Two new anticancer phenolic derivatives from leaves of Piper betle Linn

A novel off-line multi-dimensional high-speed countercurrent chromatography strategy for preparative separation of bioactive neolignan isomers from Piper betle. L

Separation and purification of naturally occurring isomers from herbs are still challenging. High-speed counter-current chromatography (HSCCC) has been applied to isolate natural products. In this study, an off-line multi-dimensional high-speed counter-current chromatography (multi-D HSCCC) strategy was developed utilizing the in situ concentration technique with online storage recycling elution to rapidly separate bioactive isomeric neolignans from chloroform-partitioned samples of the plant Piper betle L. In the procedure, the crude sample (105 mg) was implemented using the online storage recycling technique in a two-phase solvent system composed of petroleum ether-ethyl acetate-methanol-water (7: 5: 12: 3), which first simply afforded a neolignane kadsurenone (1, 5.3 mg) and its epimer (-)-denudatin B (2, 6.4 mg). Then, the remains fr a was subjected to the second-dimensional HSCCC elution using the in situ concentration technique with online storage recycling technique in another solvent system of petroleum ether-ethyl acetate-methanol-water (5: 5: 11, 15). As a result, kadsurenin I (3, 0.6 mg) and its regioisomer pibeneolignan C (4, 5.0 mg), together with the fractional remaining fr b and fr c, were obtained. Thirdly, the fr c was reloaded to allow the HSCCC for recycling elution with the former solvent system employing the in situ concentration strategy and yielded a pair of epimers, (7R,8S,1'S)-1'-allyl-5-methoxy-8-methyl-7-piperonyl-7,8,3,6-tetrahydro-2-oxobenzofuran (5, 10.2 mg), and 3-epi-(-)-burchullin (6, 2.6 mg). Finally, the three pairs of less amount and the structurally similar isomers 1-6 were isolated from the crude fraction of P. betle with a high HPLC purity of over 95.0 % for compound 2, 4-6 and 92.5 % for compound 1, 91.0 % for 3, while the purity of 1 and 3 in 1H NMR were 89.9 % and 91.1 %, respectively. The whole isolation process was quick and efficient. Compounds 1, 2, 4 and 5 showed significantly synergistic activities combining several antibiotics against five drug-resistant Staphylococcus aureus with FICIs from 0.156 to 0.375. This novel off-line multi-dimensional HSCCC strategy could be broadened to application for the rapid separation of complex natural products.

Discovery of plant-derived anti-tumor natural products: Potential leads for anti-tumor drug discovery

Natural products represent a paramount source of novel drugs. Numerous plant-derived natural products have demonstrated potent anti-tumor properties, thereby garnering considerable interest in their potential as anti-tumor drugs. This review compiles an overview of 242 recently discovered natural products, spanning the period from 2018 to the present. These natural products, which include 69 terpenoids, 42 alkaloids, 39 flavonoids, 21 steroids, 14 phenylpropanoids, 5 quinolines and 52 other compounds, are characterized by their respective chemical structures, anti-tumor activities, and mechanisms of action. By providing an essential reference and fresh insights, this review aims to support and inspire researchers engaged in the fields of natural products and anti-tumor drug discovery.

Flavored Food Additives on the Leaves of Piper betle L.: A Human Health Perspective

Natural products and traditional ethnomedicines are of great effect in therapeutics. Such types of medicine have been practiced in certain areas of the world to treat different health conditions. This pilot investigation aims to review the cumulative health effect of addendums used in betel quid such as areca nut, lime, and tobacco-associated betel quid chewing and without tobacco-associated chewing. This review shows that betel leaf extract and its essential oil could inhibit growth of microbes and damage different gram-positive and gram-negative bacteria as well as various fungus species. Some studies concluded that the combination of Piper leaves essential oil with antibiotics have potential effect on oral microorganisms. Long-term consumption of betel quid with tobacco is known to cause cancer, chromosomal aberrations, and pharynx tumors. However, consumption of betel leaf without tobacco has health benefits because of ethnomedicinal properties. Its essential is oil utilized as raw material for perfumes and mouth fresheners manufacturing. Scientific researches on this plant revealed that it possesses many beneficial activities to be used for developing novel drugs. However, compounds of betel leaves have beneficial natural antioxidant. Chewing and intake of leaves have effect on moving parts of salivary gland which is the main step of digestion. Its components also act as heartbeat regulators in relaxing the blood vessels to reduce hypertension. So this review discussed the natural compounds of betel leaves which is used as traditional medicine to further develop drug discovery.

