A Review on Phytochemicals of the Genus Maytenus and Their Bioactive Studies.

The genus Maytenus is a member of the Celastraceae family, of which several species have long been used in traditional medicine. Between 1976 and 2021, nearly 270 new compounds have been isolated and elucidated from the genus Maytenus. Among these, maytansine and its homologues are extremely rare in nature. Owing to its unique skeleton and remarkable bioactivities, maytansine has attracted many synthetic endeavors in order to construct its core structure. In this paper, the current status of the past 45 years of research on Maytenus, with respect to its chemical and biological activities are discussed. The chemical research includes its structural classification into triterpenoids, sesquiterpenes and alkaloids, along with several chemical synthesis methods of maytansine or maytansine fragments. The biological activity research includes activities, such as anti-tumor, anti-bacterial and anti-inflammatory activities, as well as HIV inhibition, which can provide a theoretical basis for the better development and utilization of the Maytenus.

Eremantholide C from aerial parts of Lychnophora trichocarpha, as drug candidate: fraction absorbed prediction in humans and BCS permeability class determination.

BACKGROUND: Lychnophora trichocarpha (Spreng.) Spreng. ex Sch.Bip has been used in folk medicine to treat pain, inflammation, rheumatism and bruises. Eremantholide C, a sesquiterpene lactone, is one of the substances responsible for the anti-inflammatory and anti-hyperuricemic effects of L. trichocarpha. OBJECTIVES: Considering the potential to become a drug for the treatment of inflammation and gouty arthritis, this study evaluated the permeability of eremantholide C using in situ intestinal perfusion in rats. From the permeability data, it was possible to predict the fraction absorbed of eremantholide C in humans and elucidate its oral absorption process. METHODS: In situ intestinal perfusion studies were performed in the complete small intestine of rats using different concentrations of eremantholide C: 960 µg/ml, 96 µg/ml and 9.6 µg/ml (with and without sodium azide), in order to verify the lack of dependence on the measured permeability as a function of the substance concentration in the perfusion solutions. RESULTS: Eremantholide C showed Peff values, in rats, greater than 5 × 10-5 cm/s and fraction absorbed predicted for humans greater than 85%. These results indicated the high permeability for eremantholide C. Moreover, its permeation process occurs only by passive route, because there were no statistically significant differences between the Peff values for eremantholide C. CONCLUSION: The high permeability, in addition to the low solubility, indicated that eremantholide C is a biologically active substance BCS class II. The pharmacological activities, low toxicity and biopharmaceutics parameters demonstrate that eremantholide C has the necessary requirements for the development of a drug product, to be administered orally, with action on inflammation, hyperuricemia and gout.

In Vitro Anti-Inflammatory, Anti-Oxidant, and Cytotoxic Activities of Four Curcuma Species and the Isolation of Compounds from Curcuma aromatica Rhizome.

The genus Curcuma is part of the Zingiberaceae family, and many Curcuma species have been used as traditional medicine and cosmetics in Thailand. To find new cosmeceutical ingredients, the in vitro anti-inflammatory, anti-oxidant, and cytotoxic activities of four Curcuma species as well as the isolation of compounds from the most active crude extract (C. aromatica) were investigated. The crude extract of C. aromatica showed 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity with an IC50 value of 102.3 µg/mL. The cytotoxicity effect of C. aeruginosa, C. comosa, C. aromatica, and C. longa extracts assessed with the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay at 200 µg/mL were 12.1 2.9, 14.4 4.1, 28.6 4.1, and 46.9 8.6, respectively. C. aeruginosa and C. comosa presented apoptosis cells (57.7 3.1% and 32.6 2.2%, respectively) using the CytoTox-ONE™ assay. Different crude extracts or phytochemicals purified from C. aromatica were evaluated for their anti-inflammatory properties. The crude extract of C. aromatica showed the highest potential to inhibit NF-κB activity, followed by C. aeruginosa, C. comosa, and C. longa, respectively. Among the various purified phytochemicals curcumin, germacrone, curdione, zederone, and curcumenol significantly inhibited NF-κB activation in tumor necrosis factor (TNF) stimulated HaCaT keratinocytes. Of all compounds, curcumin was the most potent anti-inflammatory.

New Sesquiterpenoids from the Fermented Broth of Termitomyces albuminosus and their Anti-Acetylcholinesterase Activity.

