Anuchit Plubrukarn

The inhibition of steroid 5-alpha reductase (S5AR), a key mechanism for managing dihydrotestosterone-dependent conditions, has been demonstrated in teak (Tectona grandis L.f.) leaf extracts. Our recent clinical study confirmed the effectiveness of a hair growth formulation containing teak leaf extract in males with androgenic alopecia. However, significant variability in S5AR inhibitory activity among teak leaf samples from different regions underscores the need for quality control of raw materials. This study applied a metabolomics approach to investigate the influence of leaf age, harvesting period, and geographic origin on chemical composition and S5AR inhibitory activity, as well as to identify active S5AR inhibitors. Geographic origin emerged as the primary determinant of variations in chemical profiles and S5AR inhibitory activity. Using orthogonal partial least squares analysis, six diterpenoid S5AR inhibitors were identified, including four compounds reported for the first time as S5AR inhibitors: rhinocerotinoic acid, 7-oxo-8-labden-15-oic acid, 8-hydroxy-labd-13-en-15-oic acid, and a novel diterpene, 7-hydroxy-labd-8,13-dien-15-oic acid. These findings highlight the potential of metabolomics as a powerful tool for discovering bioactive compounds and optimizing raw material selection. By prioritizing proven geographic sources, consistent bioactivity can be achieved, supporting the therapeutic potential of teak leaves in managing S5AR-related conditions.

Matrix‐assisted laser desorption ionization‐time of flight imaging mass spectrometry (MALDI‐TOF IMS) is used to examine the deposition of trisoxazole macrolides in the tissues of the Penares nux sponge. IMS showed that kabiramides, the major trisoxazole macrolides in P. nux, were allocated preferentially in the external tissues of the sponge. The deposition covered the outer tissue layers from the pinadoderm through mesohyl and ectosome to the outer portion of the choanosome. The presence of each macrolide varied independently from one sponge specimen to others and showed no inductive or suppressive influences on each other compounds nor particular preferences on any specific cell types or tissues. The results provided new and additional evidence of the specificity of the sponge's toxic metabolite distribution at the tissue level. The outward distribution of the toxic macrolides in P. nux aligned with the optimal defense theory, and suggested that the sponge has evolved its chemical defensive mechanisms purposely for the best protection of the most vulnerable, newly generated branches of the colony.

Introduction: Diterpene lactones in Andrographis paniculata are essential bioactive compounds that contribute to the herb's medicinal properties. The main diterpene lactones in A. paniculata are andrographolide and its derivatives. Spontaneous degradation of the diterpene leads to a short‐term stability and casts a significant problem in storage and distribution of A. paniculata raw materials and products. Objective: To determine the stability of diterpene lactones in A. paniculata extracts and their transformation dynamics. Materials and Methods: A ¹ H NMR‐based metabolomics workflow and HPLC‐based quantitative determination were used to map the stability profiles in A. paniculata extract stored in the standard storage conditions over a 6‐month period. Results: Qualitatively, NMR‐based PCA detected both descending and ascending dynamics in transformation of diterpene lactones in A. paniculata extracts over a 6‐month storage period. The contents of five lactone markers, compounds 1 – 5 , in storage A. paniculata extracts were monitored to show that compounds 1 and 5 degraded with decelatory rates and presumably transformed via dehydration into compound 3 , which otherwise increased also in a coherently decelatory manner. Lacking of the labile allylic hydroxyl group, compounds 2 and 4 were more stable and remained unchanged throughout the storage period. Conclusion: The short‐term stability of A. paniculata extracts and related products was primarily attributed to the dehydration of 1 and it allylic hydroxy analogs, for example, 5 , into a diene as in 3 . Compound 3 is hence recommended as a plausible candidate as the stability and age marker of A. paniculata raw materials and products.

Due to the challenge of prostate cancer (PCa) management, there has been a surge in efforts to identify more safe and effective compounds that can modulate the epithelial–mesenchymal transition (EMT) for driving metastasis. Holothurin A (HA), a triterpenoid saponin isolated from Holothuria scabra, has now been characterized for its diverse biological activities. However, the mechanisms of HA in EMT-driven metastasis of human PCa cell lines has not yet been investigated. Moreover, runt-related transcription factor 1 (RUNX1) acts as an oncogene in prostate cancer, but little is known about its role in the EMT. Thus, the purpose of this study was to determine how RUNX1 influences EMT-mediated metastasis, as well as the potential effect of HA on EMT-mediated metastasis in endogenous and exogenous RUNX1 expressions of PCa cell lines. The results demonstrated that RUNX1 overexpression could promote the EMT phenotype with increased EMT markers, consequently driving metastatic migration and invasion in PC3 cell line through the activation of Akt/MAPK signaling pathways. Intriguingly, HA treatment could antagonize the EMT program in endogenous and exogenous RUNX1-expressing PCa cell lines. A decreasing metastasis of both HA-treated cell lines was evidenced through a downregulation of MMP2 and MMP9 via the Akt/P38/JNK-MAPK signaling pathway. Overall, our approach first demonstrated that RUNX1 enhanced EMT-driven prostate cancer metastasis and that HA was capable of inhibiting the EMT and metastatic processes and should probably be considered as a candidate for metastasis PCa treatment.

