Four New Podocarpane‐Type Trinorditerpenes from Aleurites moluccana

Four new podocarpane‐type trinorditerpenenes, (5β,10α)‐12,13‐dihydroxypodocarpa‐8,11,13‐trien‐3‐one ( 1 ), (5β,10α)‐12‐hydroxy‐13‐methoxypodocarpa‐8,11,13‐trien‐3‐one ( 2 ), (5β,10α)‐13‐hydroxy‐12‐methoxypodocarpa‐8,11,13‐trien‐3‐one ( 3 ), and (3α,5β,10α)‐13‐methoxypodocarpa‐8,11,13‐triene‐3,12‐diol ( 4 ), together with four known diterpenes, 12‐hydroxy‐13‐methylpodocarpa‐8,11,13‐trien‐3‐one ( 5 ), spruceanol ( 6 ), ent‐3α‐hydroxypimara‐8(14),15‐dien‐12‐one ( 7 ), and ent‐3β,14α‐hydroxypimara‐7,9(11),15‐triene‐12‐one ( 8 ), were isolated from the twigs and leaves of Aleurites moluccana. Their structures were elucidated by means of comprehensive spectroscopic analyses, including NMR and MS. Except 8 , all compounds were evaluated for their cytotoxicity; compound 4 exhibited moderate inhibitory activity against Raji cells with an IC₅₀ value of 4.24 μg/ml.     

Huangqiyenins G – J,Four New 9,10‐Secocycloartane (=9,19‐Cyclo‐9,10‐secolanostane) Triterpenoidal Saponins from Astragalus membranaceus Bunge Leaves

Four new 9,10‐secocycloartane (=9,19‐cyclo‐9,10‐secolanostane) triterpenoidal saponins, named huangqiyenins G–J ( 1 – 4 , resp.), were isolated from Astragalus membranaceus Bunge leaves. The acid hydrolysis of 1 – 4 with 1M aqueous HCl yielded D ‐glucose, which was identified by GC analysis after treatment with L ‐cysteine methyl ester hydrochloride. The structures of 1 – 4 were established by detailed spectroscopic analysis as (3β,6α,10α,16β,24E)‐3,6‐bis(acetyloxy)‐10,16‐dihydroxy‐12‐oxo‐9,19‐cyclo‐9,10‐secolanosta‐9(11),24‐dien‐26‐yl β‐D ‐glucopyranoside ( 1 ), (3β,6a,10α,24E)‐3,6‐bis(acetyloxy)‐10‐hydroxy‐12,16‐dioxo‐9,19‐cyclo‐9,10‐secolanosta‐9(11),24‐dien‐26‐yl β‐D ‐glucopyranoside ( 2 ), (3β,6α,9α,10α,16β,24E)‐3,6‐bis(acetyloxy)‐9,10,16‐trihydroxy‐9,19‐cyclo‐9,10‐secolanosta‐11,24‐dien‐26‐yl β‐D ‐glucopyranoside ( 3 ), and (3β,6α,10α,24E)‐3,6‐bis(acetyloxy)‐10‐hydroxy‐16‐oxo‐9,19‐cyclo‐9,10‐secolanosta‐9(11),24‐dien‐26‐yl β‐D ‐glucopyranoside ( 4 ).     

Five New Sesquiterpenoids from Parasenecio petasitoides

From the whole plants of Parasenecio petasitoides, five new sesquiterpenoids were isolated, (E,E)‐3α,9β‐dihydroxy‐6βH,11βH‐13‐norgermacra‐1(10),4‐dien‐11,6‐carbolactone ( 2 ), (E,E)‐2α,9β‐dihydroxy‐6βH,11βH‐13‐norgermacra‐1(10),4‐dien‐11,6‐carbolactone ( 3 ), (E,E)‐2α,9β‐dihydroxy‐6βH,11αH‐13‐norgermacra‐1(10),4‐dien‐11,6‐carbolactone ( 4 ), (E)‐15‐hydroxy‐2‐oxo‐6βH,11αH‐13‐norguaia‐3‐ene‐11,6‐carbolactone ( 7 ), and (E)‐11β,15‐dihydroxy‐2‐oxo‐6βH‐13‐norguaia‐3‐ene‐11,6‐carbolactone ( 8 ), together with three known compounds, deacetyl herbolide A ( 1 ), jacquilenin ( 5 ), and (E)‐15‐hydroxy‐2‐oxo‐6βH,11βH‐13‐norguaia‐3‐ene‐11,6‐carbolactone ( 6 ). The structures of these natural products were elucidated spectroscopically, especially by 1D‐ and 2D‐NMR techniques, in combination with high‐resolution mass spectroscopy.     

