Novel Approaches for the Analysis and Isolation of Benzylisoquinoline Alkaloids in Chelidonium majus.

Benzylisoquinoline alkaloids are the major bioactive components in Chelidonium majus, a plant that has a long usage history for the treatment of gastrointestinal ailments in European and Asian phytomedicine. This study reports on the development and application of a supercritical fluid chromatography technique for the simultaneous qualitative and quantitative determination of seven benzylisoquinoline alkaloids in under six minutes using a Viridis BEH 2-EP column and a modifier comprising methanol with 30% acetonitrile and 20 mM ammonium formate. The method was fully validated according to ICH guidelines showing, e.g., excellent linearity (≥ 0.9997) and maximum deviations for intraday and inter-day precision of 2.99 and 2.76%, respectively. The new supercritical fluid chromatography assay was not only employed for the analysis of several C. majus samples but was also used for the subsequent development of a fast centrifugal partition chromatography technique, whereby five benzylisoquinoline alkaloids could be isolated within approximately 2.5 h, with only two of them, protopine and chelidonine, requiring an additional purification step. To achieve this, a solvent system composed of chloroform/methanol/0.3 M hydrochloric acid was used in descending mode. By injecting 500 mg of crude extract, stylopine (1.93 mg), sanguinarine (0.57 mg), chelidonine (1.29 mg), protopine (1.95 mg), and coptisine (7.13 mg) could be obtained. The purity of compounds was confirmed by supercritical fluid chromatography and MS.

Isolation and Structure Elucidation of Novel Mycosporine-like Amino Acids from the Two Intertidal Red Macroalgae Bostrychia scorpioides and Catenella caespitosa.

This study presents a phytochemical survey of two common intertidal red algal species, Bostrychia scorpioides and Catenella caespitosa, regarding their MAA (mycosporine-like amino acid) composition, which are known as biogenic sunscreen compounds. Six novel MAAs from Bostrychia scorpioides named bostrychines and two novel MAAs from Catenella caespitosa named catenellines were isolated using a protocol which included silica gel column chromatography, flash chromatography on reversed phase material and semipreparative HPLC (High-Performance Liquid Chromatography). The structure of the novel MAAs was elucidated using NMR (Nuclear Magnetic Resonance) and HR-MS (High-Resolution Mass Spectrometry), and their absolute configuration was confirmed by ECD (Electronic Circular Dichroism). All isolated MAAs possess a cyclohexenimine scaffold, and the metabolites from B. scorpioides are related to the known MAAs bostrychines A-F, which contain glutamine, glutamic acid and/or threonine in their side chains. The new MAAs from C. caespitosa contain taurine, an amino sulfonic acid that is also present in another MAA isolated from this species, namely, catenelline. Previous and new data confirm that intertidal red algae are chemically rich in MAAs, which explains their high tolerance against biologically harmful ultraviolet radiation.

A convenient separation strategy for fungal anthraquinones by centrifugal partition chromatography.

As recently shown, some fungal pigments exhibit significant photoactivity turning them into promising agents for the photodynamic treatment of microbial infections or malignant diseases. In the present study, a separation strategy for fungal anthraquinones was developed based on centrifugal partition chromatography. A suitable method was explored employing a methanolic extract of the fruiting bodies of Cortinarius sanguineus (Agaricales, Basidiomycota). An excellent fractionation was achieved using a biphasic solvent system comprising chloroform/ethyl acetate/methanol/water/acetic acid (3:1:3:2:1, v/v/v/v/v) operating in ascending mode. Experiments on an analytical scale with extracts of closely related Cortinarius species exhibited broad applicability of the devised system. Up to six pigments could be purified directly from the crude extract. Preparative-scale fractionation of the methanol extracts of C. malicorius and C. sanguineus demonstrated that up-scaling was possible without compromising selectivity.

Fast and Efficient Separation of Eleven Mycosporine-like Amino Acids by UHPLC-DAD and Their Quantification in Diverse Red Algae.

