Phytochemical Analysis and Dermo-Cosmetic Evaluation of Cymbidium sp. (Orchidaceae) Cultivation By-Products

Cymbidium is one of the most popular genera in Orchidaceae family, commercialized either as loose flowers or as potted plants in floriculture worldwide. The non-marketable parts are typically discarded (e.g., unsuitable flowers, leaves, pseudobulbs, roots), generating an enormous quantity of unutilized biomass. The above by-products were studied through phytochemical analysis and investigated for their dermo-cosmetic potential. The initial antioxidant, anti-tyrosinase, anti-elastase, and anti-collagenase assays of the total extracts indicated that the pseudobulb and root ethyl acetate extracts were the most potent. Those extracts were then submitted to chromatographic separation leading to the isolation of 16 secondary metabolites (four phenanthrenes, three 1,4-phenanthrenquinones, three dibenzyls, two phenolic acid derivatives, two sterols, one dehydrodiconiferyl alcohol derivative, and one simple phenolic compound), including 6-hydroxy-5,7-dimethoxy-1,4-phenanthrenequinone (cymbisamoquinone), which was identified as a new natural product. In parallel, 48 metabolites were identified by UPLC-HRMS analysis of the extracts. The biological evaluation of the isolated compounds revealed that gigantol and tristin present important anti-tyrosinase activity, while bulbophyllanthrin, 3-hydroxy-2,4,7-trimethoxy-phenanthrene, marylaurencinol A, 5-hydroxy-2-methoxy-1,4-phenanthrenequinone, and ephemeranthroquinone B show dose-dependent anti-collagenase activity. In contrast to isolated metabolites, which may act selectively on specific enzymes, the initial total extracts exhibited inhibitory activity against tyrosinase, elastase, and collagenase enzymes, thus showing better prospects for use in dermo-cosmetic formulations.

Constituents of Xerolekia speciosissima (L.) Anderb. (Inuleae), and Anti-Inflammatory Activity of 7,10-Diisobutyryloxy-8,9-epoxythymyl Isobutyrate

Xerolekia speciosissima (L.) Anderb., a rare plant from the north of Italy, is a member of the Inuleae-Inulinae subtribe of the Asteraceae. Despite its close taxonomic relationship with many species possessing medicinal properties, the chemical composition of the plant has remained unknown until now. A hydroalcoholic extract from the aerial parts of X. speciosissima was analyzed by HPLC-DAD-MSn, revealing the presence of caffeic acid derivatives and flavonoids. In all, 19 compounds, including commonly found chlorogenic acids and less frequently occurring butyryl and methylbutyryl conjugates of dicaffeoylquinic and tricaffeoylhexaric acids, plus two flavonoids, were tentatively identified. Chromatographic separation of a hydroalcoholic extract from the capitula of the plant led to the isolation of (+)-dehydrodiconiferyl alcohol 4-O-β-glucopyranoside, quercimeritrin, astragalin, isoquercitrin, 6-hydroxykaempferol-7-O-β-glucoside, quercetagitrin, methyl caffeate, caffeic acid, protocatechuic acid, chlorogenic acid and 1,5-dicaffeoylquinic acid. Composition of a nonpolar extract from the aerial parts of the plant was analyzed by chromatographic methods supported with 1H-NMR spectroscopy. The analysis revealed the presence of loliolide, reynosin, samtamarine, 2,3-dihydroaromaticin, 2-deoxy-4-epi-pulchellin and thymol derivatives as terpenoid constituents of the plant. One of the latter compounds—7,10-diisobutyryloxy-8,9-epoxythymyl isobutyrate—at concentrations 0.5, 1.0 and 2.5 μM, significantly reduced IL-8, IL-1β and CCL2 excretion by LPS-stimulated human neutrophils.

In Silico Identification and Biological Evaluation of Antioxidant Food Components Endowed with Human Carbonic Anhydrase IX and XII Inhibition

The tumor-associated isoenzymes hCA IX and hCA XII catalyze the hydration of carbon dioxide to bicarbonate and protons. These isoforms are highly overexpressed in many types of cancer, where they contribute to the acidification of the tumor environment, promoting tumor cell invasion and metastasis. In this work, in order to identify novel dual hCA IX and XII inhibitors, virtual screening techniques and biological assays were combined. A structure-based virtual screening towards hCA IX and XII was performed using a database of approximately 26,000 natural compounds. The best shared hits were submitted to a thermodynamic analysis and three promising best hits were identified and evaluated in terms of their hCA IX and XII inhibitor activity. In vitro biological assays were in line with the theoretical studies and revealed that syringin, lithospermic acid, and (-)-dehydrodiconiferyl alcohol behave as good hCA IX and hCA XII dual inhibitors.