Sterols from the Stems of Momordica charantia

A new sterol, 5α,6α‐epoxy‐3β‐hydroxy‐(22E,24R)‐ergosta‐8,22‐dien‐7‐one ( 1 ), together with eight known sterols, 5α,6α‐epoxy‐(22E,24R)‐ergosta‐8,22‐diene‐3β,7α‐diol ( 2 ), 5α,6α‐epoxy‐(22E,24R)‐ergosta‐8,22‐diene‐3β,7β‐diol ( 3 ), 5α,6α‐epoxy‐(22E,24R)‐ergosta‐8(14),22‐diene‐3β,7α‐diol ( 4 ), 3β‐hydroxy‐(22E,24R)‐ergosta‐5,8,22‐trien‐7‐one ( 5 ), ergosterol peroxide ( 6 ), clerosterol ( 7 ), decortinol ( 8 ), and decortinone ( 9 ), were isolated from the stems of Momordica charantia. Their structures were elucidated by mean of extensive spectroscopic methods, including ¹H, ¹³C, 2D‐NMR and HR‐EI‐MS, as well as comparison with the literature data. Compounds 1 , 4 , 5 , 8 , and 91 were not cytotoxic against the SK‐Hep 1 cell line.     

Cyclopeptide and Terpenoids from Tripterygium wilfordii Hook. f.

The EtOH extract of dried root bark of Tripterygium wilfordii Hook. f. (Celastraceae) afforded a novel macrolactone cyclopeptide named triptotin L (=cyclo[L ‐alanyl‐L ‐alanyl‐3‐(4,4,9‐trimethyldecyl‐3‐hydroxypropanoylglycyl‐L ‐valyl‐L ‐leucyl; 1 ), the new triterpene 2β,6α,22β‐trihydroxy‐24,29‐dinor‐D:A‐friedoolean‐4‐ene‐3,21‐dione named 6α‐hydroxytriptocalline A (=(2β,6α,8α,9β,10α,13α,14β,20β,22β)‐2,6,22‐trihydroxy‐9,13‐dimethyl‐24,25,26,30‐tetranorolean‐4‐ene‐3,21‐dione; 2 ), the new diterpenoid 11,16‐dihydroxy‐14‐methoxy‐18(4→3) abeo‐abieta‐3,8,11,13‐tetraene‐18‐oic acid named 16‐hydroxytriptobenzene H (=(4aS,10aS)‐3,4,4a,9,10,10a‐hexahydro‐5‐hydroxy‐7‐(2‐hydroxy‐1‐methylethyl)‐8‐methoxy‐1,4a‐dimethylphenanthrene‐2‐carboxylic acid; 3 ), and the abietane diterpenoid alkaloid named triptotin J (=(7aS,11aS,11bS)‐7,7a,8,9,10,11,11a,11b‐octahydro‐11b‐hydroxy‐α,α,8,8,11a‐pentamethyl‐6H‐naphth[1,2‐d]azepine‐4‐methanol; 4 ). Their structures were established on the basis of spectroscopic studies.     

Three New Abietane‐type Diterpenes from the Bark of Cryptomeria japonica

Three new abietane‐type diterpenoids, 7β‐acetoxy‐12‐methoxyabieta‐8,11,13‐triene‐6α,11‐diol ( 1 ), 7α‐acetoxy‐12‐methoxyabieta‐8,11,13‐triene‐6α,11‐diol ( 2 ), and 6α‐acetoxy‐12‐methoxyabieta‐8,11,13‐triene‐7α,11‐diol ( 3 ), as well as two known abietane‐type diterpenoids, 12‐methoxyabieta‐8,11,13‐triene‐6α,7β,11‐triol ( 4 ) and 6α‐acetoxy‐12‐methoxyabieta‐8,11,13‐triene‐7β,11‐diol ( 5 ), were isolated from the MeOH extract of the bark of Cryptomeria japonica. Their structures were determined by analysis of spectroscopic data and comparison of NMR data with those of related metabolites.     

