Serhat Sezai Çiçek

The dried herb of blue fenugreek is used as a spice in the alpine region for the preparation of traditional bread and cheese. After drying, the herb is stored for a period of six to twelve months. During this time, the herb is expected to undergo changes in the compositions of the major flavor- and odor-determining compounds. To identify eventual biochemical processes, we applied different growing (conventional and sterile) and drying (air- and freeze drying) conditions and subsequently conducted periodical analysis of key aroma constituents (α-keto acids and volatile compounds) by LC-MS and GC-MS. The amount of glyoxylic acid was drastically increased in the air-dried sample, while the freeze-dried sample showed significantly higher amounts of α-keto-glutaric acid and pyruvic acid, respectively. During storage, a decrease in sulfuric compounds and an increase in alkane aldehydes were observed when comparing conventional and sterile samples. However, this increase was even greater for monoterpenes (especially camphor and p-cymene), showing thrice as high amounts after storage. Interestingly, both compounds were only formed significantly during the storage under conventional conditions, indicating that their production is induced/caused by microbial organisms.

Objectives: Multiple myeloma and acute myeloid leukemia are severe forms of blood cancer, which lack effective therapies for treatment. In our search for new chemical lead structures from nature, we were investigating the Brazilian medicinal plant arnica-do-cerrado (Lychnophora ericoides). Methods: Repeated chromatography led to the isolation of four flavonoids and three sesquiterpenoids, which were evaluated for their cytostatic and cytotoxic properties against HL-60, MOLM-13, AMO-1, and KMS-12 PE cancer cells as well as the non-malignant HS-5 cell line. Results: Whereas the isolated flavonoids displayed only moderate activity, the three sesquiterpene lactones goyazensolide, centratherin, and lychnopholide exhibited pronounced effects against all four tested cell lines. Goyazensolide was the most effective compound, inhibiting proliferation and metabolic activity with IC₅₀ values between 1.0 and 1.6 µM, as well as 1.0 to 2.0 µM, respectively. Centratherin and lychnopholide were somewhat less active but showed higher selectivity towards malignant cell lines, which was most pronounced for MOLM-13 cells. Conclusion: The results of this study revealed interesting natural products that will be further evaluated for their potential as new lead compounds for the treatment of acute myeloid leukemia and multiple myeloma.

Novel antiretroviral drugs are constantly needed for human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) patients to confront the continuously emerging resistance to the commonly prescribed combination of anti-HIV synthetic agents and their side effects. Amazonian medicinal plants, Licania macrophylla (LM) (Chrysobalanaceae) and Ouratea hexasperma (OH) (Ochnaceae), were assayed for antiretroviral and immunomodulatory activity, by utilizing an established human leukocyte cell line and the simian immunodeficiency virus (SIV). Interleukin (IL)-4, IL-6, IL-8, IL-10, and interferon-gamma were quantified after leukocyte culture was stimulated with ethanolic plant extracts and subsequently challenged with lentivirus infection. Mitotic activity induced by OH extract was significantly more pronounced than that of LM extract. Cytokine modulation was observed in SIV-infected cells under independent treatment with OH and LM extracts. Betulinic acid, niruriflavone, (-)-epigallocatechin, (-)-gallocatechin, and 4’-O-methyl-epigallocatechin were isolated from LM. In summary, the tested extracts hold application potential in the therapy of HIV/AIDS pathology by regulating cellular proliferative activity and cytokine levels, as the isolated compounds from these plants have been reported to exhibit antiviral activity.

Background: Novel antiretroviral drugs are in constant need for HIV/AIDS patients to face the continuous emerging resistance to the commonly prescribed combination of anti-HIV synthetic agents and their side effects. Methods: Amazonian medicinal plants, Licania macrophylla (Chrysobalanaceae) and Ouratea hexasperma (Ochnaceae) were assayed for antiretroviral and immunomodulatory activity, utilizing an established human leukocyte cell line and the Simian Immunodeficiency Virus. The IL-4, IL-6, IL-8, IL-10 and IFN-y cytokines were quantified after leukocyte culture stimulation with ethanolic plant extracts and challenged with lentivirus infection. Results: Mitotic activity induced by O. hexasperma extract was significatively more pronounced than L. macrophylla extract. Cytokine modulation was recorded in SIV infected cells under independent treatment with O. hexasperma and L. macrophylla extracts. Betulinic acid, ninuriflavone, (-)epigallocathechine, (-)gallocatechine and 4-O-methyl-epigallocatechin were isolated from L. macrophyla . Conclusions: Cellular proliferative activity and cytokine modulation by the extracts assayed have potential applications in the therapy of HIV/AIDS pathology, as the isolated compounds of these plants have been reported for antiviral activity.

The roots of Salvia miltiorrhiza are the source of the traditional Chinese medicine danshen and the class of tanshinones, particular quinoid nor-diterpenoids of the abietane type. Of these compounds, cryptotanshinone, dihydrotanshinone I, tanshinone I, and tanshinone IIA, have been extensively studied for their anticancer potential, not only but as well because of their high abundance in S. miltiorrhiza and their thus easy availability. However, also additional Salvia species are known to contain tanshinones, mainly such of the subgenus Glutinaria, of which S. glutinosa is the only species widely occurring in Europe. Using UHPLC-DAD-MS, the tanshinone profile of S. glutinosa roots collected from two different locations was compared to the profile in S. miltiorrhiza roots. In addition, tanshinone IIA and another six diterpenoids from S. glutinosa were investigated for their antiproliferative and cytotoxic potential against MDA-MB-231 and HL-60 cells. Apart from dihydrotanshinone I, which has been previously characterized due to its anticancer properties, we determined danshenol A as a highly antiproliferative and cytotoxic agent, significantly surpassing the effects of dihydrotanshinone I. With regard to the diterpenoid profile, S. miltiorrhiza showed a higher concentration for most of the tanshinones, except for (+)-danshexinkun A, which was present in comparable amounts in both species. Danshenol A, in contrast, was only present in S. glutinosa as were dehydroabietic acid and (+)-pisiferic acid. The results of our study underlines the long traditional use of danshen due to its high amount on tanshinones, but also demonstrates the potential value of investigating closely related species for the discovery of new biologically active lead compounds.