Due to their hostile habitats, characterized by a high exposure to UV-A and UV-B radiation, red algae are known to synthesize unique secondary metabolites: mycosporine-like amino acids (MAAs). These small molecules possess an extremely high UV absorption capacity and therefore mainly act as photoprotective agents. In this study, the first ultrahigh-performance liquid chromatography (UHPLC) method with diode-array detection (DAD) was developed for the determination of eleven MAAs in various algal species. All of the analytes could be separated in under 8 min on a Phenomenex Luna Omega C18 1.6 µm column. The mobile phase comprised water with 0.25% formic acid and 20 mM ammonium formate (A) and acetonitrile (B). Elution was carried out in gradient mode. Method validation following ICH guidelines confirmed excellent linearity (R2 ≥ 0.9998), selectivity, precision and accuracy (from 97.41 to 103.38%) for all analytes. The assay's LOD was always 0.01 µg/mL; its LOQ was not higher than 0.04 µg/mL. Practical applicability was assured by analyzing several algae (e.g., Gracilaria chilensis, Pyropia plicata) using the developed method, and results indicated a high variation in MAA profiles as well as content. Whilst some MAAs were only found in specific samples, shinorine, which was always present, occurred in concentrations from 0.05 to 4.14 mg/g of dried biomass. As UHPLC-MS was also feasible, this method showed high flexibility concerning the detection mode, surpassing established procedures for MAA analysis not only concerning separation efficiency and analysis time.

Efficient Isolation of Mycosporine-Like Amino Acids from Marine Red Algae by Fast Centrifugal Partition Chromatography.

Marine rhodophyta are known to synthesize specific secondary metabolites, mycosporine-like amino acids (MAAs), to protect themselves from harmful UV-radiation. Shinorine and porphyra-334 are among the most abundant representatives of this compound class. In the present work, a novel approach for their isolation is described. As a first step, a fast centrifugal partition chromatography method, with an aqueous two-phase system comprising water, ethanol, ammonium sulfate and methanol in ascending mode, was developed to isolate the two MAAs from crude aqueous-methanolic extracts of three algal species within 90 min. The compounds could be isolated when just one of them was present in a sample or also both at the same time. By employing solid phase extraction as a second purification step, the individual MAAs were obtained in high purity and good quantity within a much shorter time frame than the established purification protocols, e.g., semi-preparative HPLC. For example, from 4 g Porphyra sp. (Nori) crude extract, 15.7 mg shinorine and 36.2 mg porphyra-334 were isolated. Both were highly pure, as confirmed by TLC, HPLC-MS and NMR analyses.

Analysis of the Mycosporine-Like Amino Acid (MAA) Pattern of the Salt Marsh Red Alga Bostrychia scorpioides.

This study presents the validation of a high-performance liquid chromatography diode array detector (HPLC-DAD) method for the determination of different mycosporine-like amino acids (MAAs) in the red alga Bostrychia scorpioides. The investigated MAAs, named bostrychines, have only been found in this specific species so far. The developed HPLC-DAD method was successfully applied for the quantification of the major MAAs in Bostrychia scorpioides extracts, collected from four different countries in Europe showing only minor differences between the investigated samples. In the past, several Bostrychia spp. have been reported to include cryptic species, and in some cases such as B. calliptera, B. simpliciuscula, and B. moritziana, the polyphyly was supported by differences in their MAA composition. The uniformity in the MAA composition of the investigated B. scorpioides samples is in agreement with the reported monophyly of this Bostrychia sp.

Chemotaxonomic Study of Bostrychia spp. (Ceramiales, Rhodophyta) Based on Their Mycosporine-Like Amino Acid Content.

This study presents a chemotaxonomic investigation of the genus Bostrychia through the quantitation of the major mycosporine-like amino acids (MAAs). The presence of some cryptic species had been suggested in the B. moritziana/B. radicans complex and MAA-profiling in respective samples revealed different chemotypes within this species complex. Another possibly polyphyletic species is Bostrychia simpliciuscula; previous molecular phylogenetic analyses showed four genetic lineages within this species, one of which was recently distinguished as a new species. Phytochemical profiling of those samples used for DNA analyses revealed four different chemotypes, corresponding to the above four lineages and it supports the re-circumscription of the other three B. simpliciuscula lineages. Therefore, mycosporine-like amino acids are considered as suitable chemotaxonomic markers for the reassessment of the classification of B. simpliciuscula. The determination of the MAA patterns in these algae was possible after developing and validating a suitable high-performance liquid chromatography-diode array detector (HPLC-DAD) method.

Terpenoids from the Stems of Fissistigma polyanthoides and Their Anti-Inflammatory Activity.

