic Micromycetes

Extremophilic microorganisms, which are capable of functioning normally at extremely high or low temperatures, pressure, and in other environmental conditions, have been in the focus of microbiologists' attention for several decades due to the biotechnological potential of enzymes inherent in extremophiles. These enzymes (also called extremozymes) are used in the production of food and detergents and other industries. At the same time, the inhabitants of extreme econiches remained almost unexplored for a long time in terms of the chemistry of natural compounds. In recent years, the emergence of new antibiotic-resistant strains of pathogens, which affect humans and animals has become a global problem. The problem is compounded by a strong slowdown in the development of new antibiotics. In search of new active substances and scaffolds for medical chemistry, researchers turn to unexplored natural sources. In recent years, there has been a sharp increase in the number of studies on secondary metabolites produced by extremophiles. From the discovery of penicillin to the present day, micromycetes, along with actinobacteria, are one of the most productive sources of antibiotic compounds for medicine and agriculture. Many authors consider extremophilic micromycetes as a promising source of small molecules with an unusual mechanism of action or significant structural novelty. This review summarizes the latest (for 2018-2019) experimental data on antibiotic compounds, which are produced by extremophilic micromycetes with various types of adaptation. Active metabolites are classified by the type of structure and biosynthetic origin. The data on the biological activity of the isolated metabolites are summarized.

Xidaosterols A and B, two new steroids with unusual α-keto-enol functionality from the South China Sea sponge Neopetrosia chaliniformis

Two new C29 steroids, xidaosterols A (1) and B (2), characterised by a common unusual α-keto-enol functionality bearing A-ring, together with three related known ones (3-5), were isolated from the South China Sea sponge Neopetrosia chaliniformis. Their structures were elucidated by extensive spectroscopic analyses and comparison with the spectral data reported in the literature, Xidaosterol B is an A-nor derivative of 1.

Novel abietane diterpenoids from Salvia prionitis

Two hitherto unknown highly modified abietane diterpenoids, namely salviapritin A (1) and salviapritin B (2), were isolated from the ethanol extract of Salvia prionitis, together with 17 known compounds. Their chemical structures were established by extensive spectroscopic methods (ESIMS, HRESIMS, 1D and 2D NMR) and by comparison of their NMR data with those of related analogues. Salviapritin A is the first example of a trinorabietane diterpenoid possessing an acenaphthylene skeleton from the Salvia genus. Additionally, a plausible biogenetic pathway for salviapritin B is proposed. [Formula: see text].

Four active monomers from Moutan Cortex exert inhibitory effects against oxidative stress by activating Nrf2/Keap1 signaling pathway

Paeonol, quercetin, β-sitosterol, and gallic acid extracted from Moutan Cortex had been reported to possess anti-oxidative, anti-inflammatory, and antitumor activities. This work aimed to illustrate the potential anti-oxidative mechanism of monomers in human liver hepatocellular carcinoma (HepG2) cells-induced by hydrogen peroxide (H2O2) and to evaluate whether the hepatoprotective effect of monomers was independence or synergy in mice stimulated by carbon tetrachloride (CCl4). Monomers protected against oxidative stress in HepG2 cells in a doseresponse manner by inhibiting the generation of reactive oxygen species, increasing total antioxidant capacity, catalase and superoxide dismutase (SOD) activities, and activating the antioxidative pathway of nuclear factor E2-related factor 2/Kelchlike ECH-associated protein 1 (Nrf2/Keap1) signaling pathway. We found that the in vitro antioxidant capacities of paeonol and quercetin were better than those of β-sitosterol and gallic acid. Furthermore, paeonol apparently diminished the levels of alanine transaminase and aspartate aminotransferase, augmented the contents of glutathione and SOD, promoted the expressions of Nrf2 and heme oxygenase-1 proteins in mice stimulated by CCl4. In HepG2 cells, paeonol, quercetin, β-sitosterol, and gallic acid play a defensive role against H2O2-induced oxidative stress through activating Nrf2/Keap1 pathway, indicating that these monomers have anti-oxidative properties. Totally, paeonol and quercetin exerted anti-oxidative and hepatoprotective effects, which is independent rather than synergy.

