Kadpolysperins A–N, lanostane triterpene acids possessing rich structure types from Kadsura polysperma

Targeted isolation of lignans and triterpenoids from kadsura coccinea by molecular networking and anti-RA-FLS activity

In this study, six compounds (four triterpenoids named heilaohutriterpenes A-D and two lignans name heilaohusuins F and G) together with 21 known compounds were isolated from roots of Kadsura coccinea (Lem.) A. C. Smith guided by molecular networking. Their structures were determined using a combination of HR-ESI-MS, 1D, 2D-NMR anatysis, NMR calculation, and electronic circular dichroism (ECD) calculations. Moreover, the ability of the isolated compounds to inhibit the proliferation of rheumatoid arthritis-fibroblastoid synovial (RA-FLS) cells was evaluated in vitro. Heilaohutriterpene B (2), heilaohutriterpene D (4), coccinone B (7), and kadsuralignan H (24) demonstrated significant inhibitory activities against RA-FLS cells, with IC50 values of 9.57 ± 0.84, 16.22 ± 1.71, 3.08 ± 1.59, and 19.09 ± 2.42 μM, respectively. Meanwhile, western blotting analysis revealed that compound 2 down-regulated the level of P-NF-κB p65 and up-regulated that of Bax and IκBα. These results collectively suggest that compound 2 promoted the apoptosis of RA-FLS cells by inhibiting the NF-κB pathway. Taken together, this study contributed to the structural diversity of compounds derived from K. coccinea and lays a basis for further anti-RA-related studies.

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.

Potential natural product 3,4-seco-schitriterpenoids from Kadsura japonica L. as anti-neuroinflammatory agents

In the present study, the undescribed schitriterpenoids, kadsujanonols A-I (1-9), and eleven reported compounds (10-20) were isolated from K. japonica L. vines. Their structures of 3,4-seco-schitriterpenoids were elucidated mainly by spectroscopic analyses including 1H-, 13C-, and 2D-NMR, IR, HRESIMS spectra. The spatial configurations were determined by the single-crystal X-ray diffraction analysis of kadsujapnonol A (1), 15, 17, and 18, CD data and computational analysis. Furthermore, all isolates were evaluated for the anti-neuroinflammatory activity on LPS-stimulated NO production in BV2 microglial cells and compounds 2, 4, 5, 7, 9, 11, 13-16, and 18 exposed better or comparable suppression abilities than PDTC. Among them, kadlongilactone B (14) showed the best significant inhibiting ability (IC50 = 0.87 μg/mL) and the effect is through the attenuation of the inflammatory transcription factor p65NF-κB. Preliminary structure-activity relationship revealed that δ-lactone at the side chain and 7-member lactone at C-3/C-4, and 3,4:9,10 ring opening are important.

Plant triterpenoids with bond-missing skeletons: biogenesis, distribution and bioactivity

Covering: up to December 2018 The polycyclic ABCD(E) framework of triterpenoids can miss a single endocyclic C-C bond as a result of a modification of the cyclization cascade that triggers their formation (interrupted- or diverted cascades), or can be the result of post-cyclization ring cleavage by late-stage oxidative modifications (seco-triterpenoids). Because of mechanistic and biogenetic differences, ring opening associated with loss of a skeletal fragment, as in nor-seco-triterpenoids (limonoids, quassinoids), will not be covered, nor will compounds where ring opening is part of a fragmentation cascade or of a multiple diversion from it. Even with these limitations, 342 bond-missing triterpenoids could be retrieved from the literature, with transversal distribution in the plant kingdom. Their structural diversity translates into a variety of biological targets, with dominance of potential applications in the realm of cancer, neuroprotection, and anti-infective therapy. In addition to the bioactivity and chemotaxonomic relevance of bond-missing triterpenoids, current knowledge on the genetic basis of interrupted- and diverted oxidosqualene cyclases will be summarized. This untapped source of enzymes could be useful to selectively modify triterpenoids by metabolic engineering, circumventing the bottlenecks of their isolation (poor yield or inadequate supply chain) to explore new areas of their chemical space.

Triterpenoids and lignans from the stems of Schisandra glaucescens

Two new triterpenoids, 24( E)-3 α,12 α-dihydroxyl-lanost-9(11),24-dien-26-oid acid (1) and 3,4- seco-24( Z)-6 α,7 β-dihydroxyl-cycloart-4(28),24-dien-3,26-dioic-3-methyl ester (2), and ten known ones (3-12), together with eight lignans (13-20), were isolated from the stems of Schisandra glaucescens. Their structures were established on the basis of extensive spectroscopic analyses. Compounds 1-3, 5-7, 9, 11-13 and 15-18 were isolated from this species for the first time. 1 and 2 were evaluated for their in vitro cytotoxicities against the mouse cancer B16 cell line, human cancer HepG2 and MCF7 cell lines by MTT assay.

