The genus Canthium: A comprehensive summary on its traditional use, phytochemistry, and pharmacological activities.

Canthium Lam. is a genus of flowering plants of the Rubiaceae family with about 80-102 species mainly distributed in Asia, tropical and subtropical Africa. The genus is closely related to Keetia E. Phillips and Psydrax Gaertn. and plants of this genus are used in folk medicine for the treatment of diarrhea, worms, leucorrhoea, constipation, snake bites, diabetes, hypertension, venereal diseases, and malaria. The present review covers a period of 52 years of biological and chemical investigations into the genus Canthium and has resulted in the isolation of about 96 secondary metabolites and several reported biological properties. For the Rubiaceae family, iridoids were reported as being the chemotaxonomic markers of this genus (∼25%). Other reported classes of compounds include alkaloids, flavonoids, phenolic compounds, cyanogenic glycosides, coumarins, sugar alcohols, lignans, triterpenoids, and benzoquinones. The main reported pharmacological properties of most species of this genus include antioxidant, antiplasmodial, antipyretic, anti-inflammatory, antidiabetic, neuroprotective and antimicrobial activities with the latter being the most prominent. Considering the diversity of compounds reported from plants of this genus and their wide range of biological activities, it is considered to be worthy to further investigate them for the discovery of potentially new and cost effective drugs.

Knowledge, Attitudes and Perceptions towards COVID-19 Vaccinations: A Cross-Sectional Survey in Pakistan.

Background and Objectives: Several vaccines have been approved for the prevention of the coronavirus disease, discovered on 31 December in Wuhan, China. Pakistan procured vaccines from various countries. However, the lack of knowledge and reluctance of the general population to embrace the use of the vaccines are considered to be the major determinant of the slow vaccination rate. Hence, it is necessary to evaluate the willingness of the general population about their perception of the COVID-19 vaccination. Materials and Methods: A cross sectional survey based on a self-structured questionnaire comprising 18 questions was conducted (from 21 April-21 June) on 400 Pakistani participants to evaluate their knowledge, attitude, and perception towards the COVID-19 vaccination. Chi-square independent t-test and one-way Anova including a multiple step wise linear regression were used to draw conclusions about the results. p < 0.05 was considered significant. Results: A total of 400 participants responded in the knowledge, attitude, and perception (KAP) survey of which 46.5% were female and 53.5% were male. The mean age of participants was 36.08 years. This survey showed a poor knowledge (50.5%), a fair attitude (75.1%) and a poor perception (58.1%) towards the COVID-19 vaccination. Higher mean knowledge and attitude scores were reported in the age group 21-40, females, and unmarried urban citizens. Regression analysis showed that age, education, residence, and employment status influenced the knowledge and perception score to a considerable extent. Conclusions: The findings reflect an inadequate knowledge and perception on the one hand, but a better attitude towards the COVID-19 vaccination. This knowledge attitude and perception (KAP) survey will help in better understanding the opinion of the general population towards vaccination, and will be useful for policy makers and health care authorities aiming to increase the vaccination rate.

Marine life as a source for breast cancer treatment: A comprehensive review.

Breast cancer, one of the most significant tumors among all cancer cells, still has deficiencies for effective treatment. Moreover, substitute treatments employing natural products as bioactive metabolites has been seriously considered. The source of bioactive metabolites are not only the most numerous but also represent the richest source. A unique source is from the oceans or marine species which demonstrated intriguing chemical and biological diversity which represents an astonishing reserve for discovering novel anticancer drugs. Notably, marine sponges produce the largest amount of diverse bioactive peptides, alkaloids, terpenoids, polyketides along with many secondary metabolites whose potential is mostly therapeutic. In this review, our main focus is on the marine derived secondary metabolites which demonstrated cytotoxic effects towards numerous breast cancer cells and have been isolated from the marine sources such as marine sponges, cyanobacteria, fungi, algae, tunicates, actinomycetes, ascidians, and other sources of marine organisms.

Unusually cyclized triterpenoids: occurrence, biosynthesis and chemical synthesis.