A series of scalarane sesterterpenes were prepared using heteronemin (1) as a primary precursor. Combined with the scalarane derivatives obtained from natural sources, a total of 22 antitubercular scalaranes were used to build QSAR models based in the 2D-QSAR and CoMFA approaches. Both models indicated the influences of substitutions in the vicinity of C-12 and C-16 of the scalaranes. A 2D-QSAR model suggested the necessity of hydrophilic functionalities on the peripherals with hydrophobic cores, and the lowering steric repulsion to improve the potential energy. This was complemented by the pictorial CoMFA model, which indicated the importance of the positive electrostatic with shortened steric extension crowning over C-12 and the lengthy negative functionalities extended from C-16.

Colorectal cancer (CRC) is a frequently occurring malignant disease with still low survival rates, highlighting the need for novel therapeutics. Merosesquiterpenes are secondary metabolites from marine sponges, which might be useful as antitumor agents. To address this issue, we made use of a compound library comprising 11 isolated merosesquiterpenes. The most cytotoxic compounds were smenospongine > ilimaquinone ≈ dactylospontriol, as shown in different human CRC cell lines. Alkaline Comet assays and γH2AX immunofluorescence microscopy demonstrated DNA strand break formation in CRC cells. Western blot analysis revealed an activation of the DNA damage response with CHK1 phosphorylation, stabilization of p53 and p21, which occurred both in CRC cells with p53 knockout and in p53-mutated CRC cells. This resulted in cell cycle arrest followed by a strong increase in the subG1 population, indicative of apoptosis, and typical morphological alterations. In consistency, cell death measurements showed apoptosis following exposure to merosesquiterpenes. Gene expression studies and analysis of caspase cleavage revealed mitochondrial apoptosis via BAX, BIM, and caspase-9 as the main cell death pathway. Interestingly, the compounds were equally effective in p53-wild-type and p53-mutant CRC cells. Finally, the cytotoxic activity of the merosesquiterpenes was corroborated in intestinal tumor organoids, emphasizing their potential for CRC chemotherapy.

Possessing the quinone moiety, ilimaquinone (1), a sponge–derived sesquiterpene quinone, has been hypothesised to express its cytotoxicity through a redox cycling process, yielding active product(s) that can cause DNA damage. To determine the DNA damaging effects of 1 and examine whether a redox transformation may participate in its functions, the DNA damaging properties of 1, the corresponding hydroquinone (2) and hydroquinone triacetates (3) and their 5-epimeric counterparts (4–6) were tested and compared. When incubated directly with plasmid DNA, the hydroquinones were the only active species capable of cleaving the DNA. In cell-based assays, however, the quinones and hydroquinone triacetates were active in the same range as that of the corresponding hydroquinones, and all damaged the cellular DNA in a similar manner. The in situ reduction of 1 and 4 were supported by the decreases in the cytotoxicity when cells were pre-exposed to dicoumarol, an NAD(P)H:quinone oxidoreductase 1 (NQO1) inhibitor. The results confirmed the DNA damaging activities of the ilimaquinones 1 and 4, and indicated the necessity to undergo an in-situ transformation into the active hydroquinones, thereby exerting the DNA damaging properties as parts of the cytotoxic mechanisms.

A chemical investigation of the sponge Verongula cf. rigida led to the isolation of 13 merosesquiterpenes, among which quintaquinone (2), 5-epi-nakijiquinone L (3), and 3-farnesyl-2-hydroxy-5-methoxyquinone (4) were isolated and reported here for the first time. Particularly, compound 2 is the first member of merosesquiterpenes with a polyketide side chain substituted on C-19. All of the isolated compounds were examined for steroid 5α-reductase inhibitory activity. Cyclospongiaquinone 1 (5) showed a strong activity in the same range as that of standard finasteride.

Sponges are a well-known bioresource for bioactive compounds. In this study, antibacterial activity-guided fractionation of the extract from an Indonesian marine Dactylospongia elegans sponge led to the discovery of four merosesquiterpenoids, namely, a new sesquiterpenoid aminoquinone nakijiquinone V (1), along with illimaquinone (2), smenospongine (3), and dyctioceratine C (4). The structure of compound 1 was elucidated by 1D and 2D NMR as well as by LC-HRESIMS data analysis. Compounds 2–4 showed moderate to low antimicrobial activity against Bacillus megaterium DSM32 with a minimum inhibitory concentration (MIC) of 32 μg/mL, 32 μg/mL, and 64 μg/mL, respectively. Furthermore, compounds 2 and 3 both inhibited Micrococcus luteus ATCC 4698 with a MIC of 32 μg/mL. In conclusion, the isolated merosesquiterpenoids, which are known for their cytotoxic effects, showed antibacterial activity and prompt future structure activity relationship (SAR) studies concerning the various bioactivities observed for this group of natural products.