Chanterelles are one of the most highly valued wild edible mushroom genera worldwide. This work aimed to investigate the nutritional characteristics and volatile compounds’ profile of Cantharellus alborufescens for the first time. Proximate analysis was performed according to the Association of Official Agricultural Chemists, while the mineral contents and the volatile compounds were determined using ICP-MS and GC-MS, respectively. C. alborufescens had an average of 25.8% protein, 5.5% fat, 12.7% ash, and 55.9% carbohydrates, including 11.4% fiber per dw of mushroom. Further analyses of the fat and protein contents revealed high amounts of polyunsaturated fatty acids as well as monosodium glutamate-like amino acids. Linoleic acid (42.0% of fat) and oleic acid (28.6% of fat) were the major fatty acids, while leucine (1.2%) and lysine (0.9%) were the most abundant essential amino acids. The results showed that C. alborufescens contained 3.1 µg/g vitamin D2 and 4.9 mg/g vitamin E per dw, as well as notable quantities of macro- and microelements, such as potassium, calcium, magnesium, and iron. GC-MS analysis revealed various volatile compounds such as acetaldehyde, n-hexanal, 3-methylbutanal, 1-octen-3-ol, etc. In conclusion, this study supports the use of C. alborufescens as a food rich in fiber and vitamin E, with a suitable amount of protein and other nutrients.

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the major causes for nosocomial infections and has been classified as “high priority pathogen” by the World Health Organization. Its ability to develop resistances has been a challenge for the last decades and is still a threat to health care systems, as strains with resistances to the so-called drugs of last resort have been discovered. Therefore, new antibiotics are urgently needed. Natural products are an important source for the development of new drugs, thereby mostly serving as lead compounds for further modification. In this review, the data on plant natural products with reported anti-MRSA activity until the end of 2022 is discussed, highlighting the most effective drugs with respect to their inhibitory concentrations as well as with regard to eventual synergistic effects with existing antibiotics. In the latter sense, the class of alkaloids must be mentioned, exhibiting additive or synergistic effects by inhibiting bacterial efflux pumps. With regard to the antibiotic activity, phloroglucinol derivatives certainly belong to the most promising compounds, revealing several candidates with remarkable effects, e.g., lupulone, ivesinol, rhodomyrtone, aspidinol, or hyperforin. Also, the class of terpenoids yielded noteworthy compounds, such as the sesquiterpene lactones parthenolide and lactopicrin as well as acetophenone sesquiterpenes and sphaerodiene type diterpenoids, respectively. In addition, pronounced effects were observed for the macrolide neurymenolide A and three flavonol dicoumaroylrhamnosides.

Zusammenfassung: Momordica charantia L. (Cucurbitaceae), allgemein bekannt als Bittergurke oder Bittermelone, weist eine lange Geschichte in der Behandlung von Diabetes und dessen Komplikationen auf. Über ihre antidiabetische Wirkung und ihre positive Wirkung auf den Blutzucker und die Lipidkonzentration wurde in zahlreichen In-vitro- und In-vivo-Studien berichtet, die für die beobachteten Auswirkungen verantwortlichen Substanzen sind indes noch nicht hinreichend beschrieben. In den letzten Jahren konzentrierte sich die Forschung immer mehr auf die besonderen Triterpenoide vom Cucurbitan-Typ, die in den Früchten und anderen Teilen der Pflanze reichlich vorhanden sind. Die vorliegende Arbeit fasst die antidiabetische Wirkung der sogenannten Momordicoside zusammen und erörtert ihre Verwendung in kommerziellen Präparaten.

The herb of Trigonella caerulea (Fabaceae), commonly known as blue fenugreek, is used for the production of traditional cheese and bread varieties in the Alpine region. Despite its frequent consumption, only one study so far has focused on the constituent pattern of blue fenugreek, revealing qualitative information on some flavor-determining constituents. However, with regard to the volatile constituents present in the herb, the applied methods were insufficient and did not take relevant terpenoids into account. In the present study, we analyzed the phytochemical composition of T. caerulea herb applying a set of analytical methods, such as headspace-GC, GC-MS, LC-MS, and NMR spectroscopy. We thus determined the most dominant primary and specialized metabolites and assessed the fatty acid profile as well as the amounts of taste-relevant α-keto acids. In addition, eleven volatiles were quantified, of which tiglic aldehyde, phenylacetaldehyde, methyl benzoate, n-hexanal, and trans-menthone were identified as most significantly contributing to the aroma of blue fenugreek. Moreover, pinitol was found accumulated in the herb, whereas preparative works led to the isolation of six flavonol glycosides. Hence, our study shows a detailed analysis of the phytochemical profile of blue fenugreek and provides an explanation for its characteristic aroma and its health-beneficial effects.