Covering: 2009 to 2021Biosynthetically, most of the syntheses of triterpenes follow the cascade cyclization and rearrangement of the acyclic precursors viz., squalene (S) and 2,3-oxidosqualene (OS), which lead to the very well known tetra- and pentacyclic triterpene skeletons. Aside from these, numerous other triterpenoid molecules are also reported from various natural sources and their structures are derived from "S" and "OS" via some unusual cyclization operations which are different from the usual tetra- and pentacyclic frameworks. Numerous compelling advances have been made and reported in the identification of these unusual cyclized mono-, di-, tri- and tetracyclic triterpenes between 2009 and 2021. Besides a dramatic increase in the newly isolated uncommon cyclized triterpenoids, substantial progress in the (bio)-synthesis of these triterpenes has been published along with significant progress in their biological effects. In this review, 180 new unusual cyclized triterpenoids together with their demonstrated biogenetic pathways, syntheses and biological effects will be categorized and discussed.

Fruit Peels: Food Waste as a Valuable Source of Bioactive Natural Products for Drug Discovery.

Fruits along with vegetables are crucial for a balanced diet. These not only have delicious flavors but are also reported to decrease the risk of contracting various chronic diseases. Fruit by-products are produced in huge quantity during industrial processing and constitute a serious issue because they may pose a harmful risk to the environment. The proposal of employing fruit by-products, particularly fruit peels, has gradually attained popularity because scientists found that in many instances peels displayed better biological and pharmacological applications than other sections of the fruit. The aim of this review is to highlight the importance of fruit peel extracts and natural products obtained in food industries along with their other potential biological applications.

Impact of pharmacist-led educational intervention on knowledge of self-management among asthmatic patients: a prospective cohort study.

OBJECTIVES: Poor control of asthma in the majority of patients could be partly due to their lack of knowledge concerning disease management, its triggering agents and when to seek advice from the healthcare provider. This study aims to assess the impact of pharmacist-led educational intervention on knowledge of self-management among asthmatic patients. DESIGN: A pre-post cohort study. SETTING: Outpatient department of a tertiary care hospital affiliated with Quaid-i-Azam University, Pakistan. PARTICIPANTS: Approximately 265 adult asthmatic patients selected through a spirometry process, aged ≥18 years, were approached. 240 patients gave consent to participate in the study and were divided into control and treatment groups. INTERVENTIONS: The educational intervention consisted of individual patient counselling using educational material with time varied according to each patient's comprehension and previous knowledge. PRIMARY AND SECONDARY OUTCOME MEASURES: Assessment consisted of a 14-item Asthma Self-Management Knowledge Questionnaire (ASMQ) quantifying a patient's self-management knowledge through an ASMQ score and its change following an educational intervention. RESULTS: Disease self-management knowledge was low with an average raw ASMQ score of 4.1 (max 14); which equates to a transformed score of 29.34 (max 100) and the proportion of patients who correctly answered more than 50% of questions were 16.7% preintervention. More than half of the participants (55%) did not know that asthma cannot be cured. The administration of educational intervention protocols resulted in significantly improved level of knowledge of asthma self-management (<0.001) in the treatment group (mean ASMQ score improved from 4.20 to 9.77). CONCLUSION: On baseline visit, patients possessed a poor knowledge about asthma self-management. Educational intervention protocols had a positive impact on improving patients' knowledge about disease self-management. This would suggest that education and self-management skills should be seen as an integral component of asthma management and should be incorporated in structured patient care to achieve optimal asthma control.

Frankincense diterpenes as a bio-source for drug discovery.

