Natural Products Journal, The - Volume 9, Issue 2, 2019

Background: The adipose tissue acts as a buffer storing and releasing energy according to the needs of the body. In a non-physiological context, the development of obesity is related to an unbalance in the homeostasis between calories intake and energy consumption. Objectives: This review focuses on the natural compounds and the herbal extracts used in dietary supplements that are claimed to suppress appetite and promote weight loss. Such compounds or mixture of compounds act through different molecular mechanisms that will be discussed from the point of view of the Medicinal Chemist. The reader will be also briefly updated on the recurring adulteration cases that affect the market of dietary supplements. Methods: The bibliographic research was performed using online scientific databases (PubMed, Reaxys, Scopus) exploiting different keywords and logical operators to lay the bases for an accurate, quality criteria-based literature update. Results: Over 70 papers were selected for the preparation of this review, preferring the reports that are supported by pre-clinical and clinical data. Conclusion: Activity on adrenergic receptors, modulation of adenosine receptors, interference with glucose and lipid metabolism, regulation of adipocyte cell cycle and inhibition of phosphodiesterases are the main molecular mechanisms by which different natural compounds act in promoting weight loss.

Mangroves are unique coastal forest ecosystem distributed along the tropical and subtropical region of the world. They are evolutionarily adapted to combat against hostile environmental conditions such as low oxygen, high salinity, and temperature. The adaptive features endowed with novel secondary metabolic pathways and bioactive compounds to sustain in harsh conditions. The novel metabolites are a rich source of the wide range of bioactive compounds and natural products. It includes terpenoids, alkaloids, phenolics, saponins, flavonoids, and steroids. The bioactive and natural compounds may serve as therapeutic precursors and industrial raw materials. Terpenes and polyphenols have antiviral, antibacterial, antifungal, antimalarial, anticancer or combination of activities. To date, several mangroves plants were examined and recognized as a potential source of novel natural product for exploitation in medicine. In fact, most of the isolated compounds are novel and showed promising biological activities such as gastroprotective, cytotoxic, antioxidant, antibacterial, antifungal, antiviral, enzyme activation and inhibition, immunosuppressive, anti-inflammatory, antifeedant effects. In the present review, we have compiled the achievements and progress in mangroves natural products research of the last decade.

Background: Medicinal plants are rich source of large variety of lead compounds. The plants of genus Glycosmis or its different parts valued for its therapeutic and medicinal qualities. Glycosmis belongs to the family Rutaceae. Objective: The genus Glycosmis is a rich source of pharmacologically and biologically active secondary metabolites, such as alkaloids, flavonoids, phenolic glycosides, quinones, terpenoids, glycerides isolated from different parts of Glycosmis plant. The objectives of this review is to provide updatedand complete information on the distribution, phytochemical, pharmacological, and toxicity research of Glycosmis species. Results: About 233 phytoconstituents are isolated from this genus. Recent interest in this genus has focused on isolating and identifying of different phytoconstituents that exhibit potent antioxidant, antibacterial, antiviral and anticancer activities. They show good cytotoxic activity against various cancer cell lines and also reported for good antiviral and immunomodulatory activity. In this support convincing evidence in experimental animal models are available. Conclusion: This review summarizes information about the isolated compounds their bioactivities related to same compounds present in other plants including pharmacological activities of plant extract of Glycosmis genus.

Background: Various methods of isolating compounds from plants have been described previously, which include conventional or modern techniques. A preparative-HPLC (prep-HPLC) system has become one of the most convenient methods, with high purity compound as well as consumes less purification time. Objective: This study is intended to purify compounds from E. pulchrum twig extract using prep- HPLC technique and to test all compounds in several biological activities. Methods: Prior to purification using prep-HPLC, the twig extract was injected onto HPLC to develop the method through its chromatograms. The established method from HPLC was used to separate the constituents using prep-HPLC. Purified compounds were elucidated through NMR and MS methods as well as through comparison with previously reported data. Three different biological activities were then conducted on the compounds, including cytotoxicity, DPPH, FRAP, and disc diffusion assays. Results: Cinnamic acid (1) and two aporphine alkaloids (liridine (2) and lysicamine (3)) have been successfully purified and identified. These compounds were first isolated from Enicosanthellum pulchrum using prep-HPLC. Cytotoxic activity revealed that liridine (2) showed strong inhibition against WEHI-3B leukaemic cells of 8.7 μM after 24 h of treatment. In contrast, cinnamic acid (1) and lysicamine (3) exhibited strong inhibitions in antibacterial activity against Staphylococcus aureus, S. epidermidis, Bacillus cereus, Pasteurella multocida and B. subtilis with more than 15 mm of inhibition zone. Conclusion: These phytochemical findings exhibit three isolated compounds from twig extract of E. pulchrum with diverse biological potential to be developed as new agents.

