Isolation and characterization of bioactive alkaloids and GC-MS based identification of volatile oil metabolites from fruits of Glycosmis pentaphylla and evaluation of their cytotoxic activity.

Glycosmis pentaphylla, a member of the Rutaceae family, has been extensively studied for its pharmacological activities, focusing mainly on the cytotoxic properties of its roots and stems. Conversely, limited researched has been done in terms of the phytochemical composition of the fruits. The objective of this study is to isolate and identify the bioactive compounds found in the fruits of G. pentaphylla and then evaluate their potential for anti-cancer activity in oral cancer CAL 27 cell lines. The extraction of bioactive compounds from fruits was done by maceration, and the isolation of alkaloids and volatile oil fractions (F1-F5) was performed by column chromatography. The alkaloids, such as 3-O-methoxyglycocitrine II, noracronycine, 1-hydroxy-3-methoxy-10-methyl-9-acridone and kokusaginine, were first isolated from the fruits of G. pentaphylla. Additionally, GC-MS analysis identified 78 metabolites. The isolated compounds and identified volatile oil fractions were explored for their anti-cancer activity by cell viability assay. Results demonstrated that isolated compounds were found inactive, while the volatile fraction F1 was found active in CAL 27 cell line. Fraction F1 impeded wound healing in CAL 27 cells by scratch assay, and significantly inhibited colony formation in colony formation assay. In cell cycle analysis, treatment with fraction F1 redistributed cells to the S and G2 phases of the cell cycle. α-elemol (2) is the major metabolite identified from the F1 fraction by GC-MS, which could be responsible for the anti-cancer activity. There is potential for future work to further isolate volatile oil metabolites and evaluate their anti-cancer activity through in-vivo techniques.

Isolation, Characterization of Undescribed Alkaloids, and Semisynthetic Modifications of Cytotoxic Pyranoacridone Alkaloids from Glycosmis pentaphylla.

Two undescribed alkaloids (10 and 11), along with nine known alkaloids (1-9), have been isolated from the stem and root bark of Glycosmis pentaphylla. Among them are carbocristine (11), a carbazole alkaloid first time isolated from a natural source, and acridocristine (10), a pyranoacridone alkaloid first time isolated from the genus "Glycosmis". In vitro cytotoxicity of isolated compounds has been analyzed on breast cancer (MCF-7), lung cancer (CALU-3), and squamous cell carcinoma cell lines (SCC-25). The results demonstrated that compounds are moderately active. In order to study the structural activity relationship of majorly isolated compounds, semisynthetic modifications have been done on majorly isolated compounds such as des-N-methylacronycine (4) and noracronycine (1) to synthesize 11 semisynthetic derivatives (12-22) on functionalizable -NH and -OH groups of the pyranoacridone scaffold at 12th and 6th positions. Semisynthetic derivatives are explored on the same cell lines as isolated compounds, and the results exhibit that semisynthetic compounds showed potent cytotoxic activity compared with naturally isolated compounds. In the case of CALU-3, the dimer at -OH position of noracronycine (1), i.e., compound 22, showed 24-fold better activity with an IC50 of 4.49 µM compared with noracronycine (1) with IC50 97.5 µM. In MCF-7, the dimer at -OH position of noracronycine (1), i.e., compound 22, showed 14-fold better activity with an IC50 of 13.2 µM compared with noracronycine (1) with IC50 187 µM.

One pot synthesis and anticancer activity of dimeric phloroglucinols.

A series of dimeric phloroglucinol compounds were synthesized in a single step using commercially available phloroglucinol and methanesulfonic acid. Based on the reported anticancer activity of plant derived dimeric phloroglucinols, these synthesized compounds were evaluated for their in vitro anti-proliferative activities against various cancer cell lines. Several compounds demonstrated in vitro cytotoxic effects across a wide array of tumor cell types. The compound 29 with pyridin-3-yl group on linker methylene and two diisovaleryl phloroglucinol moieties was found to be the most active in all the five cancer cell lines having a low IC(50) of 5.5 µM in colon cancer cell lines (HCT116).

Quantitative NMR: an applicable method for quantitative analysis of medicinal plant extracts and herbal products.

