Tithoniamarin and tithoniamide: a structurally unique isocoumarin dimer and a new ceramide from Tithonia diversifolia

Molecular Pathway, Epidemiological Data and Treatment Strategies of Fungal Infection (Mycoses): A Comprehensive Review

The recent increase in fungal infections is a health crisis. This surge is directly tied to the increase in immunocompromised people caused by changes in medical practice, such as the use of harsh chemotherapy and immunosuppressive medicines. Immunosuppressive disorders such as HIV have exacerbated the situation dramatically. Subcutaneous or superficial fungal infections can harm the skin, keratinous tissues, and mucous membranes. This category includes some of the most common skin disorders that impact millions of people worldwide. Despite the fact that they are seldom fatal, they can have a catastrophic impact on a person's quality of life and, in rare situations, spread to other people or become obtrusive. The majority of fungal infections under the skin and on the surface are simply and quickly cured. An opportunistic organism that preys on a weak host or a natural intruder can both result in systemic fungal infections. Furthermore, it might be exceedingly lethal and dangerous to one's life. Dimorphic fungi may pose a hazard to healthy populations that are not exposed to endemic fungi. Increased surveillance, the availability of quick, noninvasive diagnostic tests, monitoring the emergence of antifungal medication resistance, and research on the pathophysiology, prevention, and management of fungal infections are just a few potential solutions to these new health problems. The goal of this review is to summarize the data available for fungal infections and the different therapies which are involved in their treatment. Additionally, it also summarizes the molecular and scientific data of the plants which contain anti-fungal activity. Data are acquired using Google, PubMed, Scholar, and other online sources.

Rhodium-Catalyzed Selective C(sp2)-H Activation/Annulation of tert-Butyl Benzoyloxycarbamates with 1,3-Diynes: A One Step Access to Alkynylated Isocoumarins and Bis-Isocoumarins

We report here a Rh(III) catalyzed regio- and stereoselective synthesis of alkynylated and bis-isocoumarin from 1,3-dialkyne. Exclusive one-pot formation of 3,3-bis-isocoumarin isomers has been achieved by eliminating several other possibilities. This is the first example of transition metal catalyzed synthesis of alkynylated and bis-isocoumarin scaffolds. The protocol is compatible with a wide range of functional groups affording good to excellent yields. Several mechanistic investigations, including deuterium labeling experiments and kinetic isotope effect studies, have been carried out.

Present scenarios and future prospects of herbal nanomedicine for antifungal therapy

The current COVID-19 epidemic is a sobering reminder that human susceptibility to infectious diseases remains even in our modern civilization. After all, infectious diseases are still the major reason of death globally. Healthcare authorities have often underestimated and ignored the threat posed by "microbial dangers," although they put millions of lives at risk every year. Overlooked developing diseases including fungal infections (FIs) contribute to roughly 1.7 million fatalities per year. As many as 150 million cases of severe and potentially life-threatening FIs are reported each year. In the last few years, the number of instances has steadily increased. Most of them are invasive fungal infections that require specialized treatment and hospital care. In recent years herbal antifungal compounds have been explored to acquire effective and safe therapy against fungal infections. However, potential therapeutic effects are hampered by the poor solubility, stability, and bioavailability of these important chemicals as well as the gastric degradation that occurs in the gastrointestinal tract. To get around this issue, researchers have turned to novel drug delivery systems such as nanoemulsions, ethosomes, metallic nanoparticles, liposomes, lipid nanoparticles, transferosomes, etc by improving their limits, nanocarriers can enhance the medicinal effects of herbal oils and extracts. The present review article focuses on the available antifungal agents and their characteristics, mechanism of antifungal drugs resistance, herbal oils and extract as antifungal agents, challenges in the delivery of herbal drugs, and application of nano-drug delivery systems for effective delivery of antifungal herbal compounds.

Organocatalytic enantioselective construction of axially chiral (1H)-isochromen-1-imines

Heterocycloalkenyl atropisomers, derived from biaryl atropisomers and axially chiral styrenes, have emerged as a new class of nonbiaryl C-C atropisomers due to the benefit in improving the pharmacological activity and structural diversity. This paper proposes an intramolecular annulation strategy for constructing the heterocycloalkenyl atropisomers (1H)-isochromen-1-imines by organocatalysis. Various heterocycloalkenyl atropisomers (1H)-isochromen-1-imines were prepared in good to excellent yields with excellent enantioselectivity (up to 98% ee), and could be easily converted to atropisomeric lactones isocoumarins.