Spiroconyone A, a new phytosterol with a spiro [5,6] ring system from Conyza japonica

Spiroconyone A (1), the first rearranged phytosterol featuring an unusual spiro [5,6] ring system, and nine known compounds (2-10) were isolated from the aerial parts of Conyza japonica. The structure of 1 was elucidated through spectroscopic methods, and its absolute configuration was determined by single-crystal X-ray diffraction analysis. Enzyme-based assay revealed that spiroconyone A showed weak TDP1 inhibition and compounds 7 and 10 showed TDP1 inhibition with IC50 values of 36 μM and 16 μM, respectively. MTT assay indicated that 7 and 10 showed a strong synergistic effect with the clinical TOP1 inhibitor topotecan in MCF-7 cells. Compound 5 displayed the most potent cytotoxicity against MCF-7 cells with a GI50 value of 3.3 μM. Furthermore, a hypothetical biosynthetic pathway for 1 was proposed. This work provides valuable information that the secondary metabolites from Conyza japonica could be developed as anticancer agents.

Verification of Chromatographic Profile of Primary Essential Oil of Pinus sylvestris L. Combined with Chemometric Analysis

Chromatographic profiles of primary essential oils (EO) deliver valuable authentic information about composition and compound pattern. Primary EOs obtained from Pinus sylvestris L. (PS) from different global origins were analyzed using gas chromatography coupled to a flame ionization detector (GC-FID) and identified by GC hyphenated to mass spectrometer (GC-MS). A primary EO of PS was characterized by a distinct sesquiterpene pattern followed by a diterpene profile containing diterpenoids of the labdane, pimarane or abietane type. Based on their sesquiterpene compound patterns, primary EOs of PS were separated into their geographical origin using component analysis. Furthermore, differentiation of closely related pine EOs by partial least square discriminant analysis proved the existence of a primary EO of PS. The developed and validated PLS-DA model is suitable as a screening tool to assess the correct chemotaxonomic identification of a primary pine EOs as it classified all pine EOs correctly.

New Constituents from the Low Polar Fraction of the Fruits of Crataegus dahurica and Their Anti-Inflammatory Activity in RAW264.7 Cells

The fruit of Crataegus dahurica Koehne was used to treat the disease of infantile indigestion and dyspepsia as an ethnic medicine and food. As a continuous work on finding the active constituents from the edible herbs, four new biphenyl derivatives (1-4), together with two known compounds (5 and 6), were obtained from the petroleum ether fraction of the fruits of C. dahurica. Their structures were determined by the extensive 1D and 2D NMR spectra and HR-MS spectrometry. Furthermore, the anti-inflammatory activities of all the isolated compounds were investigated, in which compound 4 showed moderately inhibitory effects on NO production in RAW264.7 cells without inducing cytotoxicity.

Terpenoids of the Swamp Cypress Subfamily (Taxodioideae), Cupressaceae, an Overview by GC-MS

The resins bled from stems and in seed cones and leaves of Cryptomeria japonica, Glyptostrobus pensilis, Taxodium distichum, and T. mucronatum were characterized to provide an overview of their major natural product compositions. The total solvent extract solutions were analyzed as the free and derivatized products by gas chromatography-mass spectrometry to identify the compounds, which comprised minor mono- and sesquiterpenoids, and dominant di- and triterpenoids, plus aliphatic lipids (e.g., n-nonacosan-10-ol). Ferruginol, 7α-p-cymenylferruginol, and chamaecydin were the major characteristic markers for the Taxodioideae conifer subfamily. The mass spectrometric data can aid polar compound elucidation in environmental, geological, archeological, forensic and pharmaceutical studies.