Twelve new terpenoids (1-12) were isolated from the stems of Fissistigma polyanthoides, an anti-inflammatory medicinal plant traditionally used in Vietnam. Most of them (1-9) possess a sesquiterpenoid backbone (e.g., guaiane, germacrane, and cadinane) connected to a 2'-O-trans-cinnamoyl)-ß-d-glucopyranose moiety, which is rare in Nature. Among them, compounds 4 (5/8-fused ring) and 6 (spiran [4,5] ring) represent uncommonly rearranged sesquiterpenoids. Compounds 10-12 are a novel monoterpene and two megastigmane derivatives, respectively. The individual structures were elucidated by combining NMR and MS data, and their configuration was established in NOESY and ECD experiments. Compounds 1-9 were also examined for their potential to interact with nuclear factor-kappa B activator protein 1 (NF-κB/AP-1) signaling by using the myelomonocytic reporter cell line THP-1Blue-CD14. Compounds 1-5 showed dose-dependent inhibitory effects [IC50 13.7 µM (1) to 49.0 µM (5)] on lipopolysaccharide-stimulated cells. However, compounds 1 to 4 also negatively affected cell viability in the same concentration range, while compound 5 was less potently cytotoxic.

Mushroom Tyrosinase-Based Enzyme Inhibition Assays Are Not Suitable for Bioactivity-Guided Fractionation of Extracts.

Tyrosinase (Tyr) catalyzes the rate-limiting step of melanogenesis in human skin and is thus the main target for treating pigmentation disorders today. This has led to an increased research interest in Tyr inhibitors during the last decades, with a frequent focus on polyphenols. In the early stages of drug discovery, it is typical to avoid the high costs of human Tyr by using the more economic mushroom tyrosinase (mh-Tyr). Since some polyphenols are accepted as substrates by mh-Tyr, the present study aimed to more generally investigate this enzyme's specificity toward polyphenols and to discuss its significance in the context of bioactivity-guided fractionation. Mh-Tyr substrates can change the sample color during an inhibition assay, leading to unreliable inhibition constants or to the discontinuation of a bioactivity-guided fractionation campaign. A data set of 56 natural products was investigated and classified into assay interferers (AIs) and noninterferers, using a spectrophotometric and an LC-ESIHRMS assay. Based on these experimental findings, structure-activity relationships defining AIs were deduced and implemented into an in silico tool that will allow for rapid prescreening in the future. We anticipate that these results will aid in the search for new Tyr inhibitors and contribute to the understanding of this enzyme, as well as its optimal use in pharmacological research.

Chemical profiling of mycosporine-like amino acids in twenty-three red algal species.

Rhodophyta produce a variety of chemically different mycosporine-like amino acids (MAAs), compounds that are known as some of the strongest ultraviolet (UV) absorbing molecules in nature. Accordingly, they primarily act as photoprotectants against harmful levels of solar ultraviolet radiation in the UV-A and UV-B range. In order to get a deeper understanding of the chemical diversity of MAAs in red algae, pure standards of eleven mycosporine-like amino acids were isolated from three different species (Agarophyton chilense, Pyropia plicata and Champia novae-zelandiae) using various chromatographic methods. Their structures were confirmed by nuclear magnetic resonance and mass spectrometry. Four out of the eleven MAAs are reported for the first time in algae. In addition, a new high-performance liquid chromatography method was developed for the separation of all isolated MAAs and successfully applied for the analysis of twenty-three red algal species of marine origin. All of them contained MAAs, the most abundant compounds were shinorine, palythine, asterina-330 and porphyra-334. For some samples, the direct assignment of MAAs based on their UV spectra was not possible; therefore, the target analytes were enriched by a simple concentration step, followed by liquid chromatography-mass spectrometry analysis of the extracts. This approach enabled a deeper insight into the MAA pattern of red algae, indicating that not only the four dominant ones are synthesized but also many others, which were often described as unknown compounds in previous studies.

Bostrychines A-F, Six Novel Mycosporine-Like Amino-Acids and a Novel Betaine from the Red Alga Bostrychia scorpioides.

Various red algae have repeatedly been reported to produce a variety of UV-absorbing mycosporine-like amino acids (MAAs), compounds that are well-known as natural sun-screens, as well as a plethora of betaines, metabolites which contribute to the osmotic balance under salt stress. Among other Rhodophyta, Bostrychia scorpioides, which is thriving as epiphyte on salt marsh plants in Europe and hence experiences extreme environmental conditions such as desiccation, UV-stress and osmotic stress, has barely been investigated for its secondary metabolites. In the present study, seven mycosporine like-amino acids and two betaines were isolated from Bostrychia scorpioides using various chromatographic techniques. Their structures were confirmed by Nuclear Magnetic Resonance (NMR) spectroscopy and High Resolution Mass Spectrometry (HRMS). Six MAAs and one betaine were chemically characterized as new natural products.

