Lycophlegmariols A-D: cytotoxic serratene triterpenoids from the club moss Lycopodium phlegmaria L

Dihydrocaffeic Acid-Is It the Less Known but Equally Valuable Phenolic Acid?

Dihydrocaffeic acid (DHCA) is a phenolic acid bearing a catechol ring and three-carbon side chain. Despite its being found in minor amounts in numerous plants and fungi of different origins, it has attracted the interest of various research groups in many fields of science, from food to biomedical applications. The review article presented herein aims to show a wider audience the health benefits and therapeutic, industrial, and nutritional potential of dihydrocaffeic acid, by sheddinglight on its occurrence, biosynthesis, bioavailability, and metabolism. The scientific literature describes at least 70 different derivatives of dihydrocaffeic acid, both those occurring naturally and those obtained via chemical and enzymatic methods. Among the most frequently used enzymes that were applied for the modification of the parent DHCA structure, there are lipases that allow for obtaining esters and phenolidips, tyrosinases used for the formation of the catechol ring, and laccases to functionalize this phenolic acid. In many studies, both in vitro and in vivo, the protective effect of DHCA and its derivatives on cells subjected to oxidative stress and inflammation were acknowledged.

Abietane diterpenoids from Phlegmariurus carinatus and their biological activities

Five undescribed abietane diterpenoids, along with eight known analogs, were isolated from Phlegmariurus carinatus. Their structures were unambiguously elucidated by extensive analysis of spectroscopic data and comparison between the literature. The absolute configuration of phlecarinatone C was determined by evaluating ECD spectra. Four undescribed abietane diterpenoids and eight known analogs were tested for their neuroprotective and cytotoxic activities, separately. Teuvincenone C showed potential neuroprotective effect against Hemin-induced HT22 cell damage. Importantly, phlecarinatone C showed pronounced cytotoxic effect against U251 cells in vitro assays. The biological evaluation revealed that phlecarinatone C could inhibit proliferation, migration, and invasion in a concentration-dependent manner of U251 cells. Meanwhile, phlecarinatone C effectively reversed epithelial-to-mesenchymal transition (EMT) and promoted U251 cells apoptosis via a mitochondrial apoptotic pathway. Taken together, phlecarinatone C might be a valuable candidate for anti-metastatic agents against glioblastoma treatment.

Phlegmacaritones A and B, a Pair of Serratane-Related Triterpenoid Epimers with an Unprecedented Carbon Skeleton from Phlegmariurus carinatus

A pair of novel serratane-related triterpenoid epimers, phlegmacaritones A (1) and B (2), possessing an unprecedented 15,30-lactone-14,15-seco skeleton, six new serratane-type triterpenoids, phlegmanols G-L (3-5 and 14-16), and 16 known compounds were isolated from the whole plant of Phlegmariurus carinatus. The structures of the new metabolites were established on the basis of comprehensive spectroscopic data analysis and electronic circular dichroism calculations. A possible biosynthetic pathway for phlegmacaritones A (1) and B (2) was proposed. All compounds were submitted to cytological profiling on a cell line derived from a patient with Parkinson's disease. Phlegmacaritone B (2) induced a distinct phenotypic profile with alterations in α-tubulin, mitochondria, and autophagosomal and early endosomal features.

Two new nor-lignans, siamensinols A and B, from Selaginella siamensis Hieron. and their biological activities

Two new nor-lignans siamensinols A-B (1-2) and seven known compounds agatharesinol (3), syringaresinol-glucoside (4), noreugenin (5), 8-methyleugenitol (6), melachromone (7), uncinoside A (8) and daucosterol (9) were isolated from Selaginella siamensis Hieron. The structures of the new compounds were elucidated on the basis of comprehensive spectroscopic methods, including 1 D, 2 D-NMR, HR-ESI-MS and CD spectrometry. Compounds 1-2 showed moderate inhibitory effect on MOLT-3 cells while 8-methyleugenitol (6) exhibited moderate inhibitory effect on three tumor cells (HepG2, A549 and HuCCA-1). Compounds 2-3 showed the potent cancer chemoprevention in DPPH, XXO, IXO and AIA assays.

Two New Abietane Diterpenoids from Selaginella moellendorffii Hieron

Two new abietane diterpenoids, (3S,5R,10S)-3-hydroxy-12-O-demethyl-11-deoxy-19(4→3)-abeo-cryptojaponol, 12,19-dihydroxyabieta-8,11,13-trien-7-one, were isolated from Selaginella moellendorffii Hieron., together with one known abietane diterpenoid and four known tetracyclic triterpenoids. Their structures were characterized by their 1D- and 2D-NMR, ECD and mass spectral studies. All compounds were tested for their inhibitory effects on proliferation of three human cancer cells (human non-small-cell lung carcinoma cell lines A549 and human breast adenocarcinoma cell lines MDA-MB-231 and MCF-7) in vitro. Among them, three compounds displayed modest cytotoxic activities against the above three human cancer cell lines with IC₅₀ values ranging from 16.28 to 40.67 μM.