Synthesis of cytotoxically active derivatives based on alkylated 2,3-seco-triterpenoids

Extremely low content of biologically active triterpenoids with the fragmented or contracted ring A extractable from plants is the main disadvantage of their use in drug discovery and practical pharmacology. Development of new methods for synthesis of these compounds and their structural analogs from bioavailable triterpene precursors gives an opportunity to obtain promising agents for pharmacology with excellent yields. A new approach to synthesis of alkylated A-seco-triterpenoids, including the Beckmann fragmentation of 3-methyl-substituted allobetulin or betulinic acid methyl ester with 2-hydroxyimino group in the ring A was proposed. These compounds were used to prepare a series of 2,3-seco- and five-membered ring A lupane and oleanane derivatives, cytotoxicity of which was screened in vitro against the cancer (HEp-2, HCT 116, A549, RD TE32, MS) and non-cancerous (HEK 293) cell lines. Methyl 3-bromomethyl-1-cyano-3-oxo-2,3-seco-2-norlup-20(29)-en-30-al-28-oate was selected as the most active compound (IC₅₀ 3.4-10.4 μM for HEp-2, HCT 116, RD TE32, MS cells) capable of triggering caspase-8-mediated apoptosis in HCT 116 cells accompanied by typical apoptotic chromatin condensation, without any loss of mitochondrial membrane permeability.

Rearranged 6/6/5/6-Fused Triterpenoid Acids from the Stems of Kadsura coccinea

Fourteen new rearranged 6/6/5/6-fused triterpenoid acids, namely, kadcoccine acids A-N (1-14), were isolated from an EtOAc-soluble extract of the stems of Kadsura coccinea. Their structures were characterized mainly by analyzing 1D and 2D NMR and HRESIMS data and were shown to feature a rare 14(13→12)-abeo-lanostane skeleton. Compounds 7 and 8 represented the first examples of a 5-substituted 2(5H)-furanone motif on the C-17 side chain of this skeleton. The absolute configurations of C-23 for compounds 1, 7, and 8 were determined by comparison of their experimental electronic circular dichroism spectra. All the isolates were screened for their in vitro cytotoxicity against six human tumor cell lines (HL-60, SMMC-7721, A-549, MCF-7, SW-480, and HeLa), and compounds 2 and 8 exhibited weak inhibitory effects with IC₅₀ values ranging from 3.11 to 7.77 μM.

Kadcoccinones A-F, New Biogenetically Related Lanostane-Type Triterpenoids with Diverse Skeletons from Kadsura coccinea

Six new lanostane-related triterpenoids, kadcoccinones A-F (1-6), were isolated from Kadsura coccinea. Compound 3 possesses a novel 6/6/9-fused carbocyclic core containing a rare oxabicyclo[4.3.1]decane system. Compounds 4 and 5 are isomers representing the first example of the 18(13 → 12)-abeo-26-norlanostane triterpenoid. The absolute configurations of 1 and 4-6 were defined by X-ray diffraction and experimental ECD spectra, and that of 3 was elucidated by quantum chemical calculations. The plausible biogenetic pathway of 1-6 is postulated.

A new lanostane-type triterpene and sesquiterpene lactones from Vernonia leopoldii and their in vitro cytotoxicity

Investigation of the aerial parts of Vernonia leopoldii (Sch. Bip.) Vatke afforded a new lanostane-type triterpene along with known hirsutinolide-type sesquiterpene lactones and flavonoid glycosides, all are identified for the first time in this species. The new compound was identified as lanost-3β, 23S-dihydroxy-22(31)-ene. The structures of the isolated compounds were elucidated based on spectroscopic evidence. The hirsutinolides and the triterpene were evaluated for their cytotoxicity against four human cancer cell lines using MTT assay.

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.

Triterpenoids from the Schisandraceae family: an update

Plants from the Schisandraceae family produce architecturally interesting triterpenoids, including lanostanes, cycloartanes, and schinortriterpenoids. This review focuses on their structures, classifications, biogenetic pathways, syntheses, and bioactivities (from February 2008 to May 2014).

Kadcotriones A-C: tricyclic triterpenoids from Kadsura coccinea

Three new triterpenoids, kadcotriones A-C (1-3), together with the biogenetically related lanostane-type triterpenoid (4), were isolated from Kadsura coccinea. Compound 1 features a 12,14β-dimethyl 6/6/6-fused tricyclic skeleton, while 2 and 3 are characterized by a 6/6/5-ring system. Their structures were determined by NMR and electronic circular dichroism spectroscopic methods. Compounds 2 and 4 exhibited anti-HIV-1 activities with EC50 values of 30.29 and 54.81 μM, respectively.