Termitomyces albuminosus is the symbiotic edible mushroom of termites and cannot be artificially cultivated at present. In the project of exploring its pharmaceutical metabolites by microbial fermentation, four new selinane type sesquiterpenoids-teucdiol C (1), D (2), E (3), and F (4), together with two known sesquiterpenoids teucdiol B (5) and epi-guaidiol A (6)-were obtained from its fermented broth of T. albuminosus. Their structures were elucidated by the analysis of NMR data, HR Q-TOF MS spectral data, CD, IR, UV, and single crystal X-ray diffraction. Epi-guaidiol A showed obvious anti-acetylcholinesterase activity in a dose-dependent manner. The experimental results displayed that T. albuminosus possess the pharmaceutical potential for Alzheimer's disease, and it was an effective way to dig new pharmaceutical agent of T. albuminosus with the microbial fermentation technique.

Effect of Heat Stress on Yield, Monoterpene Content and Antibacterial Activity of Essential Oils of Mentha x piperita var. Mitcham and Mentha arvensis var. piperascens.

Heat stress affects the yield of medicinal plants and can reduce biomass and/or metabolite production. In order to evaluate the effect of heat-induced stress on the essential oil production in Mentha x piperita L. var. Mitcham (Mitcham mint) and Mentha arvensis var. piperascens Malinv. ex L. H. Bailey (Japanese mint), we studied the chemical composition of the oils of the two mint species under different heat shock stresses in growth chambers. The antibacterial activity of the essential oils was also evaluated; microscopic observation (fluorescence and electron transmission) was used to assess the effect of the tested samples on bacterial growth. The results obtained shed light on the mint essential oils composition and biological activity in relation to heat stress.

Chemical Composition and Antibacterial Activity of the Essential Oil of Vitex agnus-castus L. (Lamiaceae).

Abnormal multiplication of oral bacteria causes dental caries and dental plaque. These diseases continue to be major public health concerns worldwide, mainly in developing countries. In this study, the chemical composition and antimicrobial activity of the essential oil of Vitex agnus-castus leaves (VAC‒EO) collected in the North of Brazil against a representative panel of cariogenic bacteria were investigated. The antimicrobial activity of VAC-EO was evaluated in terms of its minimum inhibitory concentration (MIC) values by using the broth microdilution method in 96-well microplates. The chemical constituents of VAC-EO were identified by gas chromatography (GC‒FID) and gas chromatography‒mass spectrometry (GC‒MS). VAC‒EO displayed some activity against all the investigated oral pathogens; MIC values ranged from 15.6 to 200 µg/mL. VAC-EO had promising activity against Streptococcus mutans (MIC= 15.6 µg/mL), Lactobacillus casei (MIC= 15.6 µg/mL), and Streptococcus mitis (MIC= 31.2 µg/mL). The compounds 1,8-cineole (23.8%), (E)-ß-farnesene (14.6%), (E)-caryophyllene (12.5%), sabinene (11.4%), and α-terpinyl acetate (7.7%) were the major chemical constituents of VAC‒EO. VAC-EO displays antimicrobial activity against cariogenic bacteria. The efficacy of VAC-EO against S. mutans is noteworthy and should be further investigated.

Chemical Composition and Antibacterial Activity of the Essential Oil of Vitex agnus-castus L. (Lamiaceae)

ABSTRACT Abnormal multiplication of oral bacteria causes dental caries and dental plaque. These diseases continue to be major public health concerns worldwide, mainly in developing countries. In this study, the chemical composition and antimicrobial activity of the essential oil of Vitex agnus-castus leaves (VAC‒EO) collected in the North of Brazil against a representative panel of cariogenic bacteria were investigated. The antimicrobial activity of VAC-EO was evaluated in terms of its minimum inhibitory concentration (MIC) values by using the broth microdilution method in 96-well microplates. The chemical constituents of VAC-EO were identified by gas chromatography (GC‒FID) and gas chromatography‒mass spectrometry (GC‒MS). VAC‒EO displayed some activity against all the investigated oral pathogens; MIC values ranged from 15.6 to 200 μg/mL. VAC-EO had promising activity against Streptococcus mutans (MIC= 15.6 μg/mL), Lactobacillus casei (MIC= 15.6 μg/mL), and Streptococcus mitis (MIC= 31.2 μg/mL). The compounds 1,8-cineole (23.8%), (E)-β-farnesene (14.6%), (E)-caryophyllene (12.5%), sabinene (11.4%), and α-terpinyl acetate (7.7%) were the major chemical constituents of VAC‒EO. VAC-EO displays antimicrobial activity against cariogenic bacteria. The efficacy of VAC-EO against S. mutans is noteworthy and should be further investigated.