In Silico Identification and Biological Evaluation of Antioxidant Food Components Endowed with IX and XII hCA Inhibition

The tumour-associated isoenzymes, hCA IX and hCA XII catalyze the hydration of carbon dioxide to bicarbonate and protons. These isoforms are highly overexpressed in many types of cancer, where they contribute for the acidification of the tumor environment promoting the tumor cell invasion and metastasis. In this work, in order to identify novel dual hCA IX and XII inhibitors, virtual screening techniques and biological assays were combined. A structure based virtual screening towards hCA IX and XII was performed using a database of approximately 26000 natural compounds. The best shared hits were submitted to a thermodynamic analysis and 3 promising best hits were identified and evaluated in terms of their hCA IX and XII inhibitor activity. In vitro biological assays are in line with the theoretical studies and revealed that Syringin, Lithospermic acid, and (-)- Dehydrodiconiferyl alcohol behave as good hCA IX and hCA XII dual inhibitors.

Chemical Constituents of Eleutherococcus sessiliflorus (Rupr. & Maxim.)

Ten compounds were separated and purified by chromatographic methods from the 70% ethanol extract of the leaves of Eleutherococcus sessiliflorus (Rupr. & Maxim.). Their structures were identified according to their physicochemical properties and the spectral data of dihydromyricetin (1), quercetin (2), taxifolin (3), naringenin (4), liquiritigenin (5), butein (6), syringaresinol (7), dehydrodiconiferyl alcohol (8), gallic acid methyl ester (9), and alphitolic acid (10). Compounds 1, 3, 6, and 10 were isolated from the genus Eleutherococcus for the first time. All compounds showed weak cytotoxic activity against the A549 cell line.

Isolation of the Major Phenolic Compounds in the Pits of Brined Green Olive Drupes: Structure Elucidation by Comprehensive 1H/13C-NMR Spectroscopy

Pits of representative green olive drupes from Italy and Greece were evaluated for their content of phenolic compounds. The major purified polyphenols quantitated in mg/kg in the Italian and Greek pit varieties, respectively, were tyrosol (157 and 523), hydroxytyrosol (3 386 and 1723), vanillin (151 and 83), vanillic acid (58 and 101), phloretic acid (85 and 0), (+)-pinoresinol (954 and 877), (+)-1-acetoxypinoresinol (114 and 105), dehydrodiconiferyl alcohol (340 and 386) and the corresponding aldehyde (398 and 553), the erythro and threo isomers of guaiacylglycerol- β-coniferol ether (78 and 147) and (93 and 273) and their corresponding aldehydes (238 and 349) and (232 and 537), and finally nüzhenide (186 and 364). The data indicate that the waste products of olive mills should be a rich source of a variety of polyphenolic compounds. Detailed 1H- and 13C-nuclear magnetic resonance data are presented, representing the most comprehensive and unambiguous results available to date for the compounds studied.

Radical transfer system in the enzymatic dehydrogenative polymerization (DHP formation) of coniferyl alcohol (CA) and three dilignols

No clear picture has yet been elaborated concerning the mechanism of lignin growth, and thus this topic is the focus of the present paper. Namely, the enzymatic dehydrogenative polymerization (DHP formation) of coniferyl alcohol (CA, as a monolignol) and three dilignols and their reaction kinetics were investigated. The dilignols [guaiacylglycerol-β-coniferyl ether (IβO4), dehydrodiconiferyl alcohol (IIβ5), and pinoresinol (IIIββ)] and CA as a monolignol [(3-OCD3)-coniferyl alcohol (CAOCD3)] were synthesized and subjected to enzymatic DHP formation. The dilignol derived from CAOCD3 could be identified by its higher molecular weight in comparison with the starting dilignols (IβO4, IIβ5, and IIIββ). Based on the observed consumption rate of the CA and its dilignols, it was proposed that a radical transfer system exists between the dilignols, which is generated from the CA and the starting substrates.