Background: Galanthum nivalis has been used throughout history for its medicinal properties. Although traditionally used as an antidote to poison, G. nivalis has also recently been found to have effects in neurological conditions such as Alzheimer’s Disease and mild cognitive impairment. Recent studies also suggest that it may have neurological activity that may be beneficial for psychiatric and neurological disorders like anxiety. Objective: This study aimed to assess the neurological activity of G. nivalis extract using a behavioral test of anxiety-like behavior in Syrian hamsters. Methods: G. nivalis extract was administered daily to hamsters while undergoing a semi-naturalistic version of the open field test to assess anxiety. Hamsters were video recorded during their natural active times beginning an hour before and ending an hour after lights-on and lights-off. Free roaming behaviors were scored in a 2 x 4 m open pen with enrichment objects for hamsters to interact with. After 10 days, hamsters were subjected to a social interaction test with a novel conspecific. Results: Hamsters receiving G. nivalis extract showed increased time that was spent free-roaming and a greater proportion of that time was spent moving. They also spent more time interacting with enrichment objects in the open pen. The social interaction test showed that hamsters receiving G. nivalis extract spent more time playing with a novel conspecific. Conclusion: G. nivalis extract is a neurologically active natural product with behaviorally relevant effects. It improved anxiety-like behavior in hamsters, as evidenced by increased time free roaming, moving, and interacting with objects, while improving social interactions.

Background: Stenoloma chusanum (L.) Ching is a Chinese traditional medicinal fern with high total flavonoid and total phenolic content. Traditionally, phenolic compounds were separated by using column chromatography, which is relatively inefficient. Objective: This study aims to use an efficient method to separate natural products from S. chusanum by Medium-Pressure Liquid Chromatography (MPLC) and High-Speed Counter-Current Chromatography (HSCCC). Methods: In the present research, firstly, a sample (2.5 g) from the dichloromethane extract of S. chusanum was separated by MPLC. Next, fraction P5 was purified by HSCCC with a two-phase solvent system composed of hexane-ethyl acetate-methanol-water (HEMWat) at a volume ratio of 2:4:1:4 (v/v/v/v). Result: Four phenolic acids were obtained and their structures were identified by means of NMR and ESI-mass analysis. They were identified as: 1) protocatechuic acid (34 mg, purity 90.1%), 2) syringic acid (66 mg, purity 99.0%), 3) p-hydroxybenzoic acid (5 mg, purity 91.2%) and 4) vanillic acid (6 mg, purity 99.3%). Conclusion: The combination of MPLC and HSCCC is a high-efficiency separation method for natural products. This is the first report with regard to the separation of four phenolic acids in one step by MPLC and HSCCC from S. chusanum (L.) Ching.

Background: Phellinus mushrooms are locally available in Thailand. They have been traditionally used for medicinal purposes including tonics, for cancer treatment and for immune system stimulation. Objective: To evaluate the in vitro antioxidant, antibacterial activities and the phytochemical information of the extracts from 11 selected Phellinus mushrooms collected in Thailand. Methods: Eleven Phellinus mushrooms were collected from the Northeastern part of Thailand. Their ethanol and water extracts were tested for in vitro antioxidant activities using a DPPH scavenging assay, FRAP assay and TBARS method while the antibacterial effects were determined by agar disk diffusion and broth microdilution methods. The phytochemical profiles of the Phellinus mushroom extracts were evaluated using TLC and HPLC techniques. The total phenolic and total flavonoid contents of the extracts were evaluated by Folin-Ciocalteu and aluminium chloride methods, respectively. While total carbohydrate and total triterpene contents were evaluated by phenolsulfuric acid and vanillin perchloric acid methods, respectively. Results: Most ethanol extracts from Phellinus mushrooms exhibited moderate antioxidant effects especially extracts from P. everhartii, P. hippophaëicola and P. pini var. microporus while P. igniarius var. cinereus ethanol extract exhibited inhibitory effects to Helicobacter pylori both normal and resistant strains, this extract also showed the strongest inhibitory effect against Staphylococcus aureus. Most Phellinus mushroom extracts exhibited similar TLC and HPLC fingerprints with the chromatographic bands corresponding to phenolics, flavonoids and terpenoids. Protocatechuic acid was identified in most Phellinus mushroom extracts. Conclusion: Phellinus mushrooms especially, P. everhartii could be developed as sources of antioxidants while P. igniarius var. cinereus indicated the potential to inhibit H. pylori. Protocatechuic acid could be used as a marker for quality control of Phellinus mushroom raw materials and extracts.