Isolation and identification of two new compounds from the twigs and leaves of Cephalotaxus fortunei

Two new compounds, namely 5-hydroxy-7-methoxy-6-methylchromone (1), and sesquiterpene X (6), together with 21 known compounds were isolated from the twigs and leaves of Cephalotaxus fortunei Hook. f. The structures of 1-23 were elucidated on the basis of spectroscopic analysis (1D/2D NMR, HR-ESI-MS and IR) and comparison with literature. The absolute configuration of compound 6 was determined by means of electronic circular dichroism calculation. The in vitro anti-inflammatory activities of all compounds were assayed in RAW 264.7 cells by assessing lipopolysaccharide-induced nitric oxide production. Compounds 1 and 6 exhibited weak effects with percentage inhibitions of 24% and 35.60%, respectively. In addition, compounds 4, 9, and 14 have the potential to be developed as therapeutic agents for inflammatory diseases because of their significant anti-inflammatory activities and high content in C. fortunei.

Sarocladione, a unique 5,10:8,9-diseco-steroid from the deep-sea-derived fungusSarocladium kiliense

Sarocladione was isolated from the deep-sea-derived fungusSarocladium kilienseas the first example of a 5,10:8,9-diseco-steroid.

Comparative evaluation of cytotoxic, antimicrobial and antioxidant activities of the crude extracts of three Plectranthus species grown in Saudi Arabia

Natural products from medicinal plants represent major resource of novel therapeutic substances for combating serious diseases including cancers and microbial infections. The genus Plectranthus (Family: Labiatae) represents a large and widespread group of species with a diversity of traditional uses in treatment of various ailments. Therefore, this research study aimed to evaluate the cytotoxic, antimicrobial and antioxidant activities of three Plectranthus species growing in Saudi Arabia namely P. cylindraceus Hocst. ex Benth., P. asirensis JRI Wood and P. barbatus Andrews. Moreover, this work focused on the isolation of the active constituents responsible for the activities from the most active Plectranthus species.

The extracts were tested for their cytotoxic activity against three cancer cell lines (Hela, HepG2 and HT-29), using MTT-test, antimicrobial activity against Gram positive, Gram negative bacterial and fungal strains using broth micro-dilution assay for minimum inhibitory and bactericidal concentrations (MIC and MBC) and antioxidant activity using scavenging activity of DPPH radical and β-carotene-linoleic acid methods. The ethanolic extracts of the Plectranthus species showed remarkable cytotoxic activity against all cancer cell lines with IC₅₀ values ranging between 10.1 ± 0.33 to 102.6 ± 8.66 μg/mL and a great and antimicrobial activity with MIC values between 62.5 and 250 µg/mL. In addition, the three Plectranthus species showed almost moderate antioxidant activity. The most interesting cytotoxic and antimicrobial results were observed with the extract of P. barbatus. Consequently, this extract was partitioned between water and n-hexane, chloroform and n-butanol and tested. The cytotoxic activity resided predominantly in the n-hexane and chloroform fractions. The analysis of the chloroform fraction led to the isolation of four diterpenoid compounds, two of labdane- and two of abietane-type, which were identified as coleonol B, forskolin, sugiol and 5,6-dehydrosugiol. Purification of the n-hexane fraction led to isolation of a major abietane-type diterpene, which was identified as ferruginol. Sugiol, 5,6-dehydrosugiol and ferruginol were isolated for the first time from P. barbatus in this study. The isolated diterpenoids showed variable cytotoxic effects with IC₅₀ values between 15.1 ± 2.03 and 242 ± 13.3 µg/mL, a great antimicrobial activity with MIC values between 15.6 and 129 µg/mL and a total antioxidant activity ranging from 23.1 ± 2.9 to 69.2 ± 3.8%.

