Trichosides A and B, new withanolide glucosides from Tricholepis eburnea

Naturally Occurring Norsteroids and Their Design and Pharmaceutical Application

The main focus of this review is to introduce readers to the fascinating class of lipid molecules known as norsteroids, exploring their distribution across various biotopes and their biological activities. The review provides an in-depth analysis of various modified steroids, including A, B, C, and D-norsteroids, each characterized by distinct structural alterations. These modifications, which range from the removal of specific methyl groups to changes in the steroid core, result in unique molecular architectures that significantly impact their biological activity and therapeutic potential. The discussion on A, B, C, and D-norsteroids sheds light on their unique configurations and how these structural modifications influence their pharmacological properties. The review also presents examples from natural sources that produce a diverse array of steroids with distinct structures, including the aforementioned A, B, C, and D-nor variants. These compounds are sourced from marine organisms like sponges, soft corals, and starfish, as well as terrestrial entities such as plants, fungi, and bacteria. The exploration of these steroids encompasses their biosynthesis, ecological significance, and potential medical applications, highlighting a crucial area of interest in pharmacology and natural product chemistry. The review emphasizes the importance of researching these steroids for drug development, particularly in addressing diseases where conventional medications are inadequate or for conditions lacking sufficient therapeutic options. Examples of norsteroid synthesis are provided to illustrate the practical applications of this research.

Evaluation of the antimicrobial and cytotoxic potential of endophytic fungi extracts from mangrove plants Rhizophora stylosa and R. mucronata

Mangrove endophytic fungi are tolerant to numerous stresses and are inevitably capable of exhibiting excellent biological activity by producing impressive numbers of metabolites with special biological functions, based on previous work on the biological potential of mangrove-derived endophytic fungi. To obtain marked antimicrobial and cytotoxic fermentation products of culturable endophytic fungi from mangrove forests, our research evaluated the antimicrobial and cytotoxic activities of crude extracts of endophytic fungi from Rhizophora stylosa and Rhizophora mucronata. Forty-six fungal isolates were cultured on four different media, namely, dextrose agar (PDA), Czapek’s agar (CZA), rice medium (RM) and grain medium (GM) and harvested by ethyl acetate solvent at 40 days. The extracts were tested for antimicrobial activity by the microdilution method against the gram-negative bacteria Pseudomonas adaceae (PA), gram-positive bacteria Enterococcus faecalis (EF), methicillin-resistant Staphylococcus aureus (MRSA) and pathogenic fungus Monilia albicans (MA). The cytotoxic activity of the extracts was evaluated by MTT assay using A549 human lung cancer cells, HeLa human cervical carcinoma cells, and HepG2 human hepatocellular cells. The results showed that rice medium could promote the secretion of antimicrobial and antitumour secondary metabolites of endophytic fungi in comparison with other cultivation media. Seventeen strains (68%) from R. stylosa exhibited inhibitory effects on indicators, especially N. protearum HHL46, which could inhibit the growth of four microbes with MIC values reaching 0.0625 mg/mL. Fifteen strains (71.4%) from R. mucronata displayed activities against human pathogenic microbes; in particular, Pestalotiopsis sp. HQD6 and N. protearum HQD5 could resist the growth of four microbes with MIC values ranging from 0.015 to 1 mg/mL. In the cytotoxicity assay, the extracts of 10 strains (40%), 9 strains (40%) and 13 strains (52%) of R. stylosa and 13 strains (61.9%), 10 strains (47.6%) and 10 strains (47.6%) of R. mucronata displayed cytotoxicity against A549, HeLa and HepG2 cancer cells with cell viability values ≤ 50%. Neopestalotiopsis protearum HHL46, Phomopsis longicolla HHL50, Botryosphaeria fusispora HQD83, Fusarium verticillioides HQD48 and Pestalotiopsis sp. HQD6 displayed significant antitumour activity with IC₅₀ values below 20 μg/mL. These results highlighted the antimicrobial and antitumour potential of endophytic fungi from R. stylosa and R. mucronata and the possibility of exploiting their antimicrobial and cytotoxic agents.

Antitumor Profile of Carbon-Bridged Steroids (CBS) and Triterpenoids

This review focuses on the rare group of carbon-bridged steroids (CBS) and triterpenoids found in various natural sources such as green, yellow-green, and red algae, marine sponges, soft corals, ascidians, starfish, and other marine invertebrates. In addition, this group of rare lipids is found in amoebas, fungi, fungal endophytes, and plants. For convenience, the presented CBS and triterpenoids are divided into four groups, which include: (a) CBS and triterpenoids containing a cyclopropane group; (b) CBS and triterpenoids with cyclopropane ring in the side chain; (c) CBS and triterpenoids containing a cyclobutane group; (d) CBS and triterpenoids containing cyclopentane, cyclohexane or cycloheptane moieties. For the comparative characterization of the antitumor profile, we have added several semi- and synthetic CBS and triterpenoids, with various additional rings, to identify possible promising sources for pharmacologists and the pharmaceutical industry. About 300 CBS and triterpenoids are presented in this review, which demonstrate a wide range of biological activities, but the most pronounced antitumor profile. The review summarizes biological activities both determined experimentally and estimated using the well-known PASS software. According to the data obtained, two-thirds of CBS and triterpenoids show moderate activity levels with a confidence level of 70 to 90%; however, one third of these lipids demonstrate strong antitumor activity with a confidence level exceeding 90%. Several CBS and triterpenoids, from different lipid groups, demonstrate selective action on different types of tumor cells such as renal cancer, sarcoma, pancreatic cancer, prostate cancer, lymphocytic leukemia, myeloid leukemia, liver cancer, and genitourinary cancer with varying degrees of confidence. In addition, the review presents graphical images of the antitumor profile of both individual CBS and triterpenoids groups and individual compounds.