INTRODUCTION: Frankincense (Boswellia sp.) gum resins have been employed as an incense in cultural and religious ceremonies for many years. Frankincense resin has over the years been employed to treat depression, inflammation, and cancer in traditional medicines. AREAS COVERED: This inclusive review focuses on the significance of frankincense diterpenoids, and in particular, incensole derivatives for establishment future treatments of depression, neurological disorders, and cancer. The authors survey the available literature and furnish an overview of future perspectives of these intriguing molecules. EXPERT OPINION: Numerous diterpenoids including cembrane, prenylaromadendrane, and the verticillane-type have been isolated from various Boswellia resins. Cembrane-type diterpenoids occupy a crucial position in pharmaceutical chemistry and related industries because of their intriguing biological and encouraging pharmacological potentials. Several cembranes have been reported to possess anti-Alzheimer, anti-inflammatory, hepatoprotective, and antimalarial effects along with a good possibility to treat anxiety and depression. Although some slight drawbacks of these compounds have been noted, including the selectivity of these diterpenoids, there is a great need to address these in future research endeavors. Moreover, it is vitally important for medicinal chemists to prepare libraries of incensole-heterocyclic analogs as well as hybrid compounds between incensole or its acetate and anti-depressant or anti-inflammatory drugs.

Covalent Allosteric Inhibitors of Akt Generated Using a Click Fragment Approach.

Akt is a protein kinase that has been implicated in the progression of cancerous tumours. A number of covalent allosteric Akt inhibitors are known, and based on these scaffolds, a small library of novel potential covalent allosteric imidazopyridine-based inhibitors was designed. The envisaged compounds were synthesised, with click chemistry enabling a modular approach to a number of the target compounds. The binding modes, potencies and antiproliferative activities of these synthesised compounds were explored, thereby furthering the structure activity relationship knowledge of this class of Akt inhibitors. Three novel covalent inhibitors were identified, exhibiting moderate activity against Akt1 and various cancer cell lines, potentially paving the way for future covalent allosteric inhibitors with improved properties.

Meroterpenoids: A Comprehensive Update Insight on Structural Diversity and Biology.

Meroterpenoids are secondary metabolites formed due to mixed biosynthetic pathways which are produced in part from a terpenoid co-substrate. These mixed biosynthetically hybrid compounds are widely produced by bacteria, algae, plants, and animals. Notably amazing chemical diversity is generated among meroterpenoids via a combination of terpenoid scaffolds with polyketides, alkaloids, phenols, and amino acids. This review deals with the isolation, chemical diversity, and biological effects of 452 new meroterpenoids reported from natural sources from January 2016 to December 2020. Most of the meroterpenoids possess antimicrobial, cytotoxic, antioxidant, anti-inflammatory, antiviral, enzyme inhibitory, and immunosupressive effects.

Glycyrrhetinic acid: a promising scaffold for the discovery of anticancer agents.

INTRODUCTION: Oleanane-type pentacyclic triterpenes named glycyrrhetinic acids (GAs) featuring a C-30 carboxylic acid group, are extracted from the licorice (Glycyrrhiza uralensis). Numerous biological properties of GA have been reported and have attracted researchers from all over the world in recent years due to the peculiar GA scaffold-based semisynthetic cytotoxic effects. AREAS COVERED: This review represents the applications of semisynthetic derivatives of GA for the development of future cancer treatments. Included in the review are important structural features of the semisynthetic GAs crucial for cytotoxic effects. EXPERT OPINION: Numerous semisynthetic GA derivatives illustrated excellent cytotoxic effects toward various cancer cells. Notably the C-3(OH) at ring A along with C30-CO2H at ring E as vital structural features, make GA very appealing as a lead scaffold for medicinal chemistry, since these two groups permit the creation of further chemical diversity geared toward improved cytotoxic effects. Furthermore, numerous GA derivatives have been synthesized and indicate that compounds featuring cyanoenone moieties in ring A, or compounds having the amino group or nitrogen comprising heterocycles and hybrids thereof, illustrate more potent cytotoxicity. Furthermore, GA has a great capability to be conjugated with other anticancer molecules to synergistically enhance their combined cytotoxicity.

Boswellic acids: privileged structures to develop lead compounds for anticancer drug discovery.