Development and Validation of an HPLC Method for the Quantitative Analysis of Bromophenolic Compounds in the Red Alga Vertebrata lanosa.

Bromophenols are a class of compounds occurring in red algae that are thought to play a role in chemical protection; however, their exact function is still not fully known. In order to investigate their occurrence, pure standards of seven bromophenols were isolated from a methanolic extract of the epiphytic red alga Vertebrata lanosa collected in Brittany, France. The structures of all compounds were determined by NMR and MS. Among the isolated substances, one new natural product, namely, 2-amino-5-(3-(2,3-dibromo-4,5-dihydroxybenzyl)ureido)pentanoic acid was identified. An HPLC method for the separation of all isolated substances was developed using a Phenomenex C8(2) Luna column and a mobile phase comprising 0.05% trifluoroacetic acid in water and acetonitrile. Method validation showed that the applied procedure is selective, linear (R2 0.999), precise (intra-day ≤ 6.28%, inter-day ≤ 5.21%), and accurate (with maximum displacement values of 4.93% for the high spikes, 4.80% for the medium spikes, and 4.30% for the low spikes). For all standards limits of detection (LOD) were lower than 0.04 µg/mL and limits of quantification (LOQ) lower than 0.12 µg/mL. Subsequently, the method was applied to determine the bromophenol content in Vertebrata lanosa samples from varying sampling sites and collection years showing values between 0.678 and 0.005 mg/g dry weight for different bromophenols with significant variations between the sampling years. Bioactivity of seven isolated bromophenols was tested in agar diffusion tests against Staphylococcus aureus and Escherichia coli bacteria. Three compounds showed a small zone of inhibition against both test organisms at a concentration of 100 µg/mL.

Absolute Configuration of Mycosporine-Like Amino Acids, Their Wound Healing Properties and In Vitro Anti-Aging Effects.

Mycosporine-like amino acids (MAAs) are water-soluble metabolites, reported to exhibit strong UV-absorbing properties. They have been found in a wide range of marine organisms, especially those that are exposed to extreme levels of sunlight, to protect them against solar radiation. In the present study, the absolute configuration of 14 mycosporine-like-amino acids was determined by combining the results of electronic circular dichroism (ECD) experiments and that of advanced Marfey's method using LC-MS. The crystal structure of a shinorine hydrate was determined from single crystal X-ray diffraction data and its absolute configuration was established from anomalous-dispersion effects. Furthermore, the anti-aging and wound-healing properties of these metabolites were evaluated in three different assays namely the inhibition of collagenase, inhibition of advanced glycation end products (AGEs) and wound healing assay (scratch assay).

Polyols and UV-sunscreens in the Prasiola-clade (Trebouxiophyceae, Chlorophyta) as metabolites for stress response and chemotaxonomy.

In many regions of the world, aeroterrestrial green algae of the Trebouxiophyceae (Chlorophyta) represent very abundant soil microorganisms, and hence their taxonomy is crucial to investigate their physiological performance and ecological importance. Due to a lack in morphological features, taxonomic and phylogenetic studies of Trebouxiophycean algae can be a challenging task. Since chemotaxonomic markers could be a great assistance in this regard, 22 strains of aeroterrestrial Trebouxiophyceae were chemically screened for their polyol-patterns as well as for mycosporine-like amino acids (MAAs) in their aqueous extracts using RP-HPLC and LC-MS. d-sorbitol was exclusively detected in members of the Prasiolaceae family. The novel MAA prasiolin and a related compound ("prasiolin-like") were present in all investigated members of the Prasiola-clade, but missing in all other tested Trebouxiophyceae. While prasiolin could only be detected in field material directly after extraction, the "prasiolin-like" compound present in the other algae was fully converted into prasiolin after 24 h. These findings suggest d-sorbitol and prasiolin-like compounds are suitable chemotaxonomic markers for the Prasiolaceae and Prasiola-clade, respectively. Additional UV-exposure experiments with selected strains show that MAA formation and accumulation can be induced, supporting their role as UV-sunscreen.

Phytochemical and Analytical Characterization of Novel Sulfated Coumarins in the Marine Green Macroalga Dasycladus vermicularis (Scopoli) Krasser.

