Secoeuphoractin,a minor diterpenoid with a new skeleton from Euphorbia micractina

A minor diterpenoid with a novel carbon skeleton,secoeuphoractin(1),was isolated from an ethanol extract of the roots of Euphorbia micractina.Its structure including the absolute configuration was determined by extensive spectroscopic studies,especially by 2D NMR and CD data analysis,in combination with a plausible biosynthetic pathway associated with co-occurring diverse diterpenoids.This compound showed activity against HIV-1 replication with an IC_(50) value of 1.76 ± 0.61 μmol/L.     

Gersolide,a diterpenoid with a new rearranged carbon skeleton from the soft coral Gersemia rubiformis

The structure of gersolide (4), a diterpenoid isolated from extracts of the soft coral Gersemia rubiformis, has been solved via single crystal x-ray diffraction analysis.     

Spirocurcasone, a diterpenoid with a novel carbon skeleton from Jatropha curcas

Spirocurcasone (14), a diterpenoid possessing the unprecedented "spirorhamnofolane" skeleton, was isolated from the root barks of Jatropha curcas, a plant extensively cultivated throughout the world, along with 11 known and two other new diterpenoids. The stereostructure of spirocurcasone was established using HRESIMS, NMR, and quantum mechanical calculation of the electronic circular dichroic (ECD) spectrum. Some of the isolated diterpenoids showed a potent activity against L5178Y, a mouse lymphoma cell line.     

一个新骨架二萜生物碱

从黄草乌(Aconitum vilmorinianum Kom.)根中分离得到一个新骨架二萜生物碱-黄乌定(vilmoridine, 1), 其骨架为B环对开海替定型, 还从该植物中分离到5个已知二萜生物碱。     

A crotofolane-type diterpenoid and a rearranged nor-crotofolane-type diterpenoid with a new skeleton from the stems of Croton cascarilloides

From the stems of Croton cascarilloides collected in the Okinawa Islands, a structurally rare crotofolane-type diterpenoid (1) and a rearranged nor-crotofalane, a new skeletal diterpenoid (2) were isolated. The structures were determined by X-ray crystallographic analyses, establishing their absolute stereostructures for the first time. Compound 2 was probably biosynthesized from 1 through several steps, such as decarboxylation, oxidation, C-C bond migration.     

Structure of salvioccidentalin, a diterpenoid with a rearranged neo-clerodane skeleton from Salvia occidentalis

From the aerial parts of Salvia occidentalis (Labiatae) a new diterpenoid with a rearranged neo-clerodane skeleton was isolated. This new compound was named salvioccidentalin and its structure was established by spectroscopic means. A probable biogenetic relationship with salvigenolide from S. fulgens and salvileucalin A and spiroleucantholide from Salvia leucantha is proposed.     

Przewalskin B, a novel diterpenoid with an unprecedented skeleton from Salvia przewalskii maxim

Przewalskin B (1), a novel diterpenoid possessing a unique skeleton, was isolated from a Chinese medicinal plant Salvia przewalskii. Its structure and relative stereochemistry were elucidated by extensive NMR analysis and a single-crystal X-ray study. A possible biosynthetic pathway for 1 was proposed. Compound 1 exhibited modest anti-HIV-1 activity with EC50 = 30 microg/mL. [structure: see text].     

Maoecrystal V, cytotoxic diterpenoid with a novel C19 skeleton from Isodon eriocalyx (Dunn.) hara

Maoecrystal V (1), a novel C(19) diterpenoid possessing a unique 6,7-seco-6-nor-15(8-->9)-abeo-5,8-epoxy-ent-kaurane skeleton, was isolated from the leaves of a Chinese medicinal herb, Isodon eriocalyx. Its structure was determined by comprehensive NMR and MS spectroscopic analysis and confirmed by single-crystal X-ray diffraction study. Compound 1 showed remarkable inhibitory activity toward HeLa cells with IC(50) = 0.02 microg/mL (cis-platin: IC(50) = 0.99 microg/mL).     

Ajugareptansin,a new diterpenoid from ajuga reptans (L.)

The structure of a new clerodane diterpene, isolated from $\text{Ajuga}$$\text{reptans}$, has been elucidated by chemical and spectral means and confirmed by X-ray crystallographic studies of the corresponding $\text{p}$-bromobenzoate.     

Salvileucalin B, a novel diterpenoid with an unprecedented rearranged neoclerodane skeleton from Salvia leucantha Cav

Salvileucalin B (2), having an unprecedented rearranged neoclerodane skeleton, was isolated from the aerial parts of Salvia leucantha Cav. (Labiatae) along with salvileucalin A (1). The absolute structures were elucidated by spectroscopic analysis, X-ray crystallographic analysis, and vibrational circular dichroism. Compound 2 represents a novel neoclerodane, characterized by a tricyclo[3.2.1.0 (2,7)]octane substructure incorporating the exocyclic C-20 methylene of 1. This molecule exerted cytotoxic activity against A549 and HT-29 cells with IC50 values of 5.23 and 1.88 microg/mL, respectively.     