Introduction: Cancer has been identified to be the second major cause of death internationally as exemplified by ca. 9.6 million deaths in 2018 along with ca. 18 million new patients in 2018 that have been recorded. Natural boswellic acids (BAs) and their source, frankincense, have been reported to possess in vitro and in vivo anticancer effects toward various cancer cells.Areas covered: This comprehensive review focuses on the importance of boswellic acids (BAs) for the establishment of future treatments of cancer. Moreover, potent semisynthetic derivatives of BAs have been described along with their mode of action. In addition, important structural features of the semisynthetic BAs required for cytotoxic effects are also discussed.Expert opinion: Numerous semisynthetic BAs illustrate excellent cytotoxic effects. Of note, compounds bearing cyanoenone moieties in ring A, endoperoxides and hybrids display increased and more potent cytotoxic effects compared with other semisynthetic BAs. Moreover, BAs have the potential to conjugate or couple with other anticancer compounds to synergistically increase their combined anticancer effects. In addition, to get derived BAs to become lead anticancer compounds, future research should focus on the preparation of ring A cyanoenones, endoperoxides, and C-24 amide analogs.

4-Benzyloxylonchocarpin and Muracatanes A-C from Ranunculus muricatus L. and Their Biological Effects.

Ranunculus muricatus L. is a spiny fruit buttercup that is used in various traditional medicinal systems. In the current investigation of R. muricatus, the new chalcone 4-benzyloxylonchocarpin (1), the new anthraquinone muracatanes A (2), the new-to-nature anthraquinone muracatanes B (3), and the new naphthalene analog muracatanes C (4) were isolated, in addition to the three previously reported compounds, 4-methoxylonchocarpin (5), ß-sitosterol (6), and ß-sitosterol ß-D-glucopyranoside (7). Their structures were elucidated using 1D (1H and 13C) and 2D (COSY, HSQC, and HMBC) NMR spectroscopy and HR-ESI-MS. Chalcone 1 showed potent acetylcholinesterase inhibitory effects with Ki of 5.39 µM and Ki' of 3.54 µM, but none of the isolated compounds showed inhibitory activity towards butyrylcholinesterase. Anthraquinone 3 illustrated α-glucosidase inhibitory effects with IC50-values of 164.46 ± 83.04 µM. Compound 5 displayed moderate cytotoxic activity towards ovarian carcinoma (A2780, IC50 = 25.4 µM), colorectal adenocarcinoma (HT29, IC50 = 20.2 µM), breast cancer (MCF7, IC50 = 23.7 µM), and thyroid carcinoma (SW1736, IC50 = 26.2 µM) while it was inactive towards pharynx carcinoma (FaDu: IC50 > 30 µM).

Deciphering the chemical instability of sphaeropsidin A under physiological conditions - degradation studies and structural elucidation of the major metabolite.

The fungal metabolite sphaeropsidin A (SphA) has been recognised for its promising cytotoxicity, particularly towards apoptosis- and multidrug-resistant cancers. Owing to its intriguing activity, the development of SphA as a potential anticancer agent has been pursued. However, this endeavour is compromised since SphA exhibits poor physicochemical stability under physiological conditions. Herein, SphA's instability in biological media was explored utilizing LC-MS. Notably, the degradation tendency was found to be markedly enhanced in the presence of amino acids in the cell medium utilized. Furthermore, the study investigated the presence of degradation adducts, including the identification, isolation and structural elucidation of a major degradation metabolite, (4R)-4,4',4'-trimethyl-3'-oxo-4-vinyl-4',5',6',7'-tetrahydro-3'H-spiro[cyclohexane-1,1'-isobenzofuran]-2-ene-2-carboxylic acid. Considering the reduced cytotoxic potency of aged SphA solutions, as well as that of the isolated degradation metabolite, the reported antiproliferative activity has been attributed primarily to the parent compound (SphA) and not its degradation species. The fact that SphA continues to exhibit remarkable bioactivity, despite being susceptible to degradation, motivates future research efforts to address the challenges associated with this instability impediment.

Cichorins D-F: Three New Compounds from Cichorium intybus and Their Biological Effects.

