Nat-UV DB: A Natural Products Database Underlying of Veracruz-Mexico.

Background: Natural products databases are well-structured data sources that offer new molecular development opportunities in drug discovery, agrochemistry, food, cosmetics, and several other research disciplines or chemical industries. The crescent world's interest in the development of these databases is related to the exploration of chemical diversity in geographical regions with rich biodiversity.

Methods: In this work, we introduce and discuss Nat-UV DB, the first natural products database from a coastal zone of Mexico.

Complete H and C NMR Assignment of the ent-Labdane 2α-Hydroxyeperuic Acid Combining Conventional NMR Methods and HiFSA.

The complete assignment of H and C spectra of the ent-labdane 2α-hydroxyeperuic acid (3) has been achieved through spin simulation constructed with experimental data obtained from conventional NMR experiments such as H, C, HSQC, HMBC, COSY, NOESY, 1D-TOCSY, and J-resolved (Jres) and data obtained from H iterative full-spin analysis (HiFSA) in the prerelease version of Cosmic Truth (CT), a web-based software for spectral analysis. The combination of experimental and theoretical data is helpful in the complete NMR assignment of molecules where signal overlapping is complicated, as in most natural products.

Biosynthesis of oxindole alkaloids: Recent advances and challenges.

The monoterpenoid oxindole alkaloids (MOA) are specialized plant metabolites of pharmacological importance, whose biosynthesis is linked to a unique oxidative process of monoterpenoid indole alkaloids (MIA). These transformations arise from complex biosynthetic pathways defined by species, organs, tissues, and growth stages. Initial studies of their biosynthesis using labeled precursors date back more than five decades ago.

Induction of Monoterpenoid Oxindole Alkaloids Production and Related Biosynthetic Gene Expression in Response to Signaling Molecules in Plant Cultures.

(Rubiaceae), known as firebush, is a source of bioactive monoterpenoid oxindole alkaloids (MOAs) derived from monoterpenoid indole alkaloids (MIAs). With the aim of understanding the regulation of the biosynthesis of these specialized metabolites, micropropagated plants were elicited with jasmonic acid (JA) and salicylic acid (SA). The MOA production and MIA biosynthetic-related gene expression were evaluated over time.

Consensus Virtual Screening Protocol Towards the Identification of Small Molecules Interacting with the Colchicine Binding Site of the Tubulin-microtubule System.

Modification of the tubulin-microtubule (Tub-Mts) system has generated effective strategies for developing different treatments for cancer. A huge amount of clinical data about inhibitors of the tubulin-microtubule system have supported and validated the studies on this pharmacological target. However, many tubulin-microtubule inhibitors have been developed from representative and common scaffolds that cover a small region of the chemical space with limited structural innovation.

Chiral NMR analysis reveals the environmental dependence of areolal scalemization in Piptothrix areolare.

The occurrence of racemic and enantiomerically enriched (scalemic) mixtures of secondary metabolites in their natural sources is a rare phenomenon. The unprecedent case of enantiomeric variations from levorotatory to dextrorotatory, and back to levorotatory, passing through an almost racemic mixture, was recently documented for areolal, the major epoxythymol of Piptothrix areolare. In an attempt to shed some light to understand the reasons for such an unusual behavior, herein, we evaluated this phenomenon by correlating the areolal enantiomeric purity with several environmental variables, including temperature, humidity, rain precipitation, wind speed, and radiation during over 1 year of the plant life cycle.

Antineoplastic Activity of Nutt. () against Ovarian Cancer and Identification of Active Metabolites in This Pathology.

(RHTR) is a medicinal plant with cytotoxic activity in different cancer cell lines. However, the active compounds in this plant against ovarian cancer are unknown. In this study, we aimed to evaluate the antineoplastic activity of RHTR and identify its active metabolites against ovarian cancer.

Tubulin Inhibitors: A Chemoinformatic Analysis Using Cell-Based Data.

Inhibiting the tubulin-microtubules (Tub-Mts) system is a classic and rational approach for treating different types of cancers. A large amount of data on inhibitors in the clinic supports Tub-Mts as a validated target. However, most of the inhibitors reported thus far have been developed around common chemical scaffolds covering a narrow region of the chemical space with limited innovation.

New Techniques of Structure Elucidation for Sesquiterpenes.

The most significant new techniques that have been used in the twenty-first century for the structure elucidation of sesquiterpenes and some derivatives are reviewed in this chapter. A distinctive feature of these methodologies is the combination of accurate experimental measurements with theoretical data obtained by molecular modeling calculations that allow to visualize, understand, and quantify many structural characteristics. This has been the case for NMR spectroscopy, which has expanded its potential for solving complex structural problems by means of comparison with quantum mechanical molecular models.