Secondary plant metabolites as potent drug candidates against antimicrobial-resistant pathogens

Antibiotic resistance is a major public health threat of the twenty-first century and represents an important risk to the global economy. Healthcare-associated infections mainly caused by drug-resistant bacteria are wreaking havoc in patient care worldwide. The spread of such pathogens limits the utility of available drugs and complicates the treatment of bacterial diseases. As a result, there is an urgent need for new drugs with mechanisms of action capable of curbing resistance. Plants synthesize and utilize various metabolic compounds to deter pathogens and predators. Utilizing these plant-based metabolites is a promising option in identifying novel bioactive compounds that could be harnessed to develop new potent antimicrobial drugs to treat multidrug-resistant pathogens. The purpose of this review is to highlight medicinal plants as important sources of novel antimicrobial agents that could be developed to help combat antimicrobial resistance.

Antinociceptive Activity of Compounds from the Aqueous Extract of Melampodium divaricatum

A decoction prepared from the aerial parts of Melampodium divaricatum showed antinociceptive and antihyperalgesic responses when tested in the formalin model in mice. From the CH₂ Cl₂ fraction of the decoction, two non-previously reported secondary metabolites, 3-O-β-D-glucopyranosyl-16α-hydroxy-ent-kaurane (1) and melampodiamide (2) [(2'R*,4'Z)-2'-hydroxy-N-[(2S*,3S*,4R*)-1,3,4-trihydroxyoctadec-2-yl]tetracos-4-enamide] were separated and characterized by spectroscopic, spectrometric, and computational techniques. The flavonoids isoquercitrin and hyperoside, which possessed noted antinociceptive properties, were obtained from the active AcOEt fraction of the decoction. The chemical composition of the essential oil of the plant was also analyzed by gas chromatography-mass spectrometry. The major constituents were (E)-caryophyllene, germacrene D, β-elemene, δ-elemene, γ-patchoulene, and 7-epi-α-selinene. Headspace solid-phase microextraction analysis detected (E)-caryophyllene as the main volatile compound of the plant.

A Review on Antifungal Efficiency of Plant Extracts Entrenched Polysaccharide-Based Nanohydrogels

Human skin acts as a physical barrier; however, sometimes the skin gets infected by fungi, which becomes more severe if the infection occurs on the third layer of the skin. Azole derivative-based antifungal creams, liquids, or sprays are available to treat fungal infections; however, these formulations show various side effects on the application site. Over the past few years, herbal extracts and various essential oils have shown effective antifungal activity. Additionally, autoxidation and epimerization are significant problems with the direct use of herbal extracts. Hence, to overcome these obstacles, polysaccharide-based nanohydrogels embedded with natural plant extracts and oils have become the primary choice of pharmaceutical scientists. These gels protect plant-based bioactive compounds and are effective delivery agents because they release multiple bioactive compounds in the targeted area. Nanohydrogels can be applied to infected areas, and due to their contagious nature and penetration power, they get directly absorbed through the skin, quickly reaching the skin's third layer and effectively reducing the fungal infection. In this review, we explain various skin fungal infections, possible treatments, and the effective utilization of plant extract and oil-embedded polysaccharide-based nanohydrogels.

Natural Products as Fungicide and Their Role in Crop Protection

Seeking solutions from nature for solving one and all problems is the age-old practice for mankind, and natural products are proved to be the most effective one for keeping up the balance of development as well as the “healthy, wealthy, and well” condition of mother nature. Fungal pathogens are proved to be a common and popular contaminant of agroecosystem that approximately causes 70–80% of total microbial crop loss. To meet the proper global increasing need of food products as a result of population explosion, managing agricultural system in an eco-friendly and profitable manner is the prime target; thus the word “sustainable agriculture” plays it part, and this package is highly effective when coupled with nature-derived fungicidal products that can minimize the event of fungal infections in agrarian ecosystem. Present study enlists the most common and effective natural products that might be of plant or microbial origin, their mode of action, day-by-day development of phytopathogenic resistance against the prevailing fungicides, and also their role in maintenance of sustainability of agricultural practices with special emphasis on their acceptance over the synthetic or chemical one. A large number of bioactive compounds ranging from direct plant (both cryptogams algae and moss and phanerogams)-derived natural extracts, essential oil of aromatic plants, and low-molecular-weight antimicrobial compounds known as phytoalexins to secondary metabolites that are both volatile and nonvolatile organic compounds of microbes (fungal and actinobacterial members) residing inside the host tissue, called endophyte, are widely used as agricultural bioweapons. The rhizospheric partners of plant, mycorrhizae, are also a prime agent of this chemical warfare and protect their green partners from fungal invaders and emphasize the concept of “sustainable agriculture.”