The siphonous green algae form a morphologically diverse group of marine macroalgae which include two sister orders (Bryopsidales and Dasycladales) which share a unique feature among other green algae as they are able to form large, differentiated thalli comprising of a single, giant tubular cell. Upon cell damage a cascade of protective mechanisms have evolved including the extrusion of sulfated metabolites which are involved in the formation of a rapid wound plug. In this study, we investigated the composition of sulfated metabolites in Dasycladus vermicularis (Dasycladales) which resulted in the isolation of two phenolic acids and four coumarins including two novel structures elucidated by nuclear magnetic resonance spectroscopy (NMR) as 5,8'-di-(6(6'),7(7')-tetrahydroxy-3-sulfoxy-3'-sulfoxycoumarin), a novel coumarin called dasycladin A and 7-hydroxycoumarin-3,6-disulfate, which was named dasycladin B. In addition, an analytical assay for the chromatographic quantification of those compounds was developed and performed on a reversed phase C-18 column. Method validation confirmed that the new assay shows good linearity (R² ≥ 0.9986), precision (intra-day R.S.D ≤ 3.71%, inter-day R.S.D ≤ 7.49%), and accuracy (recovery rates ranged from 104.06 to 97.45%). The analysis of several samples of Dasycladus vermicularis from different collection sites, water depths and seasons revealed differences in the coumarin contents, ranging between 0.26 to 1.61%.

Quantitative Determination of Lactones in Piper methysticum (Kava-Kava) by Supercritical Fluid Chromatography.

A fast and validated supercritical fluid chromatography method for the quantitative determination of major lactones in Piper methysticum, a plant used against nervous anxiety, stress, and restlessness, was developed. The baseline separation of dihydrokavain, demethoxyyangonin, kavain, yangonin, dihydromethysticin, and methysticin was possible in less than 4 min on an Aquity UPC2 BEH 1.7 µm column, in combination with a mobile phase comprising CO2 and methanol with diethylamine. The column temperature had a great impact on the results because only at 70 °C could kavain and yangonin be fully resolved. With correlation coefficients above 0.998, recovery rates between 95.9 and 104.1 % as well as limit of detection values below 1.5 ng on-column, the procedure fulfilled all validation requirements and was well suited for the quantitative analysis of commercial products containing P. methysticum root powder and/or extract. All of them contained the target analytes, however, the absolute content of lactones was quite variable. Accordingly, depending on the product, the total daily intake of lactones varied from 56 to 312 mg. Concerning speed, selectivity, and environmental friendly operation, this supercritical fluid chromatography approach surpasses all previously reported ones.

Isolation of Three Triterpene Saponins, Including Two New Oleanane Derivatives, from Soldanella alpina and Hydrophilic Interaction Liquid Chromatography-Evaporative Light Scattering Detection of these Three Saponins in Four Soldenella Species.

INTRODUCTION: The genus Soldanella is one of the few endemic to Europe. Some of its species have relevance in local traditional medicine. Earlier work has indicated the possible presence of saponins in S. alpina. OBJECTIVE: To investigate S. alpina and other related species for the occurrence of saponins. METHODS: Following sequential extraction with n-hexane, dichloromethane and ethyl acetate the subsequent methanolic extract of S. alpina roots was fractionated after solvent precipitation using fast centrifugal partition chromatography and column chromatography. Structures were elucidated by LC-MSn , high-resolution MS, hydrolysis experiments and one-dimensional (1D)- and two-dimensional (2D)-NMR. A hydrophilic interaction liquid chromatography method was developed to quantitate saponins in the leaves and roots of four Soldanella species. RESULTS: Three triterpene saponins, two of them new natural products, were isolated from S. alpina. Based on an epoxyoleanal aglycone substituted with four sugar units, they were analytically quantitated using a Kinetex 2.6 µm hydrophilic interaction liquid chromatography (HILIC) column together with a mobile phase comprising of ammonium acetate, water and acetonitrile. Method validation confirmed that the assay meets all requirements in respect to linearity, accuracy, sensitivity and precision. All four Soldanella species investigated contained the three saponins. The lowest total level of the three saponins (1.09%) was observed in S. montana leaves while the highest saponin content (5.14%) was determined in S. alpina roots. CONCLUSION: The detection of saponins within the genus Soldanella is an indication that further phytochemical examination of this genus may reveal more secondary metabolites of interest. Copyright © 2017 John Wiley & Sons, Ltd.