Novel Sesquiterpene Skeletons by Multiple Wagner-Meerwein Rearrangements of a Longipinane-1,9-diol Derivative.

The tricyclic sesquiterpene (1,3,4,5,7,8,9,10,11)-7,8-diangeloyloxylongipinan-1,9-diol, or rasteviol (), underwent multiple Wagner-Meerwein molecular rearrangements and several hydride shifts when treated with EtO-BF to generate the six new compounds (1,3,4,5,7,8,9,10,11)-7,8-diangeloyloxy-1,9-epoxyjiquilpane (), (1,3,4,5,7,8,9,11)-8-angeloyloxy-1,7-epoxyzamor-10(14)-ene (), (2,3,4,5,6,7,8,9,10)-7,8-diangeloyloxy-6,9-epoxyjanitziane (), (4,5,7,8,9,10,11)-7,8-diangeloyloxy-9-hydroxyjiquilp-3(15)-ene (), (2,3,5,7,8,10,11)-7,8-diangeloyloxyiratzian-9-one (), and (2,3,5,10,11)-8-angeloyloxyiratzi-7-en-9-one (), of which , , , and possess new hydrocarbon skeletons. Their structures were determined by 1D and 2D NMR in combination with single-crystal X-ray diffraction analyses of derivatives , , , and , which allowed confirmation of their absolute configurations by means of the Flack and Hooft parameters. In addition, some reaction mechanism information was gained from deuterium labeling experiments.

Conformational, configurational, and supramolecular studies of podocephalol acetate from Lasianthaea aurea.

Although podocephalol (1) and its derived acetate 2 were found in Lasianthaea podocephala four decades ago, and 1 was later detected in the essential oils of several vegetal species, its absolute configuration (AC) and conformational preferences remained to be established. The structures of ar-himachalene 1, now isolated from Lasianthaea aurea, and its derived acetate 2, were herein confirmed by extensive 1D and 2D nuclear magnetic resonance (NMR) studies, while the conformational preferences of the cycloheptene was established by density functional theory (DFT) calculations, which in combination with vibrational circular dichroism measurements provided the (R) absolute configuration of the molecules. The structure and AC were further verified through the Flack and Hooft parameters calculations derived from single crystal X-ray diffraction data of 2.

In search of safe pain relief: The analgesic and anti-inflammatory activity of phytosteryl ibuprofenates.

β-Sitosteryl (S)-ibuprofenate (2), stigmasteryl (S)-ibuprofenate (3), ergosteryl (S)-ibuprofenate (4), and cholesteryl (S)-ibuprofenate (5) were prepared in 70-75% yields by Steglich esterification and were characterized by 1D and 2D NMR, as well as by MS. The new esters were evaluated in in vivo pain models of antinociception and anti-inflammation using the writhing, formalin, and carrageenan tests, in mice and rats, and the results were compared with those of (S)-ibuprofen (1). Damage to the gastric mucosa of animals was also assessed.

Antioxidant and immunomodulatory activity induced by stevioside in liver damage: In vivo, in vitro and in silico assays.

Aims: Stevioside is a diterpenoid obtained from the leaves of Stevia rebaudiana (Bertoni) that exhibits antioxidant, antifibrotic, antiglycemic and anticancer properties. Therefore, we aimed to study whether stevioside has beneficial effects in liver injury induced by long-term thioacetamide (TAA) administration and investigated the possible underlying molecular mechanism using in vivo, in vitro and in silico approaches.

Main Methods: Liver injury was induced in male Wistar rats by TAA administration (200 mg/kg), intraperitoneally, three times per week.

Rebaudioside A administration prevents experimental liver fibrosis: an in vivo and in vitro study of the mechanisms of action involved.

Rebaudioside A (Reb A) is a diterpenoid isolated from the leaves of Stevia rebaudiana (Bertoni) that has been shown to possess pharmacological activity, including anti-inflammatory and antioxidant properties. However, the ability of Reb A to prevent liver injury has not been evaluated. Therefore, we aimed to study the potential of Reb A (20 mg/kg; two times daily intraperitoneally) to prevent liver injury induced by thioacetamide (TAA) administration (200 mg/kg; three times per week intraperitoneally).

Parvifoline Derivatives as Tubulin Polymerization Inhibitors.

A series of functionalized sesquiterpenoids derived from benzocyclooctene, including natural parvifoline (1), isoparvifoline (3), epoxyparvifoline (5), epoxyisoparvifoline (7), 8,12-oxyparfivoline (9), 8,14-oxyparvifoline (11), and the respective benzoyl derivatives 2, 4, 6, 8, 10, and 12, were prepared and tested for their inhibitory effect on the in vitro α,β-tubulin polymerization process. The structural analysis and characterization of the new compounds 5-7 and 9-12 were achieved by 1D and 2D NMR spectroscopy, mass spectrometry, and X-ray diffraction analysis of 6, 7, and 9. Preparation of 9 and 12 involved molecular rearrangements of the epoxide group with transannular 1,5-hydride shifts.