Chamobtusin A, a novel skeleton diterpenoid alkaloid from Chamaecyparis obtusa cv. tetragon

The novel diterpenoid alkaloid chamobtusin A (1) was isolated from the branches and leaves of Chamaecyparis obtusa cv. tetragon. Its structure and relative stereochemistry were mainly determined by MS, 2D NMR, and X-ray methods. The methanol extracts, total alkaloids of C. obtusa cv. tetragon, and chamobtusin A were tested for their cytotoxicities against A549 and K562 human tumor cell lines.     

Lathyranone A: a diterpenoid possessing an unprecedented skeleton from Euphorbia lathyris

Lathyranone A (1), a novel diterpenoid with a rearrangement skeleton, along with a known diterpenoid, Euphorbia factor L(11) (2), was isolated from the seeds of Euphorbia lathyris. The structure and relative stereochemistry of 1 were elucidated by extensive spectroscopic analysis. A possible biosynthetic pathway for lathyranone A (1) was proposed.     

Latazienone, a new lathyrane-type diterpenoid from Euphorbia latazi Kunth

A new lathyrane-type diterpene 8alpha,15beta-diacetoxy-7beta-benzoyloxy-3beta-(2-methylpropanoyloxy)-4alphaH,9alphaH, 11alphaH-lathyra-5E,12E-dien-14-one (latazienone) has been isolated from the latex of Euphorbia latazi Kunth. The structure of the new diterpene was determined by a combination of ID- and 2D-NMR techniques.     

Borjatriol,a new diterpenoid from Sideritis mugronensis, Borja (Labiatae)

A new diterpene, borjatriol, isolated from the aerial parts of Sideritis mugronensis, Borja, is a derivative of manoyl oxide. Its structure, 6S, 14R, 15-trihydroxy-8α,13-epoxy-labdane (1), as well as the preferred conformation of ring C, has been established on the basis of chemical and spectroscopic data.     

Structure of salvigenolide,a novel diterpenoid with a rearranged neo-clerodane skeleton from salviafulgens

From the aerial parts of Salvia fulgens Cav. (Labiatae) a new diterpenoid with a rearranged neo-clerodane skeleton was isolated. This novel compound named salvigenolide, showed a six-seven A/B ring system with a trans fussion. A probable biogenetic route is proposed. Its structure and relative stereochemistry as in $\text{1}$, were established by spectroscopic means and X-ray diffraction analysis.     

Cephasinenoside A,a new cephalotane diterpenoid glucoside from Cephalotaxus sinensis

A new cephalotane diterpenoid glucoside, cephasinenoside A (1), was isolated from the twigs and leaves of Cephalotaxus sinensis (Rehd. et Wils.) Li. The structure of 1 was established on the basis of spectroscopic analyses and ECD calculations. Compound 1 represents the first cephalotane diterpenoid glycoside which inhibits the proliferation of human acute myeloid leukemia HL-60 cells with a GI₅₀ value of 7.17 ± 1.03 μM.     

Hydrangenone, a new isoprenoid with an unprecedented skeleton from Salvia hydrangea

Hydrangenone, a new heptacyclic isoprenoid with a 6/7/6/5/5 membered carbon ring skeleton, was isolated from the aerial parts of Salvia hydrangea. The structure was established by extensive NMR spectroscopic methods. The relative and absolute configuration of 1 was assigned by NOESY and X-ray crystallographic analysis and by comparison of experimental and calculated electronic circular dichroism (ECD) spectra. Compound 1 showed in vitro antiplasmodial activity, with an IC(50) value of 1.4 μM against P. falciparum. A plausible biosynthetic pathway of 1 was also proposed.     

Stolonidiol,a new marine diterpenoid with a strong cytotoxic activity from the Japanese soft coral

Structures of stolonidiol (1) and stolonidiol monoacetate (2), new marine diterpenoids with a strong cytotoxic activity from the Japanese soft coralClavularia sp., were established by means of spectroscopic analyses, chemical reactions, and X-ray crystallographic analysis.     

Salvifarinin A,a neo-clerodane diterpenoid with a 6/5/7 tricyclic skeleton from Salvia farinacea

Salvifarinin A (1), a rearrangement product of Languidulane-type clerodane diterpenoids with a 6/5/7 tricyclic ring skeleton fused with γ-lactone ring and furan ring, and two new biogenetically related diterpernoids, salvifarinins B (2) and C (3), were isolated from the aerial parts of Salvia farinacea. The absolute configuration of 1 was elucidated by extensive spectroscopic methods, and confirmed by single crystal X-ray diffraction and bio-inspired semisynthesis. The plausible biogenetic pathway was also proposed. Compound 2 displayed a potent effect on reducing hepatic steatosis.