Micropropagation of Tricholepis roylei Hook. F.-a point endemic species of the Western Himalaya

Background

Tricholepis roylei Hook. f. is a bushy annual shrub of the Asteraceae family and point endemic species of the Western Himalaya. T. roylei is a critically endangered species and factors like poor seed germination and habitat destruction are further rendering the species towards extinction. Therefore, the present investigation was designed to document the seed germination potential of the species and to establish a reproducible in vitro propagation and mass multiplication protocol for the ex situ conservation of T. roylei germplasm.

Results

Seeds of T. roylei were collected from Sangdha, Himachal Pradesh, India, and were sown in different substrates under open and controlled conditions. Though the overall seed germination potential of the species was reported to be very low and maximum 45% germination was observed in cocopeat substrate after 26 days of incubation. Half-strength Murashige and Skoog (MS) medium enriched with 6-benzylaminopurine (4.4 μM l⁻¹) and naphthalene acetic acid (1.0 μM l^-1) was observed to be the optimum medium for shoot induction in shoot tip explants of T. roylei. Maximum 98.89% shoot formation was observed with 28.42 shoots per culture and 4.4-cm shoot length, respectively. The healthy shoots (4.0 cm) were transferred onto rooting media (1/4, 1/2 and full MS) and roots were developed after 8 weeks of incubation in the half-strength MS medium. Half MS augmented with 4.9 μM l⁻¹ indole butyric acid was observed to be optimum for the root development and an average of 10.2 roots per shoot with 4.0-cm length was obtained. Rooted plantlets were successfully acclimatized under greenhouse conditions and subsequently established in the field, with a recorded survival rate of 90%. The plants acclimatized to the open environment were also planted in the wild under the habitat rehabilitation and species recovery programme.

Conclusion

The seed germination study envisages that the seed germination potential of the species is very poor and might be one of the probable factors responsible for the shrinkage of T. roylei population in the wild. The standardized micropropagation protocol can be helpful for the ex situ conservation of germplasm and rehabilitation of species in the wild. Moreover, the study could be helpful in elucidating the phytochemical and molecular analysis of species.

Three new ester glycosides with cytotoxic activity from the seeds of Caesalpinia sappan

Three new ester glycosides, named as Caesateroside A (1), Caesateroside B (2) and Caesateroside C (3) were obtained from the seeds of Caesalpinia sappan. The new structures of compounds 1-3 were elucidated by analyzing their 1 D NMR, 2 D NMR and HR-ESI-MS spectra. Compounds 1-3 showed weak-moderate cytotoxicity against Hela and HepG-2 human cancer cell lines.

Five New Cucurbitane-Type Triterpenoid Glycosides from the Rhizomes of Hemsleya penxianensis with Cytotoxic Activities

Five new cucurbitane-typetriterpenoid glycosides, named Xuedanoside F–J (1–5), were obtained from the rhizomes of Hemsleya penxianensis (Xue dan), which belongs to the family of Cucurbitaceae. These new compounds were elucidated byspectroscopic analysis, including 1D, 2D NMR, and HR-ESI-MS spectra. Additionally, all the isolates were evaluated for cytotoxicity against three human cancer cell lines (Hela, MCF-7, and A-549) with the IC₅₀ ranging from 2.25 to 49.44 µM in vitro with treatment 48 h and showed low cytotoxicity in human normal liver L-02 cells (IC₅₀ > 50 µM). Compound 5 showed the most significant cytotoxic activity with the IC₅₀ value of 2.25, 4.72, and 5.33 µM in 48 h, respectively.

Structurally Diverse Highly Oxygenated Triterpenoids from the Roots of Ailanthus altissima and Their Cytotoxicity

Ten new triterpenoids, ailanaltiolides A-J (1-10), and three known analogues (11-13) were isolated from the roots of Ailanthus altissima. Compounds 1-7 are apotirucallane-type, compounds 8 and 9 are tirucallane-type, and compound 10 is a trinordammarane-type triterpenoid. This is the first study indicating the genus Ailanthus as a potential source for apotirucallane derivatives, which contain an α,β-unsaturated-ε-lactone A-ring and diversely modified C-17 side chains. Spectroscopic data interpretation, electronic circular dichroism analysis, and X-ray crystallographic data defined the structures and absolute configurations of these triterpenoids. Compounds 2, 7, and 8 showed cytotoxicity against four tumor cell lines (HeLa, 786-O, HepG2, and A549). In particular, compound 2 exhibited the highest activity against 786-O cells with an IC₅₀ value of 8.2 μM in vitro.

A new cadinane sesquiterpenoid glucoside with cytotoxicity from Abelmoschus sagittifolius

A new cadinane sesquiterpenoid glucoside, 2β,7,3-trihydroxycalamenene 3-O-β-d-glucoside (1) together with six known compounds, N-(p-trans-coumaroyl)-N-methyl tyramine (2), Cleomiscosin A (3), 9,12,13-trihydroxy-10,15-heptadecadienoic acid (4), Cytochalasin B (5), Marmesinin (6) and N-(p-trans-coumaroyl) tyramine (7) were obtained from the stem bark of Abelmoschus sagittifolius. The new structure of compound 1 was elucidated by analysing its ¹H and ¹³C-NMR, ¹H-¹H COSY, HSQC, HMBC, NOESY and HR-ESI-MS spectra. Compounds 1-7 showed moderate cytotoxicity against Hela and HepG-2 human cancer cell lines.