Cichorium intybus L., (chicory) is employed in various traditional medicines to treat a wide range of diseases and disorders. In the current investigation, two new naphthalane derivatives viz., cichorins D (1) and E (2), along with one new anthraquinone cichorin F (3), were isolated from Cichorium intybus. In addition, three previously reported compounds viz., ß-sitosterol (4), ß-sitosterol ß-glucopyranoside (5), and stigmasterol (6) were also isolated from Cichorium intybus. Their structures were established via extensive spectroscopic data, including 1D (1H and 13C) and 2D NMR (COSY, HSQC and HMBC), and ESIMS. Cichorin E (2) has a weak cytotoxic effect on breast cancer cells (MDA-MB-468: IC50: 85.9 µM) and Ewing's sarcoma cells (SK-N-MC: IC50: 71.1 µM); cichorin F (3) also illustrated weak cytotoxic effects on breast cancer cells (MDA-MB-468: IC50: 41.0 µM and MDA-MB-231: IC50: 45.6 µM), and SK-N-MC cells (IC50: 71.9 µM). Moreover compounds 1-3 did not show any promising anthelmintic effects.

Protein tyrosine phosphatase 1B (PTP1B) inhibitors as potential anti-diabetes agents: patent review (2015-2018).

Introduction: Protein tyrosine phosphatase 1B (PTP1B) inhibition has been recommended as a crucial strategy to enhance insulin sensitivity in various cells and this fact is supported by human genetic data. PTP1B inhibitors improve the sensitivity of the insulin receptor and have the ability to cure insulin resistance-related diseases. In the latter years, targeting PTP1B inhibitors is being considered an attractive target to treat T2DM and therefore libraries of PTP1B inhibitors are being suggested as potent antidiabetic drugs. Areas covered: This review provides an overview of published patents from January 2015 to December 2018. The review describes the effectiveness of potent PTP1B inhibitors as pharmaceutical agents to treat type 2 diabetes. Expert opinion: Enormous developments have been made in PTP1B drug discovery which describes progress in natural products, synthetic heterocyclic scaffolds or heterocyclic hybrid compounds. Various protocols are being followed to boost the pharmacological effects of PTP1B inhibitors. Moreover these new advancements suggest that it is possible to get small-molecule PTP1B inhibitors with the required potency and selectivity. Furthermore, future endevours via an integrated strategy of using medicinal chemistry and structural biology will hopefully result in potent and selective PTP1B inhibitors as well as safer and more effective orally available drugs.

Dipeptidyl peptidase IV inhibitors as a potential target for diabetes: patent review (2015-2018).

INTRODUCTION: Dipeptidyl peptidase 4 (DPP-4) belongs to the family of serine proteases and is involved in the degradation of GLP-1 and GIP hormones, which enhance the production and release of insulin. Targeting DPP-4 inhibitors is increasingly being considered as promising paradigms to treat type 2 diabetes mellitus and therefore DPP-4 inhibitors are being considered as promising antidiabetic drugs. AREAS COVERE: This review provides an overview of published patents describing natural and synthetic DPP-4 inhibitors from January 2015 to December 2018. EXPERT OPINION: A fair number of new synthetic and natural DPP-4 inhibitors have been reported in the last four years which describe the progress in the development of various heterocyclic scaffolds or heterocyclic hybrid compounds. As a result of this, many marketed DPP-4 inhibitors that have been approved by the appropriate governing bodies during the past decade, have been introduced as inhibitors. Molecular hybridization is an emerging idea in medicinal chemistry and therefore hybrid compounds of DPP-4 inhibitors with other DPP-4 inhibitors or with antidiabetic drugs should be formulated for a comprehensive evaluation. More detailed pharmacovigilance of DPP-4 inhibitors is required because this will address the pancreas-related adverse events as well as their impact on cardiovascular outcomes via long-term studies.

Cucurbitacins as Anticancer Agents: A Patent Review.