Tithonia diversifolia (Hemsl.) A. Gray as a medicinal plant: A comprehensive review of its ethnopharmacology, phytochemistry, pharmacotoxicology and clinical relevance

ETHNOPHARMACOLOGICAL RELEVANCE

Tithonia diversifolia (TD) is widely valued in several cultures for its medicinal properties. A comprehensive review of the current understanding of this plant species is required due to emerging concerns over its efficacy, toxicity and allergenic potential.

AIM OF THE REVIEW

We critically summarized the current evidence on the botany, traditional use, phytochemistry, pharmacology and safety of TD, with the view to provide perspectives for developing more attractive pharmaceuticals of plant origin, but also to lay a new foundation for further investigations on this plant.

MATERIALS AND METHODS

A preliminary consultation of search engines such as Web of Science, PubMed, ScienceDirect and other published/unpublished resources provided an overview of extant literature on TD. Then, we meticulously screened all titles, abstracts and full-texts to establish consistency in the application of inclusion criteria. Studies were considered for inclusion if they dealt with taxonomy, global distribution, local and traditional knowledge, phytochemistry, toxicity and biological effects.

RESULTS

1856 articles were retrieved among which 168 were revised and included. Several studies conducted on cell lines and animals provided supporting evidence for some ethnomedicinal claims of extracts from TD. Short-term use of Tithonia extracts were effective and well-tolerated in animals when taken at lower doses. Both the toxic and therapeutic effects were attributed to bioactive principles naturally occurring in this species including sesquiterpene lactones, chlorogenic acid and flavonoids.

CONCLUSIONS

T. diversifolia is a valuable source of bioactive compounds with significant therapeutic implications and favourable safety index. However, more rigorously designed investigations are needed to recommend the whole plant or its active ingredients as a medication, and should focus on understanding the multi-target network pharmacology of the plant, clarifying the effective doses as well as identifying the potential interactions with prescribed drugs or other chemicals.

Isocoumarins, miraculous natural products blessed with diverse pharmacological activities

Isocoumarins are lactonic natural products abundant in microbes and higher plants. These are considered an amazing scaffold consecrated with more or less all types of pharmacological applications. This review is complementary to the earlier reviews and aims to focus the overlooked aspects of their fascinating chemistry with special emphasis on their classification and diverse biological activities with some SAR conclusions. The most recent available literature on the structural diversity and biological activity of these natural products has been reviewed.

Melicilamide A: a new ceramide from Milicia excelsa

This article deals with a phytochemical investigation of Melicia excelsa from which melicilamide A (1), a new ceramide has been isolated. Its structure was determined by comprehensive analyses of its (1)H- and (13)C-NMR, COSY, HMQC and HMBC spectroscopic, EI-MS and ESI-MS data. The remaining one known compound was identified as β-sitosterol glucopyranoside.

Eucleanal: A New Napthalene Derivative from Euclea divinorum

A new naphthalene derivative, named eucleanal (1), was isolated from Euclea divinorum Hiern., and its structure elucidated by detailed spectroscopic (1H, 13C NMR, COSY, HMQC, HMBC) and HREIMS analysis.

Two new phthalate derivatives from Nepeta clarkei (Labiatae)

Two new phthalates bis(2-ethylundecyl)phthalate and bis(2-ethyltridecyl)phthalate have been isolated from the chloroform-soluble portion of the whole plant of Nepeta clarkei along with one known compound β-amyrin. The structures of the two new compounds and β-amyrin were assigned on the basis of their ¹H and ¹³C NMR spectra including 2D NMR techniques such as COSY, HMQC, and HMBC experiments and compared with the literature data.