Prasiolin, a new UV-sunscreen compound in the terrestrial green macroalga Prasiola calophylla (Carmichael ex Greville) Kützing (Trebouxiophyceae, Chlorophyta).

MAIN CONCLUSION: We introduced a novel combination of chromatographic techniques for the purification and analysis of a new UV-sunscreen mycosporine-like amino acid (MAA) in the terrestrial green alga Prasiola calophylla. Prasiola calophylla (Carmichael ex Greville) Kützing (Trebouxiophyceae, Chlorophyta) is a typical member of terrestrial algal communities in temperate Europe, where it regularly experiences various stress conditions including strong diurnal and seasonal fluctuations in ultraviolet radiation (UVR). As a photoprotective mechanism Prasiola species and other related Trebouxiophycean taxa synthesize a mycosporine-like amino acid (MAA) as natural sunscreen whose chemical structure was unknown so far. In the present study a new methodological approach is described for the isolation, purification and structural elucidation of this novel sunscreen in P. calophylla. The new compound exhibits an absorption maximum at 324 nm (in the short ultraviolet-A), a molecular weight of 333 and a molecular extinction coefficient of 12.393 M(-1) cm(-1), and could be identified as N-[5,6 hydroxy-5(hydroxymethyl)-2-methoxy-3-oxo-1-cycohexen-1-yl] glutamic acid using one- and two-dimensional (1)H and (13)C-NMR spectroscopy. As trivial name for this novel MAA we suggest 'prasiolin'. The ecologically essential function of prasiolin for UVR-protection in terrestrial algae of the Trebouxiophyceae is discussed.

Fast and improved separation of major coumarins in Ammi visnaga (L.) Lam. by supercritical fluid chromatography.

The first supercritical fluid chromatography method for the determination of five major coumarins (dihydrosamidin, visnadin, samidin, khellin, and visnagin) in Ammi visnaga fruits is described. Their baseline separation was possible in less than 5 min by using a UPC2 HSS C18 SB column with 1.8 µm particle size and a mobile phase comprising CO2 , methanol, acetonitrile, and diethylamine. The type of stationary phase used was of particular relevance because, except for the selected one, the others did not resolve the two structural isomers dihydrosamidin and visnadin. Method validation confirmed that the procedure is linear (R2 ≥ 0.9996) in a concentration range from 6 to 480 µg/mL, it is accurate (recovery rates: 97.2-103.6%) and precise (intraday deviation ≤ 6.6%, intraday deviation ≤ 1.7%); injecting 1 µL of standard solution, the determined limit of detection was below 1.9 µg/mL for all compounds. The analysis of different A. visnaga samples revealed their similar compositions, and khellin (0.75-1.01%) and visnagin (0.18-0.46%) were the dominant coumarins. Visnadin and dihydrosamidin, the individual quantification of which is described for the first time, were present at concentrations below 0.14%.

Immunomodulatory Effects of the Mycosporine-Like Amino Acids Shinorine and Porphyra-334.

Mycosporine-like amino acids (MAAs) are secondary metabolites, produced by a large variety of microorganisms including algae, cyanobacteria, lichen and fungi. MAAs act as UV-absorbers and photo-protectants. MAAs are suggested to exert pharmaceutical relevant bioactivities in the human system. We particularly focused on their effect on defence and regulatory pathways that are active in inflamed environments. The MAAs shinorine and porphyra-334 were isolated and purified from the red algae Porphyra sp. using chromatographic methods. The effect of MAAs on central signaling cascades, such as transcription factor nuclear factor kappa b (NF-κB) activation, as well as tryptophan metabolism, was investigated in human myelomonocytic THP-1 and THP-1-Blue cells. Cells were exposed to the MAAs in the presence or absence of lipopolysaccharide (LPS). NF-κB activity and the activity of tryptophan degrading enzyme indoleamine 2,3-dioxygenase (IDO-1) were used as readout. Compounds were tested in the concentration range from 12.5 to 200 µg/mL. Both MAAs were able to induce NF-κB activity in unstimulated THP-1-Blue cells, whereby the increase was dose-dependent and more pronounced with shinorine treatment. While shinorine also slightly superinduced NF-κB in LPS-stimulated cells, porphyra-334 reduced NF-κB activity in this inflammatory background. Modulation of tryptophan metabolism was moderate, suppressive in stimulated cells with the lower treatment concentration of both MAAs and with the unstimulated cells upon porphyra-334 treatment. Inflammatory pathways are affected by MAAs, but despite the structural similarity, diverse effects were observed.