Radicol, a Novel Trinorguaiane-Type Sesquiterpene, Induces Temozolomide-Resistant Glioma Cell Apoptosis via ER Stress and Akt/mTOR Pathway Blockade.

Glioblastoma multiforme (GBM) is the most frequent, lethal and aggressive tumour of the central nervous system (CNS) in adults. Multidrug resistance (MDR) results in undesirable prognosis during GBM chemotherapy. In this study, we determined that Radicol (RAD), a novel trinorguaiane-type sesquiterpene originally isolated from the root of Dictamnus radicis Cortex, exhibited potently cytotoxic effect on temozolomide (TMZ)-resistant GBM cell lines in a dose-dependent manner. Radicol-induced apoptosis was confirmed with Hoechst 33342/propidium iodide and terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end-labelling (TUNEL) staining. Studies investigating the mechanism revealed that RAD triggered an attenuation of protein disulphide isomerase (PDI) and induced the unmitigated unfolded protein response (UPR) and lethal endoplasmic reticulum (ER) stress. Simultaneously, we further demonstrated that RAD suppressed the activation of Akt/mTOR/p70S6K phosphorylation by up-regulating the induction of glycogen synthase kinase-3ß (GSK-3ß). These results established a link between RAD-induced ER stress and inhibition of the Akt/mTOR/p70S6K pathway, and the attenuation of PDI and activation of GSK-3ß might be the synergistic target of antineoplastic effects during RAD-induced apoptosis. These findings suggested that RAD, possessing multiple cytotoxicity targets, low molecular weight and high lipid solubility, could be a promising agent for the treatment of malignant gliomas. Copyright © 2017 John Wiley & Sons, Ltd.

Tetranorsesquiterpenoids and Santalane-Type Sesquiterpenoids from Illicium lanceolatum and Their Antimicrobial Activity against the Oral Pathogen Porphyromonas gingivalis.

The methanol extract of the leaves of Illicium lanceolatum, indigenous to Fujian Province, People's Republic of China, was found to exhibit antimicrobial activity against the periodontal pathogen Porphyromonas gingivalis, and a bioassay-guided fractionation led to the isolation of two new compounds, 1 and 2, along with two known santalane-type sesquiterpenoids, 3 and 4. The structures of lanceolactone A (1) and lanceolactone B (2) were elucidated by analyzing their 2D NMR spectroscopic data. Compounds 1 and 2 were assigned as new tetranorsesquiterpenoids with a spiroacetal ring and tricyclic structure, respectively. Compound 3 (α-santal-11-en-10-one) showed potent antimicrobial activity against the oral pathogen P. gingivalis.

Different accumulation profiles of multiple components between pericarp and seed of Alpinia oxyphylla capsular fruit as determined by UFLC-MS/MS.

Plant secondary metabolites are known to not only play a key role in the adaptation of plants to their environment, but also represent an important source of active pharmaceuticals. Alpinia oxyphylla capsular fruits, made up of seeds and pericarps, are commonly used in traditional East Asian medicines. In clinical utilization of these capsular fruits, inconsistent processing approaches (i.e., hulling pericarps or not) are employed, with the potential of leading to differential pharmacological effects. Therefore, an important question arises whether the content levels of pharmacologically active chemicals between the seeds and pericarps of A. oxyphylla are comparable. Nine secondary metabolites present in A. oxyphylla capsular fruits, including flavonoids (e.g., tectochrysin, izalpinin, chrysin, apigenin-4',7-dimethylether and kaempferide), diarylheptanoids (e.g., yakuchinone A and B and oxyphyllacinol) and sesquiterpenes (e.g., nootkatone), were regarded as representative constituents with putative pharmacological activities. This work aimed to investigate the abundance of the nine constituents in the seeds and pericarps of A. oxyphylla. Thirteen batches of A. oxyphylla capsular fruits were gathered from different production regions. Accordingly, an ultra-fast high performance liquid chromatography/quadrupole tandem mass spectrometry (UFLC-MS/MS) method was developed and validated. We found that: (1) the nine secondary metabolites were differentially concentrated in seeds and fruit capsules; (2) nootkatone is predominantly distributed in the seeds; in contrast, the flavonoids and diarylheptanoids are mainly deposited in the capsules; and (3) the content levels of the nine secondary metabolites occurring in the capsules varied greatly among different production regions, although the nootkatone levels in the seeds were comparable among production regions. These results are helpful to evaluating and elucidating pharmacological activities of A. oxyphylla capsular fruits. Additionally, it may be of interest to elucidate the mechanisms involved in the distinct accumulation profiles of these secondary metabolites between seeds and pericarps.