Three Terpenoids and a Tocopherol‐Related Compound from Ricinus communis

Four new compounds named (3E,7Z,11E)‐19‐hydroxycasba‐3,7,11‐trien‐5‐one ( 1 ), 6α‐hydroxy‐10β‐methoxy‐7α,8α‐epoxy‐5‐oxocasbane‐20,10‐olide ( 2 ), 15α‐hydroxylup‐20(29)‐en‐3‐one ( 3 ), and (2R,4aR, 8aR)‐3,4,4a,8a‐tetrahydro‐4a‐hydroxy‐2,6,7,8a‐tetramethyl‐2‐(4,8,12‐trimethyltridecyl)‐2H‐chromene‐5,8‐dione ( 4 ) were isolated from the MeOH extracts of the aerial parts of Ricinus communis L. by chromatographic methods. Their structures were elucidated by extensive spectroscopic experiments.     

New α‐Glucosidase Inhibitors from the Mongolian Medicinal Plant Ferula mongolica

The four new and four known sesquiterpenoid derivatives 1 – 4 and 5 – 8 , respectively, were isolated from the air‐dried roots of Ferula mongolica. The structures of these compounds were determined by spectroscopic methods and found to be rel‐(2R,3R)‐2‐[(3E)‐4,8‐dimethylnona‐3,7‐dienyl]‐3,4‐dihydro‐3,8‐dihydroxy‐2‐methyl‐2H,5H‐pyrano[2,3‐b][1]benzopyran‐5‐one ( 1 ), rel‐(2R,3R)‐2‐[(3E)‐4,8‐dimethylnona‐3,7‐dienyl]‐2,3‐dihydro‐7‐hydroxy‐2,3‐dimethyl‐4H‐furo[2,3‐b][1]benzopyran‐4‐one ( 2 ), rel‐(2R,3R)‐2‐[(3E)‐4,8‐dimethylnona‐3,7‐dienyl]‐2,3‐dihydro‐7‐hydroxy‐2,3‐dimethyl‐4H‐furo[3,2‐c][1]benzopyran‐4‐one ( 3 ), rel‐(2R,3R)‐2‐[(3E)‐4,8‐dimethylnona‐3,7‐dienyl]‐2,3‐dihydro‐7‐methoxy‐2,3‐dimethyl‐4H‐furo[3,2‐c][1]benzopyran‐4‐one ( 4 ), (4E,8E)‐1‐(2‐hydroxy‐4‐methoxyphenyl)‐5,9,13‐trimethyltetradeca‐4,8,12‐trien‐1‐one ( 5 ), the rel‐(2R,3S) diastereoisomer 6 of 2 , the rel‐(2R,3S) diastereoisomer 7 of 4 , and (4E,8E)‐1‐(2,4‐dihydroxyphenyl)‐5,9,13‐trimethyltetradeca‐4,8,12‐trien‐1‐one ( 8 ). These compounds were tested as inhibitors against the enzyme α‐glucosidase. The compounds 1 – 6 and 8 exhibited significant inhibitory activity and, therefore, represent a new class of α‐glucosidase inhibitors.     