BACKGROUND: Cucurbitacins belong to a group of tetracyclic triterpenoids that display a wide range of biological effects. In the past, numerous cucurbitacins have been isolated from natural sources and many active compounds have been synthesized using the privileged scaffold in order to enhance its cytotoxic effects. OBJECTIVE: This review covers patents on the therapeutic effects of natural cucurbitacins and their synthetic analogs published during the past decade. By far, the majority of patents published are related to cancer and Structure-Activity Relationships (SAR) of these compounds are included to lend gravitas to this important class of natural products. METHODS: The date about the published patents was downloaded via online open access patent databases. RESULTS: Cucurbitacins display significant cytotoxic properties, in particular cucurbitacins B and D which possess very potent effects towards a number of cancer cells. Numerous cucurbitacins isolated from natural sources have been derivatized through chemical modification at the C(2)-OH and C(25)- OH groups. Most importantly, an acyl ester of the C(25)-OH and, iso-propyl, n-propyl and ethyl ether groups of the C(2)-OH demonstrated the most increased cytotoxic activity. CONCLUSION: The significant cytotoxic effects of natural and semi-synthetic cucurbitacins make them attractive as new drug candidates. Moreover, cucurbitacins have the capability to form conjugates with other anticancer drugs which will synergistically enhance their anticancer effects. The authors believe that in order to get lead compounds, there should be a greater focus on the synthesis of homodimers, heterodimers, and halo derivatives of cucurbitacins. In the opinion of the authors the analysis of the published patents on the cucurbitacins indicates that these compounds can be developed into a regimen to treat a wide spectrum of cancers.

Journey Describing the Cytotoxic Potential of Withanolides: A Patent Review.

Withanolides are C-28 ergostane steroids known to demonstrate some very interesting therapeutic properties. Numerous withanolides have been isolated from a variety of different plant species and can be employed to treat various types of cancers. Withanolides are indeed capable of demonstrating excellent anticancer, anti-inflammatory, and neuroprotective activities. Additionally, libraries of prepared withaferin A analogs incorporating an acyl, sulphate, amide and aldehyde functionality have demonstrated the most potential response. It is of particular interest to note that an acetyl group at either C-4, C-19 or C-27 enhances the anticancer effects. Since the majority of natural withanolides reported in patents are classified as "Type-A", it is our opinion that there should now be a focus on developing "Type-B" withanolides and an investigation into their various therapeutic applications. Moreover, very little real innovation in synthetic methodologies has been reported which opens up huge possibilities for novel synthetic methodologies to be developed for the production of larger libraries new withanolides and their analogs to incorporate chemical diversity. In addition, since withanolides have the capability to conjugate with other anticancer compounds, this should encourage scientists to prepare lead compounds in cancer drug discovery.

Therapeutic potential of glycyrrhetinic acids: a patent review (2010-2017).

INTRODUCTION: Glycyrrhetinic acids (GAs) viz., 18ß-glycyrrhetinic acid and 18α-glycyrrhetinic acid, are oleanane-type triterpenes having a carboxylic acid group at C-30, and are extracted from the Chines herbal medicine licorice (Glycyrrhiza uralensis). Although the pharmacological properties of GAs have long been known, attention to them has greatly increased in recent times due to their cytotoxic activity. AREAS COVERED: This review represents the patents granted about natural and synthetic glycyrrhetinic acid analogs from January 2010 to December 2017, the advances made by research groups in conjunction with pharmaceutical companies in the discovery of new natural or synthetic glycyrrhetinic acid analogs. EXPERT OPINION: GAs demonstrate excellent cytotoxic, antimicrobial, enzyme inhibitory, antiinflammatory, antioxidant, analgesic, and antiviral effects. It is interesting to note that the C-3(OH) and C30-CO2H functional groups make GAs very attractive lead structures for medicinal scientists since these functionalities allow the generation of further chemical diversity for improved pharmacological effects. Moreover, various GA analogues have been prepared via modification of the C30-CO2H. It is noteworthy that the C-30 amide of GA demonstrated better cytotoxic effects compared to the parent compounds. In addition, GAs have the capability to conjugate with other anticancer drugs or be converted into their halo or amino analogs which is expected to stimulate medicinal chemist to synthesize new lead compounds in cancer drug discovery.