Cordioxime: A New Dioxime γ-Lactam from Cordia platythyrsa

Cordia platythyrsa Baker is known for its medicinal value. This paper deals with a phytochemical investigation of this species, from which cordioxime (1), a new dioxime γ-lactam has been isolated. Its structure was determined by comprehensive analyses of its 1H and 13C NMR, COSY, HMQC, and HMBC spectroscopic, and HREIMS data. The remaining two known compounds were identified as β-sitosterol, and β-sitosterol glucopyranoside.

Dorstenpictanone: a new bicyclic polyprenylated compound from Dorstenia picta

One new bicyclic polyprenylated compound, dorstenpictanone (1), was isolated from Dorstenia picta. The structure of the new compound was elucidated by detailed spectroscopic analysis such as (1)H NMR, (13)C NMR, COSY, HMQC, HMBC, and HREIMS. The relative configuration of dorstenpictanone (1) was distinguished by comparative analysis of the NMR spectral data with known analogues together with the ROESY experiment.

Bioassay-guided isolation of an anti-ulcer compound, tagitinin C, from Tithonia diversifolia: role of nitric oxide, prostaglandins and sulfhydryls

Tithonia diversifolia is a medicinal plant from the Municipality of Suchiapa, Chiapas, Mexico, that according to local folk medicine is considered useful in the treatment of gastric ulcers. The aim of the present study was to investigate the gastroprotective activity of T. diversifolia by using an ethanol-induced gastric ulcer experimental model in male Wistar rats. The results showed that T. diversifolia had gastroprotective activity, and that the dichloromethane extract had the highest protective activity (close to 90% when using doses between 10 to 100 mg/kg), and that further the compound tagitinin C isolated from this extract was the main active gastroprotective agent. Rats treated with tagitinin C suspended in Tween 80 at 1, 3, 10 and 30 mg/kg showed 37.7, 70.1, 100, and 100% gastroprotection, respectively. The effect elicited by tagitinin C (30 mg/kg) was not attenuated by pretreatment with either N^G-nitro-L-arginine methyl ester (70 mg/kg, i.p.), a nitric oxide (NO) synthase inhibitor, N-ethylmaleimide (10 mg/kg, s.c.), a blocker of sulfhydryl groups, or indomethacin (10 mg/kg, s.c.), a blocker of prostaglandin synthesis, which suggests that the gastroprotective mechanism of action of this sesquiterpene lactone does not involve NO, sulfhydryl groups or prostaglandins.

Ozocardic A: a new alkylanacardic acid from Ozoroa pulcherrima

One new alkylanacardic acid, ozocardic A (1), along with the known and related metabolites 6-tridecyl anacardic acid (2) and β-sitosterol (3) was isolated from Ozoroa pulcherrima. The structure of the new compound was elucidated by detailed spectroscopic analysis such as (1)H, (13)C NMR, COSY, HMQC, HMBC, and HREIMS. The structures of known compounds (6-tridecyl anacardic acid (2) and β-sitosterol (3)) were identified by the comparison of their spectral data with those published in the literature.

Pycnangloside: A New Cerebroside from Bark of Pycnanthus Angolensis

Pycnanthus anglonensis is known for its medicinal value. This paper deals with a phytochemical investigation of this species, from which pycnangloside (1), a new cerebroside has been isolated. Its structure was determined by comprehensive analyses of its 1D and 2D NMR spectroscopic, and ESI mass spectrometric data. Four known compounds were also isolated and identified as biochanin A, formonentin, β-sitosterol, and β-sitosterol glucopyranoside.

Cameroonemide A: a new ceramide from Helichrysum cameroonense

From the extracts of all parts of the plant Helichrysum cameroonense, five compounds were isolated and identified. One of them, a ceramide, named cameroonemide A (1), is reported for the first time as a new natural product. Its structure was determined by comprehensive analyses of their 1D and 2D NMR and HR-EI-MS spectral data. The remaining four known compounds were identified by comparing their spectroscopic data with those reported in the literature as kaurenoic acid (2), 3-acetyloxykaurenoic acid (3), beta-sitosterol (4), and beta-sitosterol glucopyranoside (5). Preliminary studies showed that 3-acetyloxykaurenoic acid (3) inhibited the alga Chlorella fusca, while kaurenoic acid (2) showed strong antibacterial activity against Bacillus megaterium.