Salvisertin A, a New Hexacyclic Triterpenoid, and Other Bioactive Terpenes from Salvia deserta Root

Using various chromatographic methods, a new hexacyclic triterpenoid, 2β,3β,24β-trihydroxy-12,13-cyclotaraxer-l4-en-28oic acid (1), together with ten known compounds, 2α,3α,23-trihydroxyurs-12,20(30)-dien-28oic acid (2), 6,7-dehydroroyleanone (3), horminone (4), 7-O-methylhorminone (5), sugiol (6), demethylcryptojaponol (7), 14-deoxycoleon U (8), 5,6-didehydro-7-hydroxy-taxodone (9), ferruginol (10), and dichroanone (11), were isolated from the roots of Salvia deserta. Their structures were identified on the basis of spectroscopic analysis and comparison with the reported data. The individual compounds (1, 3 - 8) were screened for cytotoxic activity, using the sulforhodamine B bioassay (SRB) method. As the results, Compounds 3, 5, and 8 showed cytotoxic potency against A549, MDA-MB-231, KB, KB-VIN, and MCF7 cell lines with IC₅₀ values ranging from 6.5 to 10.2 μm.

Bioactive sesquiterpenoids and steroids from the resinous exudates of Commiphora myrrha

Chemical investigation of the resinous exudates of Commiphora myrrha has led to the isolation of four sesquiterpenes (1a/1b, 2, and 3), including one pair of new sesquiterpene enantiomers (1a/1b), one new racemic mixture 2, and two steroids (4 and 5). Their structures were elucidated by spectroscopic analysis, and the absolute configurations of 1a/1b were determined by CD analysis. The antimigratory potential of compounds 1-5 were evaluated and compound 3 was found to inhibit human hepatocellular liver carcinoma HepG2 cell migration in dose-dependent manner.

Efficient Separation of Four Antibacterial Diterpenes from the Roots of Salvia Prattii Using Non-Aqueous Hydrophilic Solid-Phase Extraction Followed by Preparative High-Performance Liquid Chromatography

An efficient preparative procedure for the separation of four antibacterial diterpenes from a Salvia prattii crude diterpenes-rich sample was developed. Firstly, the XION hydrophilic stationary phase was chosen to separate the antibacterial crude diterpenes-rich sample (18.0 g) into three fractions with a recovery of 46.1%. Then, the antibacterial fractions I (200 mg), II (200 mg), and III (150 g) were separated by the Megress C18 preparative column, and compounds tanshinone IIA (80.0 mg), salvinolone (62.0 mg), cryptotanshinone (70.0 mg), and ferruginol (68.0 mg) were produced with purities greater than 98%. The procedure achieved large-scale preparation of the four diterpenes with high purity, and it could act as a reference for the efficient preparation of active diterpenes from other plant extracts.

p-TsOH-Catalyzed one-pot transformation of di- and trihydroxy steroids towards diverse A/B-ring oxo-functionalization

A milder, facile, and greener transformative protocol, specifically on solid supports, to yield A-ring and/or B-ring oxo-functionalized steroids has been accomplished.

New antibacterial hydrophobic assay reveals Abies balsamea oleoresin activity against Staphylococcus aureus and MRSA

ETHNOPHARMACOLOGICAL RELEVANCE

Oleoresin of Abies balsamea (L.) Mill. was used by Native Americans of the boreal forest of Canada and French Canadians to treat various infections, suggesting that oleoresin has antibacterial properties.

AIM OF THE STUDY

In this study, the antibacterial activity of whole oleoresin from A. balsamea was investigated against E. coli, S. aureus and two methicillin-resistant S. aureus (MRSA) strains using a new sensitive assay developed to evaluate hydrophobic matrix and compounds.

MATERIALS AND METHODS

Antibacterial activity of oleoresin was first investigated using dilution and disk diffusion methods against E. coli and S. aureus, and compared to a new sensitive assay for hydrophobic matrix. Moreover, whole oleoresin was analyzed by GC-MS to characterize the composition and to identify the compounds responsible of the antibacterial activity.

RESULTS

The results showed that whole oleoresin was inactive against Gram-negative E. coli (MIC₉₀ >90µg/ml) but active against Gram-positive S. aureus and MRSA with MIC₉₀ ranging from 18.2 to 30µg/ml. The oleoresin is mainly composed of monoterpene (28%), sesquiterpenes (2%), and diterpenes (45%). Resin acids were found, in part, responsible for the antibacterial activity of whole oleoresin. Isopimaric acid and levopimaric acid are the most active with a MIC₉₀ of respectively 9.7µg/ml and 10µg/ml.

