• Bulletin of the Korean Chemical Society
• /
• 제26권9호
• /
• pp.1457-1460
• /
• 2005

• Archives of Pharmacal Research
• /
• 제27권10호
• /
• pp.1020-1022
• /
• 2004

A new ceramide alomacrorrhiza A was isolated from the ethanolic extract of the plant Alocasia macrorrhiza (L.) Schott. Its chemical structure was elucidated as (2S,3S,4R)-2N-[(2'R)-2'- hydroxy-hexacosanoyl]-tetradecane-1,3,4-triol based on extensive 1D, 2D NMR, EI-MS, FABMS, HR-FAB-MS spectroscopic data and chemical degradation studies.

• Mass Spectrometry Letters
• /
• 제14권3호
• /
• pp.110-115
• /
• 2023

The reaction of (COD)PdCl₂ with new C₃-symmetric tridentate L (COD = 1,5-cyclooctadien; L = 1,3,5-tris(picolinoyloxyethyl)cyanurate) in a mixture of acetone and dichloromethane produces single crystals consisting of unprecedented monometallacyclic [PdCl₂(L)]. This cyclic compound arises from trans-chelation of two of three donating pyridyl groups of L, while the third pyridyl group remains uncoordinated. Electrospray ionization mass spectrometry (ESI-MS) data on L exhibited the major peak corresponding to [C₂₇H₂₄N₆O₉ + H⁺]⁺. Fast atom bombardment mass spectrometry (FABMS) data on [PdCl₂(L)], however, showed the mass peak corresponding to the L instead of the present palladium(II) compound species, due to the insolubility and dissociation in solution. The physicochemical properties of the present palladium(II) compound were fully characterized by means of infrared (IR) and nuclear magnetic resonance (NMR) spectroscopy, thermal analysis, single-crystal X-ray diffraction (SC-XRD) measurement.

• Journal of Microbiology and Biotechnology
• /
• 제21권9호
• /
• pp.930-936
• /
• 2011

Two new cyclic depsipeptides wewakamide A (1) and guineamide G (2) have been isolated from the marine cyanobacterium Lyngbya semiplena and Lyngbya majuscula, respectively, collected from Papua New Guinea. The amino and hydroxy acid partial structures of wewakamide A and guineamide G were elucidated through extensive spectroscopic techniques, including HR-FABMS, 1D $^1H$ and $^{13}C$ NMR, as well as 2D COSY, HSQC, HSQC-TOCSY, and HMBC spectra. The sequence of the residues of wewakamide A was determined through a combination of ESI-MS/MS, HMBC, and ROESY. Wewakamide A possesses a ${\beta}$-amino acid, 3-amino-2-methylbutanoic acid (Maba) residue, which has only been previously identified in two natural products, guineamide B (3) and dolastatin D (4). Although both new compounds (1,2) showed potent brine shrimp toxicity, only guineamide G displayed significant cytotoxicity to a mouse neuroblastoma cell line with $LC_{50}$ values of 2.7 ${\mu}M$.

• 한국환경농학회지
• /
• 제15권2호
• /
• pp.167-178
• /
• 1996

전보에서 대두(大豆)와 벼의 현탁배양세포(懸濁培養細胞)에서 생성된 PCP의 주요 수용성대사물은 PCP를 비롯한 여러 종류의 염화페놀과 glucose간 ${\beta}-linkage$로 연결된 ${\beta}-glucoside$ 구조를 가질 것으로 추정한 바 있다. 본 연구에서는 conjugates를 가수분해시키지 않는 조건에서 기기적인 방법으로 그 구조를 확인하고자 하였다. Acetyl화(化) 한 glucose conjugates는 aglycones 분석에서 예상한 대로 3종류 이상이 존재하는 것으로 확인할 수 있었으며, 충분히 정제한 각각의 acetyl화(化) 대사물을 FAB-MS로 분석한 결과 분자량과 aglycones part와 관련된 특징적 spectral data 등 conjugates 구조 확인에 필수적인 정보를 얻을 수 있었다. 이러한 구조적 정보와 지금까지의 연구 결과, 즉 현탁배양초기에 생성된 PCP의 glucose conjugates는 ${\beta}-glucosidase$에 의해 특징적으로 가수분해되고, aglycones이 PCP 외에도 tetrachlorophenol 및 tetrachlorocatechol 등이라는 사실을 종합할 때 현탁배양에서 생성된 conjugates는 주로 pentachlorophenyl ${\beta}-D-glucopyranoside$, tetrachlorophenyl ${\beta}-D-gluco$ pyranoside 및 2-hydroxy-3,4,5,6-tetrachlorophenyl ${\beta}-D-glucopyranoside$인 것으로 확인할 수 있었다.