INTRODUCTION: Quantitative analysis and standardisation of plant extracts or herbal products is a tedious process requiring time-consuming sample preparation and analytical method development for the resolution of analyte peaks from the complex natural extract. Quantitative analysis by HPLC requires a pure authentic standard of the compound being quantified. We report here a quantitative NMR (qNMR) method for quantitative analysis of three medicinal plant extracts and their herbal products without the need of authentic standards. Quantitation can be done by using any commercially available pure sample as an internal reference standard. OBJECTIVE: To develop a reliable method for standardisation and quantitative analysis of extracts from medicinal plants Eugenia jambolana, Withania somnifera and Aegle marmelos and their herbal products using qNMR. METHODOLOGY: The (1) H-NMR spectra of known amounts of crude plant extracts with internal standards were recorded in deuterated solvents and quantitation was performed by calculating the relative ratio of the peak area of selected proton signals of the target compounds and the internal reference standard. Anthocyanins [delphinidin-3,5-diglucoside (1), petunidin-3,5-diglucoside (2) and malvidin-3,5-diglucoside (3)] for E. jambolana fruit extract and imperatorin (4) for A. marmelos fruit extract were selected as marker constituents for quantitation and 1,3,5-trimethoxybenzene (TMB) was used as an internal reference standard. Total withanolide content was determined for W. somnifera using 2,4-diformyl phloroglucinol as an internal reference standard. RESULTS: The (1) H-NMR gave a linear response for the marker constituents, anthocyanins, withaferin A and imperatorin. Using the described method, the amount of anthocyanins in Amberlite(R) XAD7HP and Sephadex enriched extracts of E. jambolana was 3.77% and 9.57% (delphinidin-3,5-diglucoside), 4.72% and 12.0% (petunidin-3,5-diglucoside), 6.55% and 15.70% (malvidin-3,5-diglucoside), respectively. The imperatorin content was 0.424% in A. marmelos fruit and 0.090 % and 0.114% in sharbat and candies. Total withanolides content was 0.191% in the chloroform extract and 0.234% in the capsule extract. These values are in accordance with HPLC results. CONCLUSION: This qNMR technique could be used for NMR fingerprinting and quantitation for the purpose of quality control and standardisation of many plant-based herbal products and medicines and has certain advantages over HPLC.

Herbal nanomedicines: Recent advancements, challenges, opportunities and regulatory overview.

BACKGROUND: Herbal Nano Medicines (HNMs) are nano-sized medicine containing herbal drugs as extracts, enriched fractions or biomarker constituents. HNMs have certain advantages because of their increased bioavailability and reduced toxicities. There are very few literature reports that address the common challenges of herbal nanoformulations, such as selecting the type/class of nanoformulation for an extract or a phytochemical, selection and optimisation of preparation method and physicochemical parameters. Although researchers have shown more interest in this field in the last decade, there is still an urgent need for systematic analysis of HNMs. PURPOSE: This review aims to provide the recent advancement in various herbal nanomedicines like polymeric herbal nanoparticles, solid lipid nanoparticles, phytosomes, nano-micelles, self-nano emulsifying drug delivery system, nanofibers, liposomes, dendrimers, ethosomes, nanoemulsion, nanosuspension, and carbon nanotube; their evaluation parameters, challenges, and opportunities. Additionally, regulatory aspects and future perspectives of herbal nanomedicines are also being covered to some extent. METHODS: The scientific data provided in this review article are retrieved by a thorough analysis of numerous research and review articles, textbooks, and patents searched using the electronic search tools like Sci-Finder, ScienceDirect, PubMed, Elsevier, Google Scholar, ACS, Medline Plus and Web of Science. RESULTS: In this review, the authors suggested the suitability of nanoformulation for a particular type of extracts or enriched fraction of phytoconstituents based on their solubility and permeability profile (similar to the BCS class of drugs). This review focuses on different strategies for optimising preparation methods for various HNMs to ensure reproducibility in context with all the physicochemical parameters like particle size, surface area, zeta potential, polydispersity index, entrapment efficiency, drug loading, and drug release, along with the consistent therapeutic index. CONCLUSION: A combination of herbal medicine with nanotechnology can be an essential tool for the advancement of herbal medicine research with enhanced bioavailability and fewer toxicities. Despite the challenges related to traditional medicine's safe and effective use, there is huge scope for nanotechnology-based herbal medicines. Overall, it is well stabilized that herbal nanomedicines are safer, have higher bioavailability, and have enhanced therapeutic value than conventional herbal and synthetic drugs.

Traditional uses, phytochemistry, pharmacology, toxicology and formulation aspects of Glycosmis species: A systematic review.

The present article is a systematic and constructive review of the traditional medicinal uses, chemistry, pharmacology, toxicology, and formulation aspects of Glycosmis species. The genus Glycosmis comprise 51 accepted species broadly distributed in Australia, China, India, and South-East Asia. Traditionally, Glycosmis species are used in folk medicines to treat cancer, anaemia, rheumatism, fever, cough, liver-related problems, skin ailments, intestinal worm infections, wounds, and facial inflammation. This review aims to provide readers with the latest information highlighting chemical constituents isolated from the Glycosmis species, plant parts utilized for their isolation and their pharmacological activities. So far, 307 chemical constituents have been isolated and characterized from different species of the genus Glycosmis; among these constituents, alkaloids, flavonoids, terpenoids, phenolics, and sulphur-containing amides are the major bioactive compounds. Modern pharmacological studies have shown that the crude extracts and compounds isolated from this genus exhibit a broad spectrum of biological activities like anticancer, antimicrobial, anti-inflammatory, antipyretic, antidiabetic, antioxidant, larvicidal, insecticidal, hepatoprotective, wound healing, antiviral, antidiarrheal, and anxiolytic. The carbazole and acridone alkaloids from this genus have shown potential anticancer activity in various in vitro and in vivo studies. Rare scaffolds like dimeric carbazoles, dimeric acridone alkaloids, flavanocoumarins and sulphur-containing amides from this genus need further exploration for their potential bioactivity. This article also briefs about the toxicological screening and discusses various polyherbal and nano formulation aspects of Glycosmis species. Most of the pharmacological studies reported from this genus were carried out in vitro. An in-depth in vivo and toxicology evaluation of the crude extracts and isolated specialized compounds is required to explore the full therapeutic potential of this genus.