CONCLUSION

This study supports the use of oleoresin of A. balsamea by the Native Americans and French Canadians to treat bacterial infections due to S. aureus.

A new cyclopeptide and a new lignan from Podocarpus neriifolius

A new cyclopeptide, neriitide A (1) and a new lignan, neriilignan (2), along with six known compounds including two diterpenoids, three sesquiterpenoids and one sterol were isolated from the leaves of Podocarpus neriifolius. Their structures were elucidated by means of extensive spectroscopic analysis including HREIMS, 1D and 2D NMR techniques. This is the first report of cyclopeptide and lignan separated from this plant.

Two new secondary metabolites from Xylaria sp. cfcc 87468

A new isocoumarin glycoside, 3R-(+)-5-O-[6'-O-acetyl]-α-d-glucopyranosyl-5-hydroxymellein (1), and a new phenylethanol glycoside, (−)-phenylethyl-8-O-α-l-rhamno-pyranoside (2), were isolated from the ethyl acetate extract of the fungus Xylaria sp. cfcc 87468, together with five known steroids, β-sitosterol (3), stigmast-4-en-3-one (4), ergosterol (5), (22E)-cholesta-4,6,8(14),22-tetraen-3-one (6), and 4α-methyl- ergosta-8(14),24(28)-dien-3β-ol (7). The structures of compounds 1 and 2 were elucidated by MS, extensive 1D and 2D NMR spectroscopy, and the circular dichroism (CD) spectroscopy.

Abietane diterpenoids and a sesquiterpene pyridine alkaloid from Euonymus lutchuensis

Four new abietane diterpenoids (1-4), a new 9(10→20)-abeo-abietane diterpenoid (5), and a new sesquiterpene pyridine alkaloid (6) were isolated from the roots of Euonymus lutchuensis along with 19 known compounds. The structures of the new compounds were elucidated by interpretation of the spectroscopic data.

A screening for antimicrobial activities of Caribbean herbal remedies

Background

The TRAMIL program aims to understand, validate and expand health practices based on the use of medicinal plants in the Caribbean, which is a “biodiversity hotspot” due to high species endemism, intense development pressure and habitat loss. The antibacterial activity was examined for thirteen plant species from several genera that were identified as a result of TRAMIL ethnopharmacological surveys or were reported in ethnobotanical accounts from Puerto Rico. The aim of this study was to validate the traditional use of these plant species for the treatment of bacterial infections, such as conjunctivitis, fever, otitis media and furuncles.

Methods

An agar disc diffusion assay was used to examine five bacterial strains that are associated with the reported infections, including Staphylococcus saprophyticus (ATCC 15305), S. aureus (ATCC 6341), Escherichia coli (ATCC 4157), Haemophilus influenzae (ATCC 8142), Pseudomonas aeruginosa (ATCC 7700) and Proteus vulgaris (ATCC 6896), as well as the fungus Candida albicans (ATCC 752). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were determined for each of the extracts that showed inhibitory activity.

Results

The decoctions of Pityrogramma calomelanos, Tapeinochilus ananassae, and Syzygium jambos, as well as the juice of Gossypium barbadense, showed > 20% growth inhibition against several bacteria relative to the positive control, which was the antibiotic Streptomycin. Extracts with the best antimicrobial activities were S. jambos that showed MIC = 31 μg/mL and MBC = 1.0 mg/mL against P. vulgaris and T. ananassae that showed MIC = 15 μg/mL against S. aureus.

Conclusion

This report confirms the traditional use of P. calomelanos for the treatment of kidney infections that are associated with stones, as well as the antimicrobial and bactericidal effects of T. ananassae against P. vulgaris and S. saprophyticus and the effects of S. jambos against S. aureus and S. saprophyticus.