Sesquiterpenoids and Lactone Derivatives from Ligularia dentata

Seven new compounds were isolated from the roots of Ligularia dentata, including five bisabolane‐type sesquiterpenoids (bisabolane=1‐(1,5‐dimethylhexyl)‐4‐methylcyclohexane), namely (8β,10α)‐8‐(angeloyloxy)‐5,10‐epoxybisabola‐1,3,5,7(14)‐tetraene‐2,4,11‐triol ( 1 ), (8β,10α)‐8‐(angeloyloxy)‐5,10‐epoxythiazolo[5,4‐a]bisabola‐1,3,5,7(14)‐tetraene‐4,11‐diol ( 2 ), (1α,2α,3β,5α,6β)‐1,5,8‐tris(angeloyloxy)‐10,11‐epoxy‐2,3‐dihydroxybisabol‐7(14)‐en‐4‐one ( 3 ), (1α,2α,3β,5α,6β)‐2,5,8‐tris(angeloyloxy)‐10,11‐epoxy‐1,3‐dihydroxybisabol‐7(14)‐en‐4‐one ( 4 ), and (1α,2β,3β,5α,6β)‐1,8‐bis(angeloyloxy)‐2,3‐epoxy‐5,10‐dihydroxy‐11‐methoxybisabol‐7(14)‐en‐4‐one ( 5 ) (angeloyloxy=[(2Z)‐2‐methyl‐1‐oxobut‐2‐enyl]oxy), and two lactone derivatives, (2α,3β,5α)‐2‐(acetyloxy)‐9‐methoxy‐5‐(methoxycarbonyl)‐2,3‐dimethylheptano‐5‐lactone ( 6 ), and (2β,4β)‐2‐ethyl‐5‐hydroxy‐5‐(methoxycarbonyl)‐4,5‐dimethylpentano‐4‐lactone ( 7 ) (α/β denote relative configurations), together with (2E,4R,5S)‐2‐ethylidene‐5‐(methoxycarbonyl)‐4‐methylhexano‐5‐lactone ( 8 ), a known synthetic compound. Compound 2 is the first sesquiterpenoid derivative containing the uncommon benzothiazole moiety. The structures of 1 – 8 were established by spectroscopic methods, especially 2D‐NMR and MS analyses.     

Novel Sesquiterpenes from the Fungus Lactarius piperatus

Four novel sesquiterpenes, namely 7α,8β,13‐trihydroxy‐5,13‐marasmanolide ( 2 ), isoplorantinone ( 5 ), 4,8,14‐trihydroxyilludala‐2,6,8‐triene ( 6 ), and 8‐hydroxy‐8,9‐secolactara‐1,6‐dien‐5,13‐olide ( 10 ), together with six known ones, 7α,8β‐dihydroxy‐5,13‐marasmanolide ( 1) , 7α,8α‐dihydroxy‐5,13‐marasmanolide ( 3 ), isolactarorufin ( 4 ), blennin A ( 7 ), blennin D ( 8 ), and lactarorufin ( 9 ), were isolated from the ethanolic extract of Lactarius piperatus. The structures of these sesquiterpenes, representing diversified structural types, were determined mainly by spectroscopic methods, especially 2D‐NMR techniques. The structure of 6 was further confirmed by a single‐crystal X‐ray‐diffraction determination.     

New Cholinesterase‐Inhibiting Steroidal Alkaloids from Sarcococca saligna

Seven new steroidal alkaloids, 2‐hydroxysalignarine‐E (=(2′E,20S)‐20‐(dimethylamino)‐2β‐hydroxy‐3β‐(tigloylamino)pregn‐4‐ene; 1 ), 5,6‐dihydrosarconidine (=(20S)‐20‐(dimethylamino)‐3β‐(methylamino)‐5α‐pregn‐16‐ene; 2 ), salignamine (=(20S)‐20‐(methylamino)‐3β‐methoxypregna‐5,16‐diene; 3 ), 2‐hydroxysalignamine (=(20S)‐20‐(dimethylamino)‐2β‐hydroxy‐3β‐methoxypregna‐5,16‐diene; 4 ), salignarine‐F (=(2′E, 20S)‐20‐(dimethylamino)‐4β‐hydroxy‐3β‐(tigloylamino)pregn‐5‐ene; 5 ), salonine‐C (=(2′E,20S)‐20‐(dimethylamino)‐3β‐(tigloylamino)pregna‐4,14‐diene; 6 ), and N‐[formyl(methyl)amino]salonine‐B (=(20S)‐20‐[formyl(methyl)amino]‐3β‐methoxypregna‐5,16‐diene; 7 ) have been isolated from the MeOH extract of Sarcococca saligna, along with the six known alkaloids dictyophlebine ( 8 ), epipachysamine‐D ( 9 ), saracosine ( 10 ), iso‐N‐formylchonemorphine ( 11 ), sarcodinine ( 12 ), and alkaloid‐C ( 13 ). The structures of 1 – 7 were deduced from spectral data. Compounds 1 – 13 demonstrated significant activity against acetyl‐ and butyrylcholinesterase.     