Biomimetic synthesis and anti-HIV activity of dimeric phloroglucinols.

Plants are an important source of a variety of bioactive compounds with different modes of action. Anti-HIV agents from plant sources can be useful in developing novel therapies for inhibiting HIV infection. Based on the reported anti-HIV activity of plant derived phloroglucinols, several new dimeric phloroglucinols were synthesized in the present study by varying substitution on aromatic ring and at methylene bridge. Some of the synthesized compounds have shown good HIV inhibitory activity in a human CD4+ T cell line (CEM-GFP) infected with HIV-1 NL(4.3) virus isolate. Structure-activity studies indicate that phenyl, 4-benzyloxy-1-phenyl and cyclohexyl substitution at methylene bridge gave compounds with better anti-HIV activity. Compounds 22 and 24 showed highest anti-HIV activity with an IC(50) of 0.28 microM and 2.71 microM, respectively, former was more active than the positive standard AZT in cell based assay.

Small molecule HIV entry inhibitors: Part I. Chemokine receptor antagonists: 2004 - 2010.

INTRODUCTION: HIV/AIDS is one of the most devastating diseases in the world affecting > 40 million people worldwide. Morbidity and mortality from AIDS are significantly reduced due to the advent of highly active antiretroviral therapy (HAART). Long-term toxicity, emergence of drug resistant HIV strains and drug-drug interactions limit the effectiveness of HAART therapy. Chemokine receptor antagonists can provide drugs with lesser side effects and enhanced anti-HIV activity. Maraviroc, a chemokine co-receptor 5 (CCR5) antagonist from Pfizer, is already in clinical use. AREAS COVERED: This review covers patents and patent applications for small molecule CCR5 and CXC chemokine receptor 4 (CXCR4) antagonists published between 2004 and 2010 and related literature with a focus on recent developments based on lead generation and lead modification. The reader will gain information about the development of small molecule CCR5 and CXCR4 antagonists from the major pharmaceutical and biopharmaceutical companies. EXPERT OPINION: Several small lead molecules (CCR5 and CXCR4 antagonists) have been modified over this period for enhanced therapeutic activity and to obtain drug-like properties. CCR5 antagonists such as TBK-652 and TBK-220 from Tobira Therapeutics, and vicriviroc from Schering Plough showed a lot of promise in the developmental stage.

Anti-HIV activity of Indian medicinal plants.

Acquired immunodeficiency syndrome patients face great socio-economic difficulties in obtaining treatment. There is an urgent need for new, safe, and cheap anti-HIV agents. Traditional medicinal plants are a valuable source of novel anti-HIV agents and may offer alternatives to expensive medicines in future. Various medicinal plants or plant-derived natural products have shown strong anti-HIV activity and are under various stages of clinical development in different parts of the world. The present study was directed towards assessment of anti-HIV activity of various extracts prepared from Indian medicinal plants. The plants were chosen on the basis of similarity of chemical constituents with reported anti-HIV compounds or on the basis of their traditional usage as immunomodulators. Different extracts were prepared by Soxhlet extraction and liquid-liquid partitioning. Ninety-two extracts were prepared from 23 plants. Anti-HIV activity was measured in a human CD4+ T-cell line, CEM-GFP cells infected with HIV-1NL4.3. Nine extracts of 8 different plants significantly reduced viral production in CEM-GFP cells infected with HIV-1NL4.3. Aegle marmelos, Argemone mexicana, Asparagus racemosus, Coleus forskohlii, and Rubia cordifolia demonstrated promising anti-HIV potential and were investigated for their active principles.

Antiprotozoal and antimicrobial activities of O-alkylated and formylated acylphloroglucinols.

In the present article, we examined the antileishmanial, antimalarial, antibacterial, and antifungal activities of several newly synthesized O-alkylated phloroglucinol compounds (11-19) which are analogues of the naturally occurring antimalarial compound 1. Analogues 12 and 16 exhibited antileishmanial activity against, Leishmania donovani promastigotes with IC(50)s of 5.3 and 4.2microg/mL, respectively. Naturally occurring monomeric formylated acylphloroglucinol compounds, grandinol (2), jensenone (3), and their analogues (29-37), were also synthesized and evaluated for antileishmanial, antimalarial, antibacterial, and antifungal activities. Amongst these, both grandinol and jensenone showed mild to moderate antibacterial, antifungal, and antileishmanial activities. Jensenone (3) was effective against Candida albicans with an IC(50) of 5.5microg/mL but was ineffective against Cryptococcus neoformans and methicillin-resistant Staphylococcus aureus. Among the analogues, 34 was the most active against C. albicans and C. neoformans with IC(50)s of 2.0 and 2.5microg/mL, respectively, and was fungicidal toward Candida albicans.