Author
Joko Ridho Witono
Other affiliations: Center for Plant Conservation
Bio: Joko Ridho Witono is an academic researcher from Indonesian Institute of Sciences. The author has contributed to research in topics: Population & Species richness. The author has an hindex of 5, co-authored 42 publications receiving 159 citations. Previous affiliations of Joko Ridho Witono include Center for Plant Conservation.
Papers published on a yearly basis
Papers
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TL;DR: Hartley et al. as discussed by the authors isolated six quinolinone alkaloids bearing a phenylpropanoid or a coumarin moiety from the leaves of Melicope denhamii.
60 citations
TL;DR: In this article, two Diels-Alder type adducts, melicodenines A (1) and B (2), were isolated from the leaves of Melicope denhamii (Seem).
22 citations
TL;DR: In this paper, Kebun Raya Indonesia (KRI) memiliki tanggung jawab untuk melaksanakan upaya konservasi tumbuhan yang ada di Indonesia.
Abstract: Sebagai bagian dari kebun raya dunia, Kebun Raya Indonesia (KRI) memiliki tanggung jawab untuk melaksanakan upaya konservasi tumbuhan yang ada di Indonesia. Hingga tahun 2010, empat kebun raya yang dikelola oleh LIPI hanya mampu mengkonservasi sekitar 21% dari seluruh tumbuhan terancam Indonesia. Oleh karena itu, diperlukan pengembangan Kebun Raya Daerah (KRD) untuk mengkonservasi tumbuhan pada tiap daerah di Indonesia. Makalah ini bertujuan untuk untuk mengetahui capaian KRD dalam konservasi tumbuhan dan menentukan strategi pengelolaan koleksi tumbuhan tiap daerah. Pada akhir 2012, KRI yang didukung KRD telah berhasil mengoleksi 24% dari tumbuhan terancam Indonesia versi IUCN Red List 2013 , dan berhasil membudidayakan 25% termasuk koleksi pembibitan. Beberapa strategi untuk pengembangan koleksi KRD antara lain: penguatan sistem data base koleksi; pengembangan koleksi tumbuhan di setiap KRD dengan mengacu pada IUCN Red List ; dan penentuan spesies prioritas untuk konservasi terkait dengan kebijakan dan kondisi alam di Indonesia. Kata kunci: koleksi, kebun raya daerah, IUCN Red List
16 citations
TL;DR: Three new guaiane‐type sesquiterpenes, named melicodenones C–E (3–5), were isolated from the root of Melicope denhamii and their structures were established by extensive NMR‐spectroscopic analyses.
Abstract: Two novel zierane-type sesquiterpenes, named melicodenones A and B (1 and 2, resp.), and three new guaiane-type sesquiterpenes, named melicodenones C-E (3-5), were isolated from the root of Melicope denhamii (Seem.) T. G. Hartley together with zierone (6). Their structures were established by extensive NMR-spectroscopic analyses. Compounds 1-6 were tested for cytotoxicity using human colon cancer DLD-1 cells, and melicodenone A (1) was found to exhibit moderate activity.
12 citations
TL;DR: Material acquired on a recent expedition to Southeastern Sulawesi, Indonesia, presents an opportunity to reassess and provide an overview of the Begonia flora of the region, recognizing eleven species including four new species described and illustrated here.
Abstract: Material acquired on a recent expedition to Southeastern Sulawesi, Indonesia, presents an opportunity to reassess and provide an overview of the Begonia flora of the region. Eleven species are recognized including four new species described and illustrated here: Begonia incudiformicarpa , B. iskandariana, and B. tumburanoensis (all in Begonia section Jackia ); and B. johntania ( Begonia section Petermannia ). The former three species are the first confirmed records of section Jackia on Sulawesi substantially extending the known eastern range limit of this section. In addition, an illustration and a lectotypification of Begonia flacca are presented, and an identification key to Begonia species in Southeastern Sulawesi is provided.
10 citations
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TL;DR: In this review, it is attempted to cover all recent aspects of [2 + 2] photocycloaddition chemistry with an emphasis on synthetically relevant, regio-, and stereoselective reactions.
Abstract: The [2 + 2] photocycloaddition is undisputedly the most important and most frequently used photochemical reaction. In this review, it is attempted to cover all recent aspects of [2 + 2] photocycloaddition chemistry with an emphasis on synthetically relevant, regio-, and stereoselective reactions. The review aims to comprehensively discuss relevant work, which was done in the field in the last 20 years (i.e., from 1995 to 2015). Organization of the data follows a subdivision according to mechanism and substrate classes. Cu(I) and PET (photoinduced electron transfer) catalysis are treated separately in sections 2 and 4, whereas the vast majority of photocycloaddition reactions which occur by direct excitation or sensitization are divided within section 3 into individual subsections according to the photochemically excited olefin.
646 citations
TL;DR: This article focuses on the occurrence and biological activities of cyclobutane-containing (CBC) alkaloid obtained from fungi, fungal endophytes, and plants and presents the structures and describes the activities of 98 CBC alkaloids.
115 citations
TL;DR: Highly functionalized 2-quinolone derivatives containing a chiral C4-quaternary stereocenter were obtained in high yields and high levels of selectivity under mild reaction conditions.
Abstract: Asymmetric expansion: A catalytic asymmetric ring-expansion reaction of the title compounds occurs in the presence of a Sc(OTf)(3) catalyst bearing an N,N'-dioxide-based ligand. Highly functionalized 2-quinolone derivatives containing a chiral C4-quaternary stereocenter were obtained in high yields and high levels of selectivity under mild reaction conditions (see scheme; Tf=trifluoromethanesulfonyl).
101 citations
TL;DR: Hartley et al. as discussed by the authors isolated six quinolinone alkaloids bearing a phenylpropanoid or a coumarin moiety from the leaves of Melicope denhamii.
60 citations