Vascular Epiphytic Medicinal Plants as Sources of Therapeutic Agents: Their Ethnopharmacological Uses, Chemical Composition, and Biological Activities

This is an extensive review on epiphytic plants that have been used traditionally as medicines. It provides information on 185 epiphytes and their traditional medicinal uses, regions where Indigenous people use the plants, parts of the plants used as medicines and their preparation, and their reported phytochemical properties and pharmacological properties aligned with their traditional uses. These epiphytic medicinal plants are able to produce a range of secondary metabolites, including alkaloids, and a total of 842 phytochemicals have been identified to date. As many as 71 epiphytic medicinal plants were studied for their biological activities, showing promising pharmacological activities, including as anti-inflammatory, antimicrobial, and anticancer agents. There are several species that were not investigated for their activities and are worthy of exploration. These epipythes have the potential to furnish drug lead compounds, especially for treating cancers, and thus warrant indepth investigations.

Role of Pentacyclic Triterpenoids in Chemoprevention and Anticancer Treatment: An Overview on Targets and Underling Mechanisms

The incidences of cancer are continuously increasing worldwide, affecting life of millions of people. Several factors associated with the internal and external environment are responsible for this deadly disease. The key internal determinants like abnormal hormonal regulation, genetic mutations and external determinants such as lifestyle and occupational factors enhances onset of cancer. From the ancient time, plants were remained as the most trusted source of medicine for the treatment of diverse disease conditions. Extensive studies have been performed for the discovery of effective anticancer agent from the plant and still it is going on. Pentacyclic triterpenoids are biologically active phytochemicals having a different range of activities such as anti-inflammatory, hepatoprotective, anti-hypertensive, antiulcerogenic and anti-tumor. These compounds generally contain ursane, oleanane, lupane and friedelane as a chief skeleton of pentacyclic triterpenoids which are generally present in higher plants. Isoprene unit, phytochemical, with good antitumor/anticancer activity is required for the biosynthesis of pentacyclic triterpenoids. Mechanisms such as cytotoxicity, DNA polymerase inhibition, regulation of apoptosis, change in signal transductions, interfere with angiogenesis and dedifferentiation, antiproliferative activity and metastasis inhibition are might be responsible for their anticancer effect. Present review spotlights diverse targets, mechanisms and pathways of pentacyclic triterpenoids responsible for anticancer effect.

Serratene triterpenoids and their biological activities from Lycopodiaceae plants

The plants of Lycopodiaceae family, distributed across China, India and also Southeast Asia, have been used as folk medicines. The phytochemical constitutent studies of this family was widely reported. Serratene trierpenoids is one of phytochemical constitutent type, which have been mainly isolated from this plant family. To date, more than 100 serratene-type triterpenoids have been reported and several of them have been shown promising biological activities, especially cytotoxicity and chemopreventive activity. This review covers the structural classification, biological activities and hypotheses about biosynthetic pathways of serratene-type triterpenes.

Huperphlegmines A and B, two novel Lycopodium alkaloids with an unprecedented skeleton from Huperzia phlegmaria, and their acetylcholinesterase inhibitory activities

Two novel Lycopodium alkaloids, huperphlegmines A and B (1 and 2), were isolated from the aerial parts of Huperzia phlegmaria collected in Vietnam, together with the five known compounds lycophlegmariol A (3), phlegmariurine B (4), 5-hydroxymethyl-2-furaldehyde (5), rhemanone C (6), and loliolide (7). The chemical structures of the present compounds were elucidated by means of 1D and 2D NMR and HRESIMS spectroscopy, and by comparisons to the reported data in the literature. Compounds 1 and 2 showed moderate acetylcholinesterase inhibitory activities, with IC₅₀ values of 25.95 ± 0.67 and 29.14 ± 0.77 μg/mL, respectively.

Phytochemicals from fern species: potential for medicine applications

Ferns are an important phytogenetic bridge between lower and higher plants. Historically they have been used in many ways by humans, including as ornamental plants, domestic utensils, foods, and in handicrafts. In addition, they have found uses as medicinal herbs. Ferns produce a wide array of secondary metabolites endowed with different bioactivities that could potentially be useful in the treatment of many diseases. However, there is currently relatively little information in the literature on the phytochemicals present in ferns and their pharmacological applications, and the most recent review of the literature on the occurrence, chemotaxonomy and physiological activity of fern secondary metabolites was published over 20 years ago, by Soeder (Bot Rev 51:442-536, 1985). Here, we provide an updated review of this field, covering recent findings concerning the bioactive phytochemicals and pharmacology of fern species.

Chemical Constituents of Plants from the Genus Phlegmariurus

Phlegmariurus is a genus of ca. 200 species in the family Huperziaceae. Up to now, six species of the Phlegmariurus genus have been chemically investigated, and 89 compounds, including Lycopodium alkaloids possessing diverse structures and serratane-type triterpenes, have been isolated. These compounds show potent bioactivities, such as acetylcholinesterase inhibitory and cytotoxic activities.

Triterpenoids

This review covers the isolation and structure determination of triterpenoids reported during 2012 including squalene derivatives, lanostanes, holostanes, cycloartanes, cucurbitanes, dammaranes, euphanes, tirucallanes, tetranortriterpenoids, quassinoids, lupanes, oleananes, friedelanes, ursanes, hopanes, serratanes, isomalabaricanes and saponins; 348 references are cited.