Hawaiian sandalwood: oil composition of Santalum paniculatum and comparison with other sandal species.

Four commercial qualities of Hawaiian sandalwood oil produced from wood of Santalum paniculatum originating from the island of Hawaii ("The Big Island") were analyzed using GC and GC-MS. Main constituents of the oils were (Z)-α-santalol (34.5-40.4%) and (Z)-ß-santalol (11.0-16.2%). An odor evaluation of the oils was carried out against East Indian sandalwood oil. In addition, the chemical composition of Hawaiian sandalwood oil was compared with four different Santalum species originating from East India, New Caledonia, Eastern Polynesia and Australia, respectively.

A bitter-sweet tale from the land of milk and honey.

A sporadic seasonal neurotoxic food poisoning, unique to northern parts of New Zealand, especially The Bay of Plenty, has recurred-with implications for our primary produce industry, as well as human health.

Application of a multidimensional gas chromatography system with simultaneous mass spectrometric and flame ionization detection to the analysis of sandalwood oil.

The production and trade of Indian sandalwood oil is strictly regulated, due to the impoverishment of the plantations; for such a reason, Australian sandalwood oil has been evaluated as a possible substitute of the Indian type. International directives report, for both the genuine essential oils, specific ranges for the sesquiterpene alcohols (santalols). In the present investigation, a multidimensional gas chromatographic system (MDGC), equipped with simultaneous flame ionization and mass spectrometric detection (FID/MS), has been successfully applied to the analysis of a series of sandalwood oils of different origin. A detailed description of the system utilized is reported. Three santalol isomers, (Z)-α-trans-bergamotol, (E,E)-farnesol, (Z)-nuciferol, epi-α-bisabolol and (Z)-lanceol have been quantified. LoD (MS) and LoQ (FID) values were determined for (E,E)-farnesol, used as representative of the oxygenated sesquiterpenic group, showing levels equal to 0.002% and 0.003%, respectively. A great advantage of the instrumental configuration herein discussed, is represented by the fact that identification and quantitation of target analytes are carried out in one step, without the need to perform two separate analyses.

Bisabolyl-derived sesquiterpenes from tobacco 5-epi-aristolochene synthase-catalyzed cyclization of (2Z,6E)-farnesyl diphosphate.

We report the structures and stereochemistry of seven bisabolyl-derived sesquiterpenes arising from an unprecedented 1,6-cyclization (cisoid pathway) efficiently catalyzed by tobacco 5-epi-aristolochene synthase (TEAS). The use of (2Z,6E)-farnesyl diphosphate as an alternate substrate for recombinant TEAS resulted in a robust enzymatic cyclization to an array of products derived exclusively (>/=99.5%) from the cisoid pathway, whereas these same products account for ca. 2.5% of the total hydrocarbons obtained using (2E,6E)-farnesyl diphosphate. Chromatographic fractionations of extracts from preparative incubations with the 2Z,6E substrate afforded, in addition to the acyclic allylic alcohols (2Z,6E)-farnesol (6.7%) and nerolidol (3.6%), five cyclic sesquiterpene hydrocarbons and two cyclic sesquiterpene alcohols: (+)-2-epi-prezizaene (44%), (-)-alpha-cedrene (21.5%), (R)-(-)-beta-curcumene (15.5%), alpha-acoradiene (3.9%), 4-epi-alpha-acoradiene (1.3%), and equal amounts of alpha-bisabolol (1.8%) and epi-alpha-bisalolol (1.8%). The structures, stereochemistry, and enantiopurities were established by comprehensive spectroscopic analyses, optical rotations, chemical correlations with known sesquiterpenes, comparisons with literature data, and GC analyses. The major product, (+)-2-epi-prezizaene, is structurally related to the naturally occurring tricyclic alcohol, jinkohol (2-epi-prezizaan-7beta-ol). Cisoid cyclization pathways are proposed by which all five sesquiterpene hydrocarbons are derived from a common (7R)-beta-bisabolyl(+)/pyrophosphate(-) ion pair intermediate. The implications of the "cisoid" catalytic activity of TEAS are discussed.