Verticillane and Norverticillane Diterpenoids from the Formosan Soft Coral Cespitularia hypotentaculata

Five new diterpenes, cespihypotins W–Z ( 1 – 4 , resp.) and cespihypotone ( 5 ) have been isolated from the AcOEt‐soluble fraction of the Formosan soft coral Cespitularia hypotentaculata. Two of them having the norverticillane skeleton, i.e., 1 and 2 , and the other three, 3 – 5 , possessing a verticillane skeleton. The structures were established as (+)‐(1βH,7E)‐6β,11β‐dihydroxynorverticilla‐4(18),7‐diene‐10,12‐dione ( 1 ), (+)‐(1βH,7E)‐6β‐acetoxy‐11β‐hydroxynorverticilla‐4(18),7‐diene‐10,12‐dione ( 2 ), (?)‐(1βH,7E)‐6β‐acetoxyverticilla‐4(18),7,11‐triene‐10,12‐γ‐lactone ( 3 ), (+)‐(1βH,7E)‐6β‐acetoxy‐10‐hydroxyverticilla‐4(18),7,11‐triene‐10,12‐γ‐lactone ( 4 ), and (+)‐(1βH,3Z)‐10β‐hydroxy‐6‐oxoverticilla‐3,11‐diene‐10,12‐γ‐lactone ( 5 ), respectively, on the basis of 1D‐ and 2D‐NMR spectroscopic analyses.     

New Sterol Derivatives from the Marine Sponge Xestospongia sp.

Chemical examination of a marine sponge Xestospongia sp. resulted in the isolation of 20 sterol derivatives ( 1 – 20 ), including eight new sterols namely aragusterols J – L ( 1 – 3 ), (5α,7α,12β,22E)‐7,12,18‐trihydroxystigmast‐22‐en‐3‐one ( 4 ), (5α,7α,12β,24R)‐ and (5α,7α,12β,24S)‐7,12,20‐trihydroxystigmastan‐3‐one ( 5 / 6 ), and (5α,7α,12β,22E,24R)‐ and (5α,7α,12β,22E,24S)‐7,12,20‐trihydroxyergost‐22‐en‐3‐one ( 7 / 8 ). The structures of new compounds were determined through extensive spectroscopic analyses and chemical conversion. The sterol diversity was mainly characterized by the presence of a cyclopropane unit at side chain, while compound 4 with 18‐hydroxymethyl group was found in stigmasterol family for the first time. Cytotoxic test revealed the inhibitory effects of compounds 1 , 4 , and 17 against human leukemia cell line K562 with IC₅₀ values of 18.3, 24.1, and 34.3 μm , respectively.     

Diterpenes from Xylopia langsdorffiana

The phytochemical investigation of Xylopia langsdorffiana A.St.‐Hil. & Tul . led to the isolation of eight diterpenes, i.e., of the four new compounds (5β,7β,8α,9β,10α,12α)‐atisane‐7,16‐diol 7‐acetate ( 1 ), named xylodiol 7‐acetate, (5β,8α,9β,10α,12α)‐16‐hydroxyatisan‐7‐one ( 2 ), named xylopinone, (3α,12Z)‐3‐hydroxy‐ent‐labda‐8(20),12,14‐trien‐18‐oic acid ( 3 ), named labdorffianic acid A, and 8,20‐epoxy‐13‐hydroxy‐ent‐labd‐14‐en‐18‐oic acid ( 4 ), named labdorffianic acid B, and of the four known compounds 5 – 8 , i.e., ent‐kauran‐16‐ol, ent‐kaur‐16‐en‐19‐oic acid, ent‐kaur‐16‐en‐19‐ol, and ent‐trachyloban‐18‐oic acid. The structures were established by IR, HR‐ESI‐MS, and NMR data analysis with the aid of 2D techniques.     