Biomimetic Transformation of p-Menthene Glucosides into p-Cymenes and Carvotanacetone.

A biomimetic transformation of p-menthene glucosides into aromatic monoterpenoids that alluded to mechanisms for essential oil metabolism, which lines up with the precepts of molecular economy, is described. Acid treatment of (-)-(3 S,4 S,6 R)-3,6-dihydroxy-1-menthene 3- O-β-d-glucopyranoside (1) and (-)-(3 S,4 R,5 R,6 S)-3,5,6-trihydroxy-1-menthene 3- O-β-d-glucopyranoside (2), from Ageratina glabrata, yielded p-cymene (7) and carvacrol (9). The stable oxidized intermediates (+)-(3 S,4 S,6 R)-3,6-dihydroxy-1-menthene (3), (+)-(1 S,4 S,6 R)-1,6-dihydroxy-2-menthene (4), (+)-(1 R,4 S,6 R)-1,6-dihydroxy-2-menthene (5), (+)-(4 S,6 R)-yabunikkeol (6), (+)-(4 S)-carvotanacetone (8), (+)-(1 S,4 S,5 R,6 R)-1,5,6-trihydroxy-2-menthene (15), (+)-(1 R,4 S,5 R,6 R)-1,5,6-trihydroxy-2-menthene (16), and the new (+)-(4 S,5 R,6 S)-1(7),2-menthadiene (17) permitted establishment of the reaction mechanisms.

Structure Elucidation, Conformation, and Configuration of Cytotoxic 6-Heptyl-5,6-dihydro-2 H-pyran-2-ones from Hyptis Species and Their Molecular Docking to α-Tubulin.

Cytotoxic 6-heptyl-5,6-dihydro-2 H-pyran-2-ones are chemical markers of Hyptis (Lamiaceae) and are responsible for some of the therapeutic properties of species with relevance to traditional medicine. The present investigation describes the isolation of known pectinolides A-C (1-3), in addition to the new pectinolides I-M (4-8), from two Mexican collections of H. pectinata by HPLC.

Quercetin reverses experimental cirrhosis by immunomodulation of the proinflammatory and profibrotic processes.

The ability of quercetin to reverse an established cirrhosis has not yet been investigated. Therefore, the aim of this study was to examine the efficacy of this flavonoid in reversing experimental cirrhosis. Cirrhosis was induced by intraperitoneal administration of TAA (200 mg/kg of body weight) three times per week for 8 weeks or by intraperitoneal petrolatum-CCl (400 mg/kg of body weight) administration three times per week for 8 weeks.

Complementarity of DFT Calculations, NMR Anisotropy, and ECD for the Configurational Analysis of Brevipolides K-O from Hyptis brevipes.

Brevipolides K-O (1-5), five new cytotoxic 6-(6'-cinnamoyloxy-2',5'-epoxy-1'-hydroxyheptyl)-5,6-dihydro-2H-pyran-2-ones (IC values against six cancer cell lines, 1.7-10 μM), were purified by recycling HPLC from Hyptis brevipes. The structures, containing a distinctive tetrahydrofuran ring, were established by comprehensive quantum mechanical calculations and experimental spectroscopic analysis of their NMR and ECD data.

Absolute Configuration of Menthene Derivatives by Vibrational Circular Dichroism.

The aerial parts of Ageratina glabrata afforded (-)-(3S,4R,5R,6S)-3,5,6-trihydroxy-1-menthene 3-O-β-d-glucopyranoside (1) and (-)-(3S,4S,6R)-3,6-dihydroxy-1-menthene 3-O-β-d-glucopyranoside (3). Acid hydrolysis of 1 yielded (+)-(1R,4S,5R,6R)-1,5,6-trihydroxy-2-menthene (5) and (+)-(1S,4S,5R,6R)-1,5,6-trihydroxy-2-menthene (6), while hydrolysis of 3 yielded (+)-(3S,4S,6R)-3,6-dihydroxy-1-menthene (10), (+)-(1R,4S,6R)-1,6-dihydroxy-2-menthene (11), and (+)-(1S,4S,6R)-1,6-dihydroxy-2-menthene (12). The structures of the new compounds 1, 2, 5-9, and 11 were defined by 1D and 2D NMR experiments, while the absolute configurations of the series of compounds were determined by comparison of the experimental vibrational circular dichroism (VCD) spectra of the 1,6-acetonide 5-acetate derived from 6 and of the 1,6-acetonide derived from 12 with their DFT-calculated spectra.