The aignopsanes, a new class of sesquiterpenes from selected chemotypes of the sponge Cacospongia mycofijiensis.

A survey of individual specimens of northern Papua New Guinea derived Cacospongia mycofijiensis has yielded novel sesquiterpenes, aignopsanoic acid A (1), methyl aignopsanoate A (2), and isoaignopsanoic acid A (3). The structures and absolute configurations of 1-3 were established using NMR data, X-ray crystallography results, and an analysis of CD properties. Two of these metabolites, 1 and 2, were moderately active against Trypanosoma brucei, the parasite responsible for sleeping sickness.

Redifferentiation of human hepatoma cells (SMMC-7721) induced by two new highly oxygenated bisabolane-type sesquiterpenes.

Bisabolane-type sesquiterpenes are a class of biologically active compounds that has antitumour,antifungal, antibacterial,antioxidant and antivenom properties.We investigated the effect of two new highly oxygenated bisabolane-type sesquiterpenes (HOBS)isolated from Cremanthodium discoideum (C.discoideum) on tumour cells. Our results showed that HOBS induced morphological differentiation and reduced microvilli formation on the cell surface in SMMC-7721 cells.Flow cytometry analysis demonstrated that HOBS could induce cell-cycle arrest in the G1 phase. Moreover,HOBS was able to increase tyrosine-alpha ketoglutarate transaminase activity,decrease alpha- foetoprotein level and gamma-glutamyl transferase activity. In addition,we found that HOBS inhibited the anchorage- independent growth of SMMC-7721 cells in a dose-dependent manner.Taken together,all the above observations indicate that HOBS might be able to normalize malignant SMMC-7721 cells by inhibiting cell proliferation and inducing redifferentiation.

Mono- and Di-sesquiterpenoids from Chloranthus spicatus.

Three new dimeric sesquiterpenoids, chloramultilides B-D ( 1- 3), along with 10 known sesquiterpenoids, were isolated from the whole plant of Chloranthus spicatus. Their structures were established by physical data (1D and 2D NMR, MS). The structure and absolute configuration of 1 was confirmed by X-ray crystallography. Compound 1 exhibited moderate in vitro antifungal activity.

Russujaponols A-F, illudoid sesquiterpenes from the fruiting body of Russula japonica.

Six new illudoid sesquiterpenes, russujaponols A-F (1-6), were isolated from the fruiting bodies of Russula japonica Hongo. Their structures were established primarily by 2D NMR experiments, and the structure of the main compound, russujaponol A (1), was confirmed by X-ray crystallographic analysis of its benzoate (1a). Russujaponol A (1) suppressed invasion of human fibrosarcoma (HT1080) cells into Matrigel in a concentration-dependent manner and caused 63% inhibition at 3.73 microM.

Humulane-type sesquiterpenoids from the mushroom Lactarius mitissimus.

Five new humulane-type sesquiterpenes, mitissimols A (1), B (2), and C (3), and a mixture of mitissimol A oleate (4) and mitissimol A linoleate (5), were isolated from the fruiting bodies of Lactarius mitissimus. Their structures were elucidated on the basis of comprehensive spectroscopic techniques and necessary chemical methods. The relative stereochemistry of 1 was determined by single-crystal X-ray diffraction analysis.

An approach to the inheritance of the sesquiterpene chemotypes within Petasites hybridus.

Sesquiterpene esters are the active principle in the medicinal plant Petasites hybridus. Two chemotypes, the petasin chemotype and the furanopetasin chemotype, are known, but only the first one is suitable for pharmaceutical purposes. Experimental crossings were performed within and between plants of both chemotypes to study the genetic basis of the occurrence of these sesquiterpenes. The chemotype was determined by TLC in extracts of a small piece of rhizome in the parent plants and the progenies. A model including the combined action of two genes is proposed to explain the inheritance of the chemotypes where the furanopetasin chemotype is under recessive genetic control.