Cucurbitane Triterpenoids from the Fruit Pulp of Momordica charantia and Their Cytotoxic Activity

Two new cucurbitane‐type triterpenes, 25‐methoxycucurbita‐5,23(E)‐diene‐3β,19‐diol ( 1 ) and 7β‐ethoxy‐3β‐hydroxy‐25‐methoxycucurbita‐5,23(E)‐dien‐19‐al ( 2 ), together with three known cucurbitane‐type triterpenes, 3β,7β,25‐trihydroxycucurbita‐5,23(E)‐dien‐19‐al ( 3 ), (23E)‐3β‐hydroxy‐7β,25‐dimethoxycucurbita‐5,23‐dien‐19‐al ( 4 ), and 3β‐hydroxy‐25‐methoxycucurbita‐6,23(E)‐dien‐19,5β‐olide ( 5 ), were isolated from the fruit pulp of Momordica charantia. The structures of two new compounds were elucidated on the basis of 1D and 2D NMR, MS, IR, optical rotation. Among these isolates, compounds 1 , 2 , and 5 showed slight cytotoxic activity against the SK‐Hep 1 cell line with IC₅₀ values of 33.1, 24.3, and 38.7 μM, respectively.     

Photooxygenation of Pregnanes

The course of the singlet‐oxygen reaction with pregn‐17(20)‐enes and pregn‐5,17(20)‐dienes was studied to compare the reactivity of the two alkene moieties present in some steroid families. Thus, from commercially available (3β,5α)‐hydroxy‐androstan‐17‐one and (3β)‐3‐hydroxyandrost‐5‐en‐17‐one, the following 3‐{[(tert‐butyl)dimethylsilyl]oxy}‐substituted, 17(20)‐unsaturated pregnanes were prepared (see Fig. 1): (3β,5α)‐21‐norpregn‐17(20)‐ene 1 ; (3β,5α,17Z)‐pregn‐17(20)‐ene 2 , (3β,5α,16α,17E)‐pregn‐17(20)‐en‐16‐ol 3 , (16β,5α,17E)‐pregn‐17(20)‐en‐16‐ol 4 , (3β,5α,16β,17E)‐pregn‐17(20)‐en‐16‐ol acetate 5 , (3β,16α)‐21‐norpregna‐5,17(20)‐dien‐16‐ol 6 , (3β,16α,17E)‐pregna‐5,17(20)‐dien‐16‐ol 7 , (3β,17Z)‐pregna‐5,17(20)‐diene 8 , (3β,17E)‐pregna‐5,17(20)‐dien‐21‐ol 9 and (3β,17E)‐5,17(20)‐dien‐21‐ol acetate 10 . The oxygenated products (see Fig. 2) obtained from 1 – 10 and ¹O₂, generated by irradiation of Rose Bengal in ³O₂‐saturated pyridine solution, were characterized by ¹H‐, ¹³C‐NMR, and MS (EI, FAB, HR‐EI, ESI‐ and UV‐MALDI‐TOF) data. Major products were those formed by the ene reaction involving as intermediates the corresponding hydroperoxides and the cyclic tautomers of the allylic hydroperoxides, i.e., the corresponding oxiranium oxide‐like intermediate (Scheme 5).     

Crotofolane‐ and Casbane‐Type Diterpenes from Croton argyrophyllus

Phytochemical analysis of Croton argyrophyllus led to the isolation of five new diterpenes named (5β,6β)‐5,6 : 13,16‐diepoxycrotofola‐4(9),10(18),13,15‐tetraen‐1‐one ( 1 ), (5β,6β)‐5,6 : 13,16‐diepoxy‐2‐epicrotofola‐4(9),10(18),13,15‐tetraen‐1‐one ( 2 ), (5β,6β)‐5,6 : 13,16‐diepoxy‐16‐hydroxy‐2‐epicrotofola‐4(9),10(18),13,15‐tetraen‐1‐one ( 3 ), (5β,6β)‐5,6 : 13,16‐diepoxy‐16‐hydroxy‐2‐epicrotofola‐4(9), 10(18),13,15‐tetraen‐1‐one ( 4 ) and (2E,5β,6E,12E)‐5‐hydroxycasba‐2,6,12‐trien‐4‐one ( 5 ), in addition to the known diterpenes crotonepetin and depressin, and acetylaleuritolic acid and spinasterol. The structures of the isolated compounds were established by a combination of spectroscopic methods, including HR‐ESI‐MS, 2D‐NMR, and X‐ray crystallography.     

New 9,10‐Secosteroids from Biotransformations of Hyodeoxycholic Acid with Rhodococcus spp.