Untargeted Metabolomics in Piper betle Leaf Extracts to Discriminate the Cultivars of Coastal Odisha, India

Betel leaf is consumed as a mouth freshener due to its characteristic flavor, aromaticity, and medicinal values. Abundance of phytochemicals in betel leaf contributes towards unique qualitative features. Screening of metabolites is quintessential for identifying flavoring betel leaves and their origin. Metabolomics presently lays emphasis on the cumulative application of gas chromatography-mass spectrometry and nuclear magnetic resonance spectroscopic approaches. Here we adopted different protocols based on the above-mentioned analytical metabolomics platform for untargeted plant metabolite profiling followed by multivariate analysis methods and a phytochemical characterization of Piper betel leaf cultivars endemic to coastal Odisha, India. Based on variation in the solvent composition, concentration of solvent, extraction temperature, and incubation periods, five extraction methods were followed in GC-MS and NMR spectroscopy of betel leaf extracts. Phytochemical similarities and differences among the species were characterized through multivariate analysis approaches. Principal component analysis, based on the relative abundance of phytochemicals, indicated that the betel cultivars could be grouped into three groups. Our results of FTIR-, GC-MS-, and NMR-based profiling combined with multivariate analyses suggest that untargeted metabolomics can play a crucial role in documenting metabolic signatures of endemic betel leaf varieties.

Bioassay-guided isolation of potent α-glucosidase inhibitory compounds from the fruit of Piper mullesua Buch-Ham ex D Don. and their in silico screening

Two bioactive compounds caffeic and sinapic acid were isolated from the fruit of the Piper mullesua Buch-Ham ex D Don using bioassay guided approach. These compounds were isolated from water fraction using column chromatography followed by semi preparative HPLC. These compounds showed very potent anti-diabetic and antioxidant activities. The molecular docking was carried out to predict the mode of interaction of the isolated compounds with α-glucosidase. The in vitro α-glucosidase inhibitory activity of caffeic and sinapic acid was determined, and their IC₅₀ values were found 0.67 and 0.82 µg/ml, respectively. A QSAR equation was generated with an R² value of 84.81%, which is suitable enough for predicting the IC₅₀ values of test molecules. The aforementioned finding confirms the isolated compounds show very significant anti-diabetic potential which is supported by the molecular docking and QSAR study. So, it has ample scope for drug development with further in vivo and clinical study.

Neolignans from Piper betle Have Synergistic Activity against Antibiotic-Resistant Staphylococcus aureus

A phytochemical investigation of an extract of the leaves of Piper betle, guided by a synergistic antibacterial screen, led to the isolation and structural elucidation of 10 new neolignans, Pibeneolignan A-J (1-10), together with 11 known compounds. The structures and absolute configurations of the new compounds were elucidated on the basis of spectroscopic data, single-crystal X-ray diffraction analysis, and experimental and calculated ECD investigations. Compounds 1 and 2 are new naturally occurring neolignan skeletons, based on the cyclohept-2-ene-1,4-dione framework. We propose that these natural products are biosynthetically formed from bicyclic [3.2.1] neolignans by oxidative cleavage and ring opening at C-1' and C-2'. Among these compounds, 9, 13, 15, and 16, in combination with norfloxacin against an effluxing S. aureus strain (SA1199B), exhibited significant synergistic activity with fractional inhibitory concentration indices (FICIs) of 0.078, 0.156, 0.125, and 0.25, respectively. Bacterial growth curves, ethidium bromide (EtBr) efflux, and qRt-PCR were further employed to verify their synergistic antibacterial mechanism. Furthermore, computational molecular modeling suggested the binding of compounds 14-17 and 19 to the active site of the modeled structure of the NorA efflux pump, which is the main efflux pump in SA1199B.