Amides with anti-platelet aggregation activity from Piper taiwanense

Feasibility of Applying Untargeted Metabolomics with GC-Orbitrap-HRMS and Chemometrics for Authentication of Black Pepper (Piper nigrum L.) and Identification of Geographical and Processing Markers

Black pepper is one of the most consumed spices all over the world. Due to its high demand and nutritional value, a metabolomics approach based on GC-Orbitrap-HRMS fingerprinting and chemometrics was applied to assess its geographical traceability and processing authenticity. GC-HRMS-based fingerprints were obtained using a simple ultrasound-assisted extraction method, which may be easily implemented in routine activities of quality control. Unsupervised methods, such as principal component analysis (PCA), were performed for sample overview according to the investigated origins (Brazil, Vietnam, and Sri Lanka) and processing (sterilized vs nonsterilized samples). Further orthogonal partial least squares discriminant analysis (OPLS-DA) models were validated by cross- and external validation, providing satisfactory performance for geographical and processing authentication, as well as excellent predictive ability for further samples. Furthermore, reliable putative identification of 12 key metabolites (markers) was performed, highlighting the feasibility of combining untargeted GC-HRMS analysis with chemometrics for quality control of black pepper.

New Tyramine- and Aporphine-Type Alkamides with NO Release Inhibitory Activities from Piper puberulum

Three new tyramine-type alkamides (1-3), three new natural products (4-6), five new N-acylated/formylated aporphine alkamides with different ratios of rotational isomers (7-11), and 20 known alkamides (12-31) were isolated from an EtOH extract of the stems and leaves of Piper puberulum. The absolute configurations of compounds 7, 8, and 10 were determined by single-crystal X-ray diffraction analysis. In the biological activity assay, compounds 3, 5, and 10-23 displayed inhibitory effects against lipopolysaccharide-induced NO release in BV-2 microglial cells, exhibiting IC₅₀ values of 0.93-45 μM.

Peppers: A "Hot" Natural Source for Antitumor Compounds

Piper, Capsicum, and Pimenta are the main genera of peppers consumed worldwide. The traditional use of peppers by either ancient civilizations or modern societies has raised interest in their biological applications, including cytotoxic and antiproliferative effects. Cellular responses upon treatment with isolated pepper-derived compounds involve mechanisms of cell death, especially through proapoptotic stimuli in tumorigenic cells. In this review, we highlight naturally occurring secondary metabolites of peppers with cytotoxic effects on cancer cell lines. Available mechanisms of cell death, as well as the development of analogues, are also discussed.

1 H and 13 C NMR data, occurrence, biosynthesis, and biological activity of Piper amides

Alkamides are the major and characteristic chemical compounds of the plants belonging to the Piper genus. These compounds are responsible for the flavor of pepper spices and for its broad use in cuisine across many regions of the world. Humans are in contact every day with these substances, which additionally show a broad variety of pharmacological activities, making them an important research target. A large amount of NMR data for these natural products is dispersed throughout literature. Its organization will help those research groups interested in their identification and structural elucidation. This review summarizes the ¹ H and ¹³ C NMR data of 268 Piper amides in a systematic and orderly way, with a discussion on their biological activities, biosynthetic aspects, and NMR analysis of typical and relevant aspects of this information.

A Survey of the Chemical Compounds of Piper spp. (Piperaceae) and Their Biological Activities

The genus Piper is one of the largest genera in the Piperaceae, with most species widely distributed globally, covering all continents. To date, many Piper species have been scientifically investigated for their chemical diversities and interesting broad spectrum of bioactivities, including central nervous system (CNS), pesticidal, antifungal and antibacterial effects. This review systematically summarizes the scaffolds of the alkaloids reported, the major chemicals isolated from Piper spp., and their biological activities. Besides the alkaloids, some neolignans with rearranged skeletons show structural diversities, while the chalcones, flavonoids and kava-pyrones have some potential activities. Herein, the sesquiterpenes and phenolic compounds from Piper species and their bioactivities are also surveyed.

Neolignans and phenylpropanoids from the roots of Piper taiwanense and their antiplatelet and antitubercular activities

Bioassay-guided fractionation of roots from Piper taiwanense led to isolation of three neolignans, diallylcatechol (1) and neotaiwanensols A, B (2, 3), two diphenylpropanoid ethers, taiwandimerols A, B (4, 5), with one phenylpropanoid, 2,3-diacetoxy-1-methoxy-5-allylbenzene (6), previously unknown in nature, together with 18 known compounds (7-24). Their structures were elucidated by spectroscopic evidence. Among the isolates, hydroxychavicol acetate (7), and 4-allylcatechol (8) showed potent inhibitory activities against platelet aggregation induced by collagen, with IC50 values of 2.1, and 5.3 μM, respectively. Hydroxychavicol acetate (7), 4-allylcatechol (8), and trans-caffeicaldehyde (9) showed antitubercular activities against Mycobacterium tuberculosis H37Rv, with MIC values of 30.3, 27.6, and 25.5 μg/mL, respectively.

Platelet-activating factor (PAF)-antagonists of natural origin

Presently herbal medicines are being used by about 80% of the world population for primary health care as they stood the test of time for their safety, efficacy, cultural acceptability and lesser side effects. The discovery of platelet activating factor antagonists (PAF antagonists) during these decades are going on with different framework, but the researchers led their efficiency in studying in vitro test models. Since it is assumed that PAF play a central role in etiology of many diseases in humans such as asthma, neuronal damage, migraine, cardiac diseases, inflammatory, headache etc. Present days instinctively occurring PAF antagonist exists as a specific grade of therapeutic agents for the humans against these and different diseases either laid hold of immunological or non-immunological types. Ginkgolide, cedrol and many other natural PAF antagonists such as andrographolide, α-bulnesene, cinchonine, piperine, kadsurenone, different Piper species' natural products and marine origin plants extracts or even crude drugs having PAF antagonist properties are being used currently against different inflammatory pathologies. This review is an attempt to summarize the data on PAF and action of natural PAF antagonists on it, which were evaluated by in vivo and in vitro assays.

Simultaneous determination of ten active components in 12 Chinese Piper species by HPLC

Piper is a genus that is recently valued for the treatment of central nervous system diseases. The major constituents, amides and lignans, are responsible for the antinociceptive and antidepressant activities. This study developed a RP-HPLC-UV method for the simultaneous determination of eight amides and two lignans in twelve different species of Piper. HPLC separation was accomplished on a C18 analytical column (5 μm, 250 mm × 4.6 mm, i.d.) with a gradient mobile phase consisting of acetonitrile and water at a flow rate of 1.0 ml/min. All the calibration curves showed good linear correlation coefficients (r > 0.9997) over the test ranges. The relative standard deviation of the current method was less than 2.90% for intra- and inter-day assays and the average recoveries were between 98.25% and 103.08%. The HPLC method established is appropriate for quality control purposes and allows for the differentiation of Piper species.