The biotransformations of hyodeoxycholic acid with various Rhodococcus spp. are reported. Some strains (i.e., Rhodococcus zopfii, Rhodococcus ruber, and Rhodococcus aetherivorans) are able to partially degrade the side chain at C(17) to afford 6α‐hydroxy‐3‐oxo‐23,24‐dinor‐5β‐cholan‐22‐oic acid ( 2 ; 23%) and 6α‐hydroxy‐3‐oxo‐23,24‐dinorchol‐1,4‐dien‐22‐oic acid ( 3 ; 23–30%), together with two new 9,10‐secosteroids 4 and 5 (10–45%), still bearing the partial side chain at C(17) and adopting an intramolecular hemiacetal form. In addition, the 9,10‐secosteroid 5 showed an unprecedented C(4)‐hydroxylation. The new secosteroids were fully characterized by MS, IR, NMR, and 2D‐NMR analyses.     

Neoclerodane Diterpenes from Amoora stellato‐squamosa

From the twigs of Amoora stellato‐squamosa, five new neoclerodane diterpenes have been isolated and characterized, methyl (13E)‐2‐oxoneocleroda‐3,13‐dien‐15‐oate (=methyl (2E)‐3‐methyl‐5‐[(1S,2R,4aR,8aR)‐1,2,3,4,4a,7,8,8a‐octahydro‐1,2,4a,5‐tetramethyl‐7‐oxo‐naphthalen‐1‐yl]pent‐2‐enoate; 1 ), (13E)‐2‐oxoneocleroda‐3,13‐dien‐15‐ol (=(4aR,7R,8S,8aR)‐1,2,4a,5,6,7,8,8a‐octahydro‐8‐[(E)‐5‐hydroxy‐3‐methylpent‐3‐enyl]‐4,4a,7,8‐tetramethylnaphthalen‐2(1H)‐one; 2 ), (3α,4β,13E)‐neoclerod‐13‐ene‐3,4,15‐triol (=(1R,2R,4aR, 5S,6R,8aR)‐decahydro‐5‐[(E)‐5‐hydroxy‐3‐methylpent‐3‐enyl]‐1,5,6,8a‐tetramethylnaphthalene‐1,2‐diol; 3 ), (3α,4β,13E)‐4‐ethoxyneoclerod‐13‐ene‐3,15‐diol (=(1R,2R,4aR,5S,6R,8aR)‐1‐ethoxydecahydro‐5‐[(E)‐5‐hydroxy‐3‐methylpent‐3‐enyl]‐1,5,6,8a‐tetramethylnaphthalen‐2‐ol; 4 ), and (3α,4β,14RS)‐neoclerod‐13(16)‐ ene‐3,4,14,15‐tetrol (=(1R,2R,4aR,5S,6R,8aR)‐decahydro‐5‐[3‐(1,2‐dihydroxyethyl)but‐3‐enyl]‐1,5,6,8a‐tetramethylnaphthalene‐1,2‐diol; 5 ), together with two known compounds, (13E)‐neocleroda‐3,13‐diene‐15,18‐diol ( 6 ) and (13S)‐2‐oxoneocleroda‐3,14‐dien‐13‐ol ( 7 ).     

Three New Atisane Diterpenoids from Spiraea japonica

Three new atisane diterpenoids, spiratisanins A – C ( 1  –  3 , resp.), featuring a phenylacryloxyl substituted ent‐atisane skeleton, were isolated from Spiraea japonica together with two known atisine diterpene alkaloids, spiramine A ( 4 ) and spiradine F ( 5 ). The structures of these new compounds were elucidated as (5β,7α,8α,9β,10α,12α,16β)‐16‐hydroxyatisan‐7‐yl (2E)‐3‐phenylprop‐2‐enoate ( 1 ), (5β,7α,8α,9β,10α,12α,16α)‐16‐hydroxyatisan‐7‐yl (2E)‐3‐phenylprop‐2‐enoate ( 2 ), and (5β,8α,9β,10α,12α,16β)‐16‐hydroxyatisan‐20‐yl (2E)‐3‐phenylprop‐2‐enoate ( 3 